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Title: Petroleum - Royal Commission - Royal Commissions - Exploratory and production drilling for petroleum in the area of the Great Barrier Reef - Report - Volume 1-Introduction and references 1 and 2
Source: Both Chambers

Date: 11-02-1975
Parliament No.: 29
Tabled in House of Reps: 11-02-1975
Tabled in Senate: 11-02-1975
Parliamentary Paper Year: 1975
Parliamentary Paper No.: 38
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Petroleum - Royal Commission - Royal Commissions - Exploratory and production drilling for petroleum in the area of the Great Barrier Reef - Report - Volume 1-Introduction and references 1 and 2

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THE PARLIAMENT OF THE COMMONWEALTH OF AUSTRALIA 1975— Parliamentary Paper No. 38

ROYAL COMMISSIONS INTO EXPLORATORY AND PRODUCTION DRILLING FOR PETROLEUM IN THE AREA OF THE

GREAT BARRIER REEF

REPORT— VOLUME 1 Principal Introduction

Term of Reference No. 1

Term of Reference No. 2

Presented by Command I I February 1975

Ordered to be printed 6 March 1975

THE GOVERNMENT PRINTER OF AUSTRALIA

CANBERRA 1975

ISBN 0 642 00863 9

Printed by Watson Ferguson & Company, 221 Stanley Street, Brisbane

AUSTRALIAN GOVERNMENT

AND

GOVERNMENT OF THE STATE OF QUEENSLAND

PERSONNEL OF ROYAL COMMISSIONS INTO

EXPLORATORY AND PRODUCTION DRILLING FOR PETROLEUM IN THE AREA OF THE GREAT BARRIER REEF

SIR GORDON WALLACE CHAIRMAN

DR J.E. SMITH C.B.E., ScD., FRS MR V.J. MORONEY

MEMBERS

MR P.C. WHITMAN

Secretary

MR E.R.G. WHITE

Assistant Secretary

iii

Preface

There were two Royal Commissions

one appointed by the Australian Government and the other by the Government of the State of Queensland.

Each Commission had the same

three Commissioners, and the same Terms

of Reference appeared in the two Letters

Patent which were issued to each of the Commissioners by their Excellencies The

Governor-General of Australia and the

Governor of Queensland respectively. There

was only one hearing and the two Commissions sat in parallel.

The two Governments considered it would be more convenient if one report only

were compiled, instead of two separate, but

identical reports. This has accordingly been done and such report will be presented concurrently to their Excellencies.

The Terms of Reference as contained in the Letters Patent appear in the Principal

Introduction paragraph PI.1.6 at pages 2 - 3 of the Report.

WEMBLEY CHAMBERS

104 Hunter Street Sydney N.S.W.

30 October, 1974

Your Excellency,

In accordance with Letters

Patent dated Fifth day of May 1970, I have

the honour to present to you on behalf of

the Commissioners the Report of the Royal Commission into exploratory and production

drilling for petroleum in the Area of the

Great Barrier Reef.

The Letters Patent issued to your Commissioners are returned herewith.

Yours sincerely,

Gordon Wallace CHAIRMAN

His Excellency the Honourable Sir John Kerr, K.C.M.G., K.St.J., Government House, YARRALUMLA '

AUSTRALIAN CAPITAL TERRITORY

WEMBLEY CHAMBERS

104 Hunter Street

SYDNEY N.S.W.

30 October 1974

Your Excellency,

In accordance with Letters

Patent dated Fifth day of May 1970, I have

the honour to present to you on behalf of

the Commissioners the Report of the Royal

Commission into exploratory and production drilling for petroleum In the Area of the

Great Barrier Reef.

The Letters Patent Issued to your Commissioners are returned herewith.

Yours sincerely,

Gordon Wallace CHAIRMAN

His Excellency Sir Colin Hannah K.C.M.G., K.B.E., C.B., Governor of Queensland, Government House, BRISBANE.

5 6 7 8

12 12

19 20

TABLE OF CONTENTS

PRINCIPAL INTRODUCTION

PART 1 - APPOINTMENT OF THE COMMISSIONS

AND THE TERMS OF REFERENCE

Appointment of the Commissions The Terms of Reference

Counsel Assisting and the Secretariat

Appearances before the Commissions

Proceedings of the Commissions

Witnesses and Exhibits

Inspections by Commissioners

Chairman's ruling on evidence

Terminology

PART 2 - NECESSITY FOR LONG-TERM EXPERIMENTS - CORRESPONDENCE BETWEEN THE

CHAIRMAN AND THE PRIME MINISTER AND THE

PREMIER OF QUEENSLAND

Necessity for long-term experiments Correspondence between the Chairman and the Prime Minister

Mr Tranter's evidence Witnesses who advocated or assented to the holding of long-term experiments Views of Senate Select Committee on the need

for research Professor Clark's view

FAO Rome recommendation of 1970 Nature and priorities of long-term experiments Commission members not unanimous throughout

The Commission's approach to TR2, TR3 and TR5

Paragraph

PI.1.1 PI.1.6

PI.1.8

PI.1.11 PI.1.12

PI.1.18

PI.1.22

PI.1.25 PI.1.26

PI.2.1

PI.2.2

PI.2.6

P I .2.7

PI.2.9 PI.2.11 PI.2.12

PI.2.14

PI.2.15

PI.2.16

Page Paragraph

21 TR4 PI.2.17

22 PART 3 - THE TERMS OF REFERENCE 22 (A) THEIR CONSTRUCTION

22 General PI.3.1

23 TR1 PI.3-3

24 TR2 PI.3.4

27 TR3 PI.3.5

28 TR4 PI.3 .6

29 TR5 PI.3-7

31 (B) THE ANSWERS GIVEN TO THE

TERMS OF REFERENCE (IN OUTLINE)

31 The answer to TR1 (Risk of oil leaks) PI.3 .8

32 The answer to TR2 (Probable effects of oil and gas leaks and of remedial measures) PI.3.9 33 The answer to TR3 (Permitted drilling localities) PI.3.10

33 The answer to TR4 (Safety Precautions) PI.3.11

35 The answer to TR5 (Probable benefits from petroleum drilling) PI.3.12

38 PART 4 - SOME FEATURES OF THE GREAT BARRIER REEF PROVINCE

38 Definition PI.4.1

39 Geography

39 Length and boundaries PI.4.5

41 Goldie Reef and Mr D.F. Jackson's

submissions PI.4.13

42 Area of the GBRP PI.4.14

42 Reefs and cays PI.4.15

42 Reef Zone PI.4.17

43 The 100 fathom line PI.4.22

44 Reef channels PI.4.23

44 Depth at which coral grows PI.4.25

45 Continental islands PI.4.27

45 The GBR coastline PI.4.29

46 The three regions PI.4.32

xii

49 50

51 52

53 54

57 60

64 64

65 67

68 69 70

73 74

Paragraph

Fringing reefs PI.4.33

Water depths PI.4.34

Meteorology and Hydrology

Climatic zones PI.4.35

Prevailing winds PI.4.36

Gales PI.4.42

Cyclones PI.4.43

Tides and currents PI.4.47

Ocean currents PI.4.50

Wind induced currents PI.4.51

Water movements generally PI.4.52

Migration of oil PI.4.57

Rainfall PI.4.62

Air temperatures PI.4.63

Sea temperatures PI.4.64

Visibility PI.4.65

PART 5 - GEOLOGY AND PETROLEUM

POTENTIAL GBRP

Origin and accumulation of oil PI.5-1

Oil basins PI.5.2

Rock types PI.5.3

The geology of the reef area PI.5.4

Inadequacy of geological knowledge PI.5.5

Basins and highs PI.5·7

The sedimentary basins and petroleum potential of the GBRP PI.5.8

Existing exploration permits PI.5.9

Names of permittees and licencees PI.5-10

Seismic stability PI.5.11

Likely oil types PI.5.12

PART 6 - CORAL. CORAL REEFS AND

THE GREAT BARRIER REEF PROVINCE

General

General description of reefs

xi ii

PI.6.1

PI.6.5

Page Paragraph

76 Reef Zones PI.6.9

83 Soft coral PI.6.27

83 Distribution of flora and fauna PI.6.28

85 Calcareous algae and the rate of reef growth PI.6.33

86 The Great Barrier Reef and how It compares with other coral reefs PI.6.35

88 The best known corals PI.6.43

88 Feeding habits of corals and reproduction PI.6.45

89 Feeding PI.6.46

90 Two methods of reproduction

90 (a) Asexual budding off PI.6 .51

95 (b) Sexual reproduction Involv

ing fertilisation and planula larvae PI.6.65

98 Zooxanthellae PI.6.76

100 The source of colour In corals PI.6.79

100 Dr Isobel Bennett's view PI.6.80

101 Expulsion of zooxanthellae by corals PI.6.82

102 Mucus PI.6 .83

103 Effects of adverse conditions PI.6.84

103 (a) Lack of oxygen PI.6.85

104 (b) Lack of light PI.6.88

105 (c) Reduced or excessive

salinity PI.6.92

106 (d) Low and high water

temperatures PI.6.95

107 (e) Low tides PI.6.97

107 (f) Cyclones PI.6.99

108 (g) Sedimentation PI.6.100

109 (h) Construction work, dredging

and explosives PI.6.101

109 (1) Predators especially crown-

of-thorns starfish PI.6.102

112 Regeneration of coral

112 Methods of regeneration PI.6 .110

114 Sequence of recovery PI.6.115

115 Rate of regeneration PI.6.119

119 Other fauna and flora of the GBRP

xiv

Page

119 120

120

121

127

128

129

131

132

134

136 138 138

139

139 140

Î4Î¸

141

142

143 143 144 145

145

145 146

146

147

149

Molluscs

Echinoderms

Crustaceans

Fish and fisheries Plankton

Zooplankton and phytoplankton

Effects of oil on plankton - Mironov and Kasymov

Foraminifera and reef formation Complexities and dependencies of GBR marine life

A stability theory

Algae Mangroves

Birds - Dr Kikkawa

A theory relating to stability

The Margelef theory and Sir Maurice Yonge's contrary view

Dr Talbot's view

Professor Stephenson's view

Professor Johannes' view

Dr Grassle says Margelef has been wrongly interpreted

Further view of Sir Maurice Yonge Dr Stoddart's view

Dr Halstead's view Dr Endean's view

Dr Mather's view

Summary of views and the necessity for research Oxygen usage in the GBRP

How oxygen is provided Seaward slopes of reefs Sir Maurice Yonge's view Dr Talbot's view

Other forms of animal life in the GBRP

Low level of biological knowledge of the GBRP

Paragraph

PI.6.131

PI.6.133 PI.6.134

PI.6.135

PI.6.151

PI.6.157

PI.6.158 PI.6.162

PI.6.164

PI.6.166

PI.6.167

PI.6.172

PI.6.176

PI.6.185 PI.6.187 PI.6.188

PI.6.189

PI.6.190

PI.6.192 PI.6.194 PI.6.196 PI.6.197

PI. 6·. 201

PI.6.203

PI.6.205 PI.6.207 PI.6.208 PI.6.210 PI.6.212

Page Paragraph

149 Generally PI.6.214

149 Professor Stephenson's view PI.6.215

150 Dr Cheat's view PI.6.216

150 Dr Stoddart's view PI.6.219

151 Dr Grassle's view PI.6.221

151 Sir Maurice Yonge's view PI.6.222

151 Lack of adequate laboratories PI.6.223

152 Reef fish PI.6.224

152 Senate Select Committee Report PI.6.225

152 Marine national parks and reserves

152 Paramountcy of the Petroleum

(Submerged Lands) Act of 196? over the Forestry Act PI.6.226

153 Section 46 of the Queensland

Mining Act PI.6 .227

153 Dr Mather's view PI.6.228

154 Mr Harrison on reserves PI.6.229

155 Mr Plesse on national parks PI.6.232

157 Concluding notes - Mr Cantley's suggestions PI.6.237

159 Appendix (see paragraph PI.2.14 supra) Appendix 159 Experiments and research recommended

TERM OF REFERENCE NO. 1

(TR1)

l6l l6l

PART 1 - INTRODUCTION

Suggested answers

1.1.1 The answer to this TR involves the making of an

assessment of the degree of risk or likelihood of an oil or

gas leak occurring.

1.1.2 On behalf of the Queensland Minister for Mines, Mr

Bennett QC suggested to the Commission after a careful analysis

of the evidence that the answer should be "nil" (T15384). On

behalf of the Australian Petroleum Exploration Association, Mr Jeffrey QC submitted that the assessment should be "negligible"

("Synopsis of Submissions on TR1" page 66). As will appear

from our answer these submissions are not acceptable to us.

1.1.3 On behalf of the Australian Conservation Foundation

and other kindred interests, Mr Connolly QC suggested that such

an occurrence is "a statistical certainty", that you can mini mise but not eliminate the risk of such an occurrence because

past events have shown that the human factor has been the

greatest cause of blowouts and spills and that human error and

equipment failure will always be with us. He quoted Mr Basire

(at T2359) who is a consultant to the Mines Department in Queensland and a member of the Australasian Institute of Mining

and Metallurgy, as one of the authorities for this proposition

161

(T18049)

1.1.4 Views of other witnesses may be appropriately

quoted at this stage before embarking on the complex task of

forming our own assessment.

Mr Thomas (General Manager of Beach Petroleum

N.L.) (T2832):

"...It appears the greatest proportion of

blowouts are caused by human error.

...Human factor can never be excluded.

...One must accept the chance of a blowout occurring wherever one is drilling ... from

time to time." Professor Thompson (Professor of Law,

University of British Columbia, who gave

evidence concerning legislative safeguards

in Canada and the United States) :-

"It is agreed by the experts that there

is a substantial hazard of oil pollution

with respect to exploratory and develop

ment drilling." (Exhibit 296 p.6l) Mr Denton (Manager for Government Relations,

Esso Standard Oil). In a paper incorporated

into Exhibit 6 and as spokesman for the oil

industry at a symposium, Mr Denton stated:-

"No one can guarantee that blowouts or oil

spills will not occur. Even before the 'Torrey Canyon' disaster, Esso, along with

other responsible oil companies, had been

working on means of dispersing oil spills."

(p·53) Mr White (Supervising Petroleum Technologist,

Bureau of Mineral Resources) said (T3120):

"I would say that a blowout would be extremely

unlikely in the area based on past experience

both around Australia and throughout the world ...

162

Is there any reason why Australian results in

regard to blowouts should be any worse than

those overseas? -- One reason could be the

fact that the off-shore areas of Australia

are relatively little known and, in addition,

they are not closely cdnnected with correspond

ing exploration on land, whereas in other

countries, particularly in the United States,

its exploration tends to come in much smaller

steps so that completely unknown conditions are very rarely experienced in the United

States. Normally one can predict with some

degree of accuracy there as to the conditions

which will exist when a well is drilled at a

particular location." These latter remarks

however may not be applicable to the salt dome areas of the Gulf of Mexico.

Mr Woodward QC (Senior Counsel assisting the

Commission during his final submission to the Commission):

"There is a danger that reference to the number

of ways in which mishaps can occur may lead to

an unduly gloomy view of the risks involved in

oil drilling ... but the initial planning of

the Japex operation in Repulse Bay seemed to

suggest that not all off-shore operations are managed with ruthless efficiency ... and

it was one of the world's major, more responsible companies which was fined $1,000,000 in the

United States recently for flagrantly cutting

a corner and defying the law in the process --an offence which seems unlikely to occur again

in view of the adverse publicity and the heavy penalties incurred both in clean-up costs and

fines. On the other hand the more recent Shell

fire is disturbing in its implications - that

the most modern equipment cannot always prevent

163

a major oil spillage from a production platform.

1.1.5 As Mr Woodward said, the evidence disclosed that

there are many ways in which a mishap may occur and this is so

even with the advances made in off-shore drilling technology

during the last decade such as the sub-sea hydraulically

controlled safety valve, and to assess the quantum of risk

or degree of likelihood clearly enough involves a knowledge

of "existing world technology". Consequently a substantial

number of overseas and local experts gave detailed evidence of

most if not all facets of off-shore drilling and associated

activities in addition to which many diagrams and coloured

slides were shown and explained to the Commission two of whom

were laymen in such matters. Furthermore all three Commission

ers spent a day on each of an exploratory drilling platform and

a production platform in the Bass Strait area and inspected

a shore installation near Sale in Victoria. This evidence

will be analysed to show the various potential hazards

involved in off-shore petroleum drilling and production and

the material on which our assessment of the risk has been made.

164

PART 2 - DIFFERENT TYPES OP OIL AND GAS LEAKS

Types of spills

1.2.1 An off-shore "oil or gas leak" may take various forms

and fall within two broad descriptions, namely:- (i) an oil or

gas blowout (or both); and (ii) a chronic spill. The former

involve sudden and major spills, the latter small but contin

uous or intermittent spills. Random spills are those which are

comparatively small but not continuous. Reference to all types

of spills will be made later and the causes of major overseas

and Australian blowouts in recent years are dealt with in-Part

6 of the answer to TR4, but the following is a preliminary out line .

Blowouts

1.2.2 These are uncontrolled flows of fluid from a bore

hole. The escaping fluid can be gas, oil or water or a com bination thereof. Before a blowout can occur, both "primary"

and "secondary" control of the well (to which reference will

be made later) must have been lost. Gas blowouts are more com

mon than oil blowouts because:- (i) the density of gas is very

much less than that of oil - .001 gas compared with .8 oil -

the consequence is that at a given bottom hole formation pres

sure, invading fluid is more likely to be kept under primary

control if it is oil than gas; (ii) gas expands significantly

when its pressure is reduced (Dr Chapman at T3486). The effect

of this is that as a given volume of gas rises it displaces a greater amount of mud than would be the case from the rise of a

comparable volume of oil and this in turn affects the velocity

at which they respectively rise.

1.2.3 But a gas blowout may convert into an oil blowout as

in the Santa Barbara blowout of 1969 · Off-shore blowouts are

generally more difficult to control than on-shore blowouts (Mr

165

White T3120).

1.2.4 Generally it can be said that before a blowout can

occur there must be an appropriate geological situation and

either a human failure or an equipment failure or both (Dr

Chapman T3486). The appropriate geological situation can occur

where hydrocarbons are present and abnormal pressures are en

countered. Human failure which can manifest itself in many

ways derives from ignorance, or lack of skill, carelessness,

rashness, forgetfulness and the like. For example, the casing

programme may be inadequate or the platform equipment may be

insufficient, or there might be a failure "to hang off" when

emergency conditions require such action.

Chronic and random spills * ( i )

1.2.5 These result (inter alia) from:-(i) accidents on drilling and production plat

forms

(ii) accidents to, fractures of and leaks from

pipelines leading from production rigs to

shore depots

(iii) deliberate or accidental discharge of oil

polluted mud or water from rigs

(iv) accidental discharge of oil from tankers or

barges and from flexible hoses when loading or unloading oil during the transportation

of oil from the production site to the shore

depot.

1.2.6 Mr Keith's evidence on tanker mishaps has interest -

from about 3,450 tankers plying the world's oceans in 1968 and

which carried 1,150 million metric tons of oil (about one half

the total sea borne trade) there were 60 tanker incidents which

involved a spill greater than 1,000 barrels each. The total

oil so spilled was estimated at 3-5 million barrels and Mr Keith estimated that this would be as high as 85% of the total

oil spilt from all causes. Other authorities put the percen-166

tage somewhat lower (e.g. Dillingham).

Tanker spills are not as such within the Terms of

Reference, but in so far as any spilled oil within the GBRP

may derive from barges, tankers or pipelines engaged in rec

eiving and transporting crude oil from a production well to a

shore depot and whilst such transportation is within the GBRP

such spilled oil would fall within the enquiry defined in TR1.

1.2.7 In this connection, it is of importance to note that

expert evidence established that if oil in quantities equal to

the existing Bass Strait output were produced within the GBRP,

two tankers per day (each of about 40,000 DWT) would be required to transport the oil southwards.

1.2.8 Comprehensive statistics of the classes of oil spills

enumerated above are not available. It is, however, certain

that the aggregate number of small and chronic spills is large.

It is only in recent years that oil spills large and small have

become news. The success of the energetic measures continuously

taken over the last decade or more in England's leading oil

port, Milford Haven, illustrates what can be done to eliminate

chronic and random spills in a comparatively small and enclosed

area which is under constant supervision. But conditions and

the situation in remoter and less confined localities are diff

erent .

167

PART 3 - STATISTICS

The approach to statistics 1.3.1 Although the answer to this enquiry as to the degree

of risk cannot be answered solely by an examination of the num

ber of blowouts and spills which have occurred in overseas and

Australian off-shore wells, the statistics relating thereto are

nevertheless a helpful and important section of the enquiry.

They also must form a background to the other sections of the

enquiry and will accordingly be dealt with first.

1.3.2 It was urged both by Mr Bennett QC and Mr Jeffrey QC,

that if the risk of an oil or gas spill is to be assessed by

reference to past experience as embodied in statistics, the appropriate measure against which to set the number of blow

outs which have actually occurred is not the number of wells

which have resulted in completions or production, but the num

ber of wells which have been sunk. "To adopt the former fig

ure" urged Mr Jeffrey (in his "Synopsis of Submissions on TR1"

at p.59) would be to give a falsely high percentage to the likelihood of a blowout and leave out of account that explora tory wells which establish that a particular area is not hydro

carbon bearing are necessarily sunk without the risk of any

blowout at all (that is, as after events proved). He illus

trated his submission as follows:-"Let it be supposed that in a given area the chance

of finding hydrocarbons is 50/50 and let it also be

supposed that statistics show that if hydrocarbons are encountered a blowout is certain; it would

nevertheless be correct to say that the risk of a blowout from exploratory drilling in that area was

50%" .

If this approach be taken, he added, a markedly diff

erent and more correct complexion is given to the statistics.

168

1.3.3 For practical purposes and in the context of the questions as put to the Commission these views are not persuas

ive. The Australian and Queensland Governments have not asked

us to express opinions as to the chances of finding oil in the

GBRP - the questions impliedly ask us to assume that explorat

ory drilling will be successful and indeed commercially

successful as both TR5 and TR3 indicate - and then with that

background TR1 asks us to evaluate the risk of a spill during

(inter alia) drilling. No useful practical purpose would be

served by taking into account the number of barren wells

which have been sunk elsewhere when statistics are being con

sidered for the purpose of assisting the governments to decide

whether oil exploration should be permitted. Everyone knows

that there is no risk of a blowout when drilling in a barren

area. But the question requires us to take into consideration modern technology and safety precautions and then asks - what

is the risk of a spill?

1.3-4 The correct approach to statistics seems to be that they are records of oil and gas blowouts which have occurred

under various conditions from wells producing hydrocarbons or

being drilled into reservoirs containing hydrocarbons.

Australian spills

1.3.5 There have been no oil blowouts in Australian waters

but there have been 4 gas blowouts including one in the north

west off-shore area. Mr Keith (Research Co-ordinator, Oil

and Gas Division, BHP) at T5509 said:-"Australia has had one gas blowout in development

wells and 2 in exploration wells. This is from

89 wells containing hydrocarbons. The percentage

is 3hi".

But since this evidence was given the Marlin A4

gas blowout occurred on 19th May, 1971 in a production well in Bass Strait. The dates, locations and causes of these 4 blow

outs are given in Part 6 of the answer to TR4.

On the other hand there have, of course, been other

169

wells completed off-shore since 1971 and drilling has continued

particularly off the north-west coast.

I.3.6 But the statistics given on behalf of APEA by Mr

Jeffrey QC (Synopsis p.57) are more up to date. They are:-

"Australia. All off-shore drilling including

exploratory and development wells from the

beginning of off-shore drilling in 1964 to

March 1972:-Total wells drilled 205

oil wells 88

gas wells 34

dry or abandoned 83

oil well blowouts NIL

gas well blowouts 4

percentage of gas blowouts 11.8"

Overseas spills 1.3.7 It was not possible for the Commission to get up-

to-date figures for overseas off-shore incidents but Mr Keith

gave helpful figures for the years 1968 and 1969 and there

were some later figures. Firstly as regards the extent of off

shore drilling. The figures given by Mr Keith (T5503-5) in relation to the number of off-shore wells drilled both explora

tory and production were:-United States 1968 - 1,487

1969 - 1,341

Latin America 1968 - 425

1969 - 438

Eastern Hemisphere 1968 - 443

1969 - 511

Outer Continental Shelf of U.S.A.

1.3.8 Mr Keith added:-

"Good statistical data is available for the

United States, the North Sea and Australia.

Other major off-shore drilling areas, notably

170

South America and Brunei are not well documented.

In the United States, there have been about

13,000 wells drilled up to 1969. Of these 7,860

have been drilled in the Outer Continental

Shelf, between .1953 and 1st August 1969- Of the latter, 133 were in the process of drilling,

4,428 had been completed for production or

service (7,324 zone completions : 5,607 oil :

1,717 gas) and 3,299 dry or abandoned holes.

During this period there had been 25 blowouts".

It appeared from Ex. 74 (a publication by the

Department of the Interior) that of these, 7 were oil well

blowouts and 18 were gas well blowouts.

1.3.9 The percentage of blowouts to wells completed for 2 R

production was thus for the 1953 - 1969 period x 100 =

4428

.56. If zone completions are taken (7,324) the percentage

was .34. The percentage of gas blowouts to gas zone complet ions was x 100 = 1.0 and the percentage of oil blowouts

1717

taking oil zone completions was about .13 or as Mr Jeffrey QC

said "about 1 or 2 for every 1,000 wells drilled into an oil containing zone".

But there have been two major blowouts in U.S.A. off

shore wells since 1969 namely Chevron and Shell so that these

figures are not fully up-to-date.

1.3.10 "Zone completions" relate to the fact that there

can be more than one zone found in a well. A well may - at

different levels - produce from several different zones (T5546).

Mr Keith also said:-"Of all the blowouts listed, only 10 (all in the United States) involved crude oil. The

others were natural gas and there is no record

that these caused any damage to the environment.

Of the 10 crude oil blowouts only 2 have

171

resulted In significant oil spillage - those

at Santa Barbara and the Chevron platform in

the Gulf of Mexico." (T5506)

The North Sea

1.3.11 Mr Keith added "... There have been 280 wells drilled in the North

Sea from 1964 to June 1970. Of these, 150 were found

to be dry. There have been 3 recorded blowouts."

Prom these figures it would appear that in respect of

North Sea drilling there were 3 blowouts from 130 wells which

were not dry, that is to say a percentage of 2.3.

Generally 1.3.12 It would appear that the large and long lasting Shell

fire in the Gulf of Mexico which began on 1 December 1970 and

which is described in Part 6 of the answer to TR4 occurred

after Mr Keith's statement and was not included in his figures.

Furthermore, Dr St Amant (Assistant Director, Louisiana Wild

Life and Fisheries Commission) at T4021-3 when referring to the West Delta Block 45 explosion and fire in the Gulf of Mexico on

15 October 1958 and in respect of which Mr Keith in his Exhibit

216 (T555D stated that the quantity of oil lost had not been

reported, said of it (T4021):-"... probably the largest amount of oil I have ever seen in the embayment system."

"... a considerable amount of oil was lost at

this site and we were aware of it and aware it was floating around in the gulf proper in a

rather large lake or flow."

1.3.13 Dr St Amant (at T3941) speaking of the total number of active wells in and off Louisiana referred to the "Inter

mediate" zone of marsh land immediately inland from the coast (in which he thought there are upwards of 15,000 wells) and

then as regards "zones 2, 3 and 4" - which are presumed to be

in the Outer Continental Shelf and beyond the 3 mile limit, he

172

said that "U.S. Geological Survey data indicates a total of

6,556 active wells."

Conclusions from blowout statistics

1.3.14 (i) Major oil blowouts are few in proportion to the number of wells successfully drilled.

(ii) Gas blowouts are more frequent than oil blow outs . The reasons for this appear in para

graph 1.2.2 supra.

(ill) Notwithstanding advances in (a) world tech nology, (b) standards of personnel training

and (c) governmental supervision at least

three major oil incidents have occurred in

United States off-shore drilling, three gas

blowouts have occurred in the North Sea and

four in Australian waters within the last few

(iv)

years.

As it is universally acknowledged that the

main cause of the American and Australian

incidents has been human frailty (see Part 6 of the answer to TR4), it is almost ce"rtain

that blowouts will never be entirely elimina ted. Recent gas blowouts in the Gulf of Mexico as recounted in the American periodi

cal "Ocean Oil" Vol. 7 No. 12 p .1 of December 11 1972 tend to confirm this view.

(v) Statistics may improve with advances taking

place in world technology, but some reserva

tions must be made.

Changes in modern technology

1.3.15 Both the industry and governmental authority in the

U.S.A. and elsewhere continue to endeavour to improve standards of equipment design, personnel training and safety precautions

but the number of major changes has not been large. Mr Thomas

(General Manager, Beach Petroleum NL) gave evidence at T2831 as follows:-

173

"When was the last radical change made In this technology? Not mere points of detail,

but when did it take its present shape?-- The

method of rotary drilling and the means of

blowout prevention have been with us for far

longer than my career in the oil industry;

possibly something of the order of 30 years.

Could you tell us when the last important

development in this area was made?-- This

would only refer to the use of sub-sea

drilling equipment as opposed to land type

drilling equipment. This I consider would

be the largest step made by the industry,

and here my actual knowledge of dates is somewhat hazy, but I would say it must have

been in the late fifties, early sixties that

the techniques of placing sub-sea blowout

preventers on the sea floor became accepted

as a standard practice.

"MR CONNOLLY: Since, say in the early sixties,

has there been any further radical changes?--In the type of equipment, no.

Of course, improvements in detail are, I suppose, being made from time to time?--Almost continually, yes. It would be right

to say then for the last ten years the tech

nology has had its present shape so far as

drilling the seabed is concerned?-- In gen

eral form, yes.

The blowouts that have occurred in the last ten years have occurred with the technology

in a satisfactory state?-- I would like to first of all define whether we are talking

of blowouts from producing wells or blowouts

while drilling. It was a perfectly general

question. If you want to draw a distinction,

would you draw it?-- While drilling certainly

17b

blowouts have occurred during the last ten

years, and how many I have not studied.

I understand.-- With essentially the same

type of equipment as Is now employed. In

the field of production, however, there have been at dates later than that ten years, but

during the last ten years, improvements In

sub-sea safety valve equipment. So that one

would anticipate that during the last ten

years the technology of preventing blowouts

from production wells has advanced somewhat

more rapidly than that In preventing blowouts from drilling wells. "I think It would be

useful for the Commission to know when the

last major Improvement in relation to sub

sea production wells occurred and what It

was?-- This would be, as I have already

stated, the Introduction of the hydraul ically controlled safety valve which became

generally accepted and used possibly from

1963 onwards.

It follows surely, that blowouts which have

occurred since, let us say, 1963, from prod uction wells and over the last ten years In

drilling operations, must have been largely

due to the Introduction of the human factor?

-- Yes. I have already stated of course that on old evidence certainly It appears the

greatest proportion of blowouts are caused

by human error."

1.3.16 But the evidence (to be referred to hereafter) estab

lishes that In addition to the sub-surface safety valve, other Improvements tending to Increase safety have In recent years

taken place such as tanks more sensitive to changes In mud

levels, audible as well as visible warning devices, remotely situated manual controls in addition to automatic controls,

175

shear rams, compensating devices reducing the amount of heave

motion and improved casing designs. The comparatively recent

introduction of semi-submersible and jack-up drilling barges

must also be noted as they reduce the effect of rough seas on

drilling operations from floating rigs and so give greater

stability than floating rigs of the "ship-shape" type. Improv

ements have sometimes resulted from lessons learnt from recent

blowout incidents.

1.3.17 It is proposed to give now a description of the main

features of "existing world technology" and its main hazards

as an introduction to our assessment of the degree of risk of

an oil or gas leak from a blowout or otherwise in the GBRP.

176

PART 4 - OFF-SHORE PETROLEUM DRILLING TECHNOLOGY

Types of off-shore rigs

1.4.1 The Industry had had over 20 years experience of off

shore drilling and is presently exploring the coastal waters of 75 countries (Mr Ericson T1122).

1.4.2 Off-shore drilling may take place from a fixed plat

form (T2610) or from platform and tender (T2611) or submersible

(maximum depth 175 feet - T2612) or from the "jack up" type

(T26l4) or the semi-submersible (T26l4) or the "ship-shape"

floating rig (T2615)·

1.4.3 (i) The fixed platform carries all the

working machinery of a rig and has

most of the advantages of a land

unit. It is not moved by tides or currents or winds and it can be built

strong enough to withstand hurricanes.

However the deeper and rougher the

water in which the platform is built

the more expensive will be its con struction. Mr Thomas (General Manager

of Beach Petroleum NL) said (T2610)

its use in deep or rough water is more suitable for development drilling on

a proven discovery.

1.4.4 (ii) The platform and tender is where a small

platform is used to mount only the der

rick and drawworks and a barge or tender

is moored alongside to carry the mud

tanks, drilling materials, etc. This is

a cheaper method but can only be safely

177

1.4.5 (111)

1.4.6 (Iv)

used In calm and comparatively shallow

waters.

The seml-submerslble rig can operate In

water depths of up to 1,000 feet using

systems of multiple anchors to hold It on

location (T26l4). The Commission considers

that, having regard to wind and wave condi

tions obtaining within the GBRP any semi-

submersible which depends solely on

conventional anchorage systems for station

keeping should not be used in depths less

than 250 feet - see paragraph 4.6.23

recommendation No. 5- Evidence given by Dr Maxwell may at this stage be appro

priately interposed. He said (T131):-

"There is a noticeable bathymetric trend from shallow to deeper water as one moves

southward from the Torres Strait area to the

Capricorn Channel. This trend, over a dis

tance of approximately 900 miles is reflect

ed in the progressive increase of maximum

depth from 16 to 70 fathoms. In addition

to the regional variation in bathymetry,

a normal shelf zonation may also be recog nised (Figure 6). This has been described

in the Atlas of the Great Barrier Reef and briefly is as follows:-(I) Near Shore Zone 0-5 fathoms,

(II) Inner Shelf 5-20 fathoms,

(III) Marginal Shelf 20-50 fathoms (divisible into eastern and western segments

in the south) and (iv) Southern Shelf Embayment, arbitrarily delineated by the 35

fathom contour, and separating the Western

and Eastern Marginal Shelves."

The submersible. This combines stability

178

1.4.7 (v)

with mobility. It is sunk so as to

sit on the ocean bottom by the use

of ballast tanks. It is there un

affected by ordinary weather con

ditions. When required it can be

raised to a towing position.

Mr White at T2983 said:-

"The submerged barge can only be

used in shallow (maximum about 15

feet) sheltered waters, with only

a low tidal range (maximum about

6 feet depending on maximum water

depth). ...Drilling operations are

carried out essentially as if the

rig were on land. This method is

relatively cheap but the limitations

are such that I doubt it would have

application in Barrier Reef waters."

The "jack-up" type can be towed and

as its name implies can be jacked up

on location (at suitable depths) and

then has most of the attributes of a

fixed platform (T2614). Mr White said

(T2983):-"This type of rig is limited to water

depths of between approximately 20 feet

and 300 feet although the only jack-up

rig to have operated in Australian

waters, the Offshore Co.'s 'Jubilee',

has a maximum depth rating of 200 feet.

A relatively level sea bed is required

and preferably the sea bed should be

fairly soft to avoid shock loadings to

the legs when jacking-up or jacking-down

in other than calm conditions. This

type of rig would have application in

179

certain areas covered by the inquiry.

1.4.8 (vi) The ship-shape rig is mobile and comp

aratively cheaper for multiple and ex

tensive exploratory work but is not

favoured by the Commission for use

within the GBRP as its operation pres

ents more hazards under GBRP conditions

than the other types. It is more in

fluenced both vertically and horizon

tally by winds, waves, tides and currents

than the more sophisticated semi-submer

sible (Mr Thomas Exhibit 205 p.24). But

this view applies only to conventional

anchorages. Technical advances in station

keeping and stability are being made (see

paragraph 4.6.23).

Directional drilling 1.4.9 A comparatively recent development is directional

drilling which has important advantages but also can create

hazards as overseas events have shown. It is possible by the use of a steel wedge or "whipstock" to deflect the drilling

bit and to achieve a hole with a succession of slight angles

amounting in effect to a curve. It is thus possible to reach

an objective distant say 6,000 feet in a horizontal direction and 6,000 feet in vertical depth from a surface location. This

has the advantages (a) of allowing a substantial number of wells to be constructed radially outwards from the one drilling plat

form and (b) to plug a well at or near its bottom and stop a

blowout from a distant surface location (as in the Petrel No. 1

gas blowout). On the other hand great care has to be taken in

the casing at the angles when drilling in a proven field as

evidenced by the Marlin A? blowout - see answer to TR4, and also to ensure that the multiple wells are not too close or do

not come into contact with each other as a North Sea gas blow

out demonstrated.

180

1.4.10 Exhibit 206, Figure 21 exhaustively illustrates the

uses of directional drilling and they may be tabulated as follows:-1. Reaching under a river or lake where

waters are too deep or swift to permit

platform or barge drilling from the surface.

2. Extinguishing an oil fire by drilling

from a site some distance away and pumping in mud.

3. Drilling under the cap of a salt dome

which forms a trap for oil.

4. Drilling under a city or other occupied

place where vertical well site is imprac ticable .

5· By-passing a blockage in an original vertical well.

6. Drilling underseas from the shore.

7. Off-shore drilling - several holes are

often drilled from the one platform to

produce oil more economically·

The drilling process

1.4.11 Different aspects of the process were referred to by several expert witnesses, the main and complete description

coming at an early stage from Mr Thomas - Exhibits 205 and 206 and at T2540 et seq. The following bare outline which is suff

icient for our present purposes has been extracted from his

evidence with the assistance of the final address of counsel assisting the Commission.

1.4.12 The principle of drilling is to impart rotary motion to a hollow steel pipe, known as the drill string, to the end

of which is attached the drilling bit. The consequent revo

lution of the bit and the weight of the drill string upon the

bit, aided by the heavier lengths of pipe immediately above the

bit, known as the drill collars, cause the earth or rock to be

181

dug away. The drill string consists of steel pipe of great strength (T2547) which is made up in about thirty feet lengths

(T2540, 28l6A) and varies in diameter up to five inches. As

the hole deepens a new thirty feet length of drill pipe is

screwed onto the existing drill string. Each length of pipe

has at each end an upset joint of larger external diameter than

the pipe itself. These are threaded to match the threads of

couplings called "tool joints" (T2547).

1.4.13 An oil drilling derrick structure is some 135 to 150

feet high (T2540). About 15 or 20 feet above the ground is the

derrick floor in which is set the rotary table (T2542). The

rotary table can be rotated in a horizontal plane by a power take-off from the draw-works or winch at a speed of rotation

which the driller can control. The rotary table has in its

centre a square or hexagonal hole. A length of high strength

steel pipe 40 to 45 feet long with a circular hole down its

centre and an external square or hexagonal shape, called a

kelly, is used to grip the drill string while the hole in the

rotary table grips the kelly (T2549)· Thus the rotary movement of the table is transmitted to the bit. The kelly can slide

freely up and down through properly shaped bushings in the rot ary table and so it slowly sinks through the table while the

bit penetrates until it reaches a point where it is appropriate

to stop, raise the kelly and add a further thirty feet of pipe.

Often three drill pipes are fixed into a ninety foot length or "stand" for quicker handling. The derrick also carries the

hoisting system consisting of a fixed crown block at the der

rick apex, a travelling block and the draw-works. These items

are threaded with the drilling line, a high tensile steel cable, to provide a pulley system for the raising or lowering of the

heavy weights of drill string or other equipment within the hole. Attached to the travelling block is a hook and a swivel

from which the drill string hangs while drilling.

1.4.14 The operation of drilling can be continued twenty

four hours a day. As the bit proceeds deeper the formations

182

usually become more compacted and harder and the bit tends to

wear out more rapidly. The failure of the bit to penetrate

shows It is worn out and then the complete drill string is

pulled out and re-run with the new bit. This procedure is

called "making a round trip" (T2549). Depending upon the

formations to be penetrated a 10,000 foot hole could take as

long as three or four months, or as short a time as thirty days,

to drill (T2550). A bit might make several thousand feet be

fore requiring changing when drilling shallower, softer form

ations; in extreme cases, when very hard materials are being

drilled, the bit might make only a few feet of progress before

wearing out (T2550). To make a round trip at about 10,000 feet

a good crew would take eight hours (T2554). The actual process

of adding a new length of pipe would take a good crew only 3-4

minutes (T2554).

1.4.15 When the driller wants to add a new length of drill

pipe the kelly is raised above the rotary table level and (the

motor being shut off or out of gear) a set of "slips" or circ

ular wedges are inserted between the drill pipe and the insides

of the rotary table bushing. When the kelly and drill string

are again lowered, sharp file like teeth in the slips grip

tightly to the drill pipe and are pressed more tightly still,

due to the conical shape of the inside of the rotary table

bushing. The full weight of the drill string below is thus

transferred to the rotary table and the kelly can be unscrewed

and stowed in a pipe known as the "rathole" set through and to

one side of the derrick floor (T2550). In this way the weight

of the drill string is temporarily taken off the winch of the

hoisting gear so that a fresh piece of pipe can be lifted out of the rack in the derrick superstructure and inserted at the

top of the drill string.

Casing the hole

1.4.16 The purpose of casing the hole was described by Mr

Thomas as follows (T2571-2):-"From time to time as the hole is deepened it

183

is necessary to run casing at various depth intervals. Casing is a steel pipe of strength

and size specifications rigidly controlled by

industry and government standards which is set

into the hole and bonded to the formation sur

rounding it by a cement sheath filling the

casing/hole annulus.

The cement acts not only to provide support

for the pipe which it surrounds but also to

prevent the interflow of reservoir fluids

behind the pipe. Depending upon the purpose

of the well, i.e. exploratory or develop

ment and the local conditions, the size and

depth setting of successively smaller strings

of casing will differ from well to well.

"Casing is set into the hole to protect the

hole, to prevent it from falling inwards; to

prevent escape of oil or gas through the cas

ing near the surface. Therefore it must have

certain strengths specifications to fulfill

these functions, the more important one being,

of course, the burst strength of the casing so

that it can safely contain within it any pres

sures met during any blowout or incipient blow out ..."

Mr Stewart at T4357 said the functions of casing

included inter alia acting as an anchor for the blowout prev

enter and making possible the control and production of the

completed well and that the functions of the cement included

sealing off the annular space between the casing and the walls

of the hole to prevent migration of water or oil or gas between

zones or leakage to the surface.

Mr White (Bureau of Mineral Resources) said (T3007A) :-

"The company engineer must select casing setting

depths in accordance with expected lithologies."

Mr Thomas also stressed the importance of casing pro

grammes in relation to safety at T2580.

184

1.4.17 But casing is to a substantial extent the subject of

governmental regulation in the U.S.A. - see answer to TR4 where

the subject is discussed at some length and where OCS Order No.

2 and Exhibit 68 are considered in detail.

1.4.18 As soon as new casing has been cemented into place it

is pressure tested to its design capacity, or to that of the

blowout preventers (as to which see below) whichever is the less

(T2659) · Thereafter the top section of the casing and the well

head should be pressure tested weekly (T2659). This is partic

ularly necessary because the inevitable wear and tear of running

the drill string in and out will be greatest here and so will

the contained pressures (T2571, 2654). It is for this reason

that thicker or stronger casing is usually considered for the

top 500-600 feet. (T2657).

1.4.19 Then there are different strings of casing each with

important operational and/or safety functions. Commencing at

the sea bed and descending they are

1.4.20 Stove Pipe. A wide diameter pipe set at a

shallow depth (100 feet or more). This pro

vides a circulation system for the drilling

fluid, referred to later.

1.4.21 Conductor casing. To cover unconsolidated

surface formations, to seal off shallow water

sands and to provide protection against shallow

gas flows. The annulus is cemented to the sur

face. Depth to 500 feet or such greater depth

as may be necessary to extend into a competent

formation (see answer to TR4).

1.4.22 Surface casing. To provide blowout protection.

To prevent loss of circulation of drilling mud

to shallow weak formations. Annulus cemented

to at least inside the conductor. Depth to

185

3,000 or 4,000 feet.

1.4.23 Intermediate casing. To protect the open hole. To prevent sloughing and caving of

formations. To protect against lost circ

ulation so that drilling mud densities can

be raised to control abnormal pressures.

Could be set at 8,000 feet. This string

has pros and cons and something may turn

on whether the well is a true exploratory

well with some unknowns or a development

well (Mr Thomas T2576).

In the former case, in spite of its cost

and accompanying necessity to use smaller

tools, it would be used for safety reasons

which are described at T2575·

1.4.24 Production casing. Used to separate pro

ductive zones from other reservoir form

ations to permit selective production (T2577)·

Could be 43$ to 5 inches in diameter - or

larger. To total depth of well.

1.4.25 Although the Commission was given several instances

of inadequate casing amongst the various blowouts, there were

no instances in which the casing itself failed.

186

PART 5 - THR MUD SYSTEM AND PRIMARY CONTROL

Nature and functions of the drilling fluid

1.5.1 The primary control of well drilling is the use of a sufficient weight and quantity of drilling mud to keep the well

bore pressure a little higher than the formation pressure.

Furthermore, one of the methods of obtaining the earliest aware

ness of formation fluids is to carry out a continuous examin

ation of the mud returning to the platform tank after its cir cuit below.

1.5.2 The mud system is therefore of crucial importance in

the drilling process and lack of care or skill can lead to a

blowout. The system was described by several experts such as

Mr Thomas, Mr Stewart and Mr White and was referred to from time to time by American experts.

Amongst the several clear expositions was the follow ing by Mr Thomas:-"The mud circulating system consists of tanks

holding some few hundred barrels of the liquid

mud. This is drawn from the 'live' tank by

heavy duty pumps and fed via a manifold system

to the drill floor where it passes through a

high pressure flexible hose to the swivel from

which the kelly is suspended. The liquid mud

then passes down the inside of the hollow kelly,

drill pipe and drill collars to emerge through

nozzles in the drill bit itself. It returns to

surface up the annulus between the drill string

and the hole to a point just under the drill floor, from where it is diverted along a flow

line, passes over a vibrating sieve ('shale

shaker') which removes the larger rock chips

or cuttings and then drops back into the tanks...

187

Anything basically larger than a grain of

sand would be removed by the sieving process."

(T2554)

1.5.3 Mr White at T2992 said:-"The primary function of the mud is to remove

cuttings produced by the drilling bit, but it

also helps to cool and to lubricate the bit,

to protect permeable formations from damage,

to prevent collapse of incompetent formations

and to provide a path for electric current

during certain wire-line logging operations."

1.5.4 Mr Stewart at T4347 said "The main functions of the drilling fluid are

as follows 1. Scavenge the bottom of the hole and the

face of the bit and carry the drill cut

tings to the surface.

2. Prevent influx of formation fluids while

drilling.

3. Support the wall of the bore hole.

4. Deposit a protective mud cake on permeable

formations.

5. Cool the bit and lubricate the bit and

drilling string.

6. Intermedium in (electric) well logging.

Function No. 2 above is to prevent an uncontrolled

escape of fluid (i.e. a blowout) from a drilling

well."

1.5.5 Mr Stewart’at T4348 referred to the planning of the mud programme as follows "The mud programme is planned so that the mud

should always have a density that will cause

an overpressure to bear on permeable formations,

so preventing the fluids contained in those

188

formations from entering the well bore

while drilling.

If for some reason the pressure in fluid-

filled permeable formations exceeds that

exerted by the mud column, then the fluid

(gas, oil or water) will enter the well

bore, displacing the mud. As the fluid

continues to enter the well bore, more

and more mud will be displaced from the

hole back into the mud tanks at the sur

face ."

Then at T4431 he dealt with pressure con

trol. He said:-"One of the primary functions of a drilling

fluid is to prevent the intrusion of form

ation fluids into the well bore. This

ability of the drilling fluid to control

sub-surface pressure is dependent on the

hydrostatic pressure. The amount of hydro

static pressure exerted against formations

depends upon the mud density and depth or

height of the fluid coloumn. The formation

fluid can be water, gas, oil or combinations

of these. Mud weight generally should be

heavy enough to provide an overbalance for

safe withdrawal of pipe; yet not so heavy as to cause lost circulation or retard pene

tration rates.

The pressure expected in a formation varies

with depth and calculations are made to arrive

at the pressure expected in formations through

which drilling will pass." "The drilling fluid used most commonly in the

rotary drilling system is a suspension of fine

clay particles in water with chemical addition

to impart certain desired properties. In the early days of drilling it was common practice

189

to mix a batch of drilling fluid by puddling

water in a surface clay outcrop and so the

name 'mud' was born. In modern practice the

clay used is a fine grade of bentonite which

although expensive has been found by experience

to produce the optimum properties when properly

treated with chemical additives." (Mr Thomas

T2555)

1.5.b The composition of the drilling fluid is of major

importance in the drilling process but in an area such as the

GBRP it would be important to ensure that it did not consist

of a mud and oil emulsion to prevent possible damage from

chronic pollution should discharges into the sea occur. On

this aspect Mr Erics on stressed that the Aquarius and Capricorn

exploratory wells to which reference has been made were drilled

with fresh water and sea water muds (T1203)· A recommendation

for controlling the use of a mud and oil emulsion and for the

prohibition of its discharge into the GBRP appears in the answer

to TR4.

1.5.7 The circulating fluid rising from the bottom of the

well bore carries the cuttings towards the surface. The effec

tiveness of the mud in removing the cuttings from the hole

depends upon (a) the velocity at which the mud circulates -

generally between 100 and 200 feet per minute, (b) its density

or weight per unit volume - barytes is added to increase weight

and (c) its viscosity.

"The proper restraint of formation pressures depends upon density or weight of the mud.

Normal pressure can lie between 0.433 to

0.465 p.s.i. per foot of depth. This is

the pressure exerted by a column of form

ation water. Normally, the weight of water

plus the solids picked up from drilling is

sufficient to balance formation pressures.

However, at times, abnormal pressure requires

190

the addition of finely ground material,

such as barytes, to increase the hydro

static head of the mud column." (T2558)

Since both the drill pipe and casing are buoyed up by

a force equal to the weight of mud displaced, an increase in

mud density necessarily results in a considerable reduction in

total weight which the surface equipment must support (T2559).

1.5.8 Drilling with lighter mud (where practicable) tends

to give the maximum warning of the advent of abnormal pressures.

1.5.9 It may be added that a pump pressure of about 2,000 pounds per square inch at surface is frequently used (Mr Thomas

at T2555).

Importance of mud levels

1.5.10 It will be apparent that continuous skilled attention

to mud levels and pressures by platform personnel is imperative

if dangerous incidents are to be avoided.

1.5.11 Not only must the properties of the mud be regularly

measured but the mud levels in the active tank must be con

stantly monitored because any sudden gain or loss of mud is a

warning of a potential blowout. Audible warning systems as well

as visible indicators appear to be very desirable if not neces sary .

1.5.12 The hydrostatic pressure must at all times be main

tained in the well so that any mud lost to the formation must

be replaced. Accordingly whenever a drill string is withdrawn

(for example to replace a worn bit) it is replaced in stages with additional mud.

1.5.13 The mud pit, the shale shaker and the mud flow line

are illustrated in the "Drilling Rig - Schematic Layout" shown

in Figure No. 1 of Exhibit 206.

191

The control of drilling; 1.5.14 As described by Mr Thomas at T256? the actual control

of the drilling process on the platform is as follows:-

"Power is supplied to the draw-works, rotary

table and pumps via gears or chain drives

from diesel or steam engines or electric

motors.

Control of all operations of pulling and

running pipe, rotating the string and run

ning mud pumps is effected from the drillers

console situated to the rear side of the drill

floor alongside the draw-works. Prom this

position the driller can observe and control

all activity on the drilling floor. Gauges

enable him to readily discern the weight on

the travelling block hook, rotary table speed

and torque, pump pressure and speed. Alarm

systems are fitted to inform him of malfunc

tions. Near to hand but more remote from the

rotary table are the BOP activation controls.

A further auxiliary control unit for the BOP's

is normally situated well away from the rig floor...To make hole the drilling crew run in

the drill string described above. With the

bit just off bottom and the kelly bushing

sitting in the rotary table, the driller

starts up the mud pumps and commences circ ulating the mud at a predetermined rate and

pressure. He then starts up the rotary table

to turn the drill string and bit at the req uired revolutions per minute. He then notes

the total weight of the drill string hanging on the hook as indicated on a weight gauge

immediately before his eyes."

"What are the required revolutions?"

"This varies from 50 to 150 or more a minute

depending on type of bit and type of form-

ation drilled. My statement continues:

By slowly releasing the handbrake con

trolling the draw-works winch drum he

lowers the entire drilling string, still

rotating, until the bit touches hole bot

tom at which point he will observe a drop

in the weight carried on the hook. He

continues to lower the string until the

weight on the hook falls back from its

free hanging total load and the bit is

taking the required weight. This too

varies with bit size and so on ...

With the bit hanging at the bottom of a

hole we can record the weight of the hang

ing drill at say 200,000 lb. The driller

then lowers the bit until it touches the

bottom of the hole, and the bit itself

takes some of the weight of the drill

string from the hook, say, 80,000 lb.;

thus the driller has 120,000 lb. on the

weight gauge reading. In the ultimate,

once that bit has drilled on and on, it

is more closely approaching the free hang

ing point again. When it has drilled sufficient hole from underneath it, it is

more closely approaching that state."

(T2569)

Some aspects of deep sea drilling

1.5.15 Some special procedures and precautions are appli cable when drilling from a floating unit and these were given

in some detail by Mr Thomas at T2633 et seq. He also dealt with situations where the BOP can for the time being, be dis pensed with. Thus he stated that he might drill to 1,000 feet

without using a BOP system because he was satisfied he would

not strike oil or gas up to that depth. He added:-"For example, drilling by Burmah Oil Company

193

under my direction off the north-west coast

of Australia, the Legendre No. 1 well, was

drilled with a BOP on top of the 30 inch

casing. Four other wells drilled in the

same area were drilled with no BOP on top

of the casing because we had ascertained

from the results of Legendre No. 1 and

from other geophysical and geological evi

dence that down to 1,000 feet depth there was no chance at all of encountering hydro

carbons." (T2635)

He expressed the view that because of the great

length of the - GBR coast and if the drilling were widely spread

involving frequent long moves then a ship or barge would prob

ably be the most economical unit notwithstanding that on occas

ions there are cyclones. But in reply to further questions he

said (T2619):-"... from the point of view of smooth action of drilling and so on I would prefer a jack

up or a fixed platform." "What about security of the hole?"--"Security of the hole also is exactly the

same with the jack-up or a fixed platform.

One can have the blowout preventers and

everything else above the surface of the

water from which you can work very easily.

From a floating unit or a ship you auto

matically must have them on the ocean floor;

so from security of all types certainly the

jack-up would be preferred ...

I am really thinking along the lines that a

vessel or a unit that is subject to violent

movement on occasions due to wind, wave and

swell obviously constitutes more of a mech anical risk than a unit which is seated four

square on the ground and is not moving - that

is all."

19 Î

1.5- 16 Mr Roe of Messrs Cullen and Roe, Consulting Engineers,

also gave evidence on the same subject of choice between rigs.

At T4127 he said:-"The type of rig that would be used for ex

ploration would probably be determined by

what type was available at the time that

the hole was started, semi-submerslble or

jack-up type being the probable choice.

Production wells would more likely be

drilled from fixed structures after a

field was proved.

A rig designed to suit the conditions at

some other location would not necessarily

suit the conditions on the Great Barrier

Reef."

1.5- 17 His view was that our knowledge of storm and surge

conditions In the GBRP Is inadequate to ensure safe designing

(T4114) and that In any event platforms would not be designed

to resist the ultimate In cyclonic storms. He dealt at some length with wave heights and storm surges In different parts

of the world and with the statistics of 100 year storms. His

maximum wave height for the GBRP (Ex. 214 p.ll) was 50' and the

maximum length between crests he gave as 650 feet. The maximum

wind gust over 100 years was 124 knots. For the Swain Reefs

area he gave the maximum wind gust as 146 knots. At page 14 of

his Exhibit he gives a quotation from one Leon E. Borgman quoted

in a paper by one P. W. Marshall:-"Furthermore there Is a natural reluctance

to pay the often exorbitant cost of Increas

ing the safety factor unless the situation

really requires it. Even with an Increase

there will usually be some risk because It

Is almost Impossible to make a structure

strong enough to withstand all conceivable

disasters. Thus In practice, risk cannot

be eliminated. It can only be reduced to

195

an acceptable level.

Detection of petroleum 1.5.18 It Is important during drilling operations for the

driller to detect at the earliest possible moment that the

drill is encountering or is about to encounter formation fluids,

particularly if there is any possibility that they may be under

abnormal pressure, so that appropriate measures can be taken to

prevent or control the flow of fluid at pressure out of the

hole. The methods presently available for detection and evalu

ation of a potential reservoir of petroleum were discussed by

Mr Thomas at T2583-96.

1.5.19 They are formation cuttings, mud logging, formation

coring, drilling speed, wire line logging and drill stem test

ing.

Details of these methods were.given by Mr Thomas at

T2583-2596. Each is of much importance in the detection of the

presence of hydrocarbons and in the safe conduct of drilling.

1.5.20 Thus samples of cuttings are normally collecting from

the vibrating screen and scientifically tested after each 10

feet of drilling.

The returning mud is subjected to a vacuum process to

detect petroleum gases and when gas intensity passes a pre-set

limit a warning bell rings (T2585).

Cylindrical pieces of core up to 60 feet in length may be removed by the driller and a geologist or engineer ex

amines the cores. .

1.5.21 Anything like a "drilling break" - i.e. a sudden

significant increase in drilling speed will be observed immed

iately because the presence of a porous formation, i.e. a

potential reservoir may be indicated (T2585)·

1.5.22 Various electronic, sonic and radio-active devices

can be suspended on a multiple-conductor cable over the section

196

of uncased hole. From these, accurately calibrated strip logs

showing many physical and electrical characteristics of the

rock strata can be obtained.

1.5.23 Then at a certain stage of exploratory or develop

mental drilling judgment must be made on the potential or prod

uctivity of the well being drilled in order to enable the imp

ortant decision to be made as to whether production casing - a

very expensive matter - will be installed. This is done by

"drill stem testing", a procedure which was described in detail

by Mr Thomas at T2589. It sometimes involves hanging a "tail

pipe" below the packer assembly. It is of such a length that

when it lands on the bottom of the hole, the packer is posi

tioned just above the zone to be tested and if possible oppo

site a firm competent and impermeable formation. At a stage of

the testing the formation below the packer is relieved of the

pressure of the mud column above the packer and the flow of formation fluids is restrained only by a closed valve in the

tester assembly. The drill pipe is run empty or with only a

short and carefully measured column of water above the tester

valve.

As Mr Woodward QC said (Tl6l85)

"The risks are perhaps greatest because you

do not have the protection of the circulating

mud column at that stage and if you are suc

cessful in your test you are introducing some

hydrocarbons into your drill stream which must

be then disposed of."

197

PART 6 - LOSS OF PRIMARY CONTROL

Kicks

1.6.1 Mr Stewart (Senior Petroleum Engineer, Queensland

Department of Mines) at T4431 when dealing with loss of primary

control spoke of "kicks". He said:-"There are ways of determining if a well is

entering a region of abnormal rock pressure.

One is to plot the rate of penetration of the

bit against the depth at which the well is drilling. A change in the gradient of the

graph indicates that rock stresses are ab

normal and any fluid encountered could be

under abnormal pressure. Another similar

type curve is to plot depth against the

density of the shale cuttings being ret

urned to surface in the mud stream.

The first warning of an impending blowout

or 'kick1 is a gain in volume of mud in

the mud pits. Careful observations of

mud volume during all phases of the drill ing operation are the best indicator of

trouble."

1.6.2 He was asked whether a loss in volume of mud could

indicate in some instances the possibility of a blowout to

which he said:-"While drilling, if you lose circulation it indicates you have a formation which is

taking fluid but I do not think it would

be 100 percent sure that it would indicate

you were going to get a blowout."

1.6.3 He added:-

198

"A 'kick' while drilling can be recognised

by an increase in mud volume and usually

just before the kick an increase in drill

ing rate is experienced and followed by a

decrease in pump pressure, and an increase

in pump strokes. These symptoms are easily

recognised by trained and experienced crews

and appropriate action taken to contain and

control the well ...

The method of controlling a kick will depend

on what operation such as drilling or pulling

out of the hole etc. , is being carried out, but the aim is the same i.e. to increase the

mud weight sufficiently to a weight whereby

the hydrostatic pressure will contain the

formation fluid within the formation."

"Kicks" are further discussed a little later

(paragraph 1.7.9).

Causes of loss of primary control

1.6.4 These include

(i) drilling with insufficient mud weight

(ii) failure to keep the hole full of mud

(iii) loss of circulation

(iv) swabbing and/or piston action due to

pulling and running tools in the hole,

i.e. too quickly.

As to (i)

1.6.5 A mud weight which is sufficient for normal pressures will be inadequate if abnormal pressures are encountered.

Further weighting material such as barytes will then have to be added.

On the other hand and whilst a high mud weight is

obviously beneficial in preventing entry of oil or gas into

the well, high mud weights are expensive to maintain and tend

to reduce drilling speeds.

199

"... they also, from the viewpoint of well

control, constitute a danger in that the

high weight may help induce loss of circu lation into low-pressure zones. Should

this occur, the loss of part of the mud

column above a potential blowout zone may

lower the mud pressure sufficiently to

allow inflow of oil or gas." (Mr Thomas

at T2652)

He added (T2665) that it is important to

"ensure that mud gel strength and viscosity

are kept as low as possible to minimise swab

bing when pulling out, pressure surges when

running in and to facilitate degassing of

gas cut mud."

As to (ii) 1.6.6 Failure to keep the hole full of mud. The flow rates

and the active tank level when circulating must be carefully

and continuously watched. Elsewhere the necessity for audible as well as visible indications of changes in levels has been

stressed. When circulation was suspended it meant the actual watching of the level of mud in the hole or carrying out a

limited circulation of mud across the top of the hole (T2641).

Particular care is needed when withdrawing the pipe because it

must be replaced with an equivalent quantity of mud as it comes

out.

Mr Thomas spoke of "thief zones" at T2640 to which

reference has been earlier made.

An increase or decrease of mud level in the tank is

a very serious matter requiring immediate action as the his tory of blowouts shows. The subject of a well "kick" is dealt

with further below.

As to (iii)

1.6.7 Loss of circulation arises from a weakness in the formation which permits drilling mud to run away to such an

200

extent that circulation back to surface ceases. In most cases

a lost-circulation zone can be dealt with by adding some solids

to the mud.

"The loss of circulation very frequently

precedes a blowout. As a matter of fact,

it is the cause of many blowouts for the

simple reason that the fluid level drops

to such an extent that the fluid from the

formation can go in with practically no

resistance.. This happens so quickly that

sometimes it is right in your eye before

you know it is going on ... I agree with

what Mr Stewart has said, that from its

lowest point it would probably increase somewhat before you actually have gas or

oil coming out through the well, but this

may be preceded only by a matter of sec

onds." (T4351)

As to (iv).

1.6.8 Swabbing or piston action:

Mr Thomas said (T2643):-

"the tools being used at the bottom part

icularly and the bit and the drill collars and other devices which are fitted to drill

collars, called stabilisers. They are close to the hole size and therefore they could

have the same effect as the piston in a pump when they move fast enough. If one drags

the drill string up the hole away from the

bottom, at a sufficient speed, depending

upon the viscosity of the mud, you can, in

actual fact, lift mud out of the hole. This

would leave a vacuum or opening below the bit

into which hydrocarbons may flow."

He went on:-"The answer to this is simply that the pulling

201

speed should be regulated so that you do

not get any swabbing action and that the

viscosity of mud should be low enough so

that the mud can flow easily down past

the drill string while it is being pulled

up.

The reference to piston action here is

actually a secondary reference to loss of

circulation by running in the drill string

too fast. This creates a pressure surge

ahead of the bit and it acts as a piston

... and it may be of such a dimension as

to break down ‘ or fracture some weaker form

ation and this could cause loss of circu

lation of mud."

PART 7 - MAINTENANCE OF PRIMARY CONTROL

1.7*1 The technical 'details of the steps which should be

taken to avoid trouble (given by Mr Thomas, Mr White and others)

are not necessary for present purposes more than to the extent

required to assist in the assessment of the degree of risk in

volved in drilling and production. Trouble may occur in at

least four situations namely (a) while making a round trip,

(b) while doing maintenance work, (c) if a thief zone is en

countered and (d) if a drilling break occurs. A blowout is always preceded by an actual "kick".

As to (a) - Making a round trip

1-7*2 As Mr Thomas said, it is essential that the hole must

take or give up mud volumes equal to the change in drill pipe

displacement. He continued:-"If the hole is taking less mud than required

when pulling out or is giving up more mud when

running in, this is an indication that form

ation fluids are entering the bore hole. A

tank of small cross-sectional area which en

ables accurate volume measurements must be used to deliver mud into the hole or receive

it from the hole ... (T2661)

If after pulling off bottom, swabbing is indi

cated, i.e. the hole does not take sufficient

mud, run back to bottom, circulate and con dition mud." (T2662)

1.7*3 An entirely different point raised by Mr Thomas rel

ating to "tripping" was the need to check and record any evi

dence in the mud of gas or brine which may have entered the mud

column during the process (T2662-4). He again stressed the need

to measure accurately any change in mud volume (T2662).

1.7.4 As already stated, the first thing to do If swabbing

Is indicated Is to return the bit to the bottom, recommence

circulation and check the mud quality for viscosity.

As to (b) - Maintenance work

1.7-5 Mr Thomas stressed that the driller should stay out

of the hole for as short a time as possible. He said in rel ation to the desirability of hanging off the drill string with

the bit inside the lowest casing shoe whilst maintenance work

is being done (T2662):-"... if a certain length of pipe is in the

hole, you can control an incipient blowout

with a lower weight of mud than would be

necessary when dealing with a hole that has

no pipe in it ... it is standard practice

that all rig maintenance, including greas

ing of parts, oiling of hoisting machinery

and pqmping equipment, is carried out with

the bit standing in the shoe of the lower

most casing.

Thus when the driller realises he must carry out maintenance, he will, on the next trip

out of the hole, stop the pipe out of the hole with the bit which is inside the cas

ing, hang it up, carry out his maintenance, then proceed out of the hole to complete

the trip. In this way he is able to run

back again immediately."

As to (c) - Thief zones 1.7.6 Thief zones are also referred to when dealing with

secondary control (infra). Mr Thomas said that he had not

known of a case of such a zone which had not been noticed dur

ing the actual drilling. Nevertheless it was important for

the crew to check the level of mud in the hole occasionally

while circulation was interrupted (T2787).

20H

As to (d) - A drilling break

1.7.7 So far as drilling breaks are concerned, Mr Thomas

said that the proper course of action was to suspend drilling,

shut down the pumps and check for inflow. This enables a check

to be made as to whether any formation fluid is entering the

hole from the presumably porous zone intercepted. The reason

for shutting down the pumps is that this eliminates the back

pressure due to friction which occurs while pumping. Thus 'the

formation fluids have only the hydrostatic head of the mud to

contend with in forcing their way into the hole. If they do

not do so at this stage, they are unlikely to do so later

(T2665). A further reason for shutting down the pumps is that

it is easier to detect an increase in mud level in the hole

than in a comparatively large mud tank which is already subject

to some disturbance due to the circulation of the mud.

1.7.8 After a drilling break, as in the case of a suspected

swabbing, one option open to the driller is to circulate "bot

toms up", that is to circulate until the mud from the bottom of

the hole reaches the surface, when it can be closely examined

for any sign of formation fluids (T2781), and the mud recon

ditioned.

Kicks

1.7-9 A "kick" has been referred to earlier paragraph 1.6.1.

It is said to take place when formation fluids actually enter the hole.

When a kick occurs secondary control is called upon to hold the position until primary control is confirmed or

regained. Secondary control will be discussed a little later.

Indications of a kick at the surface are an apparent gain in mud volume followed by a decreas-e in mud density and,

if the formation fluid is gas, an increase in the mud gas read

ing (T3011). Any increase in chloride content - indicating the

presence of brines - will also be noted as will the presence of oil in the mud.

Mr Thomas (General Manager, Beach Petroleum NL) said:-205

"A gain in mud volume while drilling or

failure of the hole to take the proper

amount of mud while pulling pipe is the

first positive sign of an incipient blow

out. The essential training of all mem

bers of the drilling crew must emphasise

the value of the mud level reading in

the active tank. Pit level indicators

with warning signals should be located

next to the driller and as a further check an independent system can be (and

usually is) connected to the mud logging

unit ..."

1.7.10 He added:-"A problem on floating vessels is caused

by the surge of mud in the active tank due

to vessel movement which can give spurious

tank level readings. This can be overcome by fitting a number of level indicators

across the tank, the readings of which can

be automatically integrated to give a mean

level. Another device consists essentially

of two meters to measure mud flow into and

out of the hole which will actuate an alarm in the event of difference between the two

rates." (T2668) With regard to controlling a kick which has occurred

Mr Thomas said:-"It should be emphasised that the fact that a well kicks does not mean that it is immed

iately going to blowout but it does mean

that rapid smooth action is necessary to

minimise the problem of gaining full primary

control once again.

Crew training is probably the most important

single factor in ensuring that an inconven-

206

ience does not degenerate to a catastrophe.

Crews must be trained to work as a team with

at least two men able to carry out any one

particular job. Teaching should consist of

demonstration and explanation of the use of

the emergency equipment followed by drills

for each shift until full competence is

attained. Thereafter alarms should be given

without notice by a senior supervisor at least

once each shift and the reaction time of the

crew noted." (T2670-1)

1.7.11 Dealing a little further with remedial steps the

evidence indicated that the remedial procedure when kicks occur

includes resort to secondary control a commonly used procedure

being (i) raise kelly above rotary table, (ii) stop pump, (iii)

open choke line, (iv) close BOP's, (v) close choke, and (vi)

read shut-in pressure on drill pipe and casing annulus pressure.

1.7.12 Mr Thomas stressed that the choke line should be kept

open at all times. In this procedure the BOP is closed before

the choke otherwise there would be a danger of creating a pres

sure that could do some damage to the equipment and possibly

break down the formation. He also gave reasons for taking an nulus pressure readings at this stage (T2672). Other steps in

this procedure were also described by him (12673-4)·

1.7.13 A possibility of a kick while round tripping with the

drill pipe exists because of the danger of swabbing. The prob

lem may be increased if the bit is high above the producing zone

before the danger is realised. Mr Thomas said (T2676):-"In such a situation the invading gas or

liquid can only be circulated out completely

by returning the bit to bottom. After fit

ting a non-return valve, known in this case

as an 'inside BOP', to prevent flow up the

inside of the drill pipe, every attempt

207

should be made to run back to bottom (as

safety and time permit) prior to closing

the BOP's. Should this be accomplished

the procedure for handling a kick while

drilling or circulating can then be taken."

Other steps In this procedure were described all

tending to show the necessity for sustained care and skill on

the part of the drill crew.

1.7.14 Of the possibility of a kick occurring while out of

the hole Mr Thomas said (T2680)

"This Is a most unusual occurrence but Is

possible If a minor zone of lost circulation

exists and the mud level In the hole drops

unnoticed by the crew who may be engaged In

other work. As a preventative, all routine

maintenance work should be done while the

drill bit hangs In the shoe of the casing

and the mud level should even then be regu

larly checked."

208

PART 8 - SECONDARY CONTROL AND BLOWOUT PREVENTERS (BOPs)

Nature of secondary control

1.8.1 Secondary control Is the use of blowout prevention

equipment (BOP) to control the well If loss of primary control Is threatened or occurs.

1.8.2 In preceding Parts we have described the mud system

and primary control. The possible causes of loss of primary control may be summarised as

(I) drilling with Insufficient mud weight (II) failure to keep the hole full of mud

(ill) loss of circulation

(iv) "swabbing" and/or piston action due

to pulling and running tools in the

hole (Mr Thomas T2638-9).

1.8.3 The importance of ensuring that mud gel strength and

viscosity are kept as low as possible was stressed in order to

minimise swabbing when pulling out and pressure surges when

running in, also to facilitate degassing of gas cut mud (Mr

Thomas at T2665).

Types of BOPs

1.8.4 But if primary control fails secondary control is adopted.

1.8.5 BOPs are hydraulically operated valves and the drill string and kelly pass through their centre into the hole.

1.8.6 In the event of loss of primary control resulting in

oil, gas or water attempting to escape through the annulus be

tween the drill string and the hole, the BOP can be closed

around the outside of the drill string.

209

1.8.7 There are three types as explained by Mr Stewart

(i) Ram type "The ram type preventer is like a gate valve

with gates which meet at the centre of the

hole which they close. The faces of the ram

which meet are equipped with heavy rubber

packers, and they are made with shapes to close around pipe when it is in the hole.

One size of ram can only close on one size of pipe. Rams are made in all of the tubing,

drill pipe and casing sizes which can be run

through the preventer. When pipe rams close

on drill pipe', they seal off the annulus be

tween the outside of the pipe and the well

bore. On the face of the rams, there are

centering guides which contact the pipe first and push it to a central position as

the rams close. Ram type preventers can

also be equipped with blind rams which seal

off the hole when there is no drill pipe in

side the well bore. The common practice on

a well is to use two ram-type preventers, one

for closing on the drill pipe and the other

with blind rams. When the casing or tubing

is run the drill pipe rams are then changed to match the new size of pipe ..."

(ii) Annular or bag type "An annular blowout preventer consists gen

erally of a massive rubber sealing element

having a circular shape which, in the rel

axed position has a bore through it to match

the drilling bore. This sealing element is

contained in a body, and there is some means

provided to constrict or close up this rubber

sealing element so that it expands inwards until it seals the hole. ... Because of the

flexibility of this large sealing element

210

an annular preventer can close on any size

of pipe, drill collar, tool joint (which is

the threaded joint connecting two lengths

of pipe), or kelly which happens to be in

the bore of the preventer when it is closed.

The ability to" close on any size and shape

is the outstanding feature of the annular-

type preventer," (T4343) (iii) "Shear- type blind rams which can cut

through any pipe in the hole, These would

only be used for this purpose as a last

resort in emergency situations but it is

an important option for the driller to have.

A recommendation regarding shear type rams

is made in the answer to TR4. The Commission

is firmly of the view they should be regarded

as necessary equipment should drilling be per

mitted in any part of the GBRP. Blind rams

may break the drill pipe even if not fitted

with shears, but they are not designed to do

so and are likely to suffer damage in the

process.

1.8.8 Depending upon the problems likely to be encountered,

a number of individual BOP units can be bolted one above the other, constituting a BOP "stack" and on this subject also a

recommendation appears in the answer to TR4. On land the limi

ting factor is the space between land surface and derrick floor. Off-shore, problems may be created by making the stack so high

that lateral stresses on it put undue strain on the point where

it is bolted to the well head (T3109). A BOP stack may weigh 40 tons (T2624).

Marine riser

1.8.9 This equipment which is virtually an extension of the

casing has to be used in off-shore drilling when floating drill

ing vessels are used because they are susceptible to both ver

211

tical and lateral movements due to tides and waves. The mar

ine riser provides a sophisticated telescopic system attached

to the well head on the sea bed by means of a hydraulically

operated latch and it is suspended from the floating drilling

vessel. Upon completion of drilling or in the event that the

unit has to move off the well due to an emergency the latch

can be released and the entire marine riser recovered for fur

ther use (T2622).

So that when a marine riser is used the well head is on the sea floor and the BOP stack is attached to the well

head. In fact a hydraulic latch is used for this purpose.

1.8.10 A similar latch at the top of the BOP stack is used

to connect a flexible joint which enables the marine riser

above to move through an angle of 5 deg. (T2623, T14753)· It is this latch below the flex joint which allows the marine

riser to be detached from the preventers.and raised to the

surface if the ship has to move away in bad weather (T2626).

The marine riser may simply stand as a column on top of the BOP stack or it may be supported from the vessel by a constant

tensioning device (T2628).

Generally 1.8.11 "Blowout preventers are supplied in a range

of sizes up to 20^" internal diameter and to

operate against well head pressures of up to

15,000 pounds per square inch, the choice of size and pressure rating being determined by

the expected conditions ..." (T2566)

When the BOP is on the sea floor the driller on the

platform cannot tell whether a tool joint is awkwardly situ

ated near or opposite a pipe ram. Thus a calculating device

is necessary to take the place of visual inspection.

The necessary testing of BOPs must be done with

care and discretion and not over frequently because of the

wear on surfaces. A proper compromise was described by Mr

Thomas at T2658A.

212

Remote controls and also auxiliary controls are, In

the interests of safety, necessary. These are described later.

Not only must the annulus be capable of being sealed

by the BOP but also the drill pipe itself must be capable of

being sealed and for this purpose an "inside BOP" is used. It

is however not practicable to have an internal BOP in position

while drilling is going ahead normally. The method of its use

was described by Mr Stewart at T434? (where he also explained

the use of another shut-off valve called the "kelly cock") and by Mr White at T3005-6.

The "Christmas tree", the lubricator and wirelining

1.8.12 As the drilling stage is completed and when production

stage is about to commence the "Christmas tree" takes the place

of the BOP - which is a production well head valve assembly.

The changeover procedure was described by Mr White (T2999) :- "When the well is abandoned the BOP stack

is removed. If it is going to become a

producing well then the BOP stack is rem

oved and tubing is run in the well. I

would add that at this stage the form

ation is not open. Production casing

will have been run and cemented against

the formation and the formation will not

be put into communication with the well

bore until the tubing has been run and

tested and then a perforating gun will

be lowered through the tubing. It will

be fired opposite the formation through

which it is intended to produce the oil and this will then enable the oil or gas,

as the case may be, to enter the wellbore,

to travel up the tubing, and be produced

through the flow manifold at the surface."

1.8.13 Valves on the Christmas tree control the rate of flow from the well or if necessary can cut it off entirely. The

213

Christmas tree may be removed and replaced by the BOP if occ asion such as some major work on the well, requires it. But

several necessary albeit minor tasks can be and are performed

by the wireline and an appropriate tool. The perforating gun

for example would be lowered perhaps by a 3/l6th inch wireline

whilst one required for logging might be 7/l6th inch.

1.8.14 These tools are inserted into the well by means of a

lubricator which is a tube about 30 feet long attached to the

top of the Christmas tree. It has a packing gland at its top

through which the wireline passes and through which it can move

without loss of pressure.

1.8.15 Mr Lowd (Executive Vice President, National Tank

Company of the United States) explained the important process

of "wirelining" and in so doing revealed the stages at which in the interests of safety much care is.needed. At T3317-8

he said:-"During the life of any oil well, it will

be necessary to effect down hole repairs,

replace artificial lift equipment, inspect

automatic down hole shut-in devices or per

form bottom hole tests. For the most part

these operations are conducted by wire line

equipment inside the tubing flow string.

Therefore, it does not require the ser

vices of a drilling-type rig. The well is not 'killed' and the operation is performed

under pressure conditions through the use of

a lubricator - or pressure lock - installed

atop the well head and of sufficient length

and strength to accommodate the necessary

tools and withstand the full well head pres sure. The head and its packing glands must be in excellent working condition and capable of preventing oil spray from occurring as the

wire line is running in or out of the hole.

214

When the well or wells being worked on are

on a platform containing process equipment,

a prudent operator will see that all per

sonnel are alerted to the work being done

and appropriate valve shut-offs made and

automatic alerts or warning systems dis

engaged during the well operation. No

unshielded fires will be permitted in the

area when such work is being done. Upon

completion of the work, all such devices

will be engaged and tested to make certain

they are operable and all personnel advised

that the operation is completed."

1.8.16 It is apparent that the use of wireline tools during

the production stage is an important facility for the operator.

It does, however, create some hazards as the lubricator gland

is a less secure container of hydrocarbons than a valve in the

production tubing or in the Christmas tree.

1.8.17 If the lubricator should be broken off as occurred through negligence in the Marlin A 4 incident (see answer to TR4)

a very serious situation exists. A wire line BOP is fitted for

use if the lubricator gland shows signs of wear, thus reducing

the risks of a blowout while wire lining.

1.8.18 Wire lining will be particularly hazardous if the oper

ation involved is the changing of the down-hole choke or if the

nature of the tool to be lowered makes the removal of the choke

necessary. For example, Mr Ericson said (T1276):-"... in 1968 ... in Louisiana ... we were

changing the down-hole chokes ... and while

going in with a wireline or coming out with

it we had a fire and there was a blowout.

There was a gas well and a high pressure

one. It burnt the rig. This was the con

tractor that was doing this work for us.

215

There were several fatalities but the blow

out was subsequently cut off and there was

no pollution."

Workover

1.8.19 The time when a producing well has to be worked over

Is another which presents some difficulty. The well must be

killed with mud or some other workover fluid, BOP installed

and necessary work carried out. The task of control will be

made easier by the fact that the nature of the hydrocarbons

present should be well known. However experience has shown

that this is a time when a blowout can occur, (e.g. as in the

cases of the Shell fire incident and incidents in two unnamed

wells - see answer to TR4).

216

PART 9 - LOSS OF SECONDARY CONTROL AND FORMATION FAILURE

Causes of loss of secondary control

1.9.1 Usually dangers arising from loss of primary control

are averted by closing one or more of the BOPs. This is the

way secondary control is obtained. Further steps must be taken

before primary control can be regained and drilling can proceed but at least the situation is in hand.

1.9.2 A loss of secondary control can occur as the result of:

(i) inability to close BOPs

(ii) inability to insert internal BOPs

(ill) failure of BOPs

(iv) failure of well head or casing

As to (i) - Inability to close BOPs

1.9.3 This could result from having (for example) a tool

joint opposite the pipe ram. (As earlier indicated estimates

have to be made to prevent this when the BOP is on the sea bed

when a floating rig is in use). The drill string should be

raised by using the drawworks to remedy this. In one example

given by Mr Thomas (see Part 6 of answer to TR4) the drawworks

were disconnected from the drill string for the purpose of

effecting repairs to the swivel from which the kelly hangs at a time when the BOPs were obstructed. This was negligence on

the part of the driller. A dangerous gas blowout occurred and

the history of this incident shows how several acts of negli

gence can occur in the one incident by an insufficiently trained crew.

Another possibility is that there may be a malfunction of the BOPs which prevents them closing properly. The seals

must be pressure tested but in so doing they are subject to

wear. One of the causes of a blowout described in paragraph

217

4.6.19 was that the supervisor allowed untested BOP equipment

to be used and It failed In an emergency. The Marlin A4 blow

out (see Part 6 of answer to TR4) exemplified the necessity

for having alternative sets of controls as far away from the

well head as possible. Damage to the hydraulic control lines

could also render the BOPs inoperable (T14765).

As to (ii) - Inability to insert internal BOPs

1.9.4 This problem could arise if there is a blowout of

formation fluids up the drill stem itself.

The internal BOP or "drill pipe float" or "drop-in

back pressure valve" was briefly referred to earlier. Its use

is to seal off the drill pipe itself. It is "basically a check

valve to keep flow from coming up through the drill pipe, but

which will allow mud to be pumped downward through the drill

pipe" (Mr Stewart T4347). It sits in a receptacle designed for

it at the top of the drill collar (Mr White T3110).

Difficulties can occur in inserting the screw-in type

of internal BOP while the well is actually flowing. The risk

of explosion or fire may become great. At the Santa Barbara

blowout the attempt to insert an internal BOP was abandoned when gas began to flow at high pressure.

As to (iii) - Failure of BOPs 1.9.5 BOPs are designed to contain well pressures for long

periods of time and this applies not only to the ram type BOP

but also to the bag type or "Hydril".

But any constant reciprocating movement of pipe

through closed BOPs as the result of movement of a floating

rig is a potential danger. The drill string should be hung

off in the case of a ship-shape or semi-submersible rig. Such

a lesson was learnt from the Petrel and Barracouta blowouts

(Part 6 of answer to TR4).

Blind rams may fail because they are damaged when

closed over drill pipe or some other obstruction. They are not designed to cut drill pipe although they may do so (as in

the Barracouta blowout).

218

But shear type blind rams should do so and it is be

coming common practice to fit them.

1.9- 6 In our view at least two bag type rams, two sets of

pipe rams and one of the blind (shear) type should be included

in a BOP stack used in drilling in the GBRP.

As to (iv) - Failure of well head or casing

1.9- 7 The well head and top section of the casing may be

included in secondary control. They are subject to high pres

sures and to wear. They must be regularly tested and if prop

erly designed and if wear bushings are replaced at proper in

tervals failure should not occur at this point.

However situations can arise when such a failure might occur. Thus if BOPs were closed with the choke line

also closed, the well head could be damaged by the hydraulic

ram effect. Indeed there could be a formation failure at some point of weakness. This is referred to later.

In another case described by Mr Stewart at T4430 a

well being drilled for Shell in the North Sea due to a miscal

culation penetrated the casing of an already completed well.

This resulted in a blowout through the casing and subsequently

through the sea bottom around and under the platform.

Formation failure outside well

1.9.8 Any natural tendency towards a formation weakness in the area outside and surrounding the well can be aggravated

with ultimate blowout effects by unskilful casing programmes and allied causes.

1.9.9 Several cases were examined by the Commission where

the ultimate blowout occurred not up the casing or drill string but outside the casing and up through some weakness in the sur rounding formation.

The causes were:-(i) an inadequate casing programme

(ii) inefficient casing setting

219

(iii) drilling too many wells too close

together from the one platform, thus

weakening the formation

(iv) excessive well pressures.

As to (i) - An inadequate casing programme

1.9.10 Since the Santa Barbara blowout in 1969 which demon

strated the need for stricter casing standards in that area,

improved and more stringent casing requirements have been laid

down in the U.S.A. off-shore drilling procedure by OCS Order

No. 8 (see Part 9 of answer to TR4 and the recommendations con

tained therein). In the Santa Barbara spill casing had only

been set 238 feet at a time when drilling had proceeded to almost 3,500 feet. The casing programme was also inadequate

in the Marlin well (see Part 6 of answer to TR4).

As to (ii) - Inefficient casing setting 1.9.11 Potential hazards to be avoided are that the cement

bonding may be defective or the casing shoe may be set in in

competent formation. The Marlin A7 blow illustrates the latter

(see answer to TR4).

As to (iii) - Too close proximity of wells 1.9.12 Obviously the drilling of a number of holes within

a few feet of each other must weaken the formations being

drilled.

Mr Thomas at T2776 dealt with this subject. He

said:-"Normally well heads are probably spaced, on

a production platform, between 6 and 8 feet

apart. One must certainly imagine that there is some disruption of the surface soil when,

first of all, the stove pipes are driven down and later when the conductor string is drilled

in and cemented. The full effect of how weak

the formation becomes would depend upon the

strata involved. However, it is a fact that

220

blowouts have occurred - so-called Internal

blowouts, If you like - presumably because

of the weakening of the upper strata with

the casing strings."

"In your opinion is the distance of 6 or

8 feet which you mentioned adequate, if

reasonable precautions against such an

event have been taken?"-- "I believe so.

It is customary, once one has reached a

depth of something of the order between

500 and 1000 feet to start deviating the

wells away to their selected positions in

the reservoir. Therefore, from that point

downwards each well is progressively get ting further and further away from its

neighbours. If we are looking at reser

voir depths of 6000 feet or more we would

not, at that stage, expect any danger from

blowout if proper security precautions were

taken and so that we do not expose the shoes

of our conductor string to any great pressure

from blowout down below."

It may be possible to meet this problem in part by

casing to a point beyond the point of deviation before contin

uing drilling into possible hydrocarbon-bearing zones (see

Marlin A? paragraph 4.6.8).

However this may not provide a sufficient answer,

and it may be that the number of holes and distance apart should

be more restricted than has sometimes been the case. In Bass

Strait there are typically about 20 wells deviated from a plat

form (T12762, 12765).

As to (iv) - Excessive well pressures

1.9.13 Excessive well pressures are caused by excessive mud

weight or too much back pressure from pumps. The Marlin A7 gas

blowout (paragraph 4.6.8) which took place in the Bass Strait

on 2 December 1968 whilst drilling ahead at 4857 feet was des

221

cribed by Mr Stewart (T436?) and Mr Lipscomb (Area Production

Manager, Esso (Australia) Ltd. Gippsland). The latter thought

that some mistake had been made in the manner in which the pro

cedures were carried out (T12679-80). He said the possibili

ties were firstly, the pump still turning over when the rams

were closed. The second possibility was incorrect regulation

of the choke when the pumps were started again. "... too great

a restriction effect, therefore too much back pressure held on

the mud column causing the mud to disperse into the surrounding

formation" (T12681). It was a deviated hole.

"The kick off point for the first deviation

was at about 1150 just below the casing?--Yes."

He added:-"On the other platforms the surface pipe is

run past the kick off point or past the point

of initial deviation."

222

PART 10 - PRODUCTION PROBLEMS

Petroleum production

1.10.1 Mr Thomas dealt with "development planning of an oil

or gas field" at T2706 and said:-"Following the success of an exploration

well in discovering a potentially commer

cial accumulation of hydrocarbons, a pro

gramme of appraisal drilling is undertaken,

the purpose of which is (i) to establish

that the accumulation is commercial, (ii)

to derive physical data pertaining to the

accumulation on which a development dril

ling and production programme may be based.

At least one, but usually more, appraisal

wells are drilled with the object of def ining as closely as possible the values of the following parameters:

a. Limits of the reservoir(s) i.e. areas

and thickness of the 'pay'.

b. Distribution of fluids i.e. gas, oil

and water within the reservoir(s).

c. Characteristics of fluids i.e. gas

gravity, composition and viscosity,

oil gravity, type and viscosity.

d . Reservoir pressures and temperatures.

e . Expansion (PVT) characteristics of

fluids from original reservoir con

ditions to atmospheric conditions ..." 1.10.2 He added;Ï "our main concern at this time is to

be able to deduce from a surface measurement

of oil and gas how these substances will

actually exist within the reservoir itself.

... if one is above the bubble point then

223

you only have oil, single phase, within

the reservoir. Obviously by the time any

oil has flowed up a tubing string and into

production facilities its pressure will

have been far below its bubble point (i.e.

the reduced reservoir pressure at which

gas will break out of solution from the

oil and by virtue of its expansion qual

ities will assist in driving both the oil

and itself towards the producing wells -

T2700) and it will be in a two-phase stage

- you will have gas and you will have oil

present.

It is important to know how these two sub

stances, the gas and the oil, combine to

form the actual fluid within the reservoir

so that you may then be able to forecast

the performance of the reservoir and in

fact derive the actual amount of useful

oil in place in the reservoir."

1.10.3 Other data obtained include rock characteristics

such as porosity and permeability and from the data thus ob

tained important information may be obtained as to reservoir

volumes, recovery efficiencies and expected well productivity

The next stage would be to make estimates relating to trans

portation, production costs and other financial factors. Mr

Lowd (T3261) and Mr Rochelle (T2895) elaborated on these fac

tors and stages.

Production wells 1.10.4 The decision to produce having been made an approp

riate number of holes will be drilled for production purposes in the same manner in which they are drilled for exploration

purposes. Directional drilling, described above, is normally

used. The "completion" of these wells may be either "open

hole" completions or set through perforated completions.

224

In the open hole completion, the production string

of casing is set and cemented immediately above the "pay zone"

or production strata. This method is used only when the res

ervoir formation is strong and will not slough or cave into

the well bore. Mr Thomas said that it is confined almost com

pletely to fractured limestone reservoirs (T2596).

1.10.5 Of the set through perforated completions, Mr Thomas

said at T2596-7:-"This category refers to those cases, by

far the most common in modern practice,

where the production string is set through

and cemented over the pay zone or zones.

Thereafter the casing through the pay zone

is perforated using what is in effect a

multi-barrelled gun fired electrically from

the surface. Precise depth control is possible

and shots may be spaced as required by the oper ator. Penetration of the casing and the cement

sheath at any given shooting point is effected

by a steel bullet or by the jetted flame of a

shaped charge. The latter device produces a

jet of hot gases travelling at some 30,000 feet

per second and exerting an impact pressure of

some 4 million pounds per square inch on the

target."

Secondary recovery

1.10.6 E-arlier Mr Thomas when speaking of fluid expansion

or depletion drives had said (T2700) :-"However, due to the much lower viscosity

and hence the higher mobility, of gas than

oil, the amount of gas produced in proportion

to the oil increases rapidly and energy dep

letion is still rapid with the result that

the recovery efficiency of a depletion drive

reservoir by primary means is very low. Dep

225

endent upon oil properties and reservoir

rock characteristics records reveal that

only 5 per cent to 35 per cent of the

original oil in place can be recovered.

Do those latter sentences mean that even

when the bubble point is reached and gas

starts to be formed in the reservoir, this

will not help greatly because that gas will

be drained off faster than the oil?-- Yes."

1.10.7 He then dealt with fluid displacement and the sec

ondary method of recovery, i.e. by water or repression of

gas. He said (T2701):-"(a) Natural Water Drive. Where an oil res

ervoir is in hydraulic connection with a large

aquifer,, the pressure energy contained in the

water will cause expansion of the water as the

oil pressure is reduced so that the water will

displace oil and drive it towards the wells.

Some residual oil may be trapped by capillary action as the water sweeps through the rock

but in many cases of significant water drive

of light crude oils, it is not unusual to re

cover up to 70 per cent of the original oil

in place.

(b) Natural Gas Cap Drive. Where an oil body

is overlain by a large gas cap the consider able elastic energy contained in the pressur

ised gas offsets to some degree the energy

lost by withdrawal of oil and by expansion

assists in sweeping the oil towards the pro ducing wells. Under favourable conditions

up to 70 per cent of the original oil in

place may be recovered.

or gas from the surface down injection wells

to the requisite points in the reservoir the

226

natural forces described above may be aug

mented and by such secondary recovery methods

the recovery from the reservoir may be in

creased significantly."

Underwater completions

1.10.8 A number of other techniques are being actively in

vestigated for operations in excess of 400 feet, such as sea

floor templates and sub-sea' habitats, also single sub-sea com

pletions linked by flow lines and control systems to a collec

tion platform in shallow water. However, having regard to the

comparatively shallow depths within the GBRP it is sufficient

to give a reference to the evidence of Mr Thomas at T2709 et

seq although Mr Lowd referred to the Second Report of the

President's Panel following the Santa Barbara oil spill (Ex.

398) which recommended that much greater use be made of this

technique. Mr Lowd added (T3416) :-"Subsequent developmental activity in the

sub-sea production area has led to the con

clusion by some, including the witness, that

there are ample economic as well as environ

mental reasons for pursuing underwater pro

duction processing even in depths so shallow

as to allow the alternative consideration of

building a fixed platform - that is, in water much LESS than 400 or 500 feet deep. From the

standpoint of protection to the environment,

there is, of course, little difference within a production processing system itself with

respect to safety and pollution, whether the

facility is located above the air-sea inter

face on a fixed platform or somewhere beneath the interface. All the procedures, rules,

and prudent operational requirements are the

same - in principle. It can be said, however,

that oil released either in & random or aggra

vated way, into the mid-water is fundamentally

22?

more 1 containable1 than that released from

above onto the air-sea interface or that

which accumulates on the interface as a

result of separation from disposed waste

water. The most difficult problems with

respect to conventional surface oriented

spill-oil containment devices accrue from

the tremendous forces applied by wind and

wave. These forces of course, do not exist

at depths very far below the interface.

Therefore 'containment', in actual fact,

can be easier IN the water than ON the sea."

Production control

1.10.9 This topic covers the various automatic and manually

operated devices which control and if necessary shut off the

flow of petroleum through the production process.

Processing 1.10.10 On the platform the production problem is to separate

the full stream flowing from a well into two parts, usable oil

and usable gas. Mr Lowd said (T3263):-"But the separating is complicated, in part,

by the fact that the oil and gas from the

well contains vari'ous contaminants. These contaminants must themselves be removed to

a greater or lesser extent in order to ob tain usable or saleable oil and gas. Thus

many separation processes are required, not

only to segregate the gas and oil but to

remove the contaminants."

1.10.11 The steps of processing (which is continuous) were

given by Mr Lowd as follows (T3267 et seq) :-"(i) Gas-liquid separation The total well head fluid flows first through

one or more gas-liquid separation steps. The

228

function of these separations Is the econ

omic segregation of gas and oil. The two

basic streams - liquid and gas - then flow

to a series of purification steps.

Raw petroleum is not a pure substance, nor

is it simply oil and gas mixed in various

combinations. Raw petroleum is, in fact,

a mixture involving hundreds of different

chemical compounds of carbon and hydrogen.

These compounds have different boiling

points, all the way from far below room

temperature up to 1000 degrees Fahrenheit, or higher. Thus the well fluid mixture

does not have a fixed 'boiling point' in

the usual sense. Instead, at any given

temperature and pressure, some portion of

the petroleum mix will be vapour - or boil -

and the remainder will be liquid. In gen

eral, the higher the temperature, the higher

the percentage vapour. Generally speaking,

producers can obtain a maximum amount of oil

for use or sale per unit of total hydrocarbon removed from the reservoir - and thus assure

the optimum benefit from this natural resource

- if the pressure is released from the raw well

stream in orderly and proper steps. But diff

erent well streams of crude petroleum will show

different responses to the pressure and temp erature steps in separating gas from oil. This

indicates the importance of carefully obtaining

and studying samples of the raw crude before

the processing plant is designed.

(ii) Stepwise gas removal

1.10.12 "The liquid from the initial gas-liquid sepa

ration is therefore subjected to one or more

subsequent gas-separation steps to render it

229

a saleable product. Each such step takes

place at succeedingly lower pressures and

additional small amounts of gas evolve ...

these streams of separated gas from succes

sive steps are then combined and further

conditioned for use or sale.

(ill) Free-water removal

1.10.13 "The liquid oil which is separated from the

total well stream may contain water in two

forms; free or emulsified. Free-water, as

the name indicates, separates easily from

the oil mostly because it is heavier. This water falls to the bottom of the free-water

separating device and is segregated from

the oil stream. Sand or other solids are also removed at this step of the process.

(iv) Dehydration

1.10.14 "Oil dehydration, or 'treating' as it is

often called, is the removal of that por

tion of the water still remaining in the oil in emulsified form. An emulsion is a

complex of tiny water-oil droplets that

will not settle out from the oil, regard

less of time. In spite of the best efforts

by producers to prevent them, emulsions of water in oil from the well head are common.

(v) Desalting

1.10.15 "The water accompanying oil has been ref erred to as 'water'. Actually it usually

is salt water or brine. If the salt con tent of this salt water is excessive, then

the oil refiner can expect troubles. This

is because salt deposition during (sic) high

temperature processing will 'boil off' the

230

remnant water and leave solid salts in his

refinery process facilities. Thus to have

a useful or saleable oil, the initial pro

ducer may have to remove this salt by wash

ing the oil with fresh water, and then accom

plish essentially total removal of the water

in a process called 'desalting'.

(vi) Hydrogen sulphide removal

1.10.16 "Hydrogen sulphide gas (H2S) may remain dis

solved in the oil at concentrations higher

than desired. The H2S is toxic and corro

sive ; its removal may be required. To do this, sweet natural gas is bubbled through

the oil. Sweet gas contains essentially no

H2S . The sweet hydrocarbon gas acts to ab

sorb the H2S out of the oil in a process

called 'cold stripping'.

(vii) Storage

1.10.17 "The oil is now a saleable product and is

placed in temporary storage. From storage,

the oil must be pumped into a pipeline to

shore or into a barge or tanker."

Sub-surface safety devices

1.10.18 During the production stage the down-hole choke or

device which is capable of closing off the well at a depth of

at least 200 feet below ocean floor is an important safety dev

ice. It is the last line of defence in such an emergency as the platform being in danger of destruction by fire or cyclone.

1.10.19 Speaking of what is now regarded as the somewhat old

fashioned "storm choke" Mr Stewart said (T4361):-"This is basically a loaded valve which is

kept open by a calibrated spring. Acting

against this spring is the force resulting

231

from the upward flowing pressure of the

producing fluid. (Such valves) are des

igned to be sensitive to decreases in

tubing pressure or pressure differential

across them created by an increase in flow

rate. In the event of a failure of the surface connections (line break, accidents,

etc.), then when the volume of production

through the storm choke exceeds a pre-deter-

mined rate, it will close automatically shut

ting the well in. The well will remain shut

in until the operator opens it ..." He went on to discuss the piston type safety valve:-

"This safety valve is similar to the storm

choke except that it is hydraulically con trolled from the surface.

The surface control unit is equipped so that

the valve will instantly close if the Christmas tree is damaged or if the flow line pressure

increases (shut valve on-shore) or decreases (broken flow line) beyond predetermined limits

1.10.20 He also spoke of a ball-type safety valve which is a

type preferred by Mr Thomas who supported a design which could

be controlled hydraulically from the surface if danger threat

ened (T2845).

1.10.21 Surface controlled sub-surface safety valves are

dealt with in the answer to TR4 and are the subject of one of

the recommendations therein.

1.10.22 The remotely controlled valve can be operated in the event of fire, or approaching cyclone or imminent collision.

Shut-down procedures

1.10.23 These can be of a routine, storm or emergency nature.

232

Highly trained personnel are necessary to instigate or deal

with a shut down as, whether it is of a routine nature or due

to an emergency, the situation is potentially dangerous (Mr Lowd T3315).

1.10.24 The routine shut down is for repair or maintenance

work, the life of a production well being 15 years or more.

The storm shut down is in anticipation of severe weather con

ditions and may involve evacuation of personnel. The emergency

shut down occurs suddenly and with little warning. Mr Lowd s ai d : -"It is usually the result of a malfunction

of equipment or a line break that portends

an uncontrolled oil or gas flow somewhere

in the system. Such a shut down is usually

instigated by automatic controls and pre

ceded by audible and visual signal warnings.

Prompt, effective action by all personnel is

mandatory if the situation is to be kept under

control. Every man must know his position and

duty responsibility. Communications with the

outside must be quickly accomplished for poss

ible aid and prompt assistance in cleaning up

a spill if such should have occurred. An emer

gency shut down may occur as a result of an

instrument malfunction or other minor misreading

of conditions. In any event, start-up proceed ings will not begin until the cause is positively

identified and rectified." (T3316)

1.10.25 Testing of controls regularly is part and parcel of

prudent management. Mr Lowd stressed that to facilitate such testing all control sensors and devices must be equipped for

testing with an external source of pressure so that both the

control response and the action of the final control valve may

be observed, verified, witnessed and duly recorded on approp

riate inspection forms - and he particularised the details of

233

control testing. Mr Thomas also dealt with Inspection and

testing of well head fittings and sub-surface equipment at

T2752 et seq.

1.10.26 Some of the fluid components produced with petroleum

are highly corrosive whilst the sea and the atmosphere produce

corrosion in most metals.

1.10.27 Mr Lowd said (T3316 et seq) that as the effect of

corrosion is usually insidious, protective measures must be

thorough and constantly monitored. He detailed methods of

detecting internal and external corrosion and said that rates

of corrosion are determined without dismantling the well head

by the insertion of metal corrosion "coupons" into the well

head. He added "Every practical means to reduce the effects

of corrosion is necessary if spills or other

dangerous situations are to be avoided.

Emergency situations during production

1.10.28 Mr Lowd explained the risk of oil spills during the

production stage in these terms (T3262) "It is particularly during the production

stage that both 'Aggravated’ and 'Random' pollution must be guarded against. The

potential of either type is ever present.

The production stage covers a span of 15

years or more. During the time span,

equipment is subject to storms, break downs, erosion, obsolescence and replace

ment. Additional facilities such as pres

sure maintenance or artificial lift equip

ment may be required. Personnel must be

retained and wells worked over."

1.10.29 He tabulated a number of possible emergency situ ations which can and do occur during the many years of the

234

production stage and in short form these were:-(i) Flow line rupture (the pipe between

the well head and the inlet to the first

separator on the platform)

"The flow line from the well head to the

manifold choke may be a few feet long or

a mile long depending upon the relative

locations of the well head and the pro

cessing platform. A break or rupture of

this flow line, however long it is, con

stitutes the greatest possible aggravated

threat to the environment. Theoretically,

the entire contents of the subsurface

petroleum reservoir could flow through

the rupture into the sea, contaminating

everything in its path. Without safety

devices, all the other wells connected

to the common production manifold could

flow backwards through the choke and

through the ruptured flow line, thus

hastening the cumulative pollution." (Î¤330Î)

(ii) Plow line plugging

In this case the well cannot produce.

The emergency situation so created should

be automatically dealt with by the closing

of the well head shut in valve.

(iii) Production manifold rupture

"Without safety controls, a rupture of the

piping or valves in the production manifold

would permit all the wells to flow through the rupture, covering the platform with oil,

creating a fire hazard, and possibly pollu

ting the sea if drip pans are overloaded.

However, any such rupture would cause an

abnormally low pressure in all the well flow

lines, thus closing all the well head shut-in

235

valves." (T3301)

(Iv) Manifold choke failure

All wells have their own individual manu

ally-operated choke valve mounted on the

production manifold (T3301) the purpose

being to permit manual control of the

individual well flow rates or to permit

shut-in of individual wells at the plat

form. Without safety controls the excess

ively high production rate might overload

the separator causing high fluid level or

high pressure or both.

(v) Separator oil dump valve failure

(vi) Separator gas valve failure

Failure of these valves leads to various

irregularities in the separator and resul

tant hazards.

(vii) -Instrument air failure

"Loss of instrument air or supply gas pres

sure may be caused by supply line rupture,

plugging, regulator failure, compressor failure or the inadvertent manual closing

of a valve in the system." (T3303) (viii) Improper manual valve manipulation

Abnormally high or low pressures and/or fluid

levels may result. Safety control devices

should monitor and automatically eliminate

such a man-made hazard.

(ix) Failure of the safety shut-in valve

But as Mr Lowd said:-"After all, little can go wrong with a com

pressed heavy metal spring ... Therefore unless the internal fluid ports of the valve

have been eroded or unless solids have lodged

between the internal valve sealing surfaces

the valve must fail in the closed or safe

position." (T3304)

1.10.30 The damage which can be caused -to the production

system by the build up over a period of internal scale and by

sand erosion with attendant serious dangers were stressed also

by Mr Thomas who added (T2754):-"... the above dangers are well known to

the oil industry and both operators and

government bodies lay down strict routine

regulations, often supplemented by A.P.I.

codes, regarding quality and design of

fittings and their proper care and main

tenance. It is therefore very rare indeed,

and has not occurred, in my personal exper

ience, that a well has blown out of control for lack of routine maintenance."

Fire prevention and control

1.10.31 Quite a number of fires have occurred at on-shore

wells and a few at off-shore wells, the largest and longest in

point of time being the Shell fire in the Gulf of Mexico which

began 1 December 1970 and which was killed four months later

by pumping mud into directional wells (T6992 et seq). The

Chevron fire began 10 February 1970 and lasted for seven weeks.

It also was killed by drilling relief wells (T6984).

1.10.32 Mr Lowd said (T3319):-"Although every effort is made to keep the

hazard of fire to a minimum, the possibility

of fire may not be discounted. The potential

loss of life, damage to natural resources, to

the environment and to property is a constant

incentive to the industry to design and install the best fire-control systems that modern tech

nology can devise."

1.10.33 Mr Lowd also said (T3318):-"1. The best method of fire control is prev

ention. Fuel, heat, oxygen and combustion

237

reactions are the four components of a

fire. No simple diagram will adequately

represent the complex phenomena of fire.

However, prevention is based on keeping

the fuel, oxygen and heat separated. The

proper design and operation of an off-shore

crude oil production installation will mini

mise the possibility of the triangle closing

with resulting combustion.

2. The principal design considerations

given to keeping the fire-supporting com

ponents separated are:

a. The judicious placement of equipment

in relation to other equipment and to

the prevailing wind directions.

b . The isolation or insulation of all

flame and heat devices from combus

tible vapours.

c. The use of automatic safety devices

to prevent leaks or breaks from devel

oping or to minimise the loss of fluids should leaks or breaks occur.

d . The use of non-combustible materials

wherever possible.

e. The containment of all combustible

fluids in closed vessels."

1.10.34 He added (T3319) "The two main differences between an on-shore

and off-shore installation are the density of

equipment and the accessibility to mobile fire

fighting equipment. It is impractical to reduce equipment density on a platform. Since an off

shore installation may be located as much as

100 miles from shore it must rely on its own fire-control system and personnel to use the

system.

238

An accepted rule Is that an untrained oper

ator of fire-control equipment is only 40

per cent as effective as a professional.

Therefore, every effort is made to increase

personnel skill by practice and training

programmes."

1.10.35 Later Mr Lowd dealt at some length with various fire

control systems, personnel training, detection of fire by auto

mated means and the use of flame arresters and internal firebox

heat detectors on fired equipment such as an emulsion treater

(T3447 et seq).

Workovers

1.10.36 The withdrawal of the production tubing to enable necessary maintenance work to be carried out will be necessary

from time to time over the long production period (15 years or more).

1.10.37 But although necessary, this procedure involves a measure of risk of a blowout. The hazards involved and the

degree of care that must govern well repairs throughout warrant

a reference in some detail to Mr Thomas' evidence at T2750-2 and this evidence and the accompanying questions and answers speak for themselves:-

1.10.38 "Well pulling

In many older completions PTWC (i.e. perm

anent type well completion) equipment has

not been installed and any well repairs

require that the tubing is pulled to allow

access to the producing intervals. Tubing pulling is also often necessary in multiple

completions or in cases where the tubing

string has become plugged with foreign mat

ter thus rendering the use of PTWC repair

techniques impossible. The task of these

239

full scale well repairs is carried out by

a well pulling unit built on the same prin

ciples and utilising the same type of equip

ment as a drilling rig, but on a smaller and

lighter scale since the loads to be handled

and the pump circulation rates necessary are

far smaller than those encountered when dril

ling a well. Since a well pulling repair

commences with a live well, that is a well

containing oil and gas, great care must be exercised to ensure that the well is killed

or otherwise incapable of production prior to the removal of well head fittings and the

pulling of the tubing string.

The well can be killed in one of two ways.

The first simply entails squeezing suffic

ient work-over fluid down the tubing string to force all hydrocarbons into the formation.

The second, and preferred, method is to open a circulating sleeve or valve just above the

production packer and, by reverse circulation

with work-over fluid, force all the hydro carbons in the tubing string out through the

Christmas tree to be safely disposed of in the production collection facilities. This

method thus ensures that both tubing and casing are full of fluid of sufficient weight to restrain the reservoir pressure.

MR WOODWARD: We will have another look at

this. In the first instance you put suffic ient work-over fluid down the tubing string

to force all the hydrocarbons back into the formation?-- Yes.

The word squeezing is the one that troubles

me a little. Does that mean force it under

pressure?-- That means pumping out under high

pressure. The second method is to open a valve

or circulating sleeve just above the pro

duction packer. The production packer is

the packer at the foot of the shoe of the tubing string?-- Yes.

Which is above that and by reverse circu

lation, that is by sending this work over

fluid down the casing through this valve

at the foot of the tubing string and thus into the tubing?-- Yes.

You thus force upward any hydrocarbons that are sitting in the tubing string?--Yes.

And dispose of them through your ordinary

facilities?-- Right.

So in other words you are saying it is

easier, since you want to get rid of the

hydrocarbons in the string, to do it by

forcing them upwards with the work over

fluid than it is by forcing them downwards?

-- Yes. It is quicker simply to squeeze the fluids down the tubing.

But not as satisfactory?-- Not as satis

factory. To my mind it often leaves small bubbles of gas and so on still left in the

tubing string or in the casing just below the tilting string.

THE CHAIRMAN: In your preferred method it

is tacit I suppose that the hydrocarbons are blocked off at the shoe at the foot of

the tubing?-- Yes. They are packed off from

escaping to the end of this.

You force what happens to be left in the

casing up the well?-- Yes. My Statement

continues:

After killing the well, the extra precaution

of fitting a screw in plug into the top of

the tubing should be taken prior to removing

2hl

the Christmas tree and installing a set

of blowout preventers.

MR WOODWARD: I note you say that that

is a step which should be taken?-- Yes.

That means it is not always?-- I have qualified that by stating that I have

known occasions when it has not been

done. My statement continues:

Once the BOP stack has been fitted and

tested, the tubing string can be pulled and the necessary well repair carried

out, after which the tubing and well

head equipment can be replaced and the

well brought back into production."

PART 11 - CHRONIC POLLUTION

Nature of chronic pollution

1.11.1 Chronic spills (and intermittent or random spills)

are forms of pollution which in the view of some experts (for

example Mr Lowd) are greater threats to the environment than

occasional instances of blowouts or "aggravated" pollution,

that is to say blowouts or major oil spills. In such a complex

biological field as the GBRP - an area which is believed to

contain a multiplicity of interdependencies, this may be cor

rect although in the present state of knowledge of the effects

of oil on the GBR communities there can be no certainty. There

is however no doubt that chronic pollution within any part of

the GBRP would at the least be both damaging to the eco-systems

therein and a serious interference with the enjoyment by man of

the environment. Generally on these aspects see answer to TR2.

1.11.2 The aggregate risk of chronic and random pollution

in their various forms is greater than that of a blowout.

1.11.3 The dangers of chronic pollution are probably greater during the production stage than during exploratory drilling.

1.11.4 The coloured films of the marshes on and close to the

foreshores of Louisiana shown to the Commission by Dr St Amant (Louisiana State Assistant Director, Wildlife and Fisheries

Commission) vividly illustrated the extensive nature of chronic

pollution which can occur in the absence of industry co-oper

ation (T4004-5 et seq). Such phrases as "biological desert"

(slides 51 and 57) and "not very pleasant to look at" (slide

6l) appear in Dr St Amant's description given during the screen

ing. The coloured slides are part of Exhibit 230 and were taken

in 1970 (T4112). It is not however suggested that such a degree

of chronic pollution would occur in the governmentally control

243

led waters of the GBRP should drilling be permitted therein

but for reasons to be given a measure of chronic and random

pollution could probably never be eliminated.

1.11.5 During drilling operations the use of a mud and oil emulsion would be very undesirable in the GBRP and in the

answer to TR4 we have recommended that its use should require

express approval of the DA and that its discharge into the

GBRP be prohibited.

1.11.6 During production the separated water should not be

allowed to be discharged into the sea whatever might be its

oil content. As appears later we recommend that no substance,

solid or liquid, be disposed of into the waters of the GBRP

(with three specified exceptions).

1.11.7 The Commission is of the opinion that there are special conditions obtaining in the GBRP which distinguish it

from such areas as the Gulf of Mexico and that restrictions

and standards acceptable in that area might not be acceptable

in the GBRP. Such special conditions include (1) the compara tively shallow nature of GBR waters, (2) their containment with in the outer Reef, (3) the large number of reefs and islands

within the GBRP of scientific and environmental interest, (4)

the nature of the currents and prevailing winds, and (5) the extensive, complex and delicately balanced ecosystems which exist throughout the length and breadth of the GBRP.

It is now proposed to discuss the various forms of

chronic pollution.

(a) Oilfield brines

1.11.8 On this subject Mr Lowd said (T3348):-"It is important not to overlook the omni present nature of this water. The original

carboniferous deposits accumulating within,

or at the edge of, ancient seas constituted

the beginning of petroleum formations. It

therefore follows that some remnant part

of those ancient seas will be produced

with the oil and gas today. This, of

course, Is the case. As a result, upon

disposition of that water, potentially

damaging oil pollution can be ... yet

need not be ... carried Into the seas.

So one of the problems of potential ran dom pollution by waste water carrying

remnant particles of oil, relates to

the quantification of the meaning of

'clean' or 'oil free' water. Such def

inition, In turn, relates to toxicity

and other possible adverse effects of raw petroleum on marine life and Its environment ..."

1.11.9 It can be said of Mr Lowd that he was more optimistic

about the ability of modern technology to separate water from oil than In regard to the extraction of oil from sand (Tl66l6)

and the general view Is that the use of a mud and oil emulsion

need not and should not take place In connection with any dril

ling In the GBRP and In our answer to TR4 we have so recommen ded .

1.11.10 Later Mr Lowd said (T3376):-"1. If a prudent benchmark level of remnant

oil contamination In waste water Is set

at the trace level of 100 ppm, a further qualifying question still remains: 'Can

this degree of cleanliness be achieved by equipment available today and usable

on off-shore platforms?' The answer Is Yes.

2. It Is Important, however, to recognise

that such conditioning of the water can

not be attained directly from oil pro

245

cessing vessels on the marine platforms

without special cleaning devices and

procedures.

3· There are two pieces of equipment, ref

erred to in previous sections, whose

job is primarily to remove contamin

ating water from the oil. These are

the so-called emulsion treater and the

free water remover or freewater knock

out. These processes are not, however,

water treating processes. Therefore,

the water separated from the oil by

them may have a rather significant contamination of a remnant oil in it.

In most processing situations, such water could not be disposed of into

the sea without significant damage to the mid-water and surface biota in the

area or to natural surface mechanism

as a result of toxicity and/or a con centrated slick development."

1.11.11 In his summary Mr Lowd added:-"The remnant oil in 1 clean waste water1 must be assured as a non-separable element in a

stable emulsified form, at least for a period of time greatly exceeding that required for

bio-degradation. Were such water disposed of

into the unrestricted universe of ocean water ... a typical procedure for oil field producing

operations ... it would thus result in no accum ulation of oil into a surface slick with its

associated possible damaging effects." (T3378)

1.11.12 However in TR4 we have firmly recommended that, with

three specified exceptions, no substances whatsoever, whether

solid or liquid, should at any time be allowed to be disposed

246

of into the waters of the GBRP. Our specified exceptions

require DA approval. If this recommendation is accepted it

will be unnecessary to fix a minimum permitted oil content how ever low.

1.11.13 (b) Gases

There was no evidence put to the Commission which proved or tended to prove that in general terms hydrocarbon

gases constitute a pollution hazard comparable with oil al

though hydrogen sulphide (HgS) which is poisonous either in

solution or in the atmosphere, can be present in variable

quantities. At 133^9 Mr Lowd said:-"I think that it is probable that some of

the oil, if it were produced on the Barrier

Reef, would have a significant quantity of

hydrogen sulphide as part of its total con

tent. I say that because, generally speak ing, in production around the world a signi

ficant quantity of the oil produced is assoc

iated with hydrogen sulphide. I think it

would be well to say if you were a producer

that you could expect on average to deal with

hydrogen sulphide in a third to a half of the cases.

However, the quantity of hydrogen sulphide

that will be present in this third to a half

of all the cases is small on average. ...

... we know around the world that a small

proportion of the total amount of oil ...

transported by tankers ... requires the rem oval of hydrogen sulphide, that is the limi

tation of hydrogen sulphide is the poisonous

effect that it may have on the crew members

and the operators generally of the ship."

Whilst at T3277 he said:-"... Hydrogen sulphide is absorbed from the

oil or gas and then burnt in a flare or pro-

2 h 7

cessed into an elemental sulphur.

1.11.14 Mr Lowd later gave details of the amounts of hydro

gen sulphide which are flared in practice, and how the H2S is

separated off in the separators at the early stages of the

platform process and he said that where only oil is sent to

shore, such H2S as is in the natural gas will, together with

all the other gas, be vented and flared at the platform (T3425).

1.11.15 The following important evidence on this subject was

also given by him (T3426-7):-"If then the burning at or near the platform

of gas which contains this concentration of H2S is not acceptable to persons whose opin

ions are entitled to respect, what is the solution?"-- "The solution then would be to

process the natural gas contaminated with hydrogen sulphide in such a way that the final product derived from the contamination

of hydrogen sulphide would be sulphur. This

sulphur could then be moved to shore in a

barge."

"Presumably another answer would be the con

struction of a pipeline to take gas from the

platform to shore for the purpose of venting

it or processing it there?"-- "That is cor

rect. I was simply assuming that this case

was a 'no pipeline' case."

"Is it possible in your opinion to have on

the platform in effect a refinery process

which decontaminates the natural gas of H2S and in the process produces elemental sulphur?" -- "It would always be questionably feasible. It would certainly be abnormal. It would prob

ably require the building of an adjacent plat form. However, I am sure there could be a cul

mination of circumstances if there was indeed

248

hydrogen sulphide contamination where it

could be seen as feasible."

"On the other hand do I understand you

to be saying that the particular circum

stances of the locality coupled with the

concentration of t^S known to be present

in the natural gas might cause or might warrant some authority forbidding the

flaring of gas at or near the platform

and requiring it to be piped to shore

to be dealt with there?"-- "Yes, sir;

this is very possible and the require

ment would be either piping ashore or

not doing this type of processing on platforms."

1.11.16 But piping ashore may produce its own problems in the absence of proper design and maintenance. This subject is dis cussed elsewhere.

1.11.17 The production processes carried out on a platform

have been referred to above. Mr Lowd said (T3263)

"In essence the production problem is simple. The producer must simply sepa

rate the full stream flowing from a well

into two parts, usable oil and usable gas.

But the separating is complicated, in part,

by the fact that the oil and gas from the

well contains various contaminants. These

contaminants must themselves be removed to

a greater or lesser extent in order to ob

tain usable or saleable oil and gas. Thus

many separation processes are required, not

only to segregate the gas and oil but to

remove the contaminants."

1 .11.18 Later he added (T3268) :-

Stepwise gas removal

"The liquid from the initial gas-liquid

separation is therefore subjected to one

or more subsequent gas-separation steps

to render it a saleable product. Each

such step takes place at succeedingly

lower pressures and additional small

amounts of gas evolve ... these streams

of separated gas from successive steps

are then combined and further conditioned

for use or sale." His comments on hydrogen sulphide gas we have given

in paragraph 1.10.16 supra.

1.11.19 As regards gas blowouts however lengthy in point of

time the evidence gave no substantial indication of damage to the environment. Whether such result would flow in the case

of a gas blowout within the waters of the GBRP cannot be asser ted with complete confidence on the evidence before us.

1.11.20 It was universally accepted in evidence before us

that the deposit of sediments and so of sand and sludge on

benthic organisms within the GBRP including coral constitute

a serious and special hazard. If drilling were to be allowed

within the GBRP special precautions and control measures would

be essential during both drilling and production procedures.

1.11.21 Of sand Mr Lowd said (T3277):-"MR WOODWARD: In figure 11-4 you set out

the kind, source, and disposition of random

wastes, in simplified column form, and you say that water may be removed from either

oil or gas and is cleaned and put into the sea or, as you have just told us, it may be

reinjected into a well or pumped to shore?

-- Correct.

250

Most usually It would be put into the sea?

-- Yes. In the case of sand,that would be removed from the oil of course and it will

be cleaned and put into the sea or sent to

shore? -- Correct.

Again that would be a question of the distance between the platform and the shore

I take it? -- Not entirely in this case

because the technology is not really adequate

to clean sand in every case. It must be

cleaned before it can be put into the sea.

Therefore, there is a technological constraint

that forces us to have the sand sent to shore.

So that cleaning oil out of sand is a significant

problem so far as protection of the environment

is concerned? -- It is.

One with which the industry is still having

technical problems in trying to solve? --Correct.

1.11.22 And of sludges (T3277-8):-"You refer next to sludges. What is meant by sludges

and what types are there? -- Sludges are in two

general categories, natural sludges and man-made, created sludges. A mixture of oil, paraffin, wax - the items I mentioned just above - would be an

example of a naturally occurring sludge, either

liquid or gas with no possibility of processing.

A man-made sludge would be, for instance, the oil-wetted flocculent material at the top of the

water processing unit.

MR WOODWARD: Is this a process whereby you float

some substance off through water in order to remove

remaining traces of oil from it - the oil wetted

flocculent material? -- Correct.

So that the water will be clean enough to be

251

released?-- Yes. And you say that may produce

a sludge at the top of the tank that has then

got to be disposed of? -- Correct.

And you have said this may come from oil and/or

from water and will be taken to the shore? --Yes, it should be taken ashore unless it is such

that there can be a separation and it can be

returned to the system but usually it is a

matter of taking it ashore."

(d) Oil and chemicals

1.11.23 One of the sources of chronic pollution which can arise from platform operations is the spilling of chemicals

and lubricants which are in constant use. Mr Lowd spoke of

collecting them and returning them to the system "if they

are compatible with the process going on " (T3278).

"And if not, as you have said in your footnote,

they would be taken to the shore? -- Exactly."

(e) Fresh water

1.11.24 On this subject Mr Lowd said:-"However clean it is, when it comes down as rain

onto the producing platform, it is contaminated by the dirtiness of the platform and so on, and

the oil, and so it must be collected, cleaned of

oil and disposed of in the sea." But within the GBRP the suggestion of cleaning it

and disposing of it into the sea does not appear attractive.

The recommended total ban on the disposal of all substances, liquid or solid, referred to in paragraph 1.11.12 above and

in the answer to TR4 would, if adopted, embrace such water.

(f) Garbage and industrial wastes

1.11.25 On garbage Mr Lowd said (T3278) "Trash - supplies and consumables - must be

collected and incinerated and taken ashore,

252

as must also be garbage resulting from

food preparation, and sewage from the

sewerage system or resident facilities

on platforms must be handled by a

conventional chemical treatment and put

into the sea.v On industrial wastes Dr St. Amant said (T3988 et seq):

"In the early days, and we are attempting to

control this now - when these rigs were put

into position, it is quite a large structure

and it requires some additional work after it

is put into position - welding, pipe cutting; there is always occasional pieces of cable and

drums of oil emptied, and they either get lost overboard or are thrown overboard. If a rig

has been in position for, say, a number of

years you can expect around the perimeter of

it to have various types of things on the bottom. It might be a piece of pipe; it might be an old cable, something they lost overboard.

Then, when they are drilling for oil, some of them had a tendency to throw Baroid sacks over board - this is a tradename. Perhaps you should use the term drilling bentonite but this material

was shipped out to this rig in 100 pound bags ...

They use hundreds of them mixing up the mud and

this bag would just be thrown overboard. This paper does not dissolve as quickly as you might think. They tend to get waterlogged and go to

the bottom. You might have hundreds of them lying around on the bottom. In shallow water you have the bags actually floating up into oyster beds until the oysters are smothered.

Again, offshore, they tend to get on the bottom

and drag around with the tide and a man would

get a netful occasionally and complain rather

253

bitterly about it. This type of thing can be

controlled and with the recent interest in the

environment and because of complaints by the

fishing industry we have managed to set up,

I would say, satisfactory surveillance and

enforcements. But some of the old stuff is

still there and we still have a problem."

(g) Drilling mud

1.11.26 This has been referred to in Part 5 (supra) and see

also answer to TR4.

In the U.S.A., OCS Order No.7 (Exhibit 401 p.7.2)

provides:-"Drilling mud containing oil or toxic substances

shall not be disposed of into the ocean waters." (T14526) But in the GBRP the regulation must go much further

because of the special hazards created by sedimentation, sands and so on (see supra). Accordingly, we recommend that

drilling mud should not be allowed to be disposed of into the sea whether it contains oil or not.

1.11.27 Mr Basire said (T2367)that he understood that in the case of the Mackay No.1 well (about to be commenced by Japex in Repulse Bay at the time this Commission was established) the Japex Company was instructed that drilling fluids must be

discharged into a tank and disposed of ashore and that they

were not to be discharged overboard. The further interesting

problem as to how and where they would be disposed of "ashore"

was not canvassed.

1.11.28 Dr St.Amant stressed the risks of injury to marine

life arising from the disposal of oil contaminated drilling muds into the sea. The risks in the GBRP are considered to be much greater than in the Gulf of Mexico of which Dr St.

Amant was speaking.

(h) Storage failure

1.11.29 References have been made to this subject In the

answer to TR4 when dealing with government regulation and

safety precautions but the present further references have

in mind the aspects of spill risks.

The collection of large quantities of oil in one

container can create a hazard leading to pollution on an

appreciable scale. If the storage is on the platform it

could be damaged by cyclone, collision or fire. If the

storage is in a moored barge or tanker moored in the vicinity

of the production platform such container could conceivably

break away and be holed under extreme weather conditions.

Even submerged storages are not entirely free from hazard.

1.11.30 The storage of oil is a necessary part of the

transportation of crude oil from the production well to the

shore if the system of transportation by tanker or barge is

employed.

1.11.31 There are two methods of transporting petroleum from off-shore production wells to the shore receiving depot

namely by pipeline or by vessel. Mr Lowd elaborated the

situation as follows:-"The options available to the marine producer for disposing of crude ... include:

a. The building of a pipeline to shore with

its continuation to a refinery.

b. The building of a pipeline to shore followed

by the transport of oil from there to a

refinery by ... tanker.

c . Movement of the oil to a refinery by export tanker or export barge train.

d. Movement of the oil to shore by a disposition

tanker, or barge train, and thus to refinery by pipeline or export tanker." ( T3324)

255

1.11.32 As distances from the shore depot Increase, batch

storage and the use of tankers or barges become more economic

(T3328). Water depths and production rates will also have a

bearing on the selection of the mode of transport. If drilling

were permitted in the GBRP the choice between pipeline and

transportation by tanker or barge would also turn on the

locality of the production well and its proximity to reefs and

islands. It is not practicable to be more specific at this

stage.

1.11.33 Mr Lowd expanded aspects of the storage of crude oil. In so doing he referred to the use of tankers, barges, "shuttle

storage", "dumb" ships or barges and submerged storage facilit

ies to which reference is made later.

At T3322 et seq he said:-1. The production processing of crude oils starts

with CONTINUOUS flow from a series of wells.

Finally that same oil moves through a CONTINUOUS

distillation process at a refinery. Thus, for

ideal balance, the intermediate movement of crude ... between the producing locations and the

refinery ... should also be a continuously flowing system. In a marine oil field, such

system would be a pipeline to shore and onward

into the distillation process at the refinery.

2. However, the distance from the marine producing

location to the shoreline, the water depth, or the nature of the fluid may demand that ...

NONCONTINUOUS, or batch-type, transportation

be used in certain links between the well heads and the refinery instead of a pipeline. There

are two particular situations in which a batch- type flow may be involved:

(a) When a pipeline from the marine producing

location to shore is unfeasible then

batch-type transportation by floating

256

vessel, from the location to some

shoreline, will be required.

Associated with this type transport

ation must be a temporary accumulation

of oil in static storage at or near

the producing location.

(b) When oil is transported to shore by

floating vessel, an additional

decision between the options of

continuous flow from that shoreline

point onward by pipeline, or by tanker,

must be made. In any event, at the shoreline point there will exist a

need for large-scale storage either to hold the oil in waiting for the discrete

scheduling of tankers or to provide surge

for the pumps at the inlet to the onward flowing pipeline."

1.11.34 Metal tanks used for storage purposes are subject to

corrosion and must be carefully and periodically inspected.

Mr Biglane elaborated on the collapse of the tank at Sewaren

at T6599. He said:-"One of the largest ones we have had in the States

was in 1969 when one tank lost about 8,000,000 gallons of crude oil. Again here is an equipment

replacement consideration ... brines are heavier

than the oil; they will then accumulate on the bottom of the tank and will act as a corrosive

agent on the bottom on the steel plates. ... This

tank up in Sewaren, New Jersey, was approximately forty years old and the bottom plates were sufficiently pitted and had enough holes in them

that when the tank was filled for the last time one plate absolutely gave way. The tank imploded ..."

257

1.11.35 Another warning given by Mr Biglane was In respect

of the "shout and holler"control method when leading or

discharging from tankers and barges. He said (T6598):-"Off-shore storage of produced products brings

about all of the problems associated with oil/

water separation, product loss from over filling,

and storage tank failure ... In our reporting procedure of course we ask for what caused the

accident and human error absolutely predominates

... I would hope we would soon get away from the

shout and holler technique ..." "... Would you expect to find the shout and holler technique used in an off-shore storage platform?

-- "You may very well. If a barge pulls up to offload oil from the storage tank, for instance..."

1.11.36 Batch-type marine transportation and the necessary

size of storage facilities were discussed by Mr Lowd at T3330.

He said:-"... whenever the decision is made to use some

sort of batch-type marine transportation, either

to the shoreline or directly to a refinery, there is a requirement for fixed oil storage unless the

shuttle storage shipment method is used temporarily.

Fixed storage must accommodate enough oil to load at least one full cargo unit on to a tanker or barge. Also the storage must be large enough to

accumulate all the oil normally produced during

the waiting time between tanker loading periods. Otherwise, the continuous flow from the wells would have to be interrupted. Therefore the

amount of oil storage required must be equal to

the size of the largest probable unit of full

cargo, plus a quantity equal to the probable maximum daily flow rate times the maximum

number of days between the arrival of successive

258

tankers. The economic decisions here involve

a balance of probable tanker arrival time

versus the risk of having to shut in the field.

It is a complex economic and operational trade-off."

1.11.37 He then dealt with the options available as to types of storage facilities and said there were three basic altern

atives, namely:-"a. Storage in conventional tankage located

on a fixed structural platform.

b. Floating storage using various types of

moored ships or barges as containers.

c. Submerged storage in either a closed unit

or an open-bottomed bell structure rigidly

fastened to the ocean bottom." (T3331)

1.11.38 He stressed that the most frequently used temporary storage at the producing location is floating and he

described the various choices available such as the use of

a dumb ship or dumb barge (T3331-3). Mr Roe also pointed out

that oil from off-shore fields is either carried ashore in pipelines or stored for shipment. This, he said, has hitherto

been done in (a) moored tankers, (b) underwater crude oil tanks

and (c) on an artificial island (T4133).

1.11.39 Mr Lowd also stressed the risks of leakages from mistakes and over-sights and undoubtedly these occur from

time to time. Some methods are safer than others. He said

C T 3 3 3 8"): -"... batch methods involve greater risks of

pollution, that is because we are accumulating a tremendously large volume of static oil in one

place. We have to start the flow, we have to stop the flow, we have to make interchanges and

connections, and we have to deal with the opening

and closing of valves and so on. Thus, the

259

incidence of possible mistakes, leakage and

other damage is relatively high. I think that

is probably the sum and substance of it."

1.11.40 Another description of storage methods came from

Mr Basire at T2346 and Mr Thomas at T2708A. The former said:-"It is often the case that the oil is piped

direct from the platform to a tanker. In the

Middle East a disused tanker may be anchored or

moored near the production platform and used

as storage. Oil is then pumped from the storage tanker into another tanker which transports it to

the nearest refinery. This would depend very

much on circumstances and the position of the discovery; if near the shore, maybe the product

would be piped ashore and stored there for

transport by tanker to the nearest refinery.

There are other cases in the Middle East where

tanks have been constructed; then completely

submerged, sitting on the bottom of the ocean,

and used for storage ... The water would be

relatively shallow, say, 100 feet."

1.11.41 Mr Lowd described in some detail the various

types of off-shore storage, the selected type being based

on operational or economic requirements.

1.11.42 Fixed platform storage is costly but is sometimes

used in very shallow water.

1.11.43 Floating storage using various types of moored ships

or barges as containers is most common.

1.11.44 "Dumb" ships or barges are usually converted tanker

hulls into which the oil is flowed directly from the producing

platform. They are equipped with pumps for off loading purposes.

260

Violent storms are a potential danger.

1.11.45 Single point mooring which allows the ship to swing

is expensive but more satisfactory. Such mooring must of

course include a rotatable fluid flow system within the

ground tackle system.

1.11.46 Other floating storage systems exist and were

described by Mr Roe and others. One illustration will

suffice (T4133):-"A large underwater storage (500,000 barrels)

in 160 ft. of water has been built 58 miles

off Dubai in the Persian Gulf, it has no bottom as the oil floats and displaces the

sea-water. Control of over filling is done by an automatic measuring device. The structure

is affected by natural phenomena, and by failure

of automatic devices."

1.11.4? Prom the foregoing it seems that if petroleum

drilling is permitted within the GBRP a measure of pollution arising from the storage of crude oil for transportation

purposes must be expected and that such pollution will be of

a chronic albeit intermittemt nature. The quantum of such pollution will depend partly on the degree of skill and care

of the operating personnel, partly on having correct designs and proper maintenance, partly on freedom from external

causes such as cyclones, collisions and fires and partly on the degree of governmental regulation and supervision. ( i )

(i) Pipelines

1.11.48 This subject is also dealt with in Parts 7 and 9 of the answer to TR4 when safety precautions and the provisions of Ex.68 are being considered. The present further references

have in mind the aspects of spill risks.

261

1.11.49 As to pipelines Mr Rochelle (Project Engineer, Brown

and Root Inc.) gave technical details of pipeline design and

construction and dealt with pipeline spills the main causes of

which are:-(a) ships' anchors being dropped on or

dragged into the lines (b) shifting from storm forces.

1.11.50 But proper burial of the lines in appropraite areas (shallow waters and shipping channels) should be a safeguard

against both. If pipelines are ever permitted within the GBRP

strict precautions and supervision will be desirable.

(d) bad maintenance Both are avoidable.

1.11.51 An example of pipeline failure was the oil spillage

at Botany Bay on 21 December 1970 described in Exhibit 364 being a report by the Maritime Services Board. Apparently an

18 inch fuel shipping pipeline fractured when a welded footing had carried away, possibly with contraction, and then had

jammed preventing the normal expansion and contraction of the pipeline. A rupture of about 10 inches by 3 inches resulted

and caused a large quantity of oil to escape (T9557)· The remedial steps taken are also set forth in Exhibit 364 and at

T9557-8.

1.11.52 As Mr Rochelle said (T2949):-"If the maintenance programme for the line is properly implemented, logged information, such as the volume of internal scaling removed during

cleaning operations, will give an indication of the condition of the pipe. The systematic

analysis of these data will allow the operating

company adequate time to introduce corrosion

inhibitors, reduce the operating pressure, or if

262

necessary even replace the section of line."

(e) absence of control valves

Mr Rochelle said (T2949):-"Spillage from a line ruptured by storm forces

may be limited to a given volume of gas or

liquid by the placement of control valves in

the line and by the implementation of emergency procedures whereby during extreme storm

conditions the flow of oil or gas is curtailed."

1.11.53 The question whether automatic shut-off valves should be put in all sub-sea pipelines was a matter of some

doubt to Mr Rochelle (T2952).

1.11.54 Mr Lowd dealt with the question of pipeline valves

at some length. He said (T3327):-"In the United States, and I believe this is

representative of world-wide operations, there

are only two valves of two different types installed in the line between the platform and the shore. One is the shut-in valve downstream of

the pumps at the location. It was the one that

had the orange colour on the model. This valve is one that senses reduction in pressure in the line indicating a leak. It shuts the line off

and also shuts down the pumps. The other valve

that is traditionally put in a prudently operated

pipeline is at or near the shore end, and against the possibility of the facilities at shore being

at some point of relatively high elevation there is usually a large check valve so that a break

would not allow oil to flow backwards in the line and out should the break occur close to shore.

These are the only valves that are traditionally

installed. In the outer continental shelf area

263

of the United States, they are required, at

least the one at the platform is required,

by law."

1.11.55 Mr Lowd said in answer to a question relating to the

quantity of oil that might be spilled if a ship's anchor

fractured a pipeline, for example 100 miles long:

" ... the risk of 100 miles of oil coming into

the water, no, because assuming that the line is

shut off so that we are not pumping the oil out of

the line, the head of water is great enough to seal the leak and stop the flow out of the line once the

system is static." (T3328)

Later he spoke of the sensory device "The first thing that would occur is that there

would be a leak of oil from the line if the line is filled with oil, regardless of our controls.

I think it follows if the line is ruptured across

its diameter, for instance, there is going to be an escape of some oil. Assuming that the line is

protected in the way that I believe we should certainly strongly recommend, there will be a valve

at the inlet end of the line near or at the platform; there will be some sort of sensory device that will

recognise the leak on the basis of the reduction of pressure which will be associated with the leak.

This sensory device will do at least one and, hopefully, we would have it set up to do two things.

It would certainly shut down the pump and it would certainly shut in all the wells. It must do this.

In addition, we would expect that it would also

close a valve on the inlet to that line." (T3^31) "Is there any relationship between the size of the sub-sea leak and the activation of the automatic

platform control to which you have just referred?"

-- "There is, indeed."

264

"What is the relationship?" -- "The relationship

is that the larger the leak the more specific

is going to be the sensing of pressure reduction."

(T3432)

"Just to understand you, the sort of sub-sea

device you are now talking about is one which

upon a reduction of pressure at its location

perhaps some miles distant from the platform

would shut in the pipeline at that distant

point? -- "Yes".

" ... the real problem is one of sensing; the

problem to be met is how to sense the fact that

a rupture has occurred.

The real weakness of the best that is done now

in good practice is solely a weakness in sensing,

as you have said, when the rupture occurs at some

extended distance." (Î¤3^33)

1.11.56 Other aspects of pipeline spillages included the

effect on the escape rate of leaked oil of the hydraulic head

of water. Thus:-"The leakage usually can be characterised almost

as a seep of oil to the surface and not a

cataclysmic discharge of all the oil in the line, and the reason for this is that there are some

counter forces at play ...

These are, for instance, the head of water. We

have salt water and it is heavier than oil. That

is bearing down on the oil at the point of the leak. We have a slightly higher head of oil

from within the line pushing against the water ...

... your escape rate would be quite slow because

of the hydraulic head of the water (Î¤3^3^) ...

and also by the fact in a packed liquid line with

a pipe shut off by the valve at the platform and

a pipe shut off by the check valve at the shore,

265

there is a situation set up where it is difficult

for the oil to flow because there is no way for

a gas pocket to take place behind it. That is,

there is a sucking action, if you will, created

by the two closed valves." (T3^35)

"... One of the things that minimises the rate

of leakage is the hydraulic pressure exerted by

the water tending, if you will, to close off the

hole. If this were under 200 feet of water -

200 feet of water is roughly 90 lbs. per square

inch of weight - so on the hole where the oil

tends to emerge we have a 90 lbs. per square inch

push ... downwards." (T3^36)

1.11.57 On another aspect related to the "replacement

process", Mr Lowd was asked:

" ... no matter how deep the ocean, the oil

would come to the top because oil is of lesser

density than water and the pressure exercised

on the oil would not make it any denser compared

with the water which just lies above it, and the oil just tends to rise. What would happen is that it will be greater with more depth of water and

the oil will accelerate as it gets to the top,

just as a submarine will, because of the lessening

density of the water."

to which he replied:-"I think that is an excellent explanation of what

I have just referred to as the replacement process

- yes." (T3439) "Does the rate at which that replacement occurs vary

with the depth and the water pressure at the point

where the replacement is occurring? -- "No, sir." "The replacement will be merely a function of the

respective densities?" -- "It will be a function

of the respective densities and the nature of the

266

rupture of course."

"Have you, in this example, taken into account

the pressure that might be exercised by gas in

the line? -- "This is an excellent considerat

ion. If this oil is over-saturated at the

pressure of operation, and the pressure on the

system reduces, which shuts the valve, then the

reduction in pressure will liberate gas (T3440).

If this occurs then there will be very large

forces at play essentially overriding the

other considerations which will tend to

displace rapidly and in large quantities oil

through the hole in front of the expanding escaping gas." (T3441)

1.11.58 Then Mr Rochelle spoke of methods of repairing

a damaged pipe and they were mechanical connections and welding. He described these methods in some detail (T2954 et seq).

The first task however is the location of the leak. Mr Rochelle said:-"Should the leak be oil, early visual sighting will

give an approximate location. The exact spot then may be located by divers. Another method often

used is the insertion of a knocker or pinger pig

into the line so that it may be transmitted through the line by differential pressure until

it reaches and becomes lodged at the damaged

section. This sound producing device is tracked

to its location by hydrophone direction and ranging equipment. Still another method of

detection is the pumping of sea water loaded with

dye into the line. This dye-loaded water will

escape at the leak and may be visually sighted

from the air. The final location of the leak

may then be made by divers ." (T2952A)

267

1.11.59 He added that the water depth exerts one of the most

significant influences on the selection of a repair method.

If the water is shallow enough and if there is enough slack in

the line it may be possible to pick up the whole line from the

bottom with davits and make the repair aboard the lay barge.

1.11.60 The factors of corrosion, proper methods of const

ruction, inspection and testing and maintenance were canvassed

by the expert witnesses.

Mr Rochelle said (T2946):-"The best deterrent (sic) against leaks after construction is the systematic implementation

of a well planned maintenance and inspection

programme which meets or exceeds code standards."

Of inspection and testing he said (inter alia)

T2930) "Throughout the pipe laying process great care

is taken to insure against leaks and harmful deformations in the pipe. At the very beginning,

in addition to visual inspection throughout the

process, the chemical and physical or strength properties of the pipe are monitored at the pipe

mill. Later, all coatings applied both at the

shore base and on board are electronically inspected for imperfections. Also every single

weld is x-rayed as the line is assembled."

Finally of burying the line (T2936):- "If a pipeline is to be buried, the usual cover

for this protection is three feet. Very special attention is given to burying the line through

areas of potential damage such as beach approaches, through shipping lanes and around platforms. In

these instances the depth of cover is increased to

a depth of 10 or more feet." "Another item of construction which is most

important in preventing leaks is the burial of the

268

line through areas such as beach approaches,

areas of high currents and potential anchorages.

This proper depth of cover on the line is good

insurance against damage." (T2946)

1.11.61 Dr St Amant said that in the U.S.A. both Federal

and State regulations required burial in shallow waters and

in navigational straits to a minimum of 3-6 feet below the

sea floor.

1.11.62 There is no doubt that burial is quite essential

but the minimum depth in which burial should be compulsory

is uncertain. Furthermore the presence of rock or coral

would make burial impracticable and the whole question of

the use of pipelines within the GBRP will turn on the particular location and perhaps on the acquisition of further

bathymetrical and geological knowledge of this still comparat

ively little known area.

1.11.63 They are of course used on shore e.g. from Moonie to Brisbane (190 miles), from Roma to Brisbane (280 miles)

and from Moomba to Adelaide (490 miles) whilst off-shore in the Bass Strait about 100 miles of underwater lines of

various diameters have been laid to bring crude oil and gas

to the treatment plant at Sale and other lines have been

laid to Melbourne, to Westernport and across Port Phillip Bay. These figures may be compared with some 40,000 miles

of pipeline in the Gulf of Mexico and even more in adjacent

marshes of Louisiana (T4053A). But the underwater terrain of the GBRP will require an appreciable amount of surveying

before pipelines can be permitted and the proximity of

numerous reefs and islands to a production site may alone

prohibit their use in special cases.

1.11.64 The actual laying and burial of pipelines may also

constitute a hazard. This aspect was referred to by the

269

Senate Select Committee on Off-shore Petroleum Resources In

Its report (Exhibit 450). Paragraph 13.262 thereof reads

"The construction of pipelines can also cause

disturbances to the Reef both through the

removal of sediment sufficient to bury the

pipeline and through the possible need to

blast holes In Reefs so that the pipeline can

pass through It. Mr Camm, Queensland Minister

for Mines, In his Second Reading speech on the

Petroleum (Submerged Lands) Bill Indicated that

It was unlikely that there would be need to blast

holes In the reef due to the large number of

natural channels between Reefs. Professor Burdon-

Jones however, considered that:

'This to me Is something that would never work In practice. The pipelines have to be laid on

the sea bed, and undoubtedly the first thing

that Is likely to take place will be to blow

a hole In the Reef to allow the line to go through.1" - but the Commission Is opposed to the

use of explosives In the GBRP and has made a recommendation

against their use In seismic surveys (paragraph 4.7.49).

1.11.65 From the foregoing It will be seen that pipelines for a number of reasons constitute a real potential for oil

leaks which In the aggregate properly fall within the descrip tion of chronic pollution. As In most other cases of potential

spills, they can In theory at all events be reduced to a

minimum by careful planning, testing and maintenance, and by

the delineation of corridors approved by the appropriate

governmental authority based on comprehensive hydrographic

and bathymetric surveys.

1.11.66 The APEA point of view on pipeline hazards was

given by Mr Jeffrey QC during his final address (Synopsis on

TR1 submissions pages 38 - 40):-

270

"It is known that a necessary condition for

the construction of a sound pipeline is an

adequate survey of its route. The route

chosen will, as far as possible, avoid

areas of heavy shipping and topographical

features which might cause undue localised

loading on the line. The survey will include -

the assembling of hydrographic and meteorol

ogical data.

Navigational systems exist which enable

bottom contours to be correctly measured and obstructions avoided.

The survey having been made, the design of

the pipe will be based upon proven experience

and code practices. Factors receiving particular

attention will be the provision of proper grade

pipe with sufficient wall thickness, a proper

corrosion protection system and burial where possible. There are a number of means whereby

corrosion protection may be supplied and among which the designer will choose for that most

suited to the particular situation; experience

shows that, with a properly designed system,

corrosion may be virtually eliminated. It is also known that a most important factor in preventing leaks is the burial of the line

through areas such as beach approaches, areas

of high currents and potential anchorages.

Where a section of pipeline is to be buried a

calculation is made of the specific gravity required to keep the pipe from shifting on bottom. Burying a pipeline reduces the

likelihood of damage to it by 90%. The result is that there is a strong trend towards burying such pipelines.

Specialist advice can be given to any operator

271

upon the design considerations which are

important for his particular activity.

1.11.67 In the construction of the pipeline, industry has

available what are virtually complete sea-going

assembly plants. Different methods of pipe-laying

suited to various conditions are available. The

construction process is completed with a rigorous

inspection and testing of the pipe as laid.

Maintenance

1.11.68 Industry is acquainted with the need to implement

a well planned maintenance and inspection programme

after construction. This programme employs various maintenance techniques such as periodic

internal cleaning, corrosion inhibiting, periodic

pressure testing, external inspection by divers, the maintenance of pressure drop surveillance

equipment and the inspection and calibration of

shut-down and relief devices. Such a maintenance programme has the capacity to prevent the occurrence of leaks from a properly designed pipe.

Reparation

1.11.69 If a break in a line should occur, a pressure drop in a valve downstream of the pumps at the location will shut the line off and shut down the pumps. Another available device having the same effect,

but more sensitive to any loss of oil from the pipe,

is one which involves two meters, one at the platform and one on shore, which are interrelated by a communications system and can detect any

difference between the volume of oil being pumped into the pipe and that coming out.

If damage has been done to the pipe, one or other

of the available methods of pipe joining - mechanical

272

connection or welding - will be chosen according

to conditions at the site. Elaborate equipment

has been designed to enable one or other of these

types of repair to be effected.

By the employment of these technical resources,

the likelihood of a pipeline leak can be greatly

reduced and effective means employed for dealing

with it, should it occur."

1.11.70 But is must always be borne in mind that the geograph

ical and other conditions of substantial areas within the QBRP

are vastly different from those obtaining (say) in the Gulf or the North Sea and whether pipelines are appropriate to be laid

and sunk and maintained in portions of the GBRP is debatable.

l . H .71 It must be borne in mind also that pipelines have been

responsible for large quantities of oil having escaped into the sea on a number of occasions in various places overseas

in recent years. Mr Keith tabulated these at T5581 to T5586.

There were various causes of the spills which were mainly

small but included some medium and large spills.

I.II.72 As regards spills from vessels whilst loading at or near the production platform, the submissions of A.P.E.A. will

again be quoted (Synopsis p.4l):~ "Means exist to prevent any overflow of oil

whilst loading. Shore loading pumps can be instantly stopped from the ship where necessary

and when the valves on the pipeline controlling

the flow of oil to the ship are closed, the oil cannot run out if the pipeline is sound.

Observance of standards of inspection and testing

can ensure that this condition is fulfilled.

Part of the experience leading to the development

of techniques to prevent spillage while loading is

the recognition of the inadequacy of the much

273

criticised 'shout and holler' technique.

So there has been drawn up by industry an

International Oil Tanker and Terminal Safety

Guide. This sets out the steps which can,

and should, be taken in loading and discharging

operations for the purpose of eliminating vessel

spillage. It is within the capacity of industry

to observe the practices there laid down.

In like recognition of the possibility of discharge

of unacceptable quantities of oil into the sea from

ballast tanks, industry has devised the 'load on

top' procedure which is now observed by more than

90% of the world's tankers. So even a 70,000 ton

ship need not discharge one drop of oily ballast.

If tanker transportation from locations in the

Great Barrier Reef to Brisbane occurred, the

carriage of ballast in separate tanks could be

made a requirement thereof.

The capacity to avoid a maritime casualty arises

from the variety of navigational aids which are available, aided by the systematic accumulation

of hydrographic data which would accompany the

presence of vessels in the waters. Advanced systems of sounding apparatus can be carried to reduce the risk of grounding. It would only be in acceptable weather conditions that a tanker would

remain at a buoy mooring."

1.11.73 But notwithstanding these views which we have quoted in full, the evidence showed that spills during loading-

and unloading - operations continue to occur from time to time.

(j) Tankers,barges and flexible hoses 1.11.74 The subject of flexible hoses is also dealt with in

Parts 7 and 9 of the answer to TR4 when safety precautions and

Exhibit 68 were being considered. The present references have

274

in mind aspects of spill risks.

It has earlier been shown (paragraph 1.11.30 supra)

that one of the methods of transporting crude oil from the

off-shore production platform to the shore receiving depot

is by the use of tankers or barges.

1.11.75 Mr Crane (Marine Engineer and Manager Shell Co.of

Australia) gave evidence which included the number and size

of tankers which would be involved if oil in substantial

commercial quantities were found within the GBRP and the

mooring and flexible hose problems which are consequential to

tanker or barge storage and transportation.

He stated that of more than 1550 ships which traverse

GBR passages annually about 380 are tankers and that tankers

coming to Brisbane have an approximate draught of 39 feet.

1.11.76 It will be remembered that the tanker 'Oceanic Grandeur' struck bottom with resultant large scale pollution

in Torres Strait waters on 3 March 1970. (Exhibit 194 and see

answer to TR2). Its maximum draught was 38 feet 4 inches and

it was fully loaded with 55,015 tons of heavy crude and in the locality where it ran aground high tide was necessary for its

passage. The cause of the incident was probably a small

unchartered reef on the sea bed.

1.11.77 Mr Crane indicated that to handle a production rate of 300,000 barrels a day in the GBRP two additional tanker

passages a day over and above the existing tanker traffic would

be necessary. He was assuming ships of between 35,000 and 60,000 DWT (T5023). (There are approximately 7 barrels to the

ton).

Mooring 1.11.78 Mooring is one of the main problems to be overcome in

transferring crude oil from a production facility to a tanker.

Mr Crane explained the different methods employing either

275

conventional buoys or single buoys and the different

conditions of wind and current which they respectively suit.

1.11.79 Loads exerted by winds and currents acting beam on

to a vessel may be ten times as high as those resulting from

head winds and currents (T5037). Mr Crane listed the advant

ages of the S.B.M. (single buoy mooring). He said:-"1. Mooring forces are much less than at a C.B.M.

(conventional) resulting in a larger vessel

being able to utilise, in safety, an off-shore

mooring.

2. Once moored, a vessel is able to remain in the berth under much worse sea and weather

conditions than that at a C.B.M. Only

extreme conditions resulting in an average

wave height of at least 15 feet will require

a vessel to vacate the berth.

3. Loading or discharging operations can be

continued under conditions which it would be impossible to do at a C.B.M. Experience indicates that cargo operations can be continued under conditions of average wave

heights up to at least 10 feet.

4. Should it become necessary to vacate the

berth, the vessel can do so without any assistance from outside.

5. No tug assistance is required for either

berthing or unberthing." (T5039) Asked whether such a system would be more likely to

be used in the Reef Province than conventional mooring, Mr

Crane said (1502*0:-"I could not express an opinion. It would depend

entirely on the results of the hydrographic survey

of the area." Asked about the holding properties of different

bottom conditions, Mr Crane replied

276

"... a good holding ground would be clay. Heavy

mud is quite good. Sand is also quite good if it

is deep sand. Silt on a hard surface is not very

good. The anchor can drag through it. Rock is

very poor because it does not give the anchor a chance to sink in. It is laying on the surface."

"What about reefal material?"-- "If it is fine I

believe it is similar to sand, if it is fine coral

material of fair depth. It is reasonably good

holding ground."

"What if it is not fine? What if it is not a coral

sand but is rather reef rubble?" -- "The same

remarks would apply as to rock. However, if these are outcrops, and we are talking about moorings

that are permanently laid, an anchor which

embedded itself in or behind such an outcrop could be judged to be a good holding anchor but

if you were using the ship's anchors as well you

would not want this situation to arise. You could

possibly lose your anchors." (T5032)

Flexible hoses

1.11.80 Flexible hoses are an integral part of the transport ation systems and attract consideration. On this subject Mr Crane said (inter alia):-"The end of the fixed submarine line near the

mooring is generally fixed by a large concrete

clump to prevent movement by the tide or lateral

displacement by a vessel in the moorings ...

The connection to the ship's manifold is made by means of a string of flexible hoses. These are

generally of the same construction as the hoses

used for handling oil over jetties. They are of

oil resisting rubber, reinforced, electrically

continuous and flanged ...

The principal difference is that the outer rubber

277

sheath is considerably thicker than that on hoses

intended for normal usage. This is to resist the

abrasive action that will occur when lifting and

lowering and also when the hose is moved on the

sea bed under the effects of ship movement or

current." (T4980)

1.11.81 Asked about the length of such hoses, Mr Crane said

that in the case of an S.B.M. system for a 200,000 ton tanker

the hoses could be 700-800 ft.long. He explained that with

this mooring system the hose must pass through the buoy

itself. (T4994) The length of the hose is designed so that it

does not touch the sea bed, because if it did, the continual movement of the buoy would cause constant abrasion.(T4992-3)

He went on:-"The connection from the buoy to the ship is by

floating flexible hose. Those hoses generally

are of normal construction but have floats

cemented on. When not in use the hose string floats freely, streaming from the buoy. In

this way they are ready to be lifted on board

when the tanker moors bow to the buoy. In some locations authorities do not permit hoses to

remain afloat when not in use.” (T4994) Whichever mooring system is used, the hose has

to be brought aboard the tanker to be connected to the ship's

manifold.

Inspection, testing and maintenance of hoses 1.11.82 The hose is of such importance and is subject to

such abrasive and other strenuous forces that in order to prevent leaks and pollution strict inspection and maintenance are at all times necessary. This subject has been referred to

elsewhere (paragraph 4.7-25) and the following passage from Mr Crane's evidence may at this stage usefully be requoted:-

"A line in regular use would be examined at three

278

monthly Intervals and the hose strings brought

ashore for thorough examination every 1. months

... Particular note would be taken of chafing or

damage and the position of individual hoses in

the string would be changed to spread the wear

over the entire string. Complete logs of hose

inspections are maintained."

"Do you know of cases where they are not examined

as frequently as that?"-- "Yes, I do."

"In Australia?" -- "Yes,in Australia, at Barrow

Island."

"What is the period of inspection there?"-- "About

six monthly intervals." "Do you know of other instances where the examination

is more frequent than every three months,?"-- "Yes,

I know of a case at Port Stanvac in South Australia

where the line is inspected every time it is used

and also at 30-day intervals." (t 4981)

"... There is no governmental regulation of these matters in either of those two cases?" -- "That

is correct." (T4982)

(k) Prevention of spill from hoses

1.11.83 The hazards both of fire and pollution exist from the use of hoses if loading operations are not at all times

properly and carefully controlled. This is another example of the risks of pollution which can exist due to human frailty.

But trained and careful personnel can and do suppress the risk.

Mr Crane said when speaking of production procedure:- "... It is usual to station a shore officer

(loading master) on the vessel and he is in

radio communication with the shore pumping installation and thus controls the rate of loading and stopping and starting of the shore

loading pumps. In some instances, shore loading

pumps can be stopped under emergency conditions

279

by means of a direct radio signal from the

loading master's transmitter, without having

to rely on voice communication.

On completion of loading, the valve on the

shore end of the pipe is closed. The hose at

the ship is slung and raised in such a manner

as to permit draining of the last length of

hose.

... When the valves on the pipeline controlling the flow of oil are closed if there is no air

getting into the pipeline, the oil cannot run

out. In the case of the very long lines such as we have with single buoy moorings and as shown

on the film there are valves at the seaward end of the steel line, these would be the valves that

would be closed under these condtions. The hose

is then lifted slightly so that it will permit

drainage. The flange bolts are eased back and the oil remaining in that length of hose will drain into the driptray provided underneath the

tanker manifold." (T4995) "We saw in yesterday's film a slug of oil leave the

pipe as the disconnection occurred?" -- "That is

correct." "Was that a normal occurrence?" -- It could be but

this would be in the nature of a few gallons ...

The flange connection is then broken, the small quantity of oil flows into the permanently fitted

drip tray, beneath the manifold valves. This tray can accommodate upwards of two hundred and

fifty gallons and can be drained away into one or another of the cargo tanks ..." (T4996)

Later he added:-"... occasionally minor spillages do occur. These are generally contained on deck. All tankers have

a coaming bar around the edges of the main deck that

280

will contain small quantities of oil. When at

sea openings are provided so that any seawater

coming on deck can run overboard again; but in

port, before commencing to load, these holes are

closed either by mechanical devices or by wood

plugs cemented in.

During all cargo operations great care is taken

to prevent spillage as there is, with most

products, a very real hazard from fire and

explosion if overflow or leakage of cargo occurs.

Any oil spilled is not only a threat to ecology

but also a very real threat to the lives of the

operator and the remainder of the crew all of

whom therefore have a very real incentive to

carry out their duties in a competent and

responsible manner, and prevent incidents that

may give rise to spillages." (T5022)

1.11.84 Asked who was in charge of the loading operation,

Mr Crane replied (T5053):-"... any of the three deck officers do

navigation work and cargo work."

"Does the officer concerned have any manual

to turn to?" -- "There is a similar manual in use on board the vessels to the one that

was produced this morning ... This manual was produced by the International Chamber of Shipping,

concurrently with the IOTTSG so that all the

instructions or recommendations in it are compat

ible with those made in the red book."

Mr Crane had earlier been asked (T5026):-"... has the industry drawn up some document

which in fact is called the International Oil Tanker and Terminal Safety Guide?" -- "That

is correct."

"Does that constitute a number of steps which

281

can and should be taken In these loading and

discharging operations?" -- "Yes, that book

represents very good general practice required

in any port in the world."

"When was it drawn up?" -- "It was given

circulation last year,1970." "Was there nothing like it before?" -- "No,

previously there was nothing referring specifically

to terminal operations."

"That is what this is concerned with?" -- "This is concerned with the operation of the terminal

and the work that goes on whilst the ship is at

the terminal." "What prompted the drawing up of these guide lines?"

-- "A series of very severe explosions on vessels loading cargo in the Persian Gulf, I think, as long

ago as 1964. They were all within a period of three

months all with serious fairly heavy loss of life

and material damage. As a result the operators of

those terminals decided that they would have to review their terminal operations. After commence

ment of the review the scope of the review was widened to include all the major oil companies

throughout the world..." "Are there any governmental regulations comparable

to these guide lines applying at any of these Australian terminals?" -- "No, not as far as I

am aware."

1.11.85 He referred also when dealing with loading procedures

to the choice which has to be made between leaving the hoses

full of oil or replacing that oil with water (Exhibit 363, T9555-7)· To clear the hoses the ships pumps are used, pushing the oil until the hose line is full of water and then

the valves are closed off. The reverse process raises a

problem of disposal of oiled water. The ship should be fitted

282

with a slop tank or the load on top procedure adopted

(T5055)· Mr Crane's evidence included the following

passage:-"How would the ship deal with that slug of water?"

-- "Ifthe quantity was not excessive I could forsee circumstances when it could be retained

on board particularly if the vessel was fitted

with a slop tank, when the initial slug of

water could be directed into the slop tank and

retained in this space. However, if all the

cargo space was needed to load the requisite

quantity of cargo, we would then have to load

oil on top, or continue to load oil on top

of this slug of water. Alternatively, if it

could be kept segregated -again, it could be

kept segregated only if the place in which it was segregated was not needed for cargo - it

could be pumped back into the hose string."

"In any event, there is a problem in finding

a place to put this extra slug of water?" --"Yes."

1.11.86 From the foregoing there appears to be little doubt

that skill and unremitting care are required in the handling

of flexible hoses and the filling of tankers and barges if the perils of fire and explosion and the damage caused by chronic pollution are to be avoided. Unless great care is

exercised, the process of uncoupling hoses is one in which minor spillages can occur. These should be caught on board

by a drip tray. In fact any spill on the deck of a tanker

should be contained on the deck if the outlets from the

coamings are plugged as they ought to be. It seems to be universally accepted that minor spills do occur from time to time and occasionally substantial spills have occurred

during such operations.

283

PART 12 - OTHER HAZARDS INCLUDING

EXTERNAL FORCES

(a) Wind and currents

1.12.1 These have been considered in the "Principal

Introduction" (supra).

They can both be strong within the GBRP (T14697) and

can create hazards if a floating rig is used. Moorings, anchors

and buoys even though multiple can be damaged or moved in

exceptional weather conditions with consequent lateral movement

of the floating rig.(T14696) This in turn could lead to a

blowout in the case of a development or production rig unless

immediate avoiding action can be taken. Evidence was given

about the 'E.C. Thornton1 which had six 20,000 lb. anchors and two 18,000 lb. anchors and which drilled the Capricorn 1 well

in November 1967· A suggestion has been made by a witness (Mr Cantley)

to the effect that there had been a 300 yards lateral movement

due to anchors parting but Mr Ericson (T14732) said this was not

so and that there had been a deliberate winching of the ship

over a distance of 170 feet to a new drilling site to overcome certain technical difficulties. At all events there can be no doubt that very strong winds and currents can constitute a

hazard to ship-shape drilling. We have elsewhere recommended

(in the answer to TR4 and see paragraph PI.3-11) that ship -

shape rigs using only conventional anchorages should not be permitted in the GBRP.

(b) Cyclones

1.12.2 There is general practice in the industry to design drilling platforms to withstand storms of a maximum known strength over a given period. The longer the period the more

costly is the construction. If drilling were permitted within the GBRP nothing less than a 100 year storm should be allowed to

govern the design of a platform for drilling followed by production or a movable rig designed for use over a number of

years. In the case of an exploratory drilling platform in

284

shallow water Intended to be dismantled after some weeks

exploratory drilling It Is arguable that a lower standard

might be acceptable.

Mr Rochelle (of Brown and Root Inc.) Indicated

that some companies might design for something less than

a 100 year storm .(T2969) The fact that platforms can be severely damaged

by cyclones was stressed by Mr Lowd (National Tank Co. of

U.S.A.) at T3316.

1.12.3 Moreover whatever the design standards may be, the

predicted storm forces may be exceeded. In such cases the

rig might suffer damage leading to a blowout If hydrocarbons were present. This could occur If the rig were of a type

which allowed the BOP's to be above sea level. If the BOP's

were on the sea bed there would probably be sufficient warning

to hang off the pipe string and close the BOP's.

1.12.4 Mr Thomas dealt with the emergency action necessary with floating rigs when a cyclone Is threatened. He spoke of the hydraulic latch which Is just below the flex joint

which Is In the marine riser. At T2626 he said:-"The purpose of this particular hydraulic latch

which Is just below the flex joint is to allow the marine riser to be detached from the preventers and raised to the surface In the event of bad

weather so that the ship Is then free to move In

any direction or If necessary, even to sail away

out of the path of the Impending cyclone, leaving behind the lower preventers which would be left

In a closed position ...

The whole of the drill string is not withdrawn. The drill string is withdrawn until the bit is in the

shoe of the last casing string where no formation may form around it. It is then hung off from the

preventer stack itself and only the drill pipe

285

above the blowout preventer Is unscrewed and

withdrawn."

1.12.5 Asked why the drill string Is withdrawn to the extent stated, Mr Thomas said: "... in the event of a cyclone approaching,

it may be some days before we can return to

carry on drilling. It is a well established fact

in the oil industry that an open hole section that is left standing will unfortunately deteriorate

in character and is quite likely to start slough

ing in or falling in. If the bit and the drill

string were deep down in this open hole we might

be faced with finding the bit and the drill string

surrounded by collapsed formation when we returned

to the site, which may, in actual fact, preclude us from withdrawing the drill string at all and we

would call that 1 losing the well'."

1.12.6 At T4528-30 Mr Stewart outlined an alternative

procedure for dealing with approaching cyclones, which involved

the complete withdrawal of the drilling string and the leaving behind in the hole of a cement plug. He said that this could

be done in 6-7 hours.

At T14754 Mr Ericson said:-" You would have several alternatives. If it was decided that you could not maintain the pipe in the

hole you could pull the pipe up into the blowout preventers and suspend it in the blowout preventers

and close your blowout preventers. If you did not

have time - if the motion became so severe and you

felt you had to move your vessel to save your vessel and you were not able to pull all your pipe out of the hole, you could close your blowout preventers on the pipe. The blind rams would shear

the pipe, the pipe would fall to the bottom, your

blowout preventers would be closed and you would

286

move your vessel off.

Which would be the safer method of drilling

If a cyclone were in the offing, namely, from

a floater or from a fixed platform? -- You

have the advantage with a floater that you

can get away from the cyclone. For myself

I think I would prefer to have a platform

assuming that it has been engineered to resist such forces. I think you would be

in better shape in that situation, but I

must qualify my remarks by saying that these

are impressions.

You are not an engineer? -- I am not an

engineer."

1.12.7 In the result it can be said that if sufficient warning of an approaching cyclone is given it should be

possible to move a floating rig away from the site leaving

behind a securely closed BOP stack and perhaps a cement plug.

Other forms of rigs, e.g. a fixed platform, must be designed

to withstand the severest cyclone known to have occurred in Coral Sea or GBR waters.

1.12.8 Exhibit 280 (sources unknown although it is probably a U.S.A. Governmental publication -T5528) gives a number of examples of blowouts and storage losses due to

hurricanes.

1.12.9 Mr Roe (of Cullen and Roe, Consulting Engineers of Brisbane) gave evidence for the purpose of demonstrating

to the Commission "that the design of structures in the sea involves

more uncertainties than for structures on the land

and that for detailed work the information

available for many areas of the Great Barrier Reef

287

Province is limited." (T4ll4)

He referred to the meteorological data which is

available and to the problems which would be encountered in

designing pipelines, storage vessels and off-shore problems.

He quoted an article in the magazine "Offshore" of April 1967

written by one F.G. West and which purported to give statistics

of platform casualties over the preceding 10 years. They were

31 in number and included hurricanes (8), excessive top side

weights and improper ballasting (5), blowout and fire (5) and

derrick structural failure (2).

1.12.10 His conclusions were:-"1. The wind, wave and storm data available is

insufficient in length of record or closeness

of stations to give first class predictions of maximum design conditions.

2. The actual site of the platform should be

checked carefully for adverse features before the design of a platform is finalised. This is also necessary in determining the suitability

of a drilling rig. (The U.S. Coast Guard in fixing sites for light towers surveys one mile in radius and discards sites where sharp drops

or abrupt shoals occur).

3. Pollution could be caused if the loss occurred

at the time oil or gas was found in a drilling rig, or if automatic valves failed to close

under a production rig." (T4137-8)

Later, (at T4196), he said: "... I think my main message is that in designing

these structures in the sea we have to assume a storm -industry seems to have taken the 100 year storm which seems very reasonable - but that this

storm will from time to time be exceeded. If it is exceeded greatly the structure could be lost. There

are uncertainties in designing structures in the sea

288

that we do not come up against on land.

(d) Vessels colliding with a platform

1.12.11 Mr Lowd said it was not uncommon for small vessels to

collide with a platform but that he had not known of a major

collision although the possibility could not be ruled out .

(T3417) He was asked questions as to the possible effects

thereof and he spoke at some length on' the reliance that

would be placed in such a contingency upon the sub-sea valves

some hundreds of feet below the surface of the earth at the

bottom of the sea. The signals that would be transmitted by

such a collision would he said, "all be in the direction of

shutting in the wells and the platform." But there can be

little doubt that the pollution effects of such a catastrophe could be very large.

1.12.12 Obviously a platform cannot be designed to withstand

the stresses produced by a large vessel colliding with it.

Mr Roe said (T4196):-"One item that is always a possibility is a ship

hitting a structure at sea. So when you consider

any fixed object in navigable waters there are more dangers to it - at least there are several

unknown dangers that are not allowed for in its

strength design. These may never occur during the time it is there, but they do exist."

1.12.13 Mr Ro.e also referred to tidal waves within the GBRP and said that a tidal wave could strike the outer Barrier and break 10 feet over it. The design of any platform within about one mile of the Barrier reefs should allow for this.

(T4157)

1.12.14 Instances have occurred of freighters colliding with

drilling or production platforms on Lake Maracaibo in

289

Venezuela and In the Gulf of Mexico (Exhibit 280) . In one of

these a 14 day gas blowout occurred on a well which was

apparently being drilled and in another a fire was caused

with the loss of 2,559 barrels of storage oil.

1.12.15 The risk of a collision in GBRP waters though

considered to be in general almost remote could to an extent

depend on (a) the location of the rig, (b) visibility

conditions and (c) winds and currents. For example, an

"untoward set" was responsible for a large freighter (ss.

'Paloma') contacting a reef close to an island near Mackay

on a clear night (T325) whilst mist or fog can appear in large areas of the GBRP. But the shipping routes running

northwards and southwards are in general close to the coast

and the outlet passages to the Coral Sea in the outer Reef (suitable for substantially sized ships) are very few. It is

unlikely, should drilling be permitted in the GBRP, that it

would be allowed in or near a shipping channel. Probably the most likely event would be that some service vessel might

misjudge its approach to a rig in the same way that ships have been known to cause damage to wharves. But such an event

would be unlikely to cause a blowout.

1.12.16 But good lighting and other warning and navigational

aids would be imperative.

At T323-4 Captain Hildebrand (Port Master, Department of Harbours and Marine) was giving evidence and the following

took place:-"It would be possible, I suppose, for areas of the Reef'which are at this moment not frequented by

large vessels, to be made safe for their navigation

if further aids were provided and investigations were carried out? -- Oh yes. Suppose for example than an oil drilling platform were constructed in

some part of the reef waters away from the

established shipping lanes, and suppose it were

290

desired to take vessels, say in the order of

39 feet draught, to that platform or as near to it

as could safely be done. What would be the

conditions that would need to be fulfilled to

render the navigation of the vessel to such a

point safe? -- This would involve an intense

hydrographic survey of the area between the

known shipping route and the suggested platform

and, after this survey has been carried out, the

erection of the necessary navigation beacons."

and a little later (T325):-"But with all those benefits might it still not

be possible, indeed probable, that as you approach

a reef the currents are getting stronger and that

a ship might swing, and even with all the navigat

ional aids, could get out of control? -- Yes.

One would have to ensure that there was plenty of

room between reefs in this area. It would be most

unwise to try to handle and swing big ships in narrow passages between the reefs."

(e) Fire risk

1.12.17 This matter has been referred to under "Fire

Prevention and Control" - Part 10 paragraph 1.10.31 supra.

Past experience suggests that fire is the most likely cause of a production well blowing out. Fire is both

more likely to occur and potentially more serious if it does

occur on a production platform because of the supply of fuel

which the various wells can provide. On the other hand there will be very much less pollution of the environment by oil if

oil is escaping. This was certainly the experience in the cases of the Shell and Chevron fires in one of which (Shell) the fires

were said to have been deliberately allowed to burn for many weeks from the deserted platform until the escape of oil had

been stopped by directional drilling. In this case the fire

was estimated to be consuming 80% of the escaping oil.

291

The hazards of fire, explosion and pollution exist

when hoses are being used during loading and transportation op

erations but fire can occur in other situations and cannot be

entirely ruled out at the drilling stage, although with modern

technology such risk must be classified as very small.

Mr Crane gave evidence of fire risk in the loading

of tankers which may illustrate the general nature of fire

hazards when oil and gas are being contained or loaded. The

following is a brief extract (T5021)

"As you are loading the tanks the oil is

displacing the air and gas that was

previously in the tanks?" -- "Yes."

"You have told us some sort of vent has

to be provided to permit that mixture of

air and gas to escape?" --- "Yes." (T5020)

"These vents rise some distance above the

deck of the vessels. What distance typically?" -- "On the modern type I

have mentioned where there are individual vents on each tank of large diameter -

these are at least 8 ft." "It does mean that at a height of 8 ft

above the deck you have a vent - a number

of them - discharging a mixture of air

and gas to the atmosphere?" -- "Correct."

"Is that a flammable mixture?" -- "It

could be." "So if someone were to strike a match

at any time on the deck of a vessel

which is loading, a resultant explosion

and fire would be by no means unlikely?"

"Correct, though the extent of vapour

concentration within the flammable limits has been fairly carefully assessed and,

in addition, it is becoming a more common practice on ships fitted with the low

vents to fit a constant orifice type of valve which will permit a fixed velocity 292

of gas exit to be maintained which will

shoot it a considerable distance into

the air and so disperse the gas more

readily." "To disperse it at a greater height above

the deck?" -- "Yes." "So the concentration, within a height of

10 or 12' above the deck, is not flammable;

is that the object of it?" "It is the object..."

1.12.18 Another possibility is that a blowout from some

other cause may result in a fire which then causes blowouts

from other completed wells.

1.12.19 Elsewhere Mr Crane said (T5003) that those in

charge of the operation ensure that there are:-"...no drip trays with volatile

products around the tanker manifold

when the connection was being broken.

Naturally the hose that has conveyed

and contained oil is not going to be

gas free, but I am trying to imply that

before the hose connection is broken all possible sources of ignition or fuel must

be removed from that area."

1.12.20 Once a fire has started the existing fuel source cannot be removed but additional feed to the fire can be

stopped by the closure of appropriate control valves. The

sub-surface safety valve is the final safeguard. Mr Lowd

however said (T3321) "But while there is no finite point of distinction as to when an operation

should be attended or unattended, it is a reasonable certainty that skilled

personnel can cope with some emergencies

293

better than remotely automated equip

ment can. People can think and make

judgments on the basis of the situation

at the moment. Obviously, a poor judg

ment decision or a miscalculation may

make matters worse, but this simply

emphasises the fact that proper train

ing and repetitive drills are vitally

important. The superiority of people

over automated machines in fighting

and controlling fire on an exposed

platform must not be overlooked. Two experienced fire fighters with proper

support equipment and system can more

quickly control an incipient blaze with less extraneous disruption or damage

to equipment than can the best conceived automatic devices. This is one reason

all safety shutdown systems are equipped

with manual alternatives."

1.12.21 As pointed out earlier, Mr Crane at T5022 said in

relation to tanker operations that "occasionally minor spillag es do occur. ... During all cargo operations great care is

taken to prevent spillage as there is, with most products, a

very real hazard from fire and explosion if overflow or leakage

of cargo occurs."

1.12.22 The foregoing shows that a risk of spills due to

fires is another small but appreciable hazard properly coming

under the general subject of "risks". Like most of the other

risks it can be avoided (except in exceptional circumstances)

by the exercise of scrupulous care and the use of modern and correctly designed and maintained equipment. For example, although as Mr Biglane said no fail-safe mechanical device is

completely fail-safe, a desirable feature to avoid damage from

fire is to have fusible material in the hydraulic lines so

294

that in the event of fire there would be automatic applica

tion of the shut-in device as soon as the relevant section of

the line had melted (T6989). Unfortunately however as in

most other walks of life, human error continues to occur and

he would be an optimist indeed who thinks it can be eliminated

in oil drilling which is so to speak a care-intensive industry.

1.12.23 Finally mention should be made of another potential

hazard - the presence of hydrogen sulphide (H^S) in hydro

carbon gases. Mr Lowd said (Part 11 paragraph 1.11.13 supra):- "I think that it is probable that some of

the oil, if it were produced on the Barrier

Reef would have a significant quantity of

hydrogen sulphide as part of its total

content. ... I think it would be well to

say that if you were a producer you could

expect on average to deal with hydrogen

sulphide in a third to a half of the

cases."

He spoke of various processes and methods of dealing with

this gas.

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PART 13 - SUMMARY OF THE CAUSES OF OIL SPILLS AND BLOWOUTS

Human error and mechanical failure

1.13.1 Human error has been the major contribution to the cause of most blowouts and spills. Such errors have on

occasions afflicted even the wealthiest and most experienced

operators and whilst they have been employing highly trained

crews. The submission put to the Commission from two quarters

(the Queensland Minister for Mines and APEA) that the risk of

a spill or blowout from petroleum drilling in the GBRP would

under modern conditions be "nil" or "negligible" is unaccept able. As Mr Thomas (General Manager, Beach Petroleum NL) said,

the technology of preventing blowouts from production wells has

advanced more rapidly in the last 10 years than that relating

to exploratory drilling but the human factor can never be

excluded:-"One must accept the chance of a blowout

occurring wherever one is drilling."

(T2832)

1.13.2 Another appreciable cause has been mechanical failure

and again this has on occasions been a contributing cause even

in operations conducted by the most experienced operators. Sometimes there has been a chain of causation and on rare occasions external violence (hurricanes and collisions and

abnormal pressure formations have been the cause). So far as

geological knowledge of the GBRP presently extends it seemed

to be the accepted view of expert witnesses that abnormal form

ation pressures are unlikely to be encountered in the GBRP although geological knowledge of large portions of the GBRP is

known to be comparatively small.

1.13.3 Human error has manifested itself in a considerable

variety of ways such as - by way only of example - faulty

296

casing design, faulty erection of important equipment, lack

of sufficient or proper equipment, lack of proper maintenance

and testing, failure to observe safe practices, failure to

take prompt or appropriate action when danger threatened or

a combination of a number of these and other forms of error.

1.13.4 We will now summarise the various situations in

which blowouts and spills can occur. Most of the material in

this summary has been elaborated in the foregoing Parts. The summary will be made under two headings, namely (A) the

drilling stage and (B) the production stage. The summary

does not and cannot purport to tabulate the various ways in

which human negligence has in the past or may in the future

manifest itself such as using a demonstrably inefficient and

dangerous method when erecting the lubricator (Marlin A4

blowout) or leaving the platform to have morning coffee when a serious emergency was clearly imminent,(the Shell fire)

(A) The drilling stage

1.13.5 (a) Less of primary control (Parts 5, 6 and 7) (i) Formation pressures

Abnormal pressures suddenly encountered during

drilling constitute a well known hazard and attract prompt

action if primary control is to be retained.

1.13.6 A good deal of evidence was given on likely pressur

es in the GBRP and Dr Chapman (Senior Lecturer in Geology,

University of Queensland) considered that abnormal pressures

were quite possible in the far north (the Papuan Basin) but unlikely elsewhere in the GBRP. This evidence was subjected to considerable cross-examination and it is very doubtful

whether sufficient geological surveys have been made to

support his conclusions. He said that abnormal pressures are encountered under one or other of three conditions:-(a) Areas of thick and rapid sedimentation

(still going on or only recently stopped),

(b) Areas that are being or have very recently

297

been subjected to tectonic loading, and

vertical thicknesses of several thousands

of feet.(T3496)

Areas with abnormal pressures due to rapid sedimentary

loadings exist for example in the Gulf of Mexico,

Areas of tectonic loading occur in California

including the Santa Barbara area.

1.13.7 He added (T3-498 -9) as regards the GBRP:-

"A. Surveys completed indicate that only

in the far north (north of latitude 10°S)

are young sediments likely to be more than 10,000 feet thick, and so only in the far

north are significant abnormal pressures

to be expected, if there are thick impermeable sequences of rocks.

B. The Great Barrier Reef is not an area of rapid

sedimentation, nor has it been in the recent past.

C. The Great Barrier Reef is not tectonically active

nor has it been in the recent past.

D. Thick gas reservoirs under the Great Barrier

Reef are extremely unlikely ..."

"There are therefore good geological reasons for

expecting a normal hydrostatic pressure gradient

in the interstitial fluids of the rocks beneath the Great Barrier Reef area, except possibly in

the far north.

Drilling in the Great Barrier Reef area to date

has followed expectation ..." But as the quantity of drilling to date in the GBRP

has been extremely small and nearly all of the GBRP remains

undrilled, it is a little difficult to appreciate the force

of this remark. Furthermore, the comparatively sparse number of seismic surveys hitherto undertaken within the GBRP was

stressed by Mr Robertson (Supervising Geophysicist of the

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Bureau of Mineral Resources).

1.13.8 Later Dr Chapman was pressed in cross-examination

about references by others, particularly Rhodes Fairbridge, to

rapid sedimentation in Reef areas. Dr Chapman explained that

there was reference to sedimentation in limited areas, not in

a geological basin. If they meant any more than this, then

he did not agree with the statements. The following

passages are relevant in this connection:-" ... I suppose you would disagree with the

statement that rapid accumulation of sediments

is now in progress in the Queensland Barrier Reef?" ... "From the geological point of view

I would disagree." (T3539) " ... Taking the area as a whole I do not regard

the Great Barrier Reef as an area of rapid

sedimentation. Taking isolated parts of the

area there are indeed parts where rapid

sedimentation is taking place. (T3540)

... the areas between some of the reefs are

areas of relatively rapid sedimentation, but

that these form an insignificant proportion of

the areas under consideration." (T35^1)

1.13.9 Dr Chapman agreed under cross-examination that his purpose was to advocate for petroleum drilling in the GBRP.

(T3550) This statement remained unqualified during his

lengthy re-examination by Mr Bennett QC a few days later.

At T3582 he said that the risks incurred from drilling operations "are out-weighed by the scientific advantages of

allowing the search for oil."

1.13.10 Dr Maxwell had earlier given evidence on sedimentation

which Dr Chapman claimed conformed in its entirety with his

views. Dr Maxwell said (Exhibit 2 p.224) that three types of

information support the view that negligible sedimentation is

299

occurring on the Reef, namely (a) large areas of the marginal

shelf reef zones have hard sediment-free floors, (b) bathymetric

and sedimentary analysis concerning ancient strandlines and

strandline deposits and (c) echogram patterns - by using a low-

frequency sounder it is possible, he said, to obtain deeper

penetration of the bottom sediment and to produce a reflection

from the hard surface under-lying the unconsolidated sediment.

He said that a traverse along the central part of the inner

shelf from Cairns to the Whitsunday Group had shown that for

the greater part there was a sediment cover of less than 15

feet.

1.13.11 The seismic stability of the GBRP has been discussed

in the Principal Introduction supra.

1.13.12 But in the present inadequate stage of geological

knowledge of the GBRP (also discussed in the Principal

Introduction) the Commission is not prepared to agree with

Dr Chapman's positive view that operators within the GBRP

are unlikely to encounter abnormal formation pressures. It

may be observed that, in two of the four gas blowouts which have occurred in Australian off-shore drilling operations,

abnormal pressures were present. In any event although

abnormal pressures tend to increase the risk of blowouts

because they test the skill and care of drilling personnel

and the efficiency of equipment and safety devices, blowouts have occurred with normal and with sub-normal pressures.

(ii) Hole not kept full of mud

1.13.13 The absence of abnormal pressures does not of course mean that risk of a blowout is eliminated. As has been shown

earlier, there are many other hazards and situations which are

potential sources of blowouts. One of these is the failure to maintain at all times the hole full of mud of the correct weight

in order to maintain primary control. Loss of circulation may

arise from a weakness in the formation which permits drilling

300

mud to run away to such an extent that circulation back to

surface ceases. A paramount requirement is to watch the

mud level in the tank and to have modern warnirtg systems

visual and audible. In most cases a lost circulation zone

can be dealt with by adding to the mud some solids which

can be of a curious variety. (T2655-6) But primary

control may be lost if supplies of lost circulation materials

kept on hand are insufficient. Loss of circulation may also

result from the piston action described by Mr Thomas as

resulting from running in the drill string too fast and

thereby creating a pressure surge ahead of the bit and

creating a piston effect.(T2643 quoted and referred to earlier)

1.13.14 In the same way swabbing of the well while withdraw

ing pipe (said by Mr Thomas to be the most prolific cause of blowouts) can produce a loss of circulation result because a

vacuum may be created below the bit into which hydrocarbons

if present may flow.(T2643)

1.13.15 Failure to fill up with a correct quantity of mud

when removing a drill string (as in the Santa Barbara blowout) or to observe and take appropriate action to meet a thief zone,

or failure to watch the mud level when circulation is suspended

for maintenance work and in general failure to keep the hole full for any other reason may all lead to dangerous situations

as the case histories of blowouts given by Mr Thomas and

referred to in the answer to TR4 exemplify.

1.13.16 Coring is a necessary operation when exploring but

some risk can be thereby incurred as by swabbing and Dr

Chapman said (T3517) that a number of blowouts around the

world have been caused indirectly by coring. He said:-" ... If you have cut a core you have in effect a solid piece of metal and rock in the hole which,

as you pull it out, can act as a piston and suck

301

in the formation fluid while displacing the mud,

whereas if you always core in a size smaller than

the hole you are drilling, the maximum extent to

which you can do this is over the length you have

cored.

This may be 10 feet or 12 feet.

... The risk of swabbing the well in, if you core

in a size smaller than the hole that has been

drilled, is reduced virtually to nil."

The Barracouta blowout (paragraph 4.6.11) occurred while coring.

Coring consists of replacing the bit by a special

core head which allows the driller to cut and remove from the bottom of the hole a cylindrical piece of undisturbed

formation up to sixty feet in length by four inches in diameter

a close examination of which by a geologist or engineer with

the appropriate apparatus can yield vital information.

(ill) Inadequate mixture or weight of mud

1.13.17 Inadequate mud mixture resulting from miscalculation

or careless mixing, was a possible cause of the Marlin A7 blowout, (paragraph 4.6.8) Absence of barytes or any inability

to provide heavier mud promptly could be of critical importance in some circumstances.

(iv) Kicks

1.13.18 A drilling break frequently precedes a kick which is a warning requiring immediate corrective action if primary

control is to be retained.(Part 6 paragraph 1.6.1. supra) Ignoring a break can be particularly dangerous if

the fluid is gas because it expands rapidly as it rises and

pressures decrease. The presence of such gas will reduce the

weight of the mud column and thus enable more fluids to enter.

1.13.19 A rig engaged in exploratory drilling is fitted with

modern detection systems to which reference has earlier been made.

302

Instant detection of changes of mud level in the tank

whether up (a kick - due to sudden influx of formation fluids)

or down (possibly a thief zone) is of the first importance.

The Marlin A7 blowout (paragraph 4.6.8) is an example where

an incipient blowout situation was not detected nor was the

blowout prevented due either to inadequate detection

equipment or individual negligence or both. However not

every kick is preceded by a drilling break and another crew

might receive no warning. Lessons from the Marlin A7 which

took place in December 1968 were said by Mr Lipscomb (Esso

Area Production Manager) to have resulted in the following

improvements: (a) top level supervision when drilling into

potential reservoirs, (b) a smaller tank - i.e. one more

sensitive to changes in mud levels and (c) greater attention

given to drilling breaks.

(b) Loss of secondary control

1.13.20 This subject is dealt with in Part 9 supra. The

causes include (i) inability to close BOPs, (ii) inability

to insert internal BOP, (iii) failure of BOPs, and (iv) failure of well head or casing.

1.13.21 These situations may in turn arise from (i) bad

design, (ii) unsafe practices, (iii) inadequate testing,

and (iv) equipment failure.

1.13.22 Usually human error will be involved as indicated

in the references to various blowouts and their causes given

in Part 6 of the answer to TR4. Two of the examples there given will be sufficient to illustrate: (a) the draw works disconnected from the drill string for some purpose of

maintenance. This should never occur whilst the BOPs are obstructed. (b) due to miscalculation a well being drilled for

Shell in the North Sea penetrated the casing of another already

completed.

303

1.13-23 But combination of circumstances can occur In a loss

of secondary control situation in which no blame could be

assigned to anyone.

1.13.24 This is dealt with in Part 9 paragraph 1.9.8.(supra)

Any natural tendency towards a formation weakness in the

neighbouring area outside the well can be aggravated with

blowout effects by unskilful casing programmes, drilling too

many wells too close together from the one platform and allied

causes deriving from human error. Blowouts due to such causes

have been referred to in the answer to TR4.

(d) External forces and fire

1.13.25 These are discussed in Part 12 paragraphs 1.12.2 and

1.12.7 (supra).

External causes include cyclones and collisions.

Fire is more likely to occur at the production stage

(e.g. the Chevron dealt with in paragraph 4.6.13) but cannot be ruled out at the drilling stage. A blowout from some other cause may result in a fire which then causes blowouts from

neighbouring completed wells. There are various ways in which fires may originate.

(e) Chronic pollution 1.13.26 This subject is dealt with in detail in Part 11 supra

This is more likely to occur during production than

when drilling yet much damage during the drilling stage can be

done by oil cut muds, cuttings, sand, sludge, diesel oils, unwanted metal, bags and garbage. Depending on the particular locality of the permitted drilling, this type of damage could and probably would in more or less degree be more severe on the environment and its marine life in the GBRP than in say the

Gulf of Mexico or the North Sea.

(f) Human error

1.13.27 No summary of the causes of oil spills could omit

human error which is by far the most common cause. It has

been discussed in several places earlier, for example at the

beginning of this Part 13-

(B) Production Stage

(a) Failure of production processing and safety

controls

1.13.28 The subject of production processing and controls

including gas-liquid separation and sub-surface safety

devices were examined in Part 10 supra.

A further brief reference to these controls will

now be made because there are many such controls on an off

shore production platform and, as with other mechanical and

electrical devices malfunction will occur from time to time.

But although the evidence on production controls given by

Mr Lowd was extensive, no evidence was led of the occurrence

of any incident or spillage of oil as the result of such

malfunction: The necessity, however, of remote control of safety devices has been stressed elsewhere particularly in the

answer to TRM.

1.13.29 Mr Lowd began by identifying two different types

of controls (T3293):-"a. Process controls, which are essential to

the normal, minute-by-minute control of

process variables.

b . Safety controls, which must perform preventive, corrective and informative functions in the event of an off-normal or potentially dangerous

situation." He went on to outline what he described as: -

" ... some of the process and safety controls

which a prudent operator will use on a typical

305

off-shore oil producing facility to ensure

safe operation and to deal with all possibilities

of environmental pollution."

He said:

" ... the basic segregation of a raw petroleum

wellstream into saleable oil and gas, and the

removal of unwanted contaminants, such as water

and sand, takes place primarily in pressure

vessels, such as separators, surge tanks and

stripping columns. Proper functioning of the

physical and chemical processes occurring in

these pressure vessels requires that certain

physical variables be held constant or within

specified allowable design limits.

Typical process variables are:

a. The pressure within a vessel.

b . The temperature within a vessel.

c . The height of various liquids within a vessel,

or the position of the interface between two immiscible liquids, such as oil and water.

d. The rate of flow of oil, water, gas, chemical solutions or contaminants entering or leaving

a vessel.

The function of process controls is to monitor and regulate these four variables ..."

As regards safety controls he said (T3294):-

"Safety controls are in most instances identical to

process controls in that they monitor pressures, temperatures, liquid levels and flow rates. The

basic difference is that their output signal is not

essential to the fundamental operation of the process. Rather, the signal is used to perform a

preventive action, a corrective action, or an

informative action.

a. Preventive actions are those such as sensing an

abnormally rising liquid level in a process

vessel and closing the inlet valve through

which fluid is entering the vessel, thus

PREVENTING an emergency high level from

occurring.

b . Corrective actions are those such as sensing

a pressure that is too high and opening a

valve to relieve the excess pressure, thus

CORRECTING the abnormal condition.

c. Informative actions are those which INFORM personnel that an abnormal or emergency condit

ion exists or has existed."

1.13.30 He then gave details of the "control theory"

(T3294).

He said that all controls whether process or safety,

and whether for pressure, temperature, liquid level or flow

rate must have a sensing element, a logic element and a final

control device (T3294) and he elaborated each of these.

Then he spoke of the control system known as "fail

safe". Of this he said (T3295-6):-"It is commonly understood and accepted in the

petroleum industry that control systems must be

designed so that in the event of failure of any part of the control system, the controlled process

will remain in a safe condition. This is expressed by the term 'fail-safe'.

For example, if a level control monitoring high liquid level in a vessel should fail because of

loss of control supply gas, the producer wants

the control action of the final control element to be such that the liquid level can go no higher. This means that level control failure must close

the vessel inlet valve.

By selecting a normally-closed valve (one requiring

a control signal to open it), loss of the control

signal would cause the valve to close on its own

307

accord. Therefore, we say the control system is

'fail-safe ' . "

1.13.31 Mr Lowd went on to explain that a complete off-shore

production facility would have many process vessels and hundreds

of controls and valves. He gave details of one small but

important section of the process namely that which takes the

well fluids from the well head through the flow line, the

production manifold, and finally through the production

separator where the wellstream fluids are disengaged from one

another and discharged as oil, water and gas. (T3297)

1.13.32 As to this chosen section he gave details of the

so-called process controls and later of the safety controls.

The following short excerpts are taken from this evidence:-"We will examine first the so-called PROCESS

controls, describing their functions and

exploring what might happen if they should fail.

Later we will examine the SAFETY controls and

see how they are capable of dealing with failures

of the process control systems ...

The OIL OUTLET. VALVE on the production separator

is controlled by a liquid level controller which

monitors the height of oil within the separator.

This valve is normally closed and will not open

unless it receives a pneumatic signal from the

level controller. (T3297) ... If this valve (meaning the oil outlet valve)

failed in the open position, all the oil would be

free to leave the separator, and a LOW-LEVEL alarm condition would exist. If the valve failed in the closed position, no oil could leave the separator

and the oil level would increase. This would cause

a HIGH-LEVEL alarm condition - It may mean there is

a bell ringing, but we are using the word 'alarm'

simply to mean an anomaly is present, a problem

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situation has developed ...

The WATER OUTLET VALVE on the production separator

is controlled by an identical type of level

controller, which monitors the height of water

within the separator.

... The GAS OUTLET VALVE on the production

separator is controlled by a pressure controller

which monitors pressure within the separator.

(T3 29 8) ... The remainder of the controls ... are SAFETY

controls, not absolutely essential to the process

but necessary to insure safe operation and deal

with all possibilities of environmental pollution.

The WELL HEAD SHUT-IN VALVE is located on the well head, immediately downstream of the manual shut-in

valve. This device is commonly called a high-low

shut-in valve because it automatically closes when

pressure in the flow line is either abnormally high or low. This valve is spring-loaded normally-

closed and requires a positive pneumatic control

signal to hold it open.

... This valve cannot re-open itself; someone

must actually go to the valve and manually reset

the controllers.

... The SEPARATOR INLET VALVE is also a normally-

closed valve requiring a positive pneumatic control

signal to hold it open. Loss of the control signal or loss of supply pressure will cause this valve

to close (T3299).

Four controllers, monitoring high and low separator

liquid levels and high and low separator pressures

are installed ... (T3300) ... The previously described safety control devices

will monitor any of these abnormal conditions and automatically eliminate the potential man-made

hazard." (T3303)

309

1.13.33 In summarising his evidence on production process

controls, Mr Lowd said (T3307):-"Typical product design of facilities will assure

that failure of any part of the processing facility,

or failure of either control system leave the

platform in a SAFE condition. It will, in most

situations, result in the SHUT-IN of all the

affected wells at the well head."

1.13.34 The general conclusions of Mr Lowd on the efficacy of these various controls should be set forth in some detail.

At T3307 he was asked:-"Is there any situation in which there could be a

significant escape of oil or gas from the system

without the shut-in of the affected well?" to which he replied:-"No. Anything that would involve a significant

release of gases or liquids to the environment

would result effectively in the shut-in of the

well. I say effectively because under, let us say, some serious condition where one of the

well head valves itself might not shut in, there is another valve ... in front of the separator,

and down through the manifold, and that would shut,

and one or more of these, some place, would always shut in in this case."

1.13-35 Of this passage Mr Jeffrey QC (for A.P.E.A.) said (T16876):-"It has to be said at once that Mr Lowd was there

speaking of the best equipped production platform which the existing world technology can at the

present time provide. It must be acknowledged

also that over the 20 or 30 years of significant

off-shore production of petroleum not all production

facilities have anywhere attained this level of

310

safety control.

Of course, the Commission is directed to take

into account existing world technology and that

is why it is permissible for us to look at the

highest technical standards which industry in

this area is capable of attaining."

The Commission agrees with Mr Jeffrey's comments

but a residue of risk though small relating to processing

and safety controls must be deemed to remain.

1.13.36 It should be added that earlier, under "Emergency situations during production-" (paragraph 1.10.28) attention

has been given to the possibilities of failure in relation to

various valves and controls and Mr Lowd's evidence was the

source of the Commission's remarks therein.

(b) Failure of sub-surface safety devices

1.13.37 This subject was mentioned in paragraph 1.10.29 supra.

In addition to the various controls designed to

lead to the shutting in of the well at the manifold immediately

downstream of the Christmas tree - and in an emergency the

valves on the Christmas tree itself can be closed manually as

was done by Messrs Lipscomb and Beall in the Marlin A 4

incident of 19 May 1971 - there are down-hole safety devices which must be fitted in every producing well. These should

shut in automatically in the event of a change in pressure or in rate of production.

In the case of the Shell fire of 1 December 1970 a

number of these valves failed to operate, apparently when the well heads collapsed and the casings became crimped. In the case of the Chevron fire of 10 February 1970 it appears that

sub-surface safety valves had been removed from 136 wells in

the Main Pass Block 41 field at various times without an approved waiver and were not in the wells at the time of the

fire on "C" platform (T6988). Other serious breaches of OCS

311

Order No.8 were also discovered (T6989).

The Chevron Oil Company was fined $1,000,000 in

respect of 500 of these breaches (T6925).

1.13.38 Mr Thomas gave examples of the effective operation

of these sub-surface safety valves which of course must be

tested at regular intervals and replaced if necessary. He said

(T2808):-"On two occasions in Lake Maracaibo, Venezuela,

well heads were struck by passing tankers. Our

method of completion in the lake was a single 30

foot platform for each single well. The well head

itself was not struck by the ship, the platform was,

and on one occasion the flow line connection at the

well head was shattered; on the other occasion

merely the line to the ball valve itself was

shattered. On both occasions the wells immediately

closed themselves in. In the shattering of the flow

line, there was a very small spillage of oil; I have

no idea of the quantity, but probably only one or two barrels. But the valves functioned."

1.13.39 It can be said therefore that well conditioned and

periodically inspected sub-surface safety valves are essential

in the avoidance of hazards and production incidents. In addition to working automatically they must have remotely

situated manual controls. The subject of surface controlled sub-surface safety valves is considered in the answer to TR4.

1.13·^0 This process was described in Part 8 paragraph 1.8.12

supra ("The Christmas tree, the lubricator and wirelining").

The use of wireline tools is an important facility for the operator.

"The well is not 'killed' and the(maintenance)

operation is performed under pressure conditions

312

through the use of a lubricator - or pressure

lock - installed atop the well head and of

sufficient length and strength to accommodate

the necessary tools and withstand the full

well head pressure." (T3318)

However the process contains hazards since the

lubricator gland is a less secure container than a valve in

the production tubing or the Christmas tree. The Marlin A 4

blowout (described in paragraph 4.6.9 infra) illustrates this.

(d) Workovers

1.13.41 This type of necessary maintenance work is

described in Part 8 paragraph 1.8.19 supra in which the

accompanying potential hazards are also discussed. The Shell

fire and other blowouts described in the answer to TR4 illust

rate some of these hazards.

(e) External forces and fire 1.13.42 These include cyclones and collisions and some

types of fire. The hazards are discussed in various paragraphs

of Part 12 (supra).

As pointed out in paragraph 1.12.17 supra fire is

more likely to occur at the production than at the drilling

stage.

(f) Chronic pollution

1.13.43 This subject is dealt with in detail in Part 11

(supra).

In most of its forms it is more likely to occur

during the production than the drilling stage although several types of chronic pollution can occur during the

drilling stage and in all cases the hazards of chronic

pollution are such as to make governmental control by

regulation, direction or terms of lease imperative.

313

(g) Storage failure

1.13.44 The hazards of storage failure are In general

peculiar to the production stage. They have been described In

paragraph 1.11.29 of Part 11 (supra).

That hazards from such source exist was conceded by

Mr Lowd and Illustrations of loss of oil from storage were given

by Mr Keith although they were few in number.

(h) Tankers, barges and flexible hoses

1.13-45 These are dealt with in paragraphs 1.11.74 et seq

of Part 11 (supra).

Failure to observe leaks, faulty hose connections, failure to adjust valves properly and voice control ("shout and

holler") have from time to time led to spillages. Allowing oil

to overflow (in some cases for appreciable periods) has also

caused spills whilst the process of uncoupling the hose is one in which minor spills can occur.

1.13.46 In transit ballast water may be released at or near

the loading point. This must be rendered virtually oil free by

use of the "load on top" technique to which earlier reference has been made.

1.13.47 Another consideration especially in relation to the waters of the GBRP relates to associated navigational hazards. Something will on this aspect turn on the location of the

production site. As has been pointed out earlier Reef waters are often not deep and currents can be strong and weather

uncertain. Clearances may be reduced near reefs and islands

by the movement of large bombies or niggerheads - coral boulders - following storms. Any repetition of the 'Oceanic Grandeur' incident involving as it did the loss of many tons of

oil into the sea (T14029) could be particularly damaging if it occurred in the more southern waters of the GBRP.

314

(i) Pipeline failure

1.13.48 Pipelines are dealt with in paragraphs 1.11.48 et

seq of Part 11 supra.

The risks of pipeline failure are just as apparent

as those of storage failure. In practice they have proved

to be more significant and large quantities of oil have

escaped into the sea on a number of occasions in various

places in recent years. Mr Keith tabulated a substantial

number of these and they are set forth at T5581 to T5586.

(j ) Human error

1.13.49 As in the "Drilling Stage" (supra) the most common

of all causes of oil and gas spills during the production

stage, namely human error, must be included in a summary of

causes. See (for example) Paragraph 1.13.1 of this Part.

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PART 14 - THE ANSWER TO TR1

Introduction to answer

1.14.1 From the foregoing it is clear that a blowout can

occur only if there is a combination of circumstances. There

must be a natural condition (namely the presence of hydrocarbons)

combining with either an equipment failure or a human failure or both.

1.14.2 Both primary and secondary control must be lost.

Human error has been by far the main cause of blowouts but

occasionally equipment failure has been a contributing cause.

External and natural forces have caused or contributed to

drilling and production incidents.

1.14.3 World technology is improving although the number of

major improvements effected in recent years has been small.

Lessons learnt from past experiences and blowouts have however

been incorporated into improved drilling procedures and

improved safety precautions and warning and safety devices.

There appears to be a general recognition by the industry of

the necessity for improved training standards of drilling personnel. A world wide governmental recognition of the

necessity for modernising the control and regulation and the

supervision of all operations has been demonstrated for example by the amendments made to the American OCS (Outer Continental

Shelf) "Pacific" Orders made after the Santa Barbara blowout and the draft regulations (Exhibit 68) prepared by Australian

authorities in 1969 and in respect of which we have made many

recommendations for amendment and improvement in our answer to TR4. These recommendations have derived directly or indirectly from the evidence given before us, and our assessment of the

risk is based on the assumption that these and other recommend ations appearing in our Report are adopted.

316

1.14.4 The Increased sense of responsibility of the

industry derives no doubt in part from the enormous expense

involved when blowouts occur (we were told that the cost of

the Petrel gas blowout off the north-west of Australia

aggregated $15 millions) but partly also from a growing

recognition by the industry of its duties to the environment.

This has been illustrated by the contingency planning of the

Esso-BHP group which began some years ago and which is

evidenced by Exhibit 174. (There is now an all-industry plan

produced by P.I.E.C.E. - Petroleum Industry Environmental

Conservation Executive referred to in Part 3 of the answer to

TR4). The industry has advocated to us its sincere belief in

the doctrine of "co-existence" .

1.14.5 The risk of a gas blowout is greater than the risk of an oil blowout as both the overseas and Australian

statistics illustrate. The reasons for this are set forth in

Part 2 paragraph 1.2.2. supra. At the time the Commission .rose

to prepare its Report, the evidence showed that the ratio of off-shore gas blowouts (there had been four) to successful gas wells sunk off-shore in Australian waters was 1 1 %. This high

percentage has now decreased somewhat as since the hearing ended there have been newspaper reports of some additional and

successful off-shore gas wells sunk apparently without incident.

The evidence showed that lessons have been learnt and improve ments made both in drilling procedure and in the taking of

safety precautions since these blowouts occurred. Moreover if our recommendations for the improvement of Exhibit 68 made in

our answer to TR4 are adopted, the risk should be appreciably

reduced.

1.14.6 There had been no off-shore oil blowouts from a

total of 88 successful oil wells drilled in the Australian

Continental Shelf as at March 1972. The overseas figures

were recognised as incomplete and indeed a full record was

said to be unobtainable.

317

1.14.7 In off-shore drilling in the U.S.A. the evidence

appears to show that the percentage of oil blowouts to success

ful wells drilled in recent years up to 1969 was about 0 .13? or

as Mr Jeffrey QC put it about 1 or 2 per 1,000 wells, but three

major blowouts occurred in American waters since 1969·

1.14.8 It might be thought that the progress which has been

made and which is still being made in world technology in

relation to safety precautions would have the ultimate and not

far distant result of eliminating all risk but with this the

Commission cannot agree. One only has to turn to the very

recent fires and blowouts experienced in U.S.A. and Australian

off-shore waters by some of the largest and wealthiest oil

companies in the world to be forced into acceptance of the

proposition that a risk of blowouts however small will ever

remain. As Mr Woodward QC said in his final address to the

Commission: " ... the more recent Shell fire is disturbing

in its implications - that the most modern equipment cannot always prevent a major oil

spillage from a production platform."

1.14.9 The reason for the permanence of the risk is that human error seems incapable of being entirely eliminated in

most forms of human activity - and successful petroleum drilling if it is to be free of incident requires not only well-designed, efficient and well-maintained mechanical

equipment and safety devices but the sustained vigilance and

skill of highly trained drilling personnel.

1.14.10 It is to be borne in mind also, that within a

comparatively short time of petroleum being discovered in commercial quantities within the GBRP there would probably be

a multiplicity of wells in various localities of this vast area with attendant barges and tankers and/or pipelines.

Although it is not suggested that the degree or measure of

318

risk is a mathematical factor of the number of wells

nevertheless the larger the number of wells the greater must

be the risk. Perhaps more importantly the larger the number

of wells the greater the risk of a degree of chronic or

random pollution.

1.14.11 The evidence as a whole tended to indicate that

drilling in the GBRP would be unlikely to involve the

encountering of such special hazards of nature as tectonic

instability and gas reservoirs of great vertical thickness,

but on this aspect and perhaps especially in respect of

another hazard, discussed by some witnesses, namely the

absence of abnormal formation pressures, it would be inadvisable to express any firm or confident views because

the evidence showed that geological knowledge of the GBRP is inadequate, that seismic surveys have not been made of a

large part of the GBRP and that all wells hitherto drilled in

this vast area could be numbered on the fingers of one hand.

1.14.12 The geographical and hydrological features of the GBRP are however appreciably different from those obtaining

in most of the off-shore areas elsewhere around Australia and

in most overseas waters.

Currents can be strong, cyclones occur and much of

the water is comparatively shallow. A large number of reefs

and islands exist and depending on the locality there can be

navigational hazards. These and allied factors make special

claims on the design and stability of the platforms and on

drilling skill and equipment and also on the method selected for the collection and transportation of the crude oil to shore receiving depots, whether by pipeline or tankers. Thus

ship-shape floating rigs of the type which was about to be

used in Repulse Bay at the time the Commission was established seem inadvisable however economical for large scale explorat

ory work their use may be in such a large area as the GBRP.

We have elsewhere made a recommendation against their use in

319

any GBR locality but this recommendation is not intended to be

inflexible - see paragraphs 1.4.8 and 4.6.23· These factors

are considered to affect the risk factor generally.

1.14.13 Although the types and causes of risk differ between

the drilling and the production stages and therefore for

practical reasons we have summarised the causes of spills

during these stages separately (see paragraph 1.13.4 supra),

there seems to be no point in attempting to assess the risk

separately because it is the totality of risk which is the

subject of the enquiry and in any event you can't have

production without drilling or - generally speaking - success

ful drilling (which is the only type under consideration)

without production.

1.14.14 The various ways in which human error has manifested

itself in the loss of primary and secondary control have earlier

been stated and discussed. We have also made it clear that some necessary operations both in the drilling and production stages

(the workover, testing, wirelining, to quote but a few) contain

potential hazards if there is any departure from high standards

of skill and care. Inadequate design and maintenance of

equipment and defective casing programmes also contribute to

the hazards as the history of blowouts demonstrates.

1.14.15 External forces and storage failures, abnormal formation conditions and the risk of fire are other components

of the total hazards. Failure to install ultra-modern platform and sub-surface safety devices and operational mistakes

such as failure to hang-off, failure to open the choke line,

failure to test BOPs properly, an inability to close a BOP, and generally any inability to take prompt action when an emergency

situation suddenly presents itself, are amongst the proved contributions to the quantum of risk which must be considered

when risk is being assessed.

320

1.14.16 Theoretically, all the various ways which give rise

to risk must be given weight in order to make an overall

assessment of risk, but as earlier quoted, Mr Woodward QC said in his final address : -"There is a danger that reference to the number

of ways in which mishaps can occur may lead to

an unduly gloomy view of the risks involved in oil drilling."

1.14.17 One way to redress the balance is to recall the

ratio of actual blowouts to successful wells drilled over the

years. But in turn statistics do little more than give an

impression of risks because (and again we adopt Mr Woodward's words):-"(a) standards of competence and of governmental

supervision vary from place to place and from time to time;

(b) technology advances with steady strides;

to tackling more difficult engineering feats; (d) off-shore drilling presents some special

difficulties which vary greatly with depth of water and other local conditions; and finally

(e) the risks of gas blowouts are very much

greater than those of oil blowouts (although

of course an initial gas blowout may become an oil blowout, as at Santa Barbara)."

1.14.18 Although with proper equipment, proper governmental supervision and control and proper training of personnel

chronic and random pollution should and can be reduced, yet in the view of some expert witnesses including Mr Lowd (Vice

President of the National Tank Company of the United States)

chronic and random pollution present a greater threat to the

environment than occasional instances of "aggravated" pollution,

321

i.e. blowouts and major oil spills.(T3259) If correct this

would apply In much stronger terms to the GBRP than (say) to

the Gulf of Mexico because of Its many eco-systems and the

presence of so many coral reefs and Islands.

1.14.19 As we have earlier shown (Part 11 supraX the ways In

which chronic or random pollution can occur are numerous. Some

are the result of deliberate action, some are the fruits of

negligence or lack of skill and some can and do occur without

any carelessness or default. The compilation and enforcement

of statutory and regulatory controls together with the insert

ion of appropriate terms and conditions in all drilling leases

should contribute to reduction of risk of such pollution.

1.14.20 During the drilling stage such sources can include

the disposal of drilling mud, sludges, sand and chemicals into

the sea. Various types of garbage and industrial wastes such as unwanted metal and bags if disposed of into the sea would

be more undesirable in the GBRP than in more open waters. The

disposition of oil-cut mud and cuttings ( a necessary product

of petroleum drilling) are included amongst the hazards. In

our answer to TR4 we have recommended that except in three specified cases and then only with governmental approval no

substances of any type whether solids or liquids should be allowed to be disposed of into the waters of the GBRP.

1.14.21 During the production stage the risk of chronic

pollution is greater than during the drilling stage (Part 11 paragraphs 1.11.3 et seq). Separated water discharged over

board from the production platform, gases (which may contain hydrogen sulphide), storage failure, pipelines, tankers and

hoses (used during the reception, collection and transportation to shore operations of the production stage) are all potential

sources of chronic pollution, as the records of petroleum drilling and production clearly show. As regards tankers it

should be added that they are also regarded as a major cause of

322

massive spills - see paragraph 4.7.2. Other hazards have

proved to be cyclones, fire and collisions.

1.14.22 A platform designed in accordance with the best

standards of existing world technology will have safety controls performing corrective action and should ensure that

in the event of failure of any part of it the process will

remain in a safe condition. Data necessary for the establish

ment of a satisfactory design for platforms include ocean

current profiles and directions, wave and wind magnitudes, long

and short-term storm characteristics and sea bottom elevation

contours. In many localities within the GBRP such data does

not presently exist and as has been elsewhere recommended

platform construction and drilling should not be permitted in any locality until proper surveys of that locality

sufficient to furnish the necessary data shall have been made.

A similar recommendation has been made with regard to the siting and construction of pipelines.

1.14.23 As an illustration of the effect of proper control

systems it was said that anything that would involve a significant release of gases or liquids to the environment

would result in the well being "shut in". A significant leak of oil in a flow line should cause a sufficient decrease in

pressure to activate the well head shut-in valve.

The answer to TR1 1.14.24 In arriving at our answer to this TRl we have taken

into account world technology as examined in earlier Parts and

the safety precautions discussed and recommended in our answer

to TR4 (infra) and we have endeavoured to give due weight both to statistics and the various hazards of exploratory drilling and production which we have enumerated and discussed above.

As indicated earlier the phrase "oil or gas leak" appearing in TRl has been construed as meaning and including

both catastrophic blowouts and chronic (and random) smaller

323

spills. The nature and causes of all types of such spills

have also been examined.

We will answer the question under the two headings,

namely "Blowouts" (which will be deemed to include fires) and

"Chronic and Random Spills."

The form of the question would not appear to require

us to assess separately the risks of oil and gas blowouts. On

the evidence the risk of the former is less than that of the

latter, although as the Santa Barbara blowout evidences, a gas

blowout can develop into an oil blowout.

Our answer cannot be given in precise or mathematical

terms because the degree of risk (and the quantum of any

pollution) will vary with and depend inter alia on such factors

as (a) the care and skill of drilling and production personnel and of all concerned with the collection storage and transport ation of oil from the well to shore, (b) the design, inspection

and maintenance of all equipment, (c) the efficiency of

governmental regulation and supervision, (d) the number of wells, and (e) external forces. We have assumed that our

recommendations relating to safety precautions as summarised in Part 10 of the answer to TR4 will substantially be adopted.

We answer the question as follows:-A . Blowouts If petroleum drilling be permitted within the GBRP,

there will be and remain a real but small to very small risk

of blowouts.

B . Chronic and Random Spills It is almost certain that some measure of chronic

and random spills and leaks of oil will from time to time occur. The amount of pollution caused thereby will range from small to

substantial, that is to say from a few gallons to hundreds of barrels - or more if a leak from a tanker during loading

operations near the production site occurred.

324

TERM OF REFERENCE NO 2

"What would be the probable effects of

such an oil or gas leak and of the subse

quent remedial measures on:-(a) the coral reefs themselves

(b) the coastline

of life In the area?"

Preface

The Interpretation placed on this term of reference

Is to be found in paragraph PI.3â 4 and the nature and sequence of the subject matter treated in TR "2, are set out in the

Table of Contents.

In summary, the subjects dealt with bear on the

following questions:

What are the compositional characteristics of crude

oils and their physical and chemical properties; when oil is spilled at sea how does it behave; in what ways is it changed with the passage of time and for what reasons; what are the

effects of oil on marine organisms and eco-systems when fresh ly spilled and in its successive stages of change (weathering);

and to what extent are these effects influenced by the differ ing physical states in which oil may be presented to organisms

and by the differing vulnerability to oil exposure of the many

kinds of situations inhabited by marine organisms?

Parts 1-6 review these questions mainly in the light

of the large body of information given to the Commission which derives from overseas experience of the nature and effects of

oil releases on marine life mainly of temperate waters.

Parts 7 and 8 review more briefly the nature and

effects of gas releases and of the various remedial measures that have been used to mitigate the adverse effects of oil

325

spills.

Part 9 gives preliminary consideration to the prob

able effects of oil and gas releases (should they occur in the

area of the Great Barrier Reef) and makes use for purposes of prediction, where in the opinion of the Commission it is justi

fiable to do so, of information and data drawn from Parts 1-8.

In Part 9 some account is also given of information reported in

evidence that bears directly on some special conditions obtain

ing within the GBRP that are relevant to the answer, and re

views the few experiments and observations on the effects of

oil that have been made on corals and other GBRP organisms.

Part 10 contains the answer to TR2.

PART 1 - CRUDE OILS - THEIR COMPOSITION AND PROPERTIES

(a) Chemical composition 2.1.1 The following account derives, mainly from the evi

dence of Professor Clark (T 3598 et seq), Mr Keith (T 5534-5)

and Dr Connell (T 7015-7043).

Crude oils are formed by the decomposition in buried sediments of animal and vegetable remains. They consist almost

entirely of hydrocarbons that at normal temperatures and pres sures may be gaseous, liquid or solid according to the complex

ity of their molecules, and which may contain from 1-38 carbon atoms combined with varying numbers of hydrogen atoms, and in a

variety of molecular shapes. The carbon atoms may be linked

together to form straight chains, be joined together in single or multiple systems of triangles, quadrilaterals, pentagons or hexagons, and be branched or unbranched. They may be sc de

signed with a sufficiency of hydrogen or other types of chemi

cal attachments as to be in some measure resistant to chemical

change in which case they are said to be 'saturated'. 'Unsat

urated ' compounds which are chemically more active and change able also occur in crude oils. Straight chain hydrocarbon

molecules are referred to as normal paraffins, branched chain

paraffins as isoparaffins and ring type structures as cyclo paraffins or naphthenes. Only saturated molecules of these

326

three types, together known as alkanes, are found In crude oil.

A further class of compounds present in crude oil are ring com

pounds made up of single or joined hexagons with or without

side branches. These substances are known as aromatics.

2.1.2 Various other compounds and substances may be present

in oils as impurities. They include sulphur compounds, nickel and vanadium. There is a considerable variation in the sulphur

content of crudes from different basins and regions of pro

duction. Figures given by Mr Keith (Exhibit 415) show Austra

lian crudes to be low in sulphur content (0.03-0.13% by weight)

with Kuwait and Boscan (Venezuela) crudes,amongst the oils

listed,having the highest sulphur loadings of 2.53% and 5-0%

respectively.

2.1.3 Mr Keith in a supplementary statement (Exhibit 415)

to his main testimony, included a table which set out the per

centage by volume of paraffins, naphthenes and aromatics

found, by analysis, to occur in different boiling point range

fractions of crude oils of different provenance. The follow

ing data are abstracted from Mr Keith's table in respect of

the 8 oils (out of a total of 15) which were fully analysed.

They are presented in a somewhat different form from Mr Keith's

arrangement.

327

r £ c t i u m c t i

o 0

1 cti

£ c t i â¢ H

£ c ti

m c t i £ â¢ H Santa

Barbara

King-fish

- P £

â¢ H r —1 c t i ! £

â¢ H

£ O O

Spec. Gravity 0.^7 0 , .852 C ).850 0.^51 0.888 0.797 0 . ,8l4 ( -=r 0 C O

Volume % Butane & Lighter

2.5 1.6 2.5 0.7 1.7 2. b 2. b U .p

Gasolene . â _

fraction C 5 - 375 F

25.5 26.9 26.8 14.8 24.0 40.2 33.1 39-1

Volume . ,

paraffins 18.6 20.1 17.7 8.9 12.5 21.7 16.6 22.5

15.6 naphthenes 4.3 3-8 5.6 5.4 10.3 15.3 13.9 aromatics 2,6 3.0 3-5 0.4 1.2 3.2 2.6 1.0

Kerosene fraction 375-450 F

8.0 8.2 7.7 6.5 7.0 8.4 7.7 10.5

Volume , â

paraffins 4.3 4.8 3.7 3.2 2.0 4.5 3.5 4 . b

naphthenes 2.1 1.8 2.4 2.5 3.0 2.5 2.7 4.4

aromatics 1.6 1.6 1.6 0.8 2.0 1.4 1.5 1.3

Gas oil _ â .

fraction 450-600 F 15.8 15-3 15.3 14.0 13.5 17.6 19.6 19.4

Volume paraffins 7.4 6,6 7.5 7.6 2.7 9.5 10.4 9.5

naphthenes 4.5 4.4 3.8 5.0 6.7 4.2 4.5 6.6

aromatics 3.8 4.3 4.0 2.0 4.7 3.9 4.7 3.3

Heavy Distillate 600-1000°F 30.7 32.2 31.9 39-6 31-9 29.2 34.3 23.0

Volume aromatics Residue 1000 F

13.5 16.7 14.7 7.1 14.0 7.9 9.6 5.3

17.5 15.8 15.8 24.4 21.9 2.0 2.7 7.5

Cumulative aromatics up to 1000 F 22 25 24 10 21 16 18 11

NOTES: (1) The addition of the follows (a) + (b) (a) Cumulative paraffins

paraffins and. naphthenes results as

up to 600 F. 30.3 31.5 28.9 (b) Cumulative naphthenes 19.7 17.2 35-7 30.5 3b .« up to 600F .10.9 10.0 11.8 12.9 20.0 22.0 21.1 26.6

a + b 41.2 41.5 40.7 32.6 37.2 57-7 51.6 63.4

(2) The varied ratios of the several fractions in oils of

328

differing origin. Basrah, Minas and Santa Barbara, for example,

are classified commercially as heavy oils. Kingfish, Halibut

and Moonie (Australian) as light crudes.

(3) The different ratios of the paraffins, naphthenes and aromatic constituents. Kingfish, Halibut and Moonie are des

ignated commercially as paraffinic/naphthenic oils; Middle East

oils have a slightly higher aromatic content.

(b) Physical properties 2.1.-4 The physical properties of crude oils are governed

by the character of the substances contained within them and

the proportions in which they occur. It is necessary for our

purposes to enumerate some physical properties that are of particular importance in determining the behaviour of' oil when

leaked into the sea and in influencing the character and rate

of progressive changes in the chemical composition and physical

state of oil, through its inter-actions with the atmosphere,

seawater and marine organisms.

(i) Specific gravity In Mr Keith's words (T12046) "This gives a measure of the buoyancy of the crude compared to water." Seawater at

normal atmospheric temperatures has a specific gravity approxi

mating to 1.025. The SG of a number of crudes from different

sources (cited by Mr Keith (Ex 424) in terms of API units and

in Exhibit 415 in conventional SG units) vary from 0.797 for the very light Kingfish oil of the Bass Straits to the heavy

asphaltic Boscan crude (Venezuela) of SG 1.005. Most of the

crudes listed by Mr Keith are of SG 0.8 - 0.9. Since even the

heavier residuals of weathered oil such as tar balls (SG about

1.02) are a little lighter than seawater (Mr Cowell T11011),

oil in liquid sheets, water-in-oil emulsions, or in more solid

form will tend to remain on the sea surface unless weighted by

the attachment of sufficient quantities of inorganic particles

or organic debris heavier than water. In near shore areas and in shallow waters wave action and confused seas may contribute

to the sinking of oil.

329

(ii) Viscosity

Viscosity is "the resistance of a fluid to flow and

is an important factor in determining the eventual thickness of

a given oil film on water and the rate of spread" (Mr Keith

T12046). Mr Mansfield (T7184) dissected this definition a

little further. "Viscosity is not concerned with the ability

to spread. Spreading is determined, if one has a heap of oil, by the dissipation of the gravity forces and also at the peri

meter there are the spreading forces." (These were later des cribed as due to the presence in oil of surfactants, i.e. sur

face-tension reducing substances). "The gravity force and

spreading force determines whether a slick is able to spread.

The viscosity dictates, amongst other things, the rate at which the spreading will occur."

Generally speaking, the heavier oils are more viscous

than the lighter oils. The following examples taken from a

table headed "Physical Properties of Selected Crude Oils" (Mr

Keith Exhibit 415) illustrate this relationship. Boscan, Lagomar, Kuwait, Basrah, Iranian (heavy oils of SG 1.005-0.847) have viscosities (centistokes at 100°F) of 26,000-5.66. King- fish, Halibut, Moonie and Barrow Island (light oils of SG 0.834

0.797) have viscosities (centistokes at lOO^F) of 3.3-1-85- The viscosity of an oil, which decreases with increasing tempera ture, is therefore important in influencing not only the form

which an oil slick will take but the extent to which the oil is

rendered susceptible to evaporation, solution and dispersion,

(ill) Pour point Pour point "is the temperature at which the crude ceases to flow under given conditions. Generally a high pour point indicates a high wax content in the crude. If the water temperature is below the pour point of the crude, a spill is likely to form lumps rather than spread in a thin film" (Mr Keith T12046). Crudes of differing origin and composition show

a wide range of pour points. Mr Keith (Exhibit 415) gave

figures varying from -25° to 95°F e.g. Santa Barbara (-25°F), Kuwait (0°), Moonie (30°), Halibut (50°), Kingfish (65°) and Minas (95°).

330

Pour Australian crudes (Kingfish, Halibut, Moonie and

Barrow Island) of differing composition are shown as having

pour points of 65°F, 50°P, 30°F and

331

PART 2 - CHANGES IN THE COMPOSITION

AND PROPERTIES OF SPILLED OILS

(a) Evaporation

2.2.1 Mr Lowd, when describing refinery production process

es by which crude oil is separated into cuts of differing gas

and liquid composition by temperature-pressure fractionation,

noted that crude oil "does not have a fixed 'boiling point' in

the usual sense. Instead, at any given temperature and press

ure, some portion of the petroleum mix will be vapour ... and

the remainder will be liquid. In general, the higher the

temperature the higher the percentage vapour." (T3267) At

normal atmospheric temperatures and pressures some of the lower molecular weight hydrocarbons in an oil are, as Mr Keith (

1120*17) and other witnesses pointed out, at a temperature above their boiling point and therefore entirely gaseous. Hydro

carbon compounds of higher molecular weight represented in

industrial terminology by the gasolene, naphtha, kerosene, gas oil and residual cuts are characterised by boiling point

ranges on the successively rising scale of 40-150°C, 150-200cC, 200-300°C, 300-400°C and>400°C (Professor Clark, Table I T36OI). At ordinary atmospheric temperatures the compounds within each range will be in some degree volatile and lose to

the atmosphere some part of their liquid phase as vapour, the rate of evaporation depending amongst other factors on the prox imity of the temperature to the boiling point of the liquid.

Mr Keith explained this in the following passage (T120*J8):-

Q. "...what I am interested in is the volatility

of the crude oil at temperatures that you get in seawater in the sunlight in the Barrier Reef area..."

A. "Let us say that gasolene materials will evaporate under ordinary atmospheric conditions. If you

332

spread gasolene on a piece of steel and

leave it outside it will evaporate very rapidly.

So will kerosene."

Q. "Less rapidly?"

A. "Less rapidly. The higher the fraction the

less rapidly it will evaporate" ...

"If you spread ... crude oil, the gasolene

fraction will evaporate, the kerosene fraction

will evaporate, but more slowly, the heavier

fractions will evaporate very much more slowly."

2.2.2 Mr Mansfield, at T7195-9, noted some circumstances

which promote the evaporation of hydrocarbons from an oil slick

at sea. He said, "At any one moment, the most volatile fractions

present at any particular part of the oil/air interface of this

slick evaporate preferentially, at a rate determined mostly by

the wind velocity, the surface temperature and the vapour

pressures of the components being evaporated." (T7195) Wind velocity is relevant to evaporation rate because

"What is happening when things evaporate is that molecules are leaving the oil and entering the air space above. Unless the

molecules are swept away, they will accumulate above the oil

and finally reach a vapour pressure which we call the equil ibrium vapour pressure, at which molecules are returning to the

oil from the vapour as fast as they are leaving the oil for

the vapour. If the wind is blowing these molecules are swept

away and more evaporation can occur, so that the faster the wind the more vapour is swept away and faster evaporation

occurs." (T7195/6) Temperature is relevant, for "As you increase the

temperature the vapour pressure rises. This means that if the

vapour can be swept away the rate at which more molecules move

out to try and reach this higher vapour pressure increases, so

evaporation of all substances increases with temperature - water,

oil and so on." Mr Mansfield confirmed, in this context, "... that in order to calculate the likely rate of evaporation

333

of any particular oil slick you would need to have some know

ledge of the vapour pressures of the components of that slick."

(T7196)

A further requirement noted by Mr Mansfield is that

"For evaporation to continue we now have to bring more of these

volatile materials up to the surface." He explained that "The

rate at which the materials move to the surface depends upon

the nature of the compounds, upon their chemical composition,

on the temperature and, in the sense that it depends on the stirring within the layer, also on the wind velocity itself." (T7196) Also of relevance to evaporation rates are "the fluid

ity of the oil ... and ... the local thickness of the layer."

(T7197) Further consideration is given to these various con ditions promoting the evaporation of oil in Part 9, paragraphs

2.9.13-1^ which deal specifically with the prediction of chang es in the composition of oils if spilled in GBRP waters.

2.2.3 The rate of evaporation of individual hydrocarbons from crude oil mixtures at atmospheric temperatures was not

made known in evidence and precise information of the rates of evaporation of oils of differing composition under varying

states of sea temperature and wind speeds does not appear to be available. Estimates have been made on theoretical grounds of the rates of evaporation of crude oil as a whole and Dr Nelson-

Smith (Exhibit 365 p.236) quotes Brunnock et al (1968) as say ing that "... it is estimated that about one-third of the 'Torrey Canyon's' cargo of Kuwait crude was lost by evaporation following the spill, equivalent in effect to the removal of all fractions boiling below about 300°C." And Mr Biglane, speaking

of the Chevron Platform C spill in the Gulf of Louisiana, 10

February 1970 said "It seems likely that at least 35 per cent ... of the total oil discharged would have evaporated within 48 hours." (T6717) Mr Mansfield, however, was of the opinion that for a

Moonie type oil in the waters of the GBRP about one half of the

original oil would have evaporated in about one day (T7199)·

334

The evidence given by several witnesses (e.g. Professor Clark,

T3609; Dr Grassle, T6l47) that evaporation from an oil slick

mainly depletes the lower boiling point components was not

contested. However, as Dr Grassle pointed out (T6l48), "... only the lowest boiling components in the gasolene range are

lost rapidly and completely. Thus, oil recovered from the

feathers of birds exposed to an oil slick off Martha's Vine

yard Island, Massachusetts, U.S.A. in February, 1970, still

contained normal heptane and normal octane (Blumer, 1970, un

published). Similarly a light paraffinic crude oil that

washed ashore on Martha's Vineyard in June 1970 was sampled

immediately and then again after eight days exposure on the

beach. The gas chromatograms of both samples were identical and extended in boiling range as low as n-octane. Even in

oil that has been exposed to weathering for several months

(tar balls from the Mediterranean Sea (Blumer et al., 1970,b), "tar" from the beaches of Santa Barbara) (Blumer, 1970, unpub

lished), hydrocarbons boiling as low as n-decane can still be

recognised." Although, as was made clear from Mr Mansfield's

evidence (T7198 et seq), much work remains to be done on evaporation of oils at sea under differing conditions of tem

perature and the play of winds, and from slicks of differing

thickness, the demonstratable retention by weathered oil of

some proportion of the low boiling point hydrocarbons, in

cluding aromatics, is of evident importance in the considera

tion later to be given to the persistence of hydrocarbons and

their potential toxicity.

(b) Solution

2.2.4 Mr Keith (T12056-8) introduced his evidence on this

subject with the following general statements "All hydrocarbons

are only very slightly soluble in water - in the range of parts per million." "The solubility decreases very rapidly with in

crease in molecular weight." "Aromatics are more soluble than

paraffins or naphthenes." Dr Grassle (T6l47) confirmed these

335

generalisations, which were not contested, in saying that "Dis

solution also removes preferentially the lower molecular weight

components of an oil. However, aromatic hydrocarbons are more

readily dissolved than alkanes of the same boiling point ..."

It therefore appears that the crude oil compounds which most readily dissolve in seawater lie within the same range of car

bon numbers as those which most readily evaporate, and which

are most toxic (Mr Cowell T10912).

2.2.5 Figures for the solubility of individual hydrocarbons

within the paraffinic, naphthenic and aromatic series were pro

vided by Mr Keith (T12056-7), Dr Nelson Smith (Ex 365, p .235) and Dr Connell (T7037) quoting sources dated 1924, 1948 and

1964. The most recent estimations of Freegarde, Hatchard and

Parker (Ex 362) are significantly lower than indicated by the

earlier analyses. Dr Connell (T7176) agreed that the more recent estimates were likely to be the more reliable and Mr

Mansfield) in subscribing to this opinion, thought that the presence of oil in fine droplets might explain the earlier de

termined higher figures. Solubilities in parts per million

(temperatures not stated) were instanced as follows:

n. paraffins: in seawater (Freegarde et al Ex 362) pentane (38 in fresh water), hexane (11), heptane (4), octane (1), decane (0.15), the solubility falling at each stage by an approximate factor of three.

branched chain paraffins: somewhat more soluble than n . paraffins, Mr Keith (T12056).

naphthenes: in fresh water. No figures. Classified as 'insoluble 1, Mr Keith (T12056).

aromatics: in fresh water, benzene (700), toluene (500) ethyl benzene (100) xylene (insoluble) (Mr Keith T12056-7)·

2.2.6 The virtual impossibility of relying on these figures for making estimations of the amounts of hydrocarbons that are

leaked into seawater from a slick was explained by Mr Keith

(T12056) in the following questions and answers.

Q . "Each hydrocarbon is also soluble in the mass

336

of the oil so that for a given hydrocarbon,

part will dissolve in the water and part in

the oil?"

A. "Yes." "The amount that will dissolve in each

phase will depend on the relative solubility in

each phase and the volume of each phase. Hydro

carbons are obviously much more soluble in oil

than water, but then in a spill, there is much more water present than oil."

Freegarde et al (Ex 362 p . 37), taking into account the solu

bilities of individual hydrocarbons and their oil/water phase

distributions, conclude tentatively that "remembering the large volumes of seawater available, it seems likely that

solution of the kerosene fraction will be significant but that

solution of the lube oil and higher fractions will be quite

negligible."

2.2.7 According to Dr Pilpel, in a passage (Ex 298 p .12)

which was several times referred to in evidence, oil when

moved about on the surface of the sea by wind and.waves may be "converted into two types of emulsion." "The oil-in-water

emulsion consists of droplets of oil up to a few millimetres in diameter, which are stabilised by the presence on their surface of hydrophilic (water-seeking) groups ... present in crude oil but removed during refining. Oil-in-water emulsions

are readily miscible with seawater, and in this form the oil

spreads out and disperses quite rapidly in the volume of the

ocean ..." "The reverse type of emulsion, the water-in-oil

type, is not miscible with seawater. It consists of droplets

of water enclosed in sheaths of oil and is rendered stable by

the presence of various resinous and asphaltic materials which also occur naturally in crudes. These emulsions may contain

up to 3 0 % of water ... and, depending on their source, have a

consistency ranging from that of thick cream to road tar. They

may remain in a thick, greasy layer or may break up into lumps.

337

Some is washed ashore under the action of wind and waves, some

sinks, and the rest is gradually decomposed."

2.2.8 Dr Connell, in making a distinction between oil

present in solution and in a fine droplet emulsion, said that

"if it was dissolved it would divide up completely into individ

ual molecules in the solution whereas the emulsion would be

very small droplets which can be filtered out or centrifuged

out by special procedures." (T7024) Mr Mansfield spoke of the

practical difficulties of distinguishing the border line be

tween very fine droplets and molecular solution" ... the dif

ficulty arises simply because these materials form very stable

finely divided emulsions or dispersions" ... "I would guess

from our laboratory experience that if one tried to measure the

solubility of material in the sea one would often measure the

amount of material dispersed in this fashion and so it would be

very difficult to decide what is the real solubility." (T7200) He noted, however, that in a solution containing droplets "As

time goes by the fine material either settles up or down de pending on whether it is less dense or heavier than water and

you approach with time the real solubility." (T7203) He re

ferred, in illustration of this, to the experiments made by

Freegarde et al (Ex 362 p .37) in which, after shaking oil with seawater and analysing at intervals of time the oil content in

parts per million of the water, they obtained the following -

results:

Time of settling 15 mins 1 hr 8 hrs 1 day 2.2 days 147 days

Oil content (ppm)31 4 3 5 3 0.6

Mr Mansfield added (T7203) "... as you can see from this table

these people found that they have to go for 147 days and they were still not quite sure whether they had reached the final

solubility ..."

2.2.9 The main point that Freegarde and his co-authors

make, however, is that "Fine dispersions containing more than 1 ppm can persist for several days and it seems therefore that,

in a choppy sea, significant amounts of oil could remain

338

dispersed long enough to be carried quite deep, and if sub

surface currents were favourable it would then be distributed

far beyond the confines of the original slick." (Ex 362, p.37)

2.2.10 No quantification was given in evidence of the rates

of production from oil slicks of these fine droplet emulsions.

Dr Spillane (T12326) indicated however that, in the open sea,

forces are at work to create them. Although small water

ripples are absorbed "within a metre or so" of the edges of an

oil slick, "larger, longer waves ... travel through the oil and

as they do so cause the thin layer of water at the oil-water

interface to be stirred by small but intense turbulent motions. This action results in an oil-water emulsion being formed and

such emulsions ... may be very stable." While it was clear

that what Dr Spillane had in mind was the eventual production

of stiff water-in-oil emulsions, it was evident that the pro

cess of stirring would produce some(unspecified)quantum of oil

in dispersed and transportable form.

2.2.11 Pew measurements have been made of oil concentrations

in the water column in the vicinity of a slick. The only

measurements in evidence are analyses made by Freegarde et al (Ex 362 Table IV). One hundred tons of oil experimentally

released at the surface in the English Channel formed a long thin slick along an east to west axis. The wind was light and

the sea calm. Water samples taken from 1-10 metres below the slick contained "significant amounts of oil", the maximum con

centrations mainly coinciding with a southerly wind blowing transversely to the oil slick axis. The authors estimated that

under maximal conditions of concentration the quantities of oil

dispersed within an area of approximately 10 sq kilometres

might be about 5 tons.

2.2.12 Oil in dispersed droplets within the sea is directly

within the surround of planktonic organisms. There is evidence,

which is considered in more detail in a later section, that it

339

may become both attached to and eaten by planktonic organisms

and particularly by the numerous copepods in the plankton (see,

for example, Blumer (Exhibit 297); Freegarde et al (Exhibit

362) .

(d) Water-in-oil emulsions 2.2.13 In contradistinction to the oil-in-water dispersions

referred to above and consisting of small droplets of oil sus pended in large volumes of water, water-in-oil emulsions con

sist, as Dr Pilpel (Exhibit 298) has noted, as water droplets

ensheathed in a mass of oil. The two states are interconvert

ible. Droplets of oil may settle out of seawater to form a

water-in-oil film and, by mechanisms which Mr Stanphill (T4563) explained in detail, dispersing agents of various kinds when

beaten up with oil and seawater cause the oil to be broken up

into individual droplets suspended in seawater.

2.2.14 Many witnesses, including Professor Clark (T36O9),

Mr Cowell (T11012), Dr Straughan (Exhibit 28l, p ,335) and Mr

Grant (T12851), in a coverage of the 'Torrey Canyon1, Santa Barbara, 'Tampico Maru' and 'Oceanic Grandeur' spills, describ ed how oil released in these spills had become, at least in part, converted into viscid sticky water-in-oil emulsions

variously described as turbid, creamy or brown ("chocolate mousse") mixtures containing from 30% (Dr Pilpel Exhibit 298) to 80% (Mr Cowell, T11012) of sea water.

In all these instances, except for the 1 Tampico Maru1 dispersants were reported to have been applied to the oil and may have promoted its emulsification. However, as Mr Mansfield (T7183) and Dr Spillane (T12326) pointed out, crude oils always

contain surface-active materials which aid emulsification, and from the evidence received it appeared that some degree of emulsification and the production of sticky viscid oil-water mixtures must be regarded as an inevitable consequence of a

large scale spill.

2.2.15 The conversion of oil into water-in-oil emulsions

340

bears some consequences which are later considered further.

In particular:

(i) The weight and volume of the objectionable material are increased;

(ii) Sinking is made easier by water weighting, and by the more ready adhesion to the sticky mass of heavier than water particles carried in suspension or picked up when the material

is stranded on shorelines;

(iii) The diffusion of oxygen through it is, according to the evidence of Mr Mansfield (T7191), slower than through either oil or water alone;

(iv) Photochemical changes of oil are likely to be slowed down when oil "is in the form of rigid water-in-oil emulsions" (Freegarde et al Ex 362) .

(e) Photochemical transformation: Oxidation.

2.2.16 Evidence on the nature and magnitude of the chemical

changes that take place in oil exposed to sunlight was frag

mentary and more revealing of deficiences in present knowledge than of facts upon which the Commission could justifiably rely.

The following statements which taken together are

not free from inconsistencies, may indicate the general charac

ter of the information available, the need for future work and

some lines of investigation that might profitably be undertaken

for a better understanding of the chemistry of oils and of the possible consequential direct and indirect effects of these

changes upon marine organisms.

"Virtually all the constituents of mineral oils can

be spontaneously oxidized and the rate depends on the temper

ature, intensity of sunlight and the physical state of the oil."

(Dr Pilpel Ex 298, p .12) "Oxidation may be catalysed by sun

light or by trace metals, such as vanadium which are present in the oil." (Mr Cowell T11011)

"Chemical degradation would occur at a very slow rate and would probably not be a significant contributor to the

degradation of oil in the natural environment." (Dr Connell

T7031) However, "the total rate of decomposition to be expected

341

in sunlight is by no means negligible." (jFreegarde et al

Exhibit 362, p.40)

2.2.17 "Oxidation affects most readily the aromatic hydro

carbons of intermediate and higher molecular weight; its

effects are recognised analytically by an increase in the in

soluble polymer fraction ("asphaltenes") (Dr Grassle T6l48),

"The products may be water soluble or surface active and may

thus reduce the bulk of the slick or contribute to its

emulsification." (Mr Cowell T11011)

2.2.18 The little known and complex photo-oxidative changes

are productive in some instances of water soluble acids,

organic acids and esters, which may not previously have been

present in the oil (Freegarde et al Exhibit 362 Table V).

(f) Biodegradation â

2.2.19 (i) General According to Dr Grassle (T6l89) "Hydrocarbons in the sea are naturally degraded by marine micro-organisms"; and Dr

Pilpel (Exhibit 298 p .12) was quoted as saying "The main de

composition of mineral oil at sea ... is due to microbial oxidation." Professor Clark enlarged upon the process further

in stating that "... all classes of gaseous, liquid and solid hydrocarbons are susceptible to oxidation by micro-organisms.

Micro-organisms in this context include bacteria, yeasts, moulds and possible protozoa, bacteria probably being the most

important of these." (T3625) When outlining in more detail the part played by

micro-organisms in the biodegradation of oils Dr Pilpel (Exhibit 298 p .12) referred to their specificity of action in bringing about chemical changes in saying "Micro-organisms may be divided into several groups according to the classes

of hydrocarbons in an oil that they are capable of oxidizing. Some act on paraffinic hydrocarbons, ... others on aromatic

hydrocarbons ... and others on naphthenic hydrocarbons" adding that "The rate of oxidation is markedly influenced by

342

a whole range of environmental conditions;" and Professor

Clark, in partial amplification of the conditions of oxida

tion, noted that "The presence of free oxygen is generally

necessary although nitrates and sulphates serve as hydrogen

acceptors for some hydrocarbon oxidisers." (T3616)

(ii) Evidence of biodegradation

2.2.20 The evidence relating to biodegradation was founded in the main on analysis of the hydrocarbon composition of

crude oils before and after they had been either experimentally

(e.g. Miget, Oppenheimer, Kator and La Rock Exhibit 304) or in

nature (e.g. Blumer, Sass, Souza, Sanders, Grassle and Hampson, Exhibit 238) exposed to bacterial attack. The methods,

sensitivity and interpretation of gas liquid chromatographic and mass spectrometry analyses of hydrocarbon mixtures were explained by Dr Connell (T7066 et seq) and the features in the

chromatographs of weathered oils indicative of the biodegrada^-

tion of some of the compounds originally present in the un weathered crudes were demonstrated by Dr Grassle (T6150 et seq). It was not questioned in evidence that biodegradation does occur.

(ill) Biodegradation and molecular structure 2.2.21 Several witnesses spoke of the differential suscep

tibility to biodegradation of hydrocarbons according to the chemical structure of their molecules and their molecular weight.

As a broad generalisation the statement that "In general, aliphatic hydrocarbons (straight and branched chain paraffins) are oxidised more readily than aromatic or naphthen ic compounds, and, within limits, long-chain hydrocarbons are

attacked more readily than similar compounds of low molecular weight" (Professor Clark Î¤3Î²Î6) was not contested in evidence.

2.2.22 The differential susceptibilities of hydrocarbons of

differing chemical structure and molecule size were however

elaborated In greater detail, and not without some inconsis

tencies, by other witnesses.

Dr Connell, relying on work by ZoBell (1964) said

that "ZoBell has found that straight chain paraffins or

alkanes are degraded (T7025) ··· Branched chain hydrocarbons

are not as readily degraded ... as the straight chain compounds

(T7030) ... Degradation of the naphthenes by micro-organisms

proceeds at a similar rate to the normal paraffins ..." (T7032),

and aromaticity "confers additional chemical stability ...

making it less susceptible to degradation in the environment." (T7038)

Dr Grassle, while agreeing that "bacteria attack

the n alkanes (straight chain paraffins)" added that "we have

not been able to detect that bacteria attack the aromatic

components of the oil ... " (T6120) However, in quoting from a paper written by Dr Blumer and others, and of which he him

self was one of the co-authors (Exhibit 238), he reveals variations in respect of the biodegradation of aromatics and of the relative susceptibility of naphthenes to biodegradation

in that he intimated that "Cycloalkanes (naphthenes) and

aromatic hydrocarbons are more resistant and disappear at a

much slower rate" (T6l47) than normal and branched paraffins.

2.2.23 In summary, though all three witnesses were in agree

ment that the hydrocarbons most susceptible to biodegradation are the normal (straight chain) paraffins and that the hydro carbons most resistant to biologically induced changes fall

within the aromatic series, the relative susceptibilities of branched paraffins and naphthenes occasioned some differences

of opinion. The differences may perhaps reflect the effects in different experiments of the presence of differently constituted populations of bacteria and other micro-organisms, or, be due to other undefined causes. There is clearly room for further investigations in this important field and

particularly for a more precise determination of the rates at which biodegradation of different types of hydrocarbon com

pounds takes place under natural conditions.

344

(iv) Biodegradation and temperature

2.2.24 Very little information was forthcoming on the rate

at which biodegradation occurs in different situations in the

sea or of the proportions of oil that can be destroyed by bio

logical processes, though Professor Clark provided some useful

literature references on this subject (T3621). Under laboratory

conditions designed to produce maximal rates Miget et al·· Ex 304

reported a 35-55% reduction in oxidisable oil after 60 hours

at 32°C, and Dr Connell (T7025) quoted ZoBell as having found

that straight chain paraffins suffer up to 83% reduction over

35 days. However, as pointed out by Dr Pilpel in Ex 298 pp.

11/12, conditions in nature may be quite different in that "The

rate of oxidation is markedly influenced by a whole range of

environmental conditions" in which he instances, among other

factors, temperature, and salinity of the water and the number

and variety of the bacteria it contains. He adds as other

important variables - "the source of the oil and.its specific

gravity, degree of refinement, quantity and physical condition."

2.2.25 In respect of temperature Professor Clark was in

volved in the following questions and answers (T3905)â

"The speed at which degradation takes place can be affected also, can it not, by the temperature of of the water?" There has been very little "One would imagine so.

study on this matter." "You ... are familiar with the work of Dr ZoBell are you not?"

"Yes, in part." "Does he not suggest that the processes of bio degradation are very much increased with the temperature?"

"Yes, in general this is certainly true." Professor Clark added, however, that different forms

of bacteria might have different temperatures of optimal ac tivity "I have been told that some bacteria ... have an optimum

temperature of around 5°C ... so it is quite possible in very

cold waters that there are bacteria which can operate at

345

extremely low temperatures. Nevertheless I think the suspicion

is that degradation in very cold waters is slow ... degradation

is probably faster in warmer waters than in cold." In this

connection Dr Pilpel (Ex 298 pp. 12/13) noted that "Below about

5°C it is rather slow and thus hardly proceeds at all in lat

itudes beyond 75°N or S . In equatorial regions, on the other

hand, the rate of oxidation may be several hundred grams of

oil per cubic metre of contaminated seawater per year."

(v) Biodegradation and nutrient materials

2.2.26 The effects of variations of water salinity were not discussed but among other environmental conditions that were

instanced as being of importance in promoting an accelerated

rate of oil destruction, particular mention was made of the

concentration of nutrient salts present and of oxygen avail

ability. Speaking of the nutrient requirements of yeasts and bacteria Professor Clark (T3641) said "They certainly need

phosphorus and nitrogen ... to make sure that they were not

prevented from multiplying at the maximum possible rate by a

shortage of these compounds"; and it was noted that in ex perimental cultures of bacteria in the presence of oil the

culture media are often enriched with nitrates and phophates

to ensure a maximum growth of micro-organisms capable

of degrading oil (e.g. Miget et al Ex 304).

(vi) Biodegradation and oxygen availability

2.2.27 Dr Grassle commenting on the oxygen requirements of oil degrading organisms said "The oxygen requirement in bac

terial oil degradation is severe; the complete oxidation of 1 gallon of crude oil requires all the dissolved oxygen in

320,000 gallons of air-saturated seawater (ZoBell, 1969). Therefore, oxidation may be slow in areas where the oxygen content has been lowered by previous pollution ..." (T6190) According to Professor Clark who was among the many witnesses

who spoke of the importance of oxygen for rapid biodegradation,

"Davis and Hughes, 1968 have argued on theoretical grounds that

346

the initial oxidation of hydrocarbons must involve the presence

of molecular oxygen" (T3625), but he added that according to

experiments conducted by ZoBell, 1969, bacteria are known which are "capable of digesting oil under anaerobic conditions."

(T3626/7) When asked whether some oxygen may have been pres

ent in the Louisiana muds which ZoBell was examining Professor

Clark agreed that this was a possibility. This did not how

ever, in his view, affect the general conclusion that "you

can have bacteria that can do the job of oxidising oil under

conditions which are practically anaerobic if not absolutely

so" (T3629/30), though in comparison with aerobic oxidation

"anaerobic decay ... does not normally act as fast." (T3628)

Dr Pilpel (Ex 298 p .13) confirms this conclusion in saying

"Anaerobic oxidation is almost always much slower than aerobic oxidation and depends on the availability of nitrates,

phosphates, sulphates, etc. which the micro-organisms use as

a source of oxygen."

(vii) Biodegradation and the physical state of oil 2.2.28 The rate of biodegradation of oil is markedly affect

ed by the state in which the oil is presented. All witnesses

who spoke on this subject, and who included Mr Cowell (T10982),

Mr Stanphill (TA582) and Professor Clark (T3625), agreed that dispersion of thick masses of oil promotes its more rapid

biodegradation. Professor Clark, having noted that "Degrada tion of hydrocarbons ... is facilitated if the hydrocarbons

present a large surface area" explained the matter further

in saying "Bacteria attack at surfaces so that if a given

quantity of oil is spread out so that it presents a very large

surface area, then this will provide a greater area which is

subject to bacterial attack. If on the other hand it is con centrated to a ball then it presents a minimal surface area

and it would be a very long time before the oil in the centre of this ball is ever within reach of the bacteria." (T3625)

347

(viii) Pathways of biodegradation

2.2.29 Little was said in evidence of the way in which

micro-organisms effect degradational changes or of the course

of the chemical reactions involved in biodegradation processes.

According to Dr Pilpel (Ex 298 p .13) "The chemical routes by

which oil is converted into carbon dioxide and water are com

plicated and have not been worked out in detail." Intermediate

products include a great variety of organic acids, alcohols,

aldehydes and ketones, some of which according to the evidence

of Mr Cowell may be more toxic to organisms than the compounds

originally in the oil and from which they were derived (T10916).

(ix) Role of bacteria and other organisms 2.2.30 Professor Clark instanced a variety of micro-organisms

capable of assimilating one or more hydrocarbons, including many

species of bacteria, yeasts, fungi and protozoa (T36l6), and it is highly improbable that any two experimental cultures will

contain exactly the same mixture of micro-organisms. Moreover,

as Dr Pilpel (Ex 298,p.12) has pointed out, micro-organisms are

highly specific in respect of the hydrocarbons they can oxidise

"Some act on paraffinic hydrocarbons, ... others on aromatic

hydrocarbons ... and others on naphthenic hydrocarbons" - the

branched chain paraffins. Dr Grassle, after noting that "bac

teria are highly selective" and that "complete degradation re

quires many different bacterial species (ZoBell, 1969)" (T6189- 90), illustrated the consequence of their specific selectivity of action on particular types of compounds in saying that "bac

terial degradation alters the ratio between paraffins and iso

paraffins or between paraffins and aromatics." (T61A9) In other

words, the proportions of each category of hydrocarbons degraded

would depend upon the nature and number of the bacteria present.

(x) Aromatics 2.2.31 We may conclude by restating an aspect of biodegrada tion which found general acceptance namely that, of all the

classes of hydrocarbons, aromatics are the most resistant to

348

degradation and that their presence in anaerobic conditions

such as are met with in compacted sediments will further

accentuate their persistance, adding the reservation that

Mr Cowell made that this does not necessarily mean that "they

stay in the environment almost forever." (T11010)

3k9

PART 3 - OIL MOVEMENTS

(a) Introduction

2.3.1 Oil when spilled on to the surface of the sea comes

under the influence of externally imposed forces which cause

it to be drifted from its place of release often over long dis

tances. Oil from the 'Torrey Canyon' spill which was reported

in the evidence of Professor Clark (T3790) and Mr Norrie

(T6019) among other witnesses as having reached the coast of Prance had, for example, travelled more than 200 nautical miles

from the place of release.

The long distances over which spilled oil may travel make consideration of the circumstances which determine its

speed and direction of movement of evident importance in de

termining the answers to be given to TR2 (the effects of oil

on eco-systems) and TR3 (the areas of the GBRP (if any) in which

drilling for oil would cause so little detriment that drilling there for petroleum might be permitted).

In this Part the general nature and action of the

forces which determine the speed and course of oil movements on the sea surface are examined in the light of the evidence

received. Probability predictions of oil movements in the

GBRP which take into account the special meteorological and

hydrological features of the Province are to be found in para graphs PI.4.57 - 61 and are also referred to in paragraph

3 -2 .2 .

Evidence on the movements of oil at sea was given by

several witnesses all of whom agreed that the speed and direc

tion of the movement of oil is determined primarily by forces

supplied by wind-generated and tidal surface currents.

(b) Wind generated surface currents 2.3.2 The Commission had the benefit of a very detailed

analysis of the action of winds in promoting surface currents

350

and oil movements in the evidence of Dr Spillane, Principal

Research Scientist, Division of Atmospheric Physics, CSIRO

(T12308-12433)· We commend Dr Spillane's account to the scientific reader but think it unnecessary to quote it in detail

for our present purposes. We therefore report on the main re

sults of Dr Spillane's findings, and relate them to the evidence

of other witnesses.

Dr Spillane estimated, from a theoretical evaluation

supported by small scale experiments, that some 90% of the

momentum supplied to floating oil would be generated by sur

face water movements, the remaining 10% being the result of the

shearing thrusts of the wind acting directly on the oil (T12318).

Wind generated surface currents were described as developing

through wind roughening of the surface into small ripples or

capillary waves "... only inches in wave length" and "... cent

imetres or less" in height which "... grip the air flow and

transfer momentum out of the air into the sea." (T12318) The

individual capillary waves are checked by viscous drag from below and their momentum is transferred into a "... steady drift

or stream at the surface" (T13419) which, thrusting behind an

oil slick, imparts to it a forward momentum.

The more familiar large and long-period sea waves are,

according to Dr Spillane, much less efficient in moving an oil

slick. Water particles in long, high energy wave-trains os

cillate backwards and forwards in the development of crests and troughs. A small residual forward movement, described by

Dr Spillane as the "Stokes wave transport" (T12322), while

effective in moving small floating objects, does not impart to

a large oil slick a substantial forward movement but creates a

turbulence which erodes the under surface of the slick and pro

motes emulsification of the oil.

2.3.3 Evidence relating the velocity of wind-developed sur

face currents to the speed of the current-generating wind was

received from a variety of sources. Dr Nelson-Smith (Ex 365

p.238) quoted figures based on observed rates of movement of oil

351

slicks and of other floating objects such as plastic cards under

varying wind speeds which ranged from 3.3 to 4,2% of wind speed.

Mr Mansfield gave support to a relationship of 3.3$ between oil

movement and wind speed (T7212); and Dr Maxwell, adopted a

probable range of 3.0 to 3.4$ for the S.E. trade wind regime

in the GBRP (T1644). Mr Rochford made the point that factors

such as a low density of the surface water might increase the

rate of transport "beyond the normal 3$ of wind speed" to "something like 5%", but added that "this is by no means con firmed from actual observations." (T2008) Some quantification

of the expected relationship of wind speed to surface current

was given by Dr Spillane who, on theoretical grounds, calculat

ed that in wind speeds up to 10 knots oil might be expected to

travel at 2.8$ of the wind speeds; at 18 knots at about 2.5$;

with a steady decrease to 2.33$ for a 26 knot wind (T12362-3). Winds of these strengths and persisting for 24 hours would, it may be noted, respectively move oil over distances of about 8,

13 and 17 miles.

(c) The determination of local winds and of local wind changes 2.3.4 The speed and direction with which an oil slick moves before the wind can only be directly and with some accuracy computed from a knowledge of the direction and force of the wind

in the place where the slick is. This knowledge is rarely if ever in practice attainable by direct measurement, for the number of localities where recordings are made are necessarily few in comparison with the sea area to be covered. Mr Shields,

Regional Director (Queensland-Papua Region) of the Commonwealth Bureau of Meteorology illustrated the difficulties in obtaining

adequate data of this kind in the GBRP in pointing out at T332- 6 that barometric pressures , surface wind directions and speeds and temperature measurements are transmitted to the Bureau at three-hourly intervals from four continuously recording stations supplemented by "good observations or long and comprehensive records" from some 21 stations listed in Exhibit 16. He added,

352

"Whilst the types of wind data presentation are satisfactory

for a general description of the wind regime over an area or

at a particular place they do not altogether meet the wind

data requirements for a study of the likely spread of oil

pollution over a given area except in a general way. The type of wind data array required would have to be specially

prepared in a form showing persistence of wind in direction

and speed at each station. Furthermore, whilst wind data

from low, small reef and island stations are representative

of a fairly large area, the wind patterns in coastal areas and off-shore islands with high topography are much mor-e

complex and are further complicated by land and sea breeze effects. A much denser network of wind stations would be

required to give a reliable wind analysis of any coastal area

under investigation." (T336) In practice it is customary, because of these

limitations, to determine and in some measure to predict the

changing patterns of wind flow in a particular area in another

way which was explained to the Commission by Dr Spillane at

T12337-50.

The method depends essentially on a knowledge of the

atmospheric pressure distribution in a given area such as are illustrated in weather maps and on calculations made "from synoptic charts simply by looking at the isobars and determin

ing the speed at which the air will be moving from a high pressure area to a low pressure area" ... "The accuracy must depend on the accuracy of the information on which the analysis

of the pressure distribution was based." (T12337) Dr Spillane explained the further calculations, assumptions and corrections

that were made in deriving from these data predictions of the direction and speed of surface winds in the area. The main

steps involve:

Ca) estimations of the velocity of what he termed the gradient wind which "is approached at some height above the ground approximately a kilometre"

(T12337):

353

(b) the estimation, by. the application of an appropriate (two-thirds) reduction factor, of the surface wind speed in terms of the speed of the gradient wind;

(c) corrections for the determination of the direction of the surface wind that take account of gradient wind deviations due to the earth's rotation (Coriolis force)

(T12338); and

(d) corrections relating to air stability (based on air/sea temperature gradients) which, as Dr Spillane noted, result in a predicted water surface drift (in the GBRP Zone) some 10-12°to the left of the surface wind (T12350).

This method of prediction though not meeting "... the

wind data requirements for a study of the likely spread of oil

pollution over a given area except in a general way" (Mr Shields, T336) nevertheless led Captain Hildebrand, Port Master

of the Department of Harbours and Marine, Queensland to give what might be called a 'users' summary of the reliability of

the accuracy of the wind forecasts issued by the Bureau of Meteorology in saying that "In my experience the forecasts ...

are accurate except for some variations from forecast wind

velocity. Examples of dramatic change of direction from those

forecast are so rare as to be negligible." (T302)

2.3.5 Predictions of this kind, though not fully reliable,

enable searches for slicks to be made by ships and aircraft with economy of effort for subsequent visual tracking or tracking by more sophisticated methods to which reference is made in para

graphs 3.3.9 and 4.4.63.

2.3.6 The wind data collected over long periods of time serve the further purpose of providing historical data upon

which to establish the general seasonal patterns of the wind regime in the several regions of a given sea area such as that

of the GBRP. When these patterns follow definable trends such as are identifiable in the prevalence in the greater part of the

GBRP over long periods of the year of South-Easterly trades

354

veering from time to time from the east or south, the informa

tion so gained can be used with some confidence in predicting

the most likely directions of oil drift within the Province.

This subject is developed in detail in paragraphs PI.4.57-61

and 3-2.2 and referred to briefly in paragraph 2.3.9 infra.

(d) Tidal currents

2.3.7 Tidal currents, which were dealt with in detail by

Dr Maxwell, are generated by gravitational forces exerted by the moon and sun, and are manifested as large scale movements

of water which develop rhythmic oscillations of ebb and flow

the scale and shape of which are largely determined in coastal

waters by physical features such as the configuration of the

coastline, the size and shape of the sea basin and the bathym

etry of the sea floor (T133 et seq). Oil slicks are moved by tidal streams in accordance with the velocity and direction of

the streams at the surface. Mr Mansfield said, in speaking to

this point, that "To a very high approximation it is moving

exactly at the same velocity as the water ... and in the same

direction." (T7214) In respect of the GBRP the data on tidal currents are

few and are almost all contained in the Australian Pilot and hydrographic charts. No doubt, for this reason, they are

particularly lacking outside the areas of navigation channels

and the approaches to harbours. Such evidence as there is

suggests that the tidal currents run fastest through reef passages of the shelf edge and in narrow channels through

which streams are funnelled. In the open waters of the shelf

the current velocities are lower.

"In most instances where tidal current directions

have been recorded in the hydrographic charts the ebb tide

direction is the reverse of the flood tide." (T19^/6) In reef

passages around reefs and near to the shore the strength and direction of the current may be different on the flood and the

ebb, and, as an additional complication, it was reported by Dr

Maxwell, in respect of the southern region, that "large gyrals

355

of turbulent water occur on leeward and ocean sides of the shelf

edge reefs and appear to be associated with tidal current flow."

(T139) Mr Rochford also agreed that "the configuration of the

reefs may produce substantial local variations in water move

ment." (T2014)

2.3-8 The difficulty of making accurate predictions of the

course which an oil slick will take following a spill is com

pounded by the often complicated and unknown vagaries of water

current patterns. This was made clear by Professor Woodhead in

describing the directions taken by drifters designed to float

at 1 metre depth when released from 24 stations off the coast of

Queensland in the southern (Heron Island) region of the GBRP.

"A striking feature of the investigation was the very widespread distribution of the sea surface drifters indicating a high

degree of horizontal dispersion in the region" ... "combinations of large and small eddy systems, imposed by the physiographic

peculiarities of the region would be expected to produce a far

higher degree of dispersion ... than would normally be the case in the open seas." (T5266) However, Mr Mansfield, at T7214,

stressed the importance of the purely surface current in the

movement of oil slicks and said that a current measured at a

metre down "may have no relation to the thrust at the surface.

It could even be in the opposite direction." For this reason

the Commission considers that the experiments carried out by

Professor Woodhead and described at T5255 et seq, whilst

interesting and important as hydrographical observations indic

ative of the unforeseen complications of local current patterns,

are not of themselves informative of the directions which oil

slicks, driven by purely surface currents would move in the area

in which he made his observations.

(e) Oil movements determined by both wind and â

tidal surface currents 2.3.9 Several witnesses spoke of oil movements as resulting

from both wind and tidal current effects (for example, Dr Max well T164; Mr Mansfield T7212, T7232; Dr Spillane T12316). Of

356

the surface currents caused by wind and tide all witnesses who

gave evidence on this subject agreed that, in the open sea,

under most circumstances wind was the more important in gen

erating movements of oil though none discounted the effects of

tidal currents. Thus: "The wind does appear to be the deter

mining factor, but ... if you have calm seas and you have

currents active they become a significant factor. In the case

of reefs and particularly the reef edge, or the edge of the

reef province, where you have extremely fast tidal currents, I

think they are factors to be taken into account ..." (Dr Max

well, T1642-3); "I would say in ... a very strong wind of

about 30 knots, you would have to have very strong water

currents to influence greatly the path the oil followed" (Mr

Rochford T2009) and "... on the average tides the wind has the

influence on the water movement of the barrier reef. It in fluences the water more." (Mr Bryson, T13548)

2.3.10 So little is known of the precise nature of set of

tidal currents over the Province as a whole, other than in

navigational channels and approaches to ports, that the Com mission is disinclined to comment on their effects in deter

mining the movements of oil slicks other than in the most

general terms. It is apparent that whenever the tide moves

across the wind, as it may frequently be expected to do, the

side to side sweep of the moving oil extends the area of its

water cover and therefore enlarges the number of the emergent

features such as islands and cays that may come within its

path. If however the tides are oscillating in the direction

of the wind the tidal effects of ebb and flow will be sub

stantially compensatory. At the approach to shore lines move

ment of oil towards the land may be expected to be accelerated on the incoming tide whilst the eddies and gyrals around shoals,

islands and the coastline may be expected to produce trans

locations and disruptions of a slick the character of which

are difficult or impossible to predict and will normally only

be evident by direct observation.

357

PART 4 - THE TOXICITY OF CRUDE OILS AND THEIR

COMPONENT HYDROCARBONS: EXPERIMENTS

(a) General

2.4.1 The types of information most needed from experiments

for the interpretation of the effects of oil spills into the

sea relate to the toxicity of oils of differing composition,

age and state of presentation; the significance of the dif

ferent time/concentration applications implicit in acute and

chronic pollution; the differential sensitivities to oil of different species of organisms; and the degree of damage

caused to organisms by oil presented under these varying sets of circumstances.

2.4.2 "At first sight", Professor Clark noted at T3643 "it should be a relatively simple matter to comment on the toxicity

of oil, but in fact, it is not. Crude oil from different

sources varies widely in its composition. ... Different organ isms show at least as great variation in their sensitivity to toxic materials of any kind and furthermore are often more

sensitive at some periods of their life than others; there is no such thing as a standard animal. There are also technical difficulties in determining the toxicity to aquatic animals of materials that are not miscible with water. ...Added to this there is no uniformity in test procedures or of recording

toxicities so that it is difficult to make more than a super

ficial comparison between such results as have been published." Professor Clark added "It is worth emphasizing the deficiencies and problems of toxicity tests of oil products and too much should not be read into the results that are available. In

particular, laboratory tests are meaningless until their find

ings can be applied to the very different situation that prevails under natural operational conditions." (T3643)

358

2.4.3 In making toxicity tests Professor Clark said "...

one performs experiments on a very large number of organisms

simply in order to get an average figure, because a single

animal is representative only of itself. One is really in

terested in what is the normal or average response of this

type of animal and that means studying a number; the larger

the number, the more accurate or reliable your answer will

be ...." (T3645) Two types of test are used. "It is common

practice to measure the time it takes for 50 per cent of the

test animals to reach whatever has been selected as a criterion

of death. This is indicated as TD 50 (time for death of 50

per cent of organisms)." Alternatively, the toxicity of a

substance may be assessed by measuring against a test organism" ...the mortality at various concentrations of the toxin ...

This is achieved by standardizing the exposure time and re

cording the concentration of toxin required to achieve 50

per cent mortality of test organisms in that interval. This is indicated by LC 50 (lethal concentration for 50 per cent

of test organisms)." (T3646) The results of experiments of these two kinds were made known to the Commission mainly

through Exhibits 289, 2993 365 and 404, and the evidence of Professor Clark (T3600 et seq), Mr Cowell (T10908 et seq)

and Dr Connell (T7071 et seq).

2.4.4 The toxicity of oils, of the different fractions of

oil, and of the individual hydrocarbon components which they contain was usefully summarized by Professor Clark (T3600) and

Mr Cowell (T10908 et seq) . Because these two witnesses coverec

for the most part the same literature sources and were sub

stantially in agreement in their interpretations of them, Mr Cowell's commentaries may be allowed to speak for them both.

(b) The toxicity of different types of hydrocarbons 2.4.5 Mr Cowell said, in introducing the subject at T10908,

"Crude oils of different origins vary widely in physical prop

erties and chemical composition. The toxicities of· different

fractions of crude oil have been investigated to some extent.

359

There is agreement that the toxicity increases along the series

paraffins, naphthenes, olefins to aromatics ... Within each

series of hydrocarbons the smaller molecules are more toxic

than the larger; octane and decane (normal paraffins) are

very toxic while dodecane (12 carbon atoms) and higher paraffins

are nearly non-toxic. However, 12 carbon atom olefins are quite

toxic, and 12 carbon aromatics more so." When Mr Cowell was

asked, at T10919, if all aromatics, whether they are high or

low in the number of their carbon atoms, are toxic he answered

"I think I would have to say that all aromatics have some tox

icity, but the ones with very large molecules and a high carbon

number are among the least toxic materials in crude oils."

2.4.6 In explanation of the different levels of toxicity of

compounds of the same series but of differing molecular size, Mr Cowell noted that solubility is a function of molecule size,

the smaller the molecule, the greater its solubility; and he

added that "the more soluble the material the higher its tox icity." (T10912). It is clear from Mr Cowell's remarks that

when he speaks of toxicity he has in mind the toxicity of a

compound when in selutlon, and it is notable that most of the

toxicity tests on organisms that were referred to in evidence

(some of which are considered in greater detail later) were of

oil or of hydrocarbon components in solution or in the fine

droplet emulsions which are often difficult to distinguish

from true solutions. But it is possible that oil may have a

different effect on organisms when in direct contact with them,

either on their surfaces especially if they are lipophilic

(oil attracting) - Mr Cowell at T11057 - or within their bodies.

Mr Cowell himself, for example, (T11019) quoted Nelson-Smith on

the lethal effects of fresh oil on limpets when placed in direct

contact with them, and Professor Clark (T3652A-55), among other witnesses, instanced damage to plants coated with oil.

2.4.7 Mr Cowell, having noted at TIO988 that "Crude oils of different origins vary very widely in physical properties

360

and chemical composition" but that "As yet ... no classifica

tion of crude oils in toto has been formulated according to

toxicity", drew the attention of the Commission to some "...

preliminary work carried out during October and November 1970,

intended to investigate the relative toxicities of different

crude oils and to establish any correlations between toxicity

and physical and chemical properties of the oils." This study,

the only one of its kind to be brought to the notice of the

Commission, had been undertaken by Miss Shiela Ottway under Mr Cowell's supervision. Her paper "The comparative tox

icities of crude oils" was tendered as Exhibit 404 at T.l0965·

Miss Ottway was not called as a witness.

2.4.8 For the purpose of the experiments, Mr Cowell said

"Twenty crude oils of widely differing origins were supplied

by the British Petroleum Co. Ltd. together with tables of some

physical and chemical properties of each oil. Each oil was

assigned to a code number (CT-^, CTg, CT^ etc.) and was then tested for toxicity ... Batches of 50 animals were treated for

one hour with the oils, then washed and put into tanks contain

ing aerated seawater, with controls. Recovery was assessed

over the following five-day period. Trials were run in the

same way at different temperatures: at 3°C, 16°C and 26°C.

Animals used at 3°C and 26°C were acclimatised to these temp eratures over the 24 hour period prior to beginning the ex periments ... Three species of intertidal animals were selected

for preliminary tests; these were Patella vulgata, Littorina littorea and Littorina littoralis ... the limpet, the edible periwinkle and the flat periwinkle (of British shores) in that

order ... Of these three species L. littoralis proved to be the most moderately resistant and therefore the most suitable animal for experiments with oils of widely differing properties.

P. vulgata, the limpet, was found to be too sensitive, being the most susceptible common shore animal (Crapp, 1969), while

L.littorea was too resistant with the range of oils used."

361

2.4.9. Details of the composition and properties of the 20

oils used in the experiments were given in Table 1 (a) and

Table 1 (b) of Exhibit 404. They included specific gravities

in a range from 'light1 to 'heavy' (0.738 to 0.973), a sulphur

content from 0.01? to 2.85? by weight, an asphaltene content

from 0 to 5.8? by weight, viscosities (at 38^0) from 1.65 to

739 centistoke units, representing "very fluid" to "very stiff"

oils, colours from light amber to black and distillate analyses

of fractions to 149°C, 232°C, 343°C, and 371°C boiling point,

indicative of the proportions of the components of differing

carbon number present in the various oils. The aromatic content

of the Cj- to l49°C cut was also determined as a percentage of

the total weight. These varied from 1% to 25.5? in the 20 oils

used in the experiments.

2.4.10 The percentage mortalities of L. littoralis after one hour of coating of oil and a five day period in clean water for

possible recovery, were also recorded for different experimen

tal temperatures. They varied from 7 - 82% at 3°C, 1 - 89? at

l6°C and 2 - 65? at 26°C.

2.4.11 Miss Ottway sought to relate the differing toxicities

of the oils used in her experiments to specific chemical and physical characteristics of the several oils. She concluded

(Ex.404,pp.7,8) that "No clear-cut correlations of toxicity with chemical composition data are immediately apparent,

although certain tendencies are indicated. For example, oils with high sulphur and asphaltene content tend to be more toxic

at low temperatures. Also, the order of toxicity of crude oils

at 16°C is fairly consistent with that of the proportion of

aromatics and total distillate to l49°C. This correlation is

not apparent at 3°C and 26°C suggesting that at these temperatures other components of oil confer more toxicity."

2.4.12 As an alternative explanation of the lowered toxicity at the higher temperature, Miss Ottway suggests at p .6. of her

paper that "This is in accordance with the attribution of much

362

of the toxicity of crude oil to its most volatile aromatic

components, which evaporate readily at such high temperatures."

2.4.13 Mr. Cowell was questioned further on these

conclusions as follows:

"This means that there appears to be a

relationship in crude oils with the quantity

of aromatic compounds in the various oils ? --That is correct." "The oils which have the highest percentage of

aromatic compounds are also the most toxic?

-- Yes." "But you qualify that by relating it particularly

to the aromatic compounds which boil below 149°C?

-- Yes. Again I would like to comment this is easy to

do in the laboratory but because of the speed with which these materials evaporate it is very

hard to repeat under field conditions."(T10913) At T10930 Mr. Cowell re-emphasised this point in

saying "High mortalities recorded in the laboratory were not found under field conditions due to the evaporation of many

toxic low boiling aromatics and the dilution of those

fractions which pass into solution. Work on the toxicity of soluble fractions is continuing but so far only low toxicities

are recorded from solutions made under simulated field

conditions using vented containers."

2.4.14 Bearing in mind some statements by Mr Keith

(T12056/8) earlier reported to the effect that " All hydro

carbons are only very slightly soluble in water - in the range of parts per million," that " The solubility decreases

very rapidly with increase in molecular weight", and that

"Aromatics are more soluble than paraffins or naphthenes"; and the conclusion we then drew "that the crude oil compounds

which most readily dissolve in sea water lie within the same

363

range of carbon numbers as those which most readily evaporate",

it is of interest to note, the following comment by Miss Ottway

(Ex. 404, pp.8 and 9) on her experimental findings:

"Different crude oils also vary in the amount of

water-soluble fractions they contain. Initial investigations

have shown that a certain proportion of the toxicity of a

crude oil is attributable to the water-soluble fraction it contains. These water-soluble fractions of crude oil are

probably of little biological importance in the open sea where

excessive dilution occurs, but may well have profound effects

on living organisms in rock pools and in shallow waters due to

their high concentration."

2.4.15 "It is also apparent ... that the blackest and thick

est crude oils are the least toxic, while the translucent thin,

brown oils are the most toxic at l6°C. This is a very import

ant fact since a thick, black oil, when washed up on a shore,

is very conspicuous and therefore readily dealt with. A thin,

brown oil washed up in the same way, however, is virtually

transparent and may therefore go unnoticed, even though its

toxicity may be 90 times as great as that of the thick black

oil. "

2.4.16 Miss Ottway stated as her conclusions:

1. Different crude oils vary widely in their toxic effects on intertidal organisms.

2. Toxicities of different crude oils vary

greatly with temperature.

3. Low-boiling fractions of crude oil confer

a considerable degree of toxicity, although other toxic elements have residual toxicities.

(d) Toxicity of weathered oil

2.4.17 The sole evidence on this subject deriving from laboratory experiments is a brief reference by Mr Cowell at

T10988 to work by Baker (1969) and Crapp (1969) who independent ly "found Kuwait residue to be far less toxic than the fresh

364

crude, indicating the high proportion of toxicity conferred by

the volatile components of crude oil." Neither paper was

tendered in evidence.

(e) Toxicity and the manner of oil presentation

(i) Intertidal animals

2.4.18 The experiments of Ottway,Baker and Crapp referred to

above were designed to test the effects on organisms of oil which has been allowed to come into direct contact with

animals, a method which simulates field conditions of stranded

oil deposited, for example, on the bodies of intertidal species.

A more realistic simulation of periodic presentation and

withdrawal of oil is provided by keeping animals in aquaria in which oil-covered water is allowed to rise and fall with the

periodicity of tidal movements. Professor Clark at T3656

quoted experiments by Griffith (1970) who maintained mussels (Mytilus) and periwinkles (Littorina littorea) under simulated

tidal cycles with oil floating on the surface of the water but periodically coating the animals as the water drained off as an

equivalent to low tide, both species being intertidal. Mussels survived 120 hrs of this regime when exposed to Aramco crude oil

from which volatiles representing 11 - 14% of the original volume

has been lost by evaporation. Littorina showed a 50% mortality in 10-12 hrs at 4.6°C and in 2-4 hrs at 11°C under these

circumstances.

(ii) Plankton ( See also paragraphs PI.6.158-161) 2.4.19 These methods of presentation are not however suitable

for testing the effects of oil on organisms that do not normally

come into direct contact with an oil slick, for example,

planktonic organisms, or fish eggs, which swim or float in the open water, and which must make their contact with oil either

in solution or droplet suspension. Professor Clark at

T3664-69A described experiments by Kuhnhold (1969,1970) designed to simulate conditions under an oil slick. Three oils of Venezuelan, Iranian and Libyan origin were each placed in

measured quantity over 30 litres of water in proportions of

10,000, 1,000 and 100 parts per million of oil to water.

365

The water was stirred and the clear extracts used to test the

visibility of cod eggs to 100 hours of exposure to the oil

components in solution in the water, clean water being used as 4

a control. Significant mortalities were found in the 10 and 1 2

10 p.p.m. oil extracts, but not in the 10 p.p.m. solutions,

and on the evidence of additional deaths occurring on transfer

to clean water it was concluded that some of the eggs that had

not died after 100 hours exposure had nevertheless suffered irreparable damage.

2.4.20 Mironov (1970) in a paper "The effect of oil pollut

ion on flora and fauna of the Black Sea", which was tendered

at T6071 as Exhibit 289, conducted similar experiments to test the viabilit _es of eleven species of the smaller planktonic

plants, of five species of copepods, and of fish eggs and larvae to different quantities of crude oil, of undefined

composition presented as a film on the surface of the water.

In Table II of Exhibit 289 Mironov shows that oil when in

sufficient concentration (1 p.p.m. and above) in the water has a toxic effect on all these animals. As an example of the

nature of the effects produced and the concentrations of oil

required to produce them it was found, in the several species of planktonic algae tested, that proportions of the order of 0.1 to 1.0 parts of oil per million parts of water produced no measurable effect; that concentrations of 10-100 p.p.m. inhibited or delayed their cell division; and that 100-1000 p.p.m. concentrations resulted in death after a five day

exposure. However, the sensitivity of individual species varied widely. "This is most clearly seen in the case of

Pitylum brightwellii and Melosira moniliformis, where the difference in sensitivity to oil pollution amounted to the

order (of magnitude)of 3-4." (Exhibit 289, p.l.)

2.4.21 It is important to recognise that the recorded levels

of sublethal and lethal dosages are valid only for the condi

tions of the experiment and do not necessarily apply to condi

tions in the open sea where Mironov himself notes at p .3 of

366

his paper that "One of the peculiarities of oil pollution is

its rapid movement under the effects of currents and winds,"

However, as Mironov further observes in respect of the survive

al of fishes under oil films, "When (in experiments) oil

products were emulsified in the sea water, the damage was

much greater than in the case of oil films on the surface" and

"emulsification can often be observed in nature as a result of

water mixing and other factors." (Exhibit 289, p.2)

2.4.22 Mironov, in speaking of the rapid movement of oil

pollution under the effects of currents and winds, goes on to

say (p.3) "This gives rise to the possibility of a short time

contact between oil and marine organisms which is followed by marine organisms re-entering the water." On the other hand, Mironov's experiments strongly indicate that, under conditions

of a continuing oil presence such as may be found in enclosed

and slowly moving waters of lagoons and embayments, more

radical and long lasting deleterious changes may be imposed on planktonic communities important as food sources for other animals and for the recruitment of new generations of a variety of marine organisms.

(f) The differential sensitivity of different types

of organisms to oil

2.4.23 It is helpful, when assessing in field observations the effects of spills of crude oil on individual marine organs

isms and on the ecosystems of which they are a part, to have some prior understanding, through experiments, of the

measure in which different kinds of organisms, in the various stages of their life history are able to tolerate the stresses imposed upon them by the pollutant substances; and this kind of information is equally of value in making predictive judge ments, as the Commission has been called upon to do, of what

may happen if oil is spilled in an area which had not previous

ly been subject to oil pollution at a biologically significant

level.

367

2.4.24 Information is usually most needed in respect of

organisms that have an especial aesthetic, recreational or

economic interest to man such as the corals of the GBRP,

game fish and the many economically valuable sources of food

to be found, for example, among the molluscs, Crustacea and

fishes; and the testing of their resistance to toxic

materials is clearly, for purely practical reasons, an obvious

prior purpose of experimentation.

2.4.25 The reports we received of experiments designed to

test the sensitivity of marine organisms to crude oils covered

a rather limited range of species and the results were often

confusing and, at times, uninformative. For example, few

investigators have made known the composition and properties

of the oil they were testing; and in many instances the manner of presentation of the oil, notably its concentration

and physical state, is not clearly stated.

2.4.26 Because the conditions of experimentation vary so

greatly in different investigations no useful purpose would

be served by quoting in detail quantitative figures of

toxicity threshold values that might invite misleading

comparisons. . Instead, a brief review will be made of the reported effects of crude oil on organisms contained within the

broader groups of plant and animal classification. ( i )

(i) Plants - including salt marsh plants and mangroves.

2.4.27 Of the algae which attach to rocks between and below

the tide marks Dr. Cribb said at T 4791, on the authority of

Dr Nelson-Smith (1968) who himself made the observations, that

following the 'Torrey Canyon' spill of Kuwait crude oil:

"There were few areas where the effects of oil alone could be

studied but such observations as were made suggest that the

oil alone was relatively harmless to plant life" and that oil polluted "rock pools contained ... photo synthesising algae and

brightly-coloured corallines although oil clung around the

sides or floated in the centre." The significant comment was

368

added that " ... oil from the 'Torrey Canyon' had been

floating at sea for at least a day, in some cases much longer,

before reaching the shore, and had probably lost some of its

toxic constituents through evaporation or solution."

Professor Clark, quoting some experiments by Tsuruga (1970)

in which intertidal weeds had been exposed in water to fresh

light marine fuel oil which presumably still retained some toxic substances, said that the red weed "Porphyra survives

2 hr exposure to light marine fuel oil without harm, but

after 3 hrs or longer exposure an increasing proportion of

plants are damaged even though then transferred to clean

water. After 10 hrs exposure to the oil, and return to

clean water, all plants show damage ’ within 72 hrs" and he

added "of the seaweeds, brown algae appear relatively resistant to oils ... but observations on the shore indicate

that red and green algae are more susceptible to damage."

(T3655) Dr. Nelson-Smith (Ex. 365, p . 255) suggested that this differential susceptibility to oil might be due to the fact that "The larger brown algae are covered with a coat

of mucilage which is not readily wetted by fresh oils".

However, "Emulsified oils or "mousses" will cling more readily ... and may cause the overweighted plants to be torn

off by waves" though "A considerable portion of most marine

plants can be damaged without necessarily destroying their

capacity to recover".

2.4.28 At the upper reaches of the tide Professor Clark said "The coastal wetlands may be developed as salt marsh or

mangrove swamps. The vegetation is primarily of land plants specialized to tolerate an elevated salt concentration in the

water and soil" (T3687) "Mangroves much more than salt marsh vegetation ... make an important biological contribution

to the marine environment. Mangrove swamps shelter an

extensive fauna particularly of fish, crustaceans and molluscs ... The swamps are also considered to be important nursery

grounds for many young prawns and fish of commercial importance." (T3688) Professor Clark said that "Both salt

369

marshes and mangroves tend to trap oil ... and that because of

the sheltered position in which mangroves develop and the slow

water movements, it is unlikely that oil deposited there would

be removed by wave action (MacNae, 1968)." (T3688)

2.4.29 In respect of salt marsh communities Mr. Cowell said

of the work with which he had been associated that: "Observa

tions following oil spills were made at Milford Haven, S.W.

Wales by Cowell, 1969, Baker, 1970 and Cowell and Baker, 1969,

and experimental simulated oil pollution had been done by spraying oil at different times of the year." (T10924) It

was found that "oil adheres firmly to the plants and very little is washed off during successive tides." Under oil

films, leaves may remain green initially but eventually yellow

and die. Plants, however, recover by producing new shoots, a

few of which can usually be seen within three weeks of polluting

unless large quantities of oil have soaked into the plant bases

and soil. Seedlings and annuals rarely recover directly."

(T10925) Earlier investigations by Mackin quoted by Dr. Nelson-Smith (Ex. 365, p. 256) confirmed these findings.

2.4.30 "Mackin (1950, a - c) tested the effects of crude

oil on salt marsh plants. Saltgrass Distychlis spicata (L) glasswort (Salicornia spp.), cordgrass (Spartina sp.) and

young mangroves (Rhizophora sp.) were more sensitive than oysters. In one series of experiments they were damaged by

25 ml oil per square ft of water surface (about 280 ml/m^).

Some plants were rapidly killed but there was a complete repopulation later." Dr. Nelson-Smith notes, however, that

experiments by Baker (1969) show that fresh oils are more toxic than weathered oils and indeed "she found that weathered

oil has a growth-stimulating effect and discusses unpublished Russian work suggesting that naphthenic acid might act as a

phytohormone." (Exhibit 365, p . 256)

2.4.31 Of the ecology of mangroves, Professor Clark said at

T3689, "The mud of mangrove swamps is anoxic and rich in

370

hydrogen sulphide, and the root systems of mangroves have

extensive air spaces which carry oxygen below the mud surface.

The air spaces open at lenticels on the air roots of Avicennia

and the prop roots of Rhizophora. When the lenticels are

covered by water, the air pressure within the roots falls as

oxygen is used up. At low tide when the lenticels are above

water air is drawn into the roots ... Removal of the air roots

of Avicennia or greasing the prop roots of Rhizophora causes

a progressive fall of oxygen concentration in the root air spaces to 1 - 2% over two days (Scholander, van Dam and

Scholander, 1955). Clogging the lenticels with oil and

preventing transpiration is an obvious danger from extensive

oil pollution and might cause damage and death of the plant.

An additional hazard is from the direct toxic effects of oils"

and he quotes the observations of Mackin already referred to in support of this.

2.4.32 Thus, Professor Johannes at T4230 said of the tanker

'Argea Prima' spill of crude oil later referred to in more

detail: "The oil striking mangrove shores settled among the roots and where the amount of oil was great, the habitat was

virtually destroyed." Dr. St. Amant, on the other hand, when asked by Mr. Woodward Q.C. at T4111 in respect of the

mangroves on the coastline of Louisiana: "Has there been any

observation of the effect of chronic or acute oil pollution to your knowledge?" replied, "All I can say is that oil did not kill them. We had plenty of mangroves, before the cold

weather (of 1960/61 and 1963) did".

(ii) Animals - including coelenterates, echinoderms and

crustaceans

2.4.33 Zoologists recognise more than twenty distinctively different architectural styles of animals, each of which is

termeda phylum. The effects of oil were reported in respect

of a relatively few species drawn from only seven of the

phyla namely the Protozoa (usually minute single-celled

animals), the Coelenterata (which include anemones and corals),

371

Annelida (ring worms and bristle worms (polychaetes)), Arthro-

poda (of which the Crustacea are the dominant marine class),

Mollusca (e.g. bivalves and sea snails), Echinodermata (e.g.

starfishes and sea urchins) and the Chordata (e.g. fishes).

No information was received on animals of other phyla which

include such forms as sponges, flat worms, round worms, arrow worms, lamp shells and sea squirts, to name but a few of the

diverse and often very abundant kinds of animals found in

coastal waters or on sea shores (see, for example, Dr Isobel

Bennett "The Great Barrier Reef" (Exhibit 451)).

2.4.34 Professor Clark introduced the subject of the tox

icity of oils to animals in saying "Animals vary widely in

their exposure to environmental changes as well as in their

physiological responses to them. Species with a protective

shell that can be sealed when external conditions are unfavourable are at a considerable advantage and can usually

withstand temporary immersion in a toxic medium. Bivalve molluscs, operculate gastropods and some barnacles fall within

this category, but within each group species differ in their

abilities to produce and maintain an effective seal." (T3655- 6) Dr. Grassle referring to the possible correlation between

the size and age of organisms and their susceptibility to

toxic compounds said, in quoting Kuhnhold, 1970 and Mironov,

1969, that "A number of laboratory studies have shown that

larvae of marine invertebrates are far more sensitive to oil

pollution than adults" (T6219), a view which found tentative

agreement in Professor Clark's statement that " ... it is

possible that the plankton, a large proportion of single-

celled organisms, eggs, larvae and unprotected animals, is

more vulnerable to the toxins than are many organisms in other

environments." (T366I) Dr. Grassle was further of the

opinion that "the sub-tidal areas in general have species

which are far less resistant to various types of disturbance

than the species in the intertidal" (T6267); and Dr Fauchauld, who had surveyed the benthic organisms in the

Santa Barbara Channel following the blowout of the production

372

well A-21, was of the opinion that "A study of the smaller,

lesser known organisms such as polychaetous annelids or amphi-

pod crustaceans might be of more value in estimating the

effects of pollutants in the water than a survey of the large

common organisms." (Exhibit 281, Volume I p.73).

It is apparent on reading the scattered references within the transcripts of evidence to the responses of differ

ent kinds of animals to oil in the sea that, whilst there is

a large measure of truth in all these generalisations, none

fully probes the subtleties of differential adaptation which

distinguish the observable differences of response shown by

animals of seemingly similar structural adaptations, size, age, or closely alike in habit, or zoological relationship. Dr

Nelson-Smith in Exhibit 365 (pp. 247-55) conveniently sum marises many of the examples which were for the most part

elsewhere quoted in evidence.

2.4.35 Among the coelenterates, many sea anemones are very

resistant to oil, the common jellyfish, Aurelia aurita "appears undeterred by floating slicks and oil scum." By con

trast, "the hydroid, Tubularia crocea (Agassiz) suffered 20%

mortality from 0.1% crude oil in tests by Chipman and Gatsoff

(1949) and all were killed within 24 hours at 5%·" Ottway's experiments (Exhibit 404) previously reported show that among

closely related shore periwinkles, the nut winkle, Littorina

littoralis is significantly more sensitive to oil than the common periwinkle, L. littorea. Among bivalves, "Although Leenhardt (1925) reported that oysters and mussels died after

7 days exposure to 3 - 4 % crude oil; recent investigations suggest that these bivalves are able to achieve a considerable resistance" (T3656) and Dr Nelson-Smith (p.250) quotes Hawkes

(1961) as saying that "... quahogs, Mercenaria mercenaria L.,

seem to be practically immune to oil pollution." By contrast, "Cockles (Cardium edule L.) in aerated aquaria .. . quickly suc

cumbed to 0.5% Kuwait crude." (p.251)

373

2.4.36 Very few references were made in evidence to the

capacities of annelids (ringed worms and bristle worms) to

withstand oil. Dr Grassle, at T6155/6, listed them among the

many kinds of animals which in consequence of the spill of No.

2 fuel oil from the barge 'Florida' in Buzzards Bay, Mass, in

September 1969, were involved in "A massive, immediate kill ...

off-shore during the first few days after the accident," but

the few animals that remained in heavily contaminated deposits

included the worm Capitella capitata which as Dr Grassle says

at T6158, "is the species we refer to as the pollution indica

tor because in unexploited habitats, habitats in which there

are very few animals because of some disturbance such as pollu

tion, these species tend to take over."

2.4.37 According to Dr Nelson-Smith (Exhibit 365, p .251)> the echinoderms as a class "are notoriously sensitive to any reduc

tion in water quality" but he adds that since "... the majority

live slightly off-shore they may escape the effects of floating

oil." This is not however a circumstance which holds for the

GBRP where starfishes, brittle-stars and sea-cucumbers are

often among the more conspicuous and common animals on tidally

exposed reef surfaces (see, for example, Dr Isobel Bennett,

Exhibit 451).

2.4.38 The crustaceans include several species that have a

similar sensitivity to oil; though many closely related spe cies are remarkably oil resistant. Mr Norrie quoted one such

instance from a report by G.H. Stander and J.A.V. Venter "Oil

pollution in South Africa", tendered as Exhibit 275, in which it is said that following a spill of crude oil from the tanker

'Esso Essen1, "In the intertidal zone it was observed that millions of sand-hoppers (Talorchestia sp.) were killed." On

the other hand, the related "Isopods (Ligia sp.) were found

covered with oil but alive,"(T6046-7) Dr Grassle commenting

on the results of the barge 'Florida' spill noted that the "Ampeliscid amphipods are highly sensitive to small concentra

374

tions of oil and serve as an excellent biological indicator

of this type of pollution" (T6155-6) whereas another amphipod,

Corophium "is much more tolerant." (T6266)

2.4.39 It would be misleading to suggest through a long

extended recital of comments made in evidence on the differen

tial susceptibilities of different types of marine organisms to oil pollution that the differences in susceptibility, as

related, can necessarily be taken at their face value because

the conditions of pollution, in the examples quoted, cover a

broad spectrum of oil types, composition and concentration.

Nevertheless, the examples given are indicative of a wide

range of oil tolerances which is perhaps best substantiated in

the comments of Professor Clark on the evident variation of

response even among individuals of the same species. At T3645, in answer to the question:

"Does that mean, and I select quite at random, if

a material is generally speaking toxic indeed to,

say, a crustacean or a prawn, nevertheless, it may

affect in very different ways 100 prawns: some might

feel the effects deeply or not at all or very little.

Is that what you mean?" Professor Clark replied:

"Yes. I mean that at low concentrations of the toxic

substances you will add 100 prawns to these toxic conditions but they won't all die simultaneously.

Some will die very quickly. Some may survive some

time in it. If you are measuring toxicity by the

concentration of toxin at which animals die within five minutes then of course you will have a range of

different concentrations within that 100 specimens.

Conversely, if you measure toxicity as a range of

time it requires before the animal dies in a particu

lar concentration of the toxin, again you will get a

range of responses. Not all animals are identical

and this is indeed the reason why one performs experi

ments on a large number of organisms simply in order

375

to get an average figure, because a single animal is

representative only of itself."

(g) Conclusion

2.4.40 We conclude that the major lesson to be learned from

experimental testing and field observations of the response of

individual species of organisms to oil is this:

When oil is present in the sea it may be regarded as

probing the defences of every one of the thousands of different

kinds of organisms that may come within its reach. According

to the nature of these defences, about which virtually nothing

is known, and according to the composition, concentration and

physical state of the oil, and the duration of the spill some

organisms will be affected and others not. However, the impor

tant possibility must be entertained that the more immediate

and observable effects could be augmented by later occurring

changes affScting not only individual species but also, because

of the species interdependencies involved, the ecosystem as a

whole.

376

PART 5

FIELD STUDIES OP MASSIVE OIL SPILLS OVERSEAS

AND OF THEIR EFFECTS ON MARINE ORGANISMS

(a) Types of oil spills: Acute and chronic spills and effects

2.5.1 Evidence was given before the Commission In respect

of a number of overseas Incidents involving spills of crude

oil at sea and was in varying degrees informative of the

effects of these spills on marine plants and animals of oil

when present on the sea surface, in solution and droplet sus

pension within the water column, when drifted on to shore

lines and coastal margins, and when carried on to or within

the sediments of the sea floor.

2.5.2 The incidents noted included spills involving

releases varying in quantity from massive to small and were illustrative of differing patterns of release, transport and

persistence of oil. As such they encompass presentations and

effects that are manifested in both acute and chronic form.

An acute spill is, in this sense, one of short term and heavy application, a chronic spill is of longer duration but smaller

intensity and may be either continuous or episodic. Persist ence of oil may result in an acute presentation being con tinued in chronic form. Acute effects, following Professor

Clark (T3651), are exhibited in fairly immediate signs of injury to or death of organisms; chronic effects in the pre

sent state of knowledge are said to develop and show them selves more slowly,often with delayed, indirect and far

reaching consequences. An account of the "Florida" spill? which,though massive (700 tons), continued in persistent and

chronic form is given in Part 6 at paragraphs 2.6.8 et seq.

377

(b) Introduction 2.5.3 In this part we consider incidents involving the

spill of large quantities of crude oil - of the order of 250 -

100,000 tons, and the more immediate (acute) effects consequen

tial on these spills that have been reported on marine organ

isms and communities (other than coral reef communities which

are considered in a later section) living in different situa

tions in the sea and subject to different types of oil presen

tation. In assessing the weight to be given to evidence it is

important that regard be paid to the detail and scale of the

investigations on which the reports were made, the skill and

facilities applied to them and the extent to which the state

ments offered were substantiated or placed in doubt by examina tion. There are also certain methodological deficiencies

inherent in field investigations which will be referred to dur

ing the course of the account. Chief among these are the

invariable absence of pre-spill 'base line' studies by which to

assess through post-spill surveys the effects on organisms and

communities of oil pollution.

documented are the wreck of the tanker 'Torrey Canyon' off

Land's End, S.W.England in March 1967 and the blowout of the

drilling well A-21 off Santa Barbara, California in January 1969. Information on the 'Torrey Canyon' spill was given by

Professor J.H.Connell (Exhibit 20), Professor Clark (Exhibit

235), Mr Norrie (Exhibit 287) Dr Kikkawa (Exhibit 187) and other witnesses. Those on the Santa Barbara spill relied

mainly on accounts given by Dr Straughan (Exhibit 269, T5612 et seq) and Professor Connell (Exhibit 20, T436 et seq).

( i) 'Torrey Canyon' and Santa Barbara 2.5.5 The two incidents had many features in common. In

the following comparisons 'Torrey Canyon' figures are given

first. Each involved a "heavy" crude (in the terminology of

the industry) of specific gravities 0.868 and 0.888 and with

378

viscosities of 10.0 and 10.45 centistokes. The quantities of

oil released were of different magnitude; 'Torrey Canyon'

more than 100,000 tons and (at Santa Barbara) variously

estimated but probably of the order of 10,000 - 20,000 tons.

However, the quantities destined for the coastlines of

California and Cornwall, the regions reviewed in evidence, were

both in the 10,000 - 20,000 ton range. The duration of the

major release was in each incident about 11 days and the

localities of the spills were approximately 15 and 7 miles from

the nearest shore line. The sea temperatures were ^12°C and

C13°C. In both instances rocky shores and sandy beaches were affected and received an oil cover varying from "thin"

to a centimetre or more in heavily oiled areas. The organisms associated with them, though dissimilar in species, had many

genera in common. Both events were examined by expert

observers in large numbers and with full facilities for

observation and analysis.

2.5-6 Two background circumstances distinguished the two

events. The Santa Barbara area, unlike the English Channel approaches, has a long history of naturally occurring oil

seepages, and at Santa Barbara heavy rains before and during

the spill caused an unusually high river outwash of fresh

water into the oil polluted waters.

2.5.7 In addition to the 'Torrey Canyon' and Santa Barbara reports evidence was given on other somewhat less well documen ted surveys of the effects on marine organisms of massive spills of crude oil in respect of the following tanker accid

ents: (1) 'Andron', 10 miles off-shore, S.W. Africa, 1968; (2) 'Argea Prima', Guayanilla Harbour, Puerto Rico, 1962; (3) 'Chryssi P. Goulandris', Milford Haven, U.K., 1967; (4) 'Esso Essen', 2\ miles off Cape Peninsula, S. Africa, 1968;

(5) 'Ford Mercer' and 'Pendleton', Massachusetts, 1952;

(6) 'Gerd Maersk', R. Elbe, Germany, 1955; (7) 'Oceanic Gran deur ', Torres Strait, Australia, 1970; (8) 'Ocean Eagle',San

Juan, Puerto Rico, 1968; (9) 'Hamilton Trader', April 1969,

379

River Mersey, England.

2.5-8 The oil carried was in most instances a heavy crude

and the estimated quantities spilled varied from 250 - 500 tons

(3) to 10,000 to 20,000 tons (6).

(d) Oil on the sea surface

(i) General

2.5·9 An account is given of the subject in paragraphs

PI.6.176-184. Animals in danger of being coated by layered oil

on the sea surface are birds which may settle upon it or, if of

diving habit, pass through it; marine mammals (e.g. whales, porpoises, dolphins and seals), swimming birds (e.g. penguins),

reptiles (e.g. turtles and sea snakes) which must from time to

time break surface to breathe air, a few fishes (e.g. basking sharks, flying fish) and floating pelagic organisms (e.g. some

jellyfishes and related forms). Evidence was presented only in

respect of birds and mammals.

(ii) Effects on birds

2.5.10 Professor Clark commented on the difficulty of making

a precise estimate of the number of birds killed or affected by

oil spilled from the 'Torrey Canyon', but the figure of 40,000 -

100,000 mentioned by Dr Kikkawa (T1904) as deriving from Bourne

(1970) was not challenged. Of 7372 oiled birds reported dead almost all were diving birds. (Auks (guillemots, razorbills and puffins), numbering in all more than 73000, were the main vict

ims. Other divers (cormorants (4l) and gannets (3)) were also

affected. The most common birds in the area, gulls, though fre quently found spotted with oil, numbered only 3 deaths in this

large sample.

2.5.11 Dr Straughan, (quoting from Exhibit 281, I, P.308),

said of the Santa Barbara spill "An estimated loss of 3,600

birds can be attributed to the oil spill up to March 31, 1969".

380

This was two months after the initial blow out at A-21. An

estimate of 3,500 dead birds was given by Mr Stewart (T4385),

and Professor Connell spoke of "the killing of several thou

sand marine birds, principally those species which dive

through the sea surface to feed ..." (T436), Of 432 dead

birds examined for species identification all but 13, (includ

ing 9 gulls and terns, the commonest birds in the area) were

divers. They included loons, grebes, cormorants, pelicans and

water fowl (Dr Straughan, T5684, Professor J .¥. Connell, T436).

2.5.12 Large numbers of birds were reported killed as a

result of the 'Andron', 'Esso Essen', 'Ford Mercer' and 1 Pen

dleton ' and 'Gerd Maersk' incidents referred to in paragraph

2.5.7 the estimates varying from "hundreds" to very approxi

mate figures of 350,000 and 500,000 respectively following

the 'Fort Mercer' and 'Pendleton' and the ' Gerd Maersk' spills.

The number and variety of the birds affected reflect the loca

lity of the spill and the number, habits and seasonal behaviour of the species found in the area. Deaths from spills far out

to sea are liable to pass unnoticed for, as Professor Clark

noted at T3740, "It is only in areas where there is a concen tration of active amateur ornithologists and a deliberate cen

tralized reporting system that valuable information can be

collected." Even allowing for this circumstance near-shore

populations in the vicinity of large populations of gregarious species or of migratory or breeding flocks were without doubt

the most damaging. The main kills were of swimming or diving

species and birds that habitually settle on the surface.

2.5.13 The significance of large scale kills on the popula

tions of birds of temperate regions was discussed fully in the evidence of Professor Clark (T3591-3926) and Dr Kikkawa

(T1903-1982). It appears that in spite of the kills the num

ber of gulls, cormorants, gannets and fulmars, among other

species are increasing (T3916)· But there are other types,

381

notably divers, auks and duck of different species, many of

them of a small world population and with a low reproductive

rate, in which the populations are already showing a downward

trend and in which large scale losses are of serious concern.

(T1913; T3744)

2.5.14 In summary: although the numbers of birds killed can

rarely if ever be accurately computed they can run into many

tens of thousands. Far out to sea where, except for migratory

flocks, birds are not usually numerous the toll may be small;

in in-shore waters where the populations are greatest, especial

ly around breeding sites, or in areas of wintering populations, large scale kills can occur. Birds that swim, dive or habitu

ally settle on water are especially vulnerable. Some birds,

especially those of a small world population and with a low

reproductive rate, may be put seriously at risk as viable

species. Birds of the GBRP are dealt with in Part (9) infra.

(ill) Effects on mammals 2.5.15 Seals and porpoises are found in the area where the

'Torrey Canyon' was wrecked. No reference was made in evidence

to kills or injury to them.

At Santa Barbara, according to Dr Straughan, oil

coating of various species of whales, elephant seals and sea-

lions was reported but the number of stranded dead mammals was

not unusually high and the causes of their death could not be unequivocally related to oil contamination or oil ingestion.

(T5679) However, although "Data on the marine mammal popula tions do not prove large scale mortality as a result of the oil spill, this does not mean there was no mortality due to the oil".

(Dr Straughan Exhibit 281 Volume I p.4ll)

(e) Oil in solution and droplet suspension

(i) Effects on plankton 2.5.16 Following the release of oil from the 'Torrey Canyon' the extensive use at sea of dispersants made it impossible to

382

find and to sample water with an oil cover that could with

certainty be said to be free of dispersants. A passage in

Professor Clark's statement (Exhibit 235) relating to the

effects of the 'Torrey Canyon' oil on plankton was, on the

Chairman's ruling, (see paragraph PI.1.25) deleted from the

evidence, because the passage derived from writings of a mem

ber of the Commission (Dr Smith).

2.5.17 Studies of primary (plant) productivity were made in

the area of the Santa Barbara spill (Exhibit 281, pp. 17-48;

Dr Straughan, T5620) before and after the spill. Productivity

was found to vary greatly in different areas according to the nutrients available and other factors, chief among which was a

long spell of heavy rain immediately before and during the

period of the spill. Variations of productivity could not for this reason be correlated with certainty with the presence or

absence of oil. In the opinion of Dr Straughan "... although

there was a lower count than at a nearby station in the pre

vious month, various factors could have brought that about." She agreed however that "It could be due to oil." (T5678)

2.5·18 In respect of other incidents Mr Norrie said that, following the grounding of the tanker 'Esso Essen' near Cape Point, South Africa and the release of oil, "Three extensive

planktological surveys in the area where oil was originally released revealed no unusual conditions which could be attri buted to oil pollution. A marked plankton mortality which was

observed and affected mainly cold-water forms ... could be

explained by the intense interaction between warm water of Agulhas Current origin and cold Benguela Current water."

(T6o 47) A report entitled "Oil Pollution of the S .A . Coast -

the 'World Glory' Disaster," tendered as Exhibit 276, includes the following quotation: (p.51) "According to Oliff (personal

communication), plankton collected two metres below the sur

face in areas which had received a heavy dosage of detergent

was generally alive"; and of the 'Oceanic Grandeur' spill off

383

Cape York in 1970 it was said: "A plankton sample was taken be

neath an outlying oil slick and in the wake of a tender spray

ing detergent. Neither sample showed any unusual mortality or

lack of vigour among the organisms caught, but later microsco

pic examination showed that some organisms had their appendages

fouled with oil droplets." (Mr Tranter T751?)

2.5.19 The sun-illuminated upper layers of the sea are in

Professor Clark's words (T3723-4) "The site of virtually all

primary production in the sea by virtue of the photosynthetic

activity of the phytoplankton, and because of this there is a

rich and varied fauna of zooplankton as well. While some ani

mals ... which as adults live in other parts of the marine environment, have eggs, young stages and larvae that spend some

time in the plankton exploiting this rich food source and dis

tributing the progeny of a population of a sedentary species over a wide area by the water movements. The dead bodies of

planktonic plants and animals settle to the seabed and provide

a food source for detritus - and filter-feeders there, and many

shore animals trap or filter out planktonic organisms for food. Poisoning of surface waters would therefore have repercussions

in many directions: the basic food source for most marine ani mals would be reduced if not eliminated, and the environment in

which the generally very sensitive young stages of many animals

spend some time would become uninhabitable."

2.5.20 In general the few plankton surveys which have been

made in the neighbourhood of spills have eithe.. failed to show

a severe or widespread destruction of plankton or, where damage or an unusually low productivity is reported, have implicated other possible causes. These include the presence of toxic

dispersants ('Torrey Canyon'), or unusually low salinities

following heavy rain (Santa Barbara), or unusually low stresses due to the apposition and mixing of currents of warm and cold

water ('Esso Essen'). Whilst the possible relevance of these

natural or artificially created environmental stresses to the

384

levels of plankton productivity must be allowed they neverthe

less do not absolve oil from the possibility of causing loss

or damage to plankton.

(11) Summary and conclusions

2.5.21 On the evidence the majority of the Commission are

of the view that, in the open sea, damage to the plankton by

massive, short-term presentations of crude oil may not have

far-reaching ecological consequences. Even if there should be

substantial kills over a wide area of oil-covered water the

affected region would probably be very small in comparison

with the immensely large surround of the unaffected ocean from which, by the continuous flow of surface and subsurface

currents, healthy plankton would be carried into the previously depleted waters.

The Chairman prefers to express no view on open sea

effects and considers that a substantial depletion of

planktonic life in the GBRP particularly in the more restricted waters of the Northern Zone even though of a temporary nature,

could have substantial and unpredictable detrimental effects

on marine life.

However, all are agreed that in less open waters not benefiting so readily from external replenishment the effects

of oil on plankton could be more serious and long lasting.

Mention has been made of this possibility in the review of laboratory experiments on the responses of planktonic organ

isms to oil (paragraph 2.4.19) and this question is considered in more detail in paragraphs 2.9·52-56 infra.

(iii) Nekton

2.5.22 Only two reports, namely Exhibits 70 and 274, make reference to damage to fishes among nektonic species. Nine

days after the 'Ocean Eagle1 spill a two hour survey was made

of the fishes in San Juan Bay during which dead fish belonging to 3^ different species were collected. Skin lesions were

observed in some members of shoals of Opisthonema oglinum,

385

much used as bait by local fishermen. In a further survey, ten

days later, it was estimated that some 95% of an estimated pop

ulation of 100,000 of this species had severe lesions. Many

were dead, but a small proportion (<5%) showed signs of healing

with regeneration of tissue. The cause of the damage was not

determined but oil and/or oil dispersants were suspected. (Exhibit 274)

Exhibit 70,being a paper by Hampson & Sanders, relates

to the 'Florida' spill of diesel oil and at p .9 contains a

photograph of many dead fish and other animals. The caption reads: -"Dead fish, crustaceans and marine worms concentrated in tidal pools of West Falmouth, Massachusetts. One

week after the oil spill none of this evidence was

left; only a few empty shells remained. If it were

not for the nearness of our laboratories we could

not have known the extent of the marine kill."

(f) Oil on shores: Effects on organisms

(i) Rocky shores

2.5.23 The events leading to the invasion by oil of the

rocky shores of the islands and mainland of the Santa Barbara

Channel following the blowout from Platform A-21 on 28 January,

1969) were described in a report entitled "Biological and Oceanographical Survey of the Santa Barbara Oil Spill", (1969

70), Volume I, which was tendered as Exhibit 28l. For several

days the oil remained at sea under the influence of prevailing

north-north-west winds. "A storm commencing on February 4 and continuing through February 7 shifted the winds from a south

easterly direction clockwise to the west. Thus, on the night of February 4, large quantities of oil entered the Santa Barbara Harbor and heavy pollution of the mainland beaches

began ... The oil was washed on and off the beaches by the

tides. This meant that contamination varied almost continu

ously and it was impossible to determine accurately the amount

of oil that any one area was exposed to" (pp. 2-3)· "Inter

386

tidal areas ... were intermittently covered with films and

lumps of oil for several months in 1969, with most of the oil

deposited on rocky areas selectively adhering on the upper

intertidal" (p.325)- Photographs of the heavy oil cover were shown to the Commission by Professor J.H. Connell (T459,

slides 1 and 2). Similar events leading to the deposition of

oil from the 1Torrey Canyon' on the shores of Cornwall,

England were described by Dr Nelson-Smith in Exhibit 365.

2.5-24 The effects on intertidal organisms of the stranded

Santa Barbara oil were only briefly referred to in evidence.

Dr Straughan (T5623, 24/25 summarised the effects of oil as

follows: "Mortality among intertidal organisms at Santa Bar

bara is discussed in several reports. Suffice to mention here

that all investigators recorded mortality among the upper

intertidal barnacle, Chthamalus fissus. Nicholson and Cimberg

indicate that this was probably due to smothering by thick layers of oil in this region. Balanus glandula, a larger

barnacle, generally protruded above the oil layer and survived.

The surf grass Phyllospadix and the alga Hesperophycus harveyanus were also killed in some areas but recovery had

commenced by August 1969." ... "In general large scale morta

lities were not recorded in Santa Barbara intertidal areas."

2.5.25 Professor Clark said of the 'Torrey Canyon' shore contamination that "The oil coming ashore in south-west

England areas treated with about 10,000 tons of old style,

very toxic dispersant-emulsifier, partly while the oil was

afloat but also very extensively for beach cleaning so that

the effect of the oil cannot be separated from the effect of

the dispersant in this case" (T3696) and according to both Professor Clark and Dr Straughan (T5624/5) "The high mortality in Cornish shores was attributed to the large scale application

of detergents." Professor Clark said "A few rocky beaches in south

west England were not treated with dispersants and examination

387

of these and a number of untreated beaches in Brittany suggests

that, while crude oil caused some physical damage to plants and

animals, there were relatively few deaths from toxins in the

oil (O'Sullivan and Richardson, 1967)· Grazing limpets (Patel

la) ingested quantities of oil without harm and, indeed gave

some assistance to the natural erosion of stranded oil from the rocks. Mussels (Mytilus) and barnacles (Balanus, Elminius)

survived well, except where covered by an exceptionally thick

layer of oil". (T3696)

Few systematic surveys were made of the larger algal

plants the main surveys being of damage by dispersants used in

clearing oil. However, several species survived after oil had

settled on their fronds while in the splash zone above the

reach of tides the lichen Xanthoria survived under a layer of

wave-thrown oil which subsequently hardened into a crust. Mr

Cowell however quoted Ranwell (1968a, b) as saying that "Consid

erable damage was caused to lichens and flowering plants on Cornish cliff tops by wind-blown oil-spray from below" though

he himself had "observed some damage to lichens but ... was unable to distinguish it on the 'Torrey Canyon' shores from

dispersant damage which was also blown from wave tops".

(T11012)

2.5.26 In respect of the other spills brought to the atten

tion of the Commission Mr Cowell, quoting Nelson-Smith (T10975)

said of a spill of 25 - 50 tons of oil at Milford Haven in November 1968 which affected shores at Hazelbeach where, in

January 1967, a lesser contamination had resulted from the 1Chryssi P. Goulandris' release that "... although many organ

isms were killed enough grazing animals survived to prevent an

algal flush from covering the shore. Detergent treatment ... was light ... Three weeks after the cleaning the number of gas

tropods ... was drastically reduced but increased again by

January 1969 ... The most susceptible animal proved to be the 2

limpet Patella vulgata which was reduced from 150 per m to 21

per m2 ... The numbers continued to decline during the spring

388

and by the time that young were recorded in June 1969 the den- 2 sity had dropped to 5m ."

2.5.27 Of oil from the 'Esso Essen' which struck a sub

merged object 23s miles off the Cape Peninsula coast in April 1968 releasing oil on to nearby shores, Mr Norrie (T6045),

quoting a paper by Stander and Venter (Exhibit 275), said "In

the intertidal zone it was observed that millions of sand-

hoppers (Talorchestia sp) were killed. Isopods (Ligia sp) were covered with oil, but alive. Oiled limpets (Patella sp) peri

winkles (Oxystele sp) and anemones (Anthozoa sp) responded

sluggishly on being prodded. An unusually large number of

fresh periwinkle and limpet shells, however, did suggest an

appreciable mortality of these species in certain localities - probably due to smothering rather than the toxic effects of the oil." (T6046-7)

2.5.28 Following the grounding of the tanker 'Argea Prima' at the mouth of Guayanilla Harbour, Puerto Rico in July 1962 about 10,000 tons of Leona (Venezuelan) crude oil were pumped

overboard (T6215). Professor Johannes CT4229) and Dr Grassle

T6215) referred to a paper by Manuel Diaz-Pifferer (1963) re porting, as a result of the 'Argea Prima' spill, that "Marine organisms along the shore suffered tremendous mortality. Adult and juvenile lobsters, crabs, sea urchins, starfish, sea

cucumbers, gastropods such as king helmets and queen conchs, octupuses, squids, a variety of fishes, particularly clupeoids, and sea turtles were found dead ... Marine vegetation was

seriously affected, especially the plants living in intertidal and sub-littoral zones." Although Professor Johannes understood that the affected shores had been examined subsequently, he added "I have attempted unsuccessfully to obtain further in

formation on this subject." (T^231) See also paragraph ^.^.82

(infra).

2.5.29 Leona crude oil was also implicated in a spill of

389

some 83, 000 barrels at the entrance to San Juan Harbour,

Puerto Rico on 3 March 1968 from the tanker 'Ocean Eagler.

Professor Clark (T38OO), Mr Keith (T5567) and Mr Cropp (T11770-

1) each reported briefly on various aspects of the accident and its aftermath. Professor Clark noted "Heavy destruction of

marine life in littoral zone reported by Gilmore et al (1970)

but no details available" as the only comment made on the

damage caused by the spill.

2.5-30 Two intensively studied large spills of diesel fuel

resulting from the wrecking of the barge 'Florida' in Buzzards

Bay, Massachusetts on September 16, 1969 and of the tanker

'Tampico Maru' at the mouth of a small cove in Baja California, Mexico on March 29, 1957 are of particular interest for their

bearing on some aspects of the behaviour of crude oil at sea. Each caused immediate and considerable damage to marine life which was attributed by the investigators who reported on the

'Tampico Maru1 accident to the emulsification of oil in the

early stages of release, and which led in the 'Florida1 sur veys to the gathering of useful information on the persistence

and effects on benthic organisms of oil in sea floor sediments. The 'Florida' spill surveys are referred to later in paragraphs 2.6.8 et seq. Reports on the 'Tampico Maru' accident and its consequences were tendered in evidence as Exhibits 32 and 77, and were extensively quoted by Professor Connell (T443 et seq)

and Professor Clark (T3699 - 3701).

2.5.31 "At the time of the shipwreck, the 'Tampico'

carried approximately 59,000 barrels (some 8,400 tons) of dark diesel oil about l/3rd of which was lost upon stranding."(T458) "Further liberations continued sporadically during the next 8

months as the ship broke up." (T451-2) The composition of the

oil was not stated.

The oil affected organisms along "...at least 1,000

metres of coast " but "... studies were concentrated primarily on the small cove containing the wreck." (T451~2) "There was

an immediate heavy kill of barnacles, crabs, mussels and other

390

bivalves, and of starfish, and sea urchins. Most of the shore

algae were also affected.'1 CT3699) Apart from several species

of anemones and some species of molluscs which survived the

spill (T470) "...the area was utterly impoverished at first

but traces of recovery were perceptible in a few months. The

year 1958 witnessed a slight improvement but by 1959 extens ive changes were evident, many species were present in

abundance and the area for the first time since the disaster gave an appearance of a normal marine environment, teeming with animals... The year 1961 saw an even richer fauna, both

in species and numbers ... and the changes since then seem

relatively minor." (T*t72) Changes in the community composit ion of the regenerated fauna were attributed to the combined

effects of a slow and only partial replacement of animals

originally present and the introduction of new species in

association with the giant kelp (Macrocystis) which achieved

a dramatic proliferation in the early stages of the recovery (Ti+72-8) .

2.5.32 The early and extensive kills of organisms following

the 'Tampico Maru' spill were considered by the biologists who reported on the effects of the accident to be due primarily to the extensive emulsification and dissemination of oil by the

heavy surf of an exposed coastline and which for long periods was seen to break over the wreck into the waters of the cove... "Emulsions and slicks were present throughout the area ... sug gesting that the toxic concentration was maintained as long as

good stirring persisted in the water... ." (T550)

(ii) Sandy beaches

2.5.33 No significant information was available on the effects of oil on the animals which live within intertidal sand beaches in respect of any of the incidents reported in evidence.

(iii) Post-spill changes and the processes of recovery

2.5.3A In extension of this section on the acute effects of massive oil spills on intertidal communities mention must be

391

made of the way in which the character of an ecosystem jnay be

changed following damage by oil Gin the case of the 'Torrey

Canyon' spill) by oil and dispersant mixtures, and of the

approximate time scale of the return to normality.

2.5.35 Dr Straughan said of the shores of Cornwall (T5703-

5) that "The effects of pollution from the 'Torrey Canyon' disaster had been to alter the balance of ecosystems ... by

the destruction of grazing organisms" so that rocky shores

became "dominated by attached macrophytes (large algae)."

Professor Johannes (T4231) reported a similar development of plant cover following the 'Argea Prima' spill, the algae in

this instance being almost entirely Myxophyceae. A spill of

crude oil at Hazelbeach, Milford Haven in 196? caused, accord

ing to Dr Nelson-Smith (Mr Cowell, T10975), many organisms to be killed though "enough grazing animals survived to prevent

an algal flush from covering the shore." However, later

treatment with dispersants reduced the number of grazers so that by the spring of 1969 "the shore was covered by a growth

of the green alga Enteromorpha and this was replaced in the summer by Fucus vesiculosus. The covering of the shore by

Fucus has altered its character completely and the number of barnacles subsequently declined. This will presumably be followed by a decline in the numbers of carnivore (dog whelk) Nucella lapillus which feed on barnacles." (TIO976)

The Santa Barbara surveys do not report the develop

ment of an algal flush.

2.5·36 There might therefore be a correlation between the degree of damage initially caused and the subsequently develop

ed measure of change in the ecosystem as a whole, considerable damage being followed by an algal cover, little initial damage resulting in no obvious change.

2.5.37 A re-establishment of the original community structure, which is the true index of recovery, likewise depends on the

extent of the initial damage and of the cycle of ecosystem

392

changes which follow upon it. Dr Straughan reported that at

Santa Barbara some barnacles CBalanus glandula) were resettl

ing some two months after the spill (T5626); another species

(Chthamalus fissus) made a delayed re-rentry on oiled rocks

but recovery was well on the way within a year. (Professor Connell, T440) At Milford Haven Mr Cowell noted (T11100) a

virtual recovery following the 1Chryssi P. Goulandris' spill

in about two years. The 'Torrey Canyon' shores, on the other hand, though well on the way to full recovery, were still in some respects abnormal to the professional eye after five

years, and Mr Cowell considered that a complete return to

normality might take ten years (T10977).

(iv) Distance of spill from shore a relevant factor 2.5.38 A possible significant factor when considering the

capacity of spilled oil to damage intertidal organisms is the time the oil has been at sea prior to stranding. Pew reliable

figures are available. The 'Torrey Canyon' oil, as indicated in evidence by Mr Norrie when quoting from a publication by a journalist named Petrow (T6019), was 3-4 days at sea before

reaching the coast of Cornwall, but as stated in the answer to TR3 the Chairman regards this evidence as imprecise. The Santa Barbara shore strandings began some 7 days after the initial blowout, and the 'Esso Essen' oil (Mr Norrie T6014)

stranded after about 3 days. The 'Argea Prima' oil was pumped from a vessel which ran aground in-shore at the mouth of

Guayanilla Harbour, Puerto Rico. In the order of damage done according to reports sometimes but not always substantiated,

the 'Argea Prima' and 'Esso Essen' were the most destructive, the 'Torrey Canyon' and Santa Barbara spills much less so.

(v) Summary and conclusions

2.5.39 Reports on overseas experiences which came to the Commission's attention seem to indicate that when crude oil has been washed on to shores as the result of a single but not long continuing massive spill, intertidal and coastal

fringe plants and animals have suffered damage or death in con

393

siderable numbers but the effects were not catastrophic In the

sense that they were Incapable of reparation with the passage

of time. It is however necessary to qualify this general con

clusion to some extent by drawing attention to some limitations

of the surveys and in the character of the reporting.

2.5.40 First, it must be borne in mind that the oil-caused damage, as reported, invariably refers only to deaths or

damage suffered by the larger, more easily seen and most readily identifiable plants and animals. Almost all the animals listed

as having been affected by oil belong to the groups of the

vertebrates, molluscs, Crustacea, echinoderms (e.g. starfishes, brittle stars, sea urchins) and coelenterates (e.g. anemones,

corals). There are, in fact, more than twenty different major groups (or phyla) of animals each of which may be represented by a few, some tens, or some hundreds of species on temperate

or tropical shores. Only a relatively few species drawn mainly

from five phyla are mentioned in the majority of the reports.

It cannot be assumed that these smaller and often unnoticed

components of intertidal communities are more susceptible to oil injury than are the larger species but the restricted

character of the reporting should be noted.

2.5.41 Secondly, it is important to note that prev-spill surveys are rarely available as base line studies by which to

compare the effects of an oil spill, and in none of the report ed incidents had an adequate base line study been made.

2.5.42 Thirdly, death and damage must of necessity be

assessed from the presence of dead or injured plants and animals, many of which may have been rapidly removed by tides or currents or merged in the litter of organisms, some of which may have died from other causes. An example where this is

illustrated occurs in Exhibit 70 p .9 (Hampson and Sanders quoted in paragraph 2.5-22 supra). There is also a possibility

that a litter of dead organisms may include some which have

died from other causes.

394

(g) Oil on or in sea floor sediments; Effects

on benthic organisms

(i) Sediment deposition and transport

2.5.43 The deposition of oil on the sea floor, its transr

port at depth and incorporation and persistence in bottom

sediments were explored in respect of well-head and seepage

discharge of crude oil in the Santa Barbara Channel, and in the spill of diesel (No. 2) fuel oil from the ruptured hull of the barge 1 Florida' off West Falmouth, Massachusetts, in

September 1969.

2.5.44 The 1 Floridar spill and its consequences are exam

ined in detail a little later, (paragraphs 2.6.8-19). The Santa Barbara spill was the only instance of a crude oil spill

reported to the Commission in which surveys were made to determine the presence and spread of oil in sediments and to

assess the character of the communities living in the affected

sediments before and after the spill.

Before and during the Santa Barbara spill heavy rain

caused the transport of suspended and surface sediment particl es from the Santa Ynez, Ventura and Santa Clara Rivers into the waters of the Channel. In Volume II of the Biological and

Oceanographical Survey of the Santa Barbara Channel Oil Spill

(Exhibit 281, 341-343) the following passages occur "A large portion of the oil slicks emanating from the well blowout were transported into areas of high suspended sediment con

centrations in the surface water." The weighting of the oil with sediments was regarded as the "mechanism which resulted in sinking (of) large quantities of oil from the water surface" ... "Subsequently, much of the oil deposited at the sediment- water interface was removed from the area of initial deposition

... into deeper water."

2.5.45 Two methods were used in an attempt to trace the

rate of spread and changing patterns of deposition of the estimated 50 million tons or so of material discharged from

the Santa Clara and Ventura rivers:

395

(a) Surveys of the sea floor distribution of the sedi^-

ments, which were identifiable by their red colour and mineral

composition, were made in surveys initiated in March-April 1969

and extending to February-June 1970 (Exhibit 28l II pp. 195, 211). Comparison of the sediment thickness maps covering these

two periods (Drake et al Exhibit 28l II Chapter 5) shows clearly the extent of the transportation and deposition of

river-derived sediment from areas S.E. of Santa Barbara west^ wards for a distance of some 30 nautical miles or more into the

deep basin of the Channel.

(b) Infrared spectroscopic analyses were made of the

amounts of hydrocarbons in the sediments at selected stations

in the area and they were claimed to be accurate to 0.2 parts

per thousand (hydrocarbon to sediment by weight) and to mini mum detectable level of 0.2ppt (Kolpack et al Exhibit 28l II

Chapter 7). The authors, noting the association of the hydro

carbons analysed with the recently deposited and identifiable river sediments, were "certain that the hydrocarbons of these surficial sediments were also deposited after the floods

occurred."

2.5·^6 Although they could not "positively determine what

proportions of the hydrocarbon concentration in the surficial sediments were derived from Well A-21, and from natural seeps

in the area" they concluded from their analysis that "most ... were derived from Well A-21." "The pattern of hydrocarbon

deposition with time showed that initial deposition occurred south-east of Well A-21. Subsequently, hydrocarbons were deposited or re-deposited at the sediment-water interface in

the western portions of the Channel" (Exhibit 28l II p .29^) · These observations strongly suggest that crude oil may persist for some time in association with suspended or deposit ed sediments and be carried by bottom currents considerable

distances, (in this instance of the order of 30 miles or so)

from its point of origin.

396

(_ii) Effects on benthic organisms

2.5.47 A detailed survey of the polychaete worms, molluscs,

brittle stars and other invertebrates living on or in the

sediments of the Santa Barbara Channel beginning a little over

a month after the A-21 spill and continuing over the period March - October 1969 was made by K. Fauchald (who was not a witness) (Exhibit 28l I Chapter 5) for comparison with a sur

vey which had been made over the same general area ten years earlier.

2.5.48 The general conclusion drawn from the survey was

that "The standing crop of benthic macro-organisms has

decreased dramatically over the ten-year period separating the

State Survey and the Pollution Study" (Exhibit 28l I p .76).

The author points out, however, the difficulty which biologists

have in relating faunistic changes to specific environmental factors and therefore, in the proper exercise of caution, in

attributing to the presence of oil effects which may be due in whole or in part to other causes. In particular he notes

in respect of the populations of the echiuroid worm Listriolobus pelodes which were greatly reduced in numbers that "the heavy rainfall in the winter of 1969 may have caused some damage ..." and that with the rapid population growth in

the Santa Barbara area "It is possible that the increased flow of sewage ... may have an effect." In summarising the results

of the survey Dr Fauchald says (p.75): "No effects directly attributable to the oil spill could be seen in this part of the

study. As mentioned above, with the technique used it was not

possible to separate the effects of the oil spill from the general background "noise" of other factors influencing the benthos. This does not in any way or manner imply that the oil spill was without effects. The change in consistency in the

sediments alone would be enough to influence those organisms

that are heavily dependent on sediment-structure for their survival. The effects are not visible because the technique and the time allotted is not conducive to showing such effects."

397

2.5.49 Dr Straughan expressed a similar opinion in paying

"There was a decrease in the benthos over the whole ar^a from

that recorded 10 years ago, but because it was over the whole

area one feels that it is due to some other source. It could

be abnormal population fluctuations, it could be a gradual in

crease in pollution from human populations building up 41ong

that area, it could be many reasons. There was no significant

change in the benthos between May and October 1969." (15621)

(iii) Conclusions

2.5-50 On the evidence presented it is questionable whether

acute damage was inflicted on benthic communities following the

large scale Santa Barbara spill save for the deaths of barnacles and scallops which were in the immediate vicinity of Wellhead A-21 (Dr Straughan T5666). It must be pointed out however that

the conditions for proof of oil-caused damage are rarely in

practice attainable. In deep water communities out of rangle of direct observation, and whose composition can only be patchily

sampled by ship borne apparatus, a confident relationship between oil cover and oil-caused acute damage can only be established by closely approximating "before and after" surveys.

Apart from the scale of the operation involved, the siting of

the-antecedent base line studies cannot be planned for in advance of a spill which, because of the mobility of the oil released, may result in the deposition of oil in places the locations of which cannot be accurately predicted in advance.

Reference must also be made to Dr Blumer's letter to Dr Hunt of March 29, 1971 (Exhibit 303) in which Dr Blumer states that in

the West Falmouth study (consequent upon the 'Florida1 spill)

"we find deep and lasting damage to the benthic fauna, specific

ally to the 'smaller, lesser known organisms'."

398

PART 6 - FIELD STUDIES OF OVERSEAS CHRONIC

SPILLS AND OP* THEIR EFFECTS ON MARINE ORGANISMS

(a) Introduction 2.6.1 As noted earlier (paragraph 2.5.2) the possibility

must be allowed that chronic presentations of oil and chronic

damage to organisms may develop either as an aftermath of

massive spills or through a continuing or repeated admission

of low level concentrations of oil. In the former instance the acute and immediate damage to organisms wrought by a mas

sive spill might be expected, through the persistence of oil,

either to delay recovery, maintain an impoverished ecosystem

or intensify the damage caused to it according to the quantity

and toxicity of the persisting oil. Repeated or continuing

low level admission of oil might likewise be manifested in the

progressive appearance of detrimental changes affecting

individual organisms and ecosystems.

(b) Persistent oil: Effects on benthic organisms 2.6.2 The persistence of oil following major spills was reported in respect of both well head blowouts and tanker

accidents. Examples cited included the blowouts at Santa Barbara, Platform A-Well 21 (Exhibit 28l Volume I, T5682 and elsewhere) and at Chevron Block 41, Gulf of Mexico (Mr Biglane,

T6718 quoting from Exhibit 302); and the tanker spills of the

'Torrey Canyon' (Nelson-Smith, Exhibit 365 p.275), the 'Arrow'

(Dr Grassle, T6264), the 'Witwater' (Exhibit 259) and the barge

'Florida' (Exhibits 70, 72, 238, 532 and 533)· The Santa Bar bara, Chevron and 'Torrey Canyon' spills were of crude oils,

the 'Arrow', 'Witwater' and 'Florida' incidents involved res

pectively Bunker C, Bunker C/Diesel, and No. 2 Fuel oils. Naturally occurring seepages from the formations drilled at Santa Barbara and chronic production leakages in the area of

the Chevron spill (T6718, 6722) made it difficult to determine

399

with certainty the extent to which oil derived from the acute

spill and oil from natural leakages might be contributory to

faunistic changes.

The most fully documented surveys and most closely

examined evidence on the distribution and effects of oil per

sisting in sediments and of the effects of the oil on benthic

organisms were associated with the 'Florida1 and Santa Barbara

spills and, although the 'Florida' oil was not of the type

which we were called upon to consider under TR2, other aspects

of the aftermath of the spill carry with them possible general

consequences of oil pollution which it is of importance to

resolve in advance of our later assessments of the effects of

oil spills in the area of the GBR. We propose therefore to

examine the evidence received in respect of the 'Florida1 spill

in some detail. (paragraphs 2.6.8 et seq below)

2.6.3 The determination and interpretation of the distribu

tion, transport and persistence of oil in the West Falmouth sediments relied heavily on the methods used to determine the

composition of the oil and the changes to which it was subject

with the passage of time. For this reason a brief account is given of the methods referred to in evidence for the recogni

tion and analysis of oils.

Oil in sediments and living organisms can be identi fied, quantitatively determined and analysed into the component

hydrocarbons by various methods of which three namely gravi

metric determination, gas chromatography and mass spectrometry,

were referred to in evidence.

(i) Gravimetric analysis 2.6.4 Treatment of known weights of sediments and living tissue with a suitable solvent extract , in solution, "hydro

carbons plus other things." Subsequent treatment of the extrac

ted materials with caustic potash converts some of the materials

into soaps which can be selectively removed leaving an unsaponi-

400

fiable part of the extract. This consists largely of hydro

carbons which, by evaporation of the solvent, can be recovered

and weighed (Professor Clark T3711). The method is a simple

way of determining the presence and approximate quantities of

hydrocarbons but does not identify the constituent components of an oil.

(ii) Gas chromatography

2.6.5 According to Dr Connell "by far the best tool for

analysing hydrocarbons which is available is the technique of

gas chromatography" (T7070). The theory and practice of gas

chromatography were explained in detail by Dr Connell (T7066 et seq).

In essence the method involves the volatilisation of oil and the subsequent separation and identification, as peaks

showing up in a tracing, of the component hydrocarbons, the succession of peaks representing compounds of differing mole cular size and carbon number.

Dr Connell said that every compound displays its own

peak, but When several compounds of the same carbon number but differing molecular composition are present, or are represen ted in small quantity, the individual peaks may be so small or

close together as not to be resolvable as distinctive substan ces (T708O). The technique of gas chromatography, though limited in its capacity fully to analyse complex mixtures into

their separate components, is nevertheless a powerful tool for

establishing the identity or degrees of similarity or differ

ence of oils of differing origin and history. It is mainly in this context that we will be examining the results obtained by

chromatographic analysis in the West Falmouth studies.

(ill) Mass spectrometry

2.6.6 Dr Connell referred briefly to mass spectrometry as a

third method of hydrocarbon analysis. This method is used for the determination of the molecular structure of individual hydrocarbons that have been extracted from a mixture, but the

401

identity of which is unknown. (T706.9) The method was not

otherwise referred to in evidence.

(d) Biologically manufactured hydrocarbons and pollutant

hydrocarbons

2.6.7 The distinction here made is between hydrocarbons

manufactured by living organisms and compounds of fossil

(petroleum reservoir) origin which occur in the sea as pollu

tants .

Dr Blumer and Dr Sass, scientists at the Woods Hole Oceanographic Institution, Massachusetts, having drawn atten

tion in Exhibit 533 to the existence of these two classes of

oils go on to say that sufficient structural and compositional

differences exist between biologically-produced and pollution- derived hydrocarbons to permit their qualitative distinction

and their detection in each others presence (Exhibit 533 p.4).

They base their statement on their interpretation of gas chro

matographic records several of which are figured in the exhibit

and which show that naturally produced hydrocarbons of contemp

orary or recent origin consist of "a simple assemblage of pro

ducts" for "in all cases where hydrocarbons of marine organisms or of recent (unpolluted) sediments have been studied by medium

resolution gas chromatography ... the hydrocarbons in the range to at least C22 have been resolved into individual compounds;·

no continuous unresolved background was found." By contrast,

the processes involved in petroleum formation at depth in sedi mentary basins "produce a hydrocarbon mixture of enormous com

plexity which cannot be resolved completely by medium or high

resolution gas chromatography" (Exhibit 533, pp· 9-10). Other,

more specific, differences between natural and fossil hydro carbons which were referred to in evidence include the occur

ence in natural oils of a higher proportion of compounds of odd

carbon number, the presence of olefins and the frequent domin

ance of pristane (C^ H ^ ) (Blumer and Sass, Exhibit 533)· Fossil crude oils contain smaller proportions of pristane and

no olefins but are "rich in the toxic aromatic hydrocarbons

*102

and in cycloparaffins." (Dr Grassle T6l42)

(e) The 'Florida' spill

(i) Sources of information

2.6.8 Published information on the distribution and

characteristics of the oil contained within the sediments of

Buzzard's Bay following the 'Florida' spill and on the effects

on benthic organisms of the spilled oil were made available to the Commission through Exhibits 70, 72, 238, 290, 532 and 533.

The first four papers report the more immediate consequences

of the spill and were examined mainly through the evidence of

Dr Grassle. Exhibits 532 and 533 deal more particularly with

later occurring events such as the spread and persistence of

oil in sediments, and the partial recovery of the faunas affec

ted by the pollution. These were not put in evidence until the

closing stages of the Commissions, hearings. (Î¤165^5 :

23/5/72) Dr Blumer, the senior author of Exhibit 533, whose

views on the toxicity of persistent oils were of particular

interest to the Commission, was not available for examination though his testimony was invited on more than one occasion.

The more important aspects of the data presented and the con

clusions reached by the authors of Exhibits 532 and 533 were however reviewed in some detail by Mr Bennett, Q.C. "Some Submissions concerning papers of Dr M. Blumer" (which were

elaborated in the closing address of his junior Mr Helman (T18209-46A)) and also in the closing addresses of Mr Connolly,

Q.C. (T18802-7) and Mr Greenwood (T18247-50) .

(ii) General account

2.6.9 "Early on the morning of September 16, 1969, the barge 'Florida' came ashore off Fassett's Point, West Fal

mouth, Massachusetts and ruptured her steel hull, spilling an

estimated ... 60,000 - 70,000 gallons of No. 2 fuel oil along

the (eastern) shores of Buzzard's Bay." (Exhibit 70) Later

estimates put the quantity lost at about 170,000 gallons or 600-650 tons. (Professor Clark, T3702, Dr Grassle, T6130).

403

Dr Grassle added that analyses showed it to contain some 4l% of

aromatic hydrocarbons. A strong S.W. gale carried much of the

oil towards West Falmouth Harbour and Wild Harbour.(Dr Grassle,

T6130) Wild Harbour and its inner reaches of Silver Beach

Harbour, which received the heaviest cover, lie roughly north

wards of the site of the spill and from the map appended to

Exhibit 532 (Fig.l), about 2\ miles from it.

2.6.10 According to the account given by Mr G.R. Hampson and

Dr H.L. Sanders "The toll taken on marine life was obvious -

the oil-soaked beaches were littered with dead or dying fish as

well as worms, crustaceans and molluscs. Windrows of fish,

crabs and other invertebrates covered the shores of the Wild

Harbour River and large masses of marine worms, forced from

their natural habitat in the sediments, lay exposed and decay

ing in the tidal pools ... Lobsters and certain species of fish

... washed up on Silver Beach ... are primarily bottom-living

forms. This was surprising for it implied that the impact of the spill must have been felt not only between the tide levels, but also on the bottom below low tide ... preliminary observa

tions suggest that the oil may have consistently penetrated the

sediments of water depths at 7 - 10 metres in the heavily

polluted zones." (Exhibit 70)

2.6.11 From late September 1969 the month in which the spill occurred, samples of bottom sediment were collected and collated

over threemonth periods until October 1971 from a cluster of'

stations within Wild Harbour, Wild Harbour River and Silver Beach Harbour and from a more widely spaced series of localities

off-shore, some lying along the line between Wild Harbour and

the wrecked barge and a smaller number westwards out to sea for

a maximum distance of some 2 miles (Exhibit 532 Fig. 1). The hydrocarbon concentrations found, and recorded in milligrammes

per 100 grammes of dry sediments, are set out in Table II of

Exhibit 533.

2.6.12 Dr Grassle, quoting from Exhibit 72 p. 5, reported

on the nature of the oil found in the Wild Harbour sediments

in the following words (T6137-8) "Sediments in Wild Harbour

Basin (water depth 10 ft) were sampled 12 days after the acci

dent. The chromatogram of the total hydrocarbon fraction is

reproduced ... The similarity with the chromatogram of No. 2

fuel oil is striking. The carbon number range, boiling point

distribution and relative contribution of different isomers is

nearly identical. The major difference is a general decrease

of the lower molecular weight hydrocarbons in the oil recover

ed from the sediment; these hydrocarbons are more readily

soluble and should be depleted in an oil which has been in

contact with sea water for an appreciable length of time.

Conversely, these hydrocarbons are the most immediately toxic

fraction of the oil and their dissolution may be responsible in part for the lethal effect of the oil on the faunas ... Oil

continued to be released from the sediments for a long time

after the accident. Water with a patchy oil film was sampled in the Wild Harbour Basin ... more than 2 months after the

spill. The chromatogram of the extracted oil shows ... the

carbon number range extends from C ^ *° ^22 " ' " - * - ower boiling hydrocarbons are further, but not drastically depleted

... This suggests that the principal alteration may well have taken "place immediately after the accident and before the oil

became incorporated into the sediment."

(ill) Character and distribution of the pollutant oil

2.6.13 According to Blumer and Sass, the No. 2 fuel oil carried by the 'Florida' consisted mainly of hydrocarbons with

in the 170-370°C boiling point range and with carbon numbers

C10 ~ C22 (Exhibit 533, p. 7). Analyses of sediments in local ities within Buzzard's Bay that were deemed to be unpolluted

showed that they contained, on the average, 5-7 mgm of indige

nous (natural) and pollutant hydrocarbons per 100 g. dried

weight of sediment. Blumer and Sass regarded levels of 10 mgm plus as indicative of a significant admission of pollutant

(P.6).

They found in the sediments at the most heavily poll

uted station (Station 31) in Silver Beach Harbour oil concen

trations which rose from 110 mgm shortly after the first arri

val of oil from the spill to 1240 mgm 5 months later, with the

retention of an approximate average 200 mgm level over a 21

month period. Two years after the spill the last of the ana lyses recorded gave a level of 130 mgm. Nearby stations in

Wild Harbour River (II, IV and V), less heavily polluted,

showed levels starting around 50 - l80 mgm which declined

fairly steadily over 2 years to some 14 - 40 mgm (Table II

p.59). Two off-shore stations ( 7 and 10) showed the following sequences. Station 7 from 19 to 12 during the three months

commencing a month after the spill and Station 10 from 15 to 14

with several months not recorded, over the 10 months following the spill. In both cases subsequent recordings showed that the

concentration of oil fell below the 10 mgm level of "signifi

cant pollution" (Exhibit 533, p.6 and Table II).

2.6.14 Blumer and Sass, as a result of their analyses at

monthly intervals of the persistent but declining quantity of

oil contained in the Buzzard's Bay and Wild Harbour sediments

say at p.40 of Exhibit 533 that the depletion was mainly of straight chain paraffinic hydrocarbons which however "persist

at low concentration levels" and that "Even after two years, isoprenoid and cyclic saturated and aromatic hydrocarbons are

still very much in evidence ..." (p. 4l)

(iv) Toxicity of persistent oil 2.6.15 The two authors regard persistent oil as toxic to

organisms. The toxicity of oil, they argue, derives both from the presence of compounds of low and high carbon number. In

respect of the first category they say "It is environmentally

significant that the lower boiling hydrocarbons are removed from

the sediments by dissolution rather than by bacterial degrada

tion. This implies that a polluted sediment can supply these

406

toxic hydrocarbons to the water column, unaltered for a long

time after the spill", (p. 4-4) Of the compounds of higher

carbon number they say "The fuel oil spilled at West Falmouth

contained little tricyclic aromatics and none of the four or

higher membered polycyclic aromatics which are common in high

er fuel oils and whole crude oils. These hydrocarbons ...

possess both short and long term toxicity. They are less soluble and therefore more persistent than the benzenes and

naphthalenes. Thus a higher boiling fuel oil or a whole crude

oil would retain its toxicity considerably longer than the

fuel oil spilled at West Falmouth." (p. 45)

2.6.16 The question that Blumer and Sass did not resolve in

their writings was the measure of toxicity of the persistent oils. They say that because of the preferential depletion of

compounds of low carbon number "... the oil which appeared

several months after the spill ... was less immediately toxic than the fresh oil ..." (p. 43) but they give no evidence of

the toxicity of the more persistent aromatics of high carbon numbers which earlier in evidence had been described as "... among the least toxic materials in crude oils." (Mr Cowell,

T10919)

2.6.17 The measure of toxicity of the persistent 'Florida' oil is however perhaps best assessed from the results of the

biological investigations of the benthic fauna within the polluted localities (Exhibit 532) and from the extent to which it is possible, from the data given, to relate depletion and

recovery to the patterns of oil deposition reported in Exhibit

533.

(v) Biological surveys 2.6.18 In the West Falmouth surveys particular attention was

paid to the polychaete faunas of muds from heavily oil polluted

stations (e.g. station 31 in Silver Beach Harbour at 10ft depth) at lightly polluted stations (e.g. station 10, approxi

407

mately half a mile southwest of the Wild Harbour entrance In

about 40 ft of water) and an unpolluted station (station 35

about 1.8 miles WSW from the mouth of Wild Harbour in about 38 1 2

ft of water). Grab samples of ^ m were taken at intervals

from September 1969, a few days after the spill, until January

- March 1971, 15 - 18 months later; and all the worms present

in them counted and identified.

The majority of the Commission consider that the

samples were too small and infrequent for accurate comparisons

of individual and species numbers to be valid, for example a

sample 11.8 times as large as a grab sample contained twice as

many species (Exhibit 532 Table 3); and it is not stated in

the report whether the sediments at the different stations were

of a similar type and texture and therefore likely to carry

similar communities. The Chairman would prefer to express no

opinion thereon.

Nevertheless, even allowing for these considerations,

the species numbers at the unpolluted, lightly polluted and

heavily polluted stations (35, 10 and 31) following the spill,

which were respectively 27, 16 and 4, are strongly demonstra tive of an initial depletion in the presence of oil; and the

subsequent sequence of the species counts are indicative of the

measure and rate of recovery. At station 35 the counts are 27,

21; at station 10: 16, 17, 13, 17, 16, 16, 15* 36, 26, 21, 32: and at station 31: 4,1,4,4,6 * 11, 18, 12, 12 The asterisks would appear to mark break points of

the re-entry of species initially absent. At station 10 the hydrocarbon level for the first time fell to the boundary level

of a significant pollution as defined by Blumer and Sass (Exhibit 533). At station 31 the hydrocarbon levels were still

very high at the break point but the recovery process was only partial. The times after the spill of the break points were

respectively 10 and 9 months.

Because there seemed from the diversity and abundance

of worms in the unpolluted areas to be a sufficient supply of

organisms and larvae to effect repopulation of damaged areas,

408

it seems justifiable to conclude that the delayed recovery of

the polluted sediments is due to the persistence within them

of oil and of conditions of chronic pollution which, in this

area and according to the amount of oil originally present,

can persist for varying lengths of time up to 2 years and

more. Nevertheless, on the evidence of the results reported

in Exhibit 532 even the most heavily polluted locality in

Silver Beach Harbour (Station 31) was beginning to recover 9 to 10 months after the initial pollution.

(vi) Summary and conclusions

2.6.19 We conclude from the observations made on the 'Florida' spill in the light of the commentaries upon t'hem that

(a) the initial serious damage inflicted upon the

faunas of Wild Harbour and adjacent areas of Buzzard's Bay resulted primarily from the solu

tion of the more soluble low boiling point and

low molecular weight hydrocarbon components of the spilled oil (paragraphs 2.6.10 and 2.6.12

supra)

(b) the toxic components responsible for the initial kill had suffered a general decrease during the 12 days following the release at which time the first analyses of oil incorporated into the bottom sedi

ments were made. They showed the retention of

hydrocarbons to of which a large propor tion were aromatic hydrocarbons.

an oil trapping bay (Wild Harbour) downwind of the spill. Unequivocal evidence of a substantial sub sequent off-shore spread of oil of indicative pol

lution (10 mgm) levels to other areas seems however

to be lacking.

(d) oil initially present in the sediments in large

quantities, persisted for at least two years, but

some regeneration of the fauna seemed to occur even

409

when the oil was present in sediments at a level

of significant pollution after a period of about

10 or 11 months.

(f) Continuous pollution and its ecological effects: Case histories

2.6.20 The effects on marine eco-systems of a long continu

ing admission of oil into the sea were referred to in evidence

in respect of a number of localities illustrative of differing

intensities of pollution by crude oil and mixed, in some ins

tances, with refinery products.

(i) Caspian Sea

2.6.21 Professor Clark (T3768) said that "The western part

of the middle and southern Caspian Sea is subject to intense

and continuous oil pollution from several sources (Kasymov, 1970; Exhibit 299). Off-shore drilling coupled with numerous

natural and artificial oil seepages from the sea bed account

for 500,000 kg of crude oil per day escaping into the sea in

the region of Neftyanye Kamni Island alone. Waste waters from

refineries and the petrochemical industry contribute a further

substantial amount of oil to the sea while the Caspian tanker fleet and fishing vessels are estimated to discharge some

900,000 cubic metres of oily water into the sea daily. In

addition, large quantities of untreated sewerage are discharged into the sea, but the chief pollutant is oil. The consequences have been dramatic. The production of phytoplankton on which

all life in the sea ultimately depends has fallen markedly

between 1962 and 1969 and this has been reflected also in a decline in zooplankton production. Since 1930, catches of stur

geon in the Caspian as a whole have fallen by two-thirds and in

the southern Caspian are now only a quarter of what they were.

Salmon catches have been reduced to a tenth of their former

figure." Professor Clark observes, however, that "It is possi

ble that, as an enclosed sea with a large, heavy, industrial

ised complex and a major urban area on its shores, the Caspian presents a special case unlikely to be parallelled in more

410

open seas." (T3768)

(ii) Gulf of Mexico

2.6.22 Dr L.S. St Amant, Assistant Director Louisiana Wild

Life and Fisheries Commission said, at T3938, the coast of

Louisiana comprises "...some seven million acres of marshland

which is largely uninhabited." He added, "The production of

oil in the coastal estuaries of Louisiana began in the late

1920's but reached its greatest intensity during and after

World War II ... major off-shore discoveries did not occur

until 1947 and reached a high level in the late 50's and throughout the 60's ... a great many wells have been drilled

and miles of pipelines have interlaced the estuarine and off

shore areas of Louisiana." (T3941) "There are 1089 single well structures and 703 multiple well platforms ... in water

depths ranging up to 350 feet but the bulk of these structures occur in water depths from 0-150 feet." (T3943)

2.6.23 The Louisiana coastal area, according to Dr St Amant, has been "noted for its high production of oysters, shrimp,

fish, fur and water fowl for many years." (T3939) Off-shore, a variety of fish are taken commercially while barracouta, jew- fish, red schnapper and spade fish are present in large numbers

around oil rigs (Mr Gusey, T5177), the waters in the vicinity of these structures furnishing "some of the finest sport fish ing ever known." (Dr St Amant, T3983)

2.6. 24 Dr St Amant said that "In evaluating pollution

effects in any area, one should immediately make a distinction between accidental and chronic pollution. While accidental pollution can be catastrophic ... it will very rarely ...have a gross permanent and lasting effect on the ecosystem." How

ever, "minor or long range accumulative effects are not readily

demonstrable." (T3960-1) But Dr St Amant stressed that "By con

trast, of more critical concern is the continuing low-level chronic oil pollution associated with intensive operations in

in shallow water embayments and marshy areas." Here there are

"numerous local areas of high petroleum production where chron

ic oil loss and mechanical obstructions have resulted in a bio

logical desert or have ruled out any other use of the area." (T3966) In amplification of this statement Dr St Amant said

that the desert area around a single unit or tank battery might

be "perhaps one to five acres", that "in a large field you might have several such units scattered over every hundred

acres" and that in places where the ecology may not be distur

bed the presence of industrial operations "rules out every

other use of the area ... and a large oil field might usurp

several hundred acres in the embayment." (T3967)

2.6.25 Dr St Amant was of the opinion that the Louisiana State Fisheries statistics give "... no evidence that the oil

industry has had any significant effect on fish or shellfish

production in aggregate over the years since 1939" (T3981) but he added that "if we had put as much effort into the oyster

industry as we do now and still had a great many of the optimal areas which have been usurped by the petroleum industry our

production might be greater than ever" adding "I have no proof

of this; this is an opinion." (T3992)

2.6.26 Dr St Amant's evidence bore almost entirely on the effects of the oil industry's activities on commercially fished species. Although he frequently used the term 'ecosystem' as

indicative of the larger and more diverse communities of organ

isms present in Louisiana waters no indication was given of the nature of these communities or of any surveys that had been made of the planktonic, benthic and intertidal populations with

in the area. It was evident that he had in mind these deficien cies of knowledge when towards the end of his evidence he obser

ved that "The greatest gap in our knowledge of the effect of oil on marine life involves the questions of chronic and minimal

pollution levels ... Does it materially affect the ecosystem?

What effect does the chronic and cumulative oil pollution have

on a local area? Does this effect extend beyond the local site?

These and many related problems should be Investigated before

final conclusions are drawn about the mechanics of oil pollu

tion in marine eco-systems. Certainly the significance of the

continual addition to and accumulative effects of sub-lethal

pollutants on the environment is probably the most important ecological question facing us today. While this question

remains unanswered, environmental management decisions based

only on our present knowledge of short-term gross effects of

pollution and/or environmental manipulation may eventually

prove to be disastrous." (T3985—6)

(ill) Milford Haven

2.6.27 Dr Nelson-Smith in a paper published in 1967 and

referred to in Exhibit 365 described Milford Haven and its oil

terminal facilities in the following words. "Milford Haven is

situated at the southwestern tip of Wales, its mouth forming part of a rocky coastline ... Its marine flora and fauna are

... amongst the most varied in the British Isles. Because of the deep and rocky nature of the inlet this variety extends far up the Haven and the common estuary of the rivers Cleddan

which opens into it. The lower Haven has long been used by

fishing vessels, coastal freighters and small naval craft with little effect on its shores, but within the last ten years it has become established as Britain's largest oil port." Mr

Cowell said that "in i960 two major oil companies added marine terminals there: one serves its own refinery and the other receives and stores crude oil ... By 1970 ... two further re

fineries had been built each with its own terminal, and the

building of a fourth refinery has just begun ... Tankers of more than 200,000 tons can be accepted in the port ..." where

"... 40 million tons (of oil) are handled annually".(T10901-2)

2.6.28 In the account which was given in evidence of chronic

pollution and its effects on the flora and fauna of the Haven particular reference was made to certain installations and

localities which can readily be pictured in their general geo

413

graphical relationship. The Haven is entered from the sea by a

north-east inclining reach roughly a mile long. A turn is then

made to the east to enter the Haven itself. On the north shore

of the Haven near to its mouth at Littlewick Bay a quarter of a

mile long Esso jetty extends into water of 60-70 feet depth.

About 3-3h miles east of the Esso jetty is a shorter jetty of the

Gulf refinery. Beyond it to the east is the indentation of

Hazelbeach. On the south shore roughly opposite to and approx

imately lh miles distant from the Esso terminal is the BP termi

nal (with an adjacent refinery) and near to it to the east is

the Texaco terminal and refinery. Both lie on the eastern head

land of the embayment of Angle Bay.

2.6.29 Apart from a serious spill of upwards of 250 tons of

oil from the tanker 'Chryssi P Goulandris' at the BP terminal

in 1967, the spillage rate of oil from these refinery terminals has been calculated over the years 1966-69 as about 0.0002

0.0001% of the tonnage handled (T10,9O2) or about 40 tons per annum. The refinery effluent discharges were stated by Mr Cowell

(T10,942A) to be "derived from three main sources. 1. Process water condensed from steam injection in the refining operation.

2. Fresh water run off from rain falling into the refinery area, and 3. Ballast water from tankers ... all discharged through the same pipe" ... and with the oil discharge "limited by law to 50 ppm, but rarely discharged in concentrations greater than 20-25

ppm". (T10943)

2.6.30 Surveys of the intertidal flora and fauna had been

made by Dr Nelson-Smith and other scientists at various times and in numerous localities along the north and south shores of the Haven from 1959 onwards. Mr Cowell summarised the nature and results of these surveys at T10984 in the following words

"Long term changes in the fauna and flora at Milford Haven as a result of the oil industry operations are being recorded using

32 monitoring transects around the shores of the port. Record

ing is done using the modified Crisp and Southward scale des

cribed by Crapp (1970). Recording began before the oil port

was established ... These surveys reveal no long term changes

In the flora and fauna of Milford Haven that are attributable

to the development and operation of the oil terminals and

refineries, the only exceptions to this being damage to two

repeatedly cleaned recreational beaches and to damage within

the Immediate vicinity of one refinery outfall pipe discharg

ing water with an oil content of approximately 25 ppm."

(T10984) The methodology of the surveys was outlined by Mr

Cowell at T10946-7 and the monitored organisms listed at

TIO963-5 .

2.6.31 Mr Cowell stated (T11062) that no biological effects of oil pollution had been found In the neighbourhood of the

Gulf and Texaco refinery outlets In Milford Haven but that

changes had been noted on the Littlewick shores adjacent to

the Esso jetty. "When this sheltered bay was first examined

In 1969 It was surprising to find that the dominant Intertidal

species was the exposed shore species of brown seaweed, Pucus veslculosus. Prom the bay's position a limpet/barnacle domin

ated shore had been expected with the sheltered shore brown

seaweed Ascophyllum nodosum as the dominant alga. Early records showed that this shore had originally been a limpet/ barnacle dominated shore. To study the changes, six transects were established up to 450 metres on either side of the out

fall. It was found that several species occurred In reduced numbers or were absent ... The severely depleted fauna and

flora took the form of a pollution gradient (Crapp, 1970)." Beyond 450 metres on either side of the outfall "the situation

was normal." (T10946)

2.6.32 Mr Cowell said of the intertidal eco-system at

Littlewick Bay that "there was no change at the time the refinery was built but the change has been documented and

observed from the time of the commencement of operation,

within a year or two " (T11080) but he agreed, In subsequent

415

cross examination, that observations prior to 1969 had been

made by untrained biologists. In his opinion there had been no

further deterioration of the eco-system attributed to oil since

1969 when Mr Crapp had made his survey; nor had the affected

area become enlarged. (111074)

2.6.33 The possible effects of chronic oil pollution on the deeper water benthos were not satisfactorily resolved in evi

dence. Mr Cowell admitted under cross examination that the only

biological surveys known to him had been undertaken in Angle Bay

which was not in the direct line of flow of effluent discharges;

that he was not aware of any biological surveys in the main

channel; and that chemical analyses of muds had been few in

number and restricted in area. (111069-70)

(iv) Summary and conclusions

2.6.34 In summary of the evidence presented on chronic pol lution overseas by oil, and its effects on marine organisms and

eco-systems in respect of the well documented examples of the

non-reefal areas of the Louisiana oil fields and the Milford

Haven oil terminal the following conclusions may be drawn.

(a) The continuous admission into the sea of oil, even

in low concentrations of 20-25 ppm, may adversely

affect a variety of organisms and induce long lasting changes in the character of marine eco

systems .

(b) The changes reported are, on occasions, sufficient

to be noticeable by untrained as well as trained

observers but no surveys have as yet been under taken which accurately and quantitatively measure

the effects of chronic pollution on all the com ponent species of an eco-system or the occurrence

of possible sub-lethal effects.

continuous oil escapes in low concentration from a

4l6

single site of release is not extensive. Disper

sion and the various processes which accompany the

ageing of oil with the passage of time and its

transportation by currents produce a gradient of diminishing effect with distance. Bearing in

mind their purely local significance the Louisiana

figures suggest an effect over 1-5 acres from a

single unit or tank battery. Milford Haven surveys

indicate an approximate 900 metres confinement of significant damage. The Chairman considers that

Dr St Amant as quoted in paragraph 2.6.24 supra was

stressing that by way of contrast with the effects of accidental pollution, low level chronic pollu

tion is of more critical concern.

(d) The views expressed in evidence give support to Dr St Amant's belief that "the significance of the

continual addition to and accumulative effects of

sub-lethal pollutants on the environment is probab ly the most important ecological question facing us

today." (T3986)

(g) Oil within organisms and food chains

(i) Introduction

2.6.35 Professor Clark, when discussing the possible public health hazard that might arise from the consumption of oil-con taminated shell fish and other sea food, made the following

comment. (T3772/3) "Until recently, oil pollution had not been thought to constitute a public health hazard - indeed, the possibility of

this had seemed so remote that the matter had received little

serious consideration - but recent research findings have prompted a number of scientists, principally in the United

States, to claim that oil pollution of the sea constitutes a serious health hazard in several different ways" ... "The claim

that oil pollution menaces human health originates in the follow ing reasoning. Naturally occurring hydrocarbons synthesized by

marine algae, diatoms, etc. are selectively accumulated by some

zooplanktonic organisms feeding upon them. Once these hydro

carbons have been incorporated in the lipid pool of an organ

ism they are immune from further digestion or degradation.

They then behave like, for example, the persistent chlorinated

hydrocarbon insecticides and are transmitted through the food

web and may reach quite high concentrations in terminal members

of food chains. Hydrocarbons are highly characteristic com

pounds identifiable with great precision by gas chromatography.

Oil pollution in the sea adds to the range of hydrocarbons al

ready there and can be distinguished from the naturally occur

ring compounds by suitably refined and analytical techniques.

Oil hydrocarbons are taken up by animals, protected from degra

dation, accumulated and concentrated in exactly the same way as naturally occurring hydrocarbons. The health hazard arises

because they include a number of known carcinogenic compounds."

2.6.36 In this section of our report we examine, on the ba

sis of the evidence received, the constituent parts of the argument which Professor Clark posed for consideration.

(ii) Biologically manufactured hydrocarbons

(a) Plants

2.6.37 Machin and Hopkins (1962), in a passage quoted by

Professor Clark (T3716) state that vegetation is the principal source of naturally produced hydrocarbons of recent origin.

The statement was not developed further in evidence, though

some examples were given of the kinds of plant which are known

to synthesize hydrocarbons and of compounds they manufacture.

Thus, it was noted that "An oleofinic hydrocarbon, identified

as heneicosahexane (C21H22) occurs in many marine planktonic algae and many centric diatoms" (Professor Clark, T3773), and that "many algae contain high concentrations of n. pentadecane,

n. heptadecane and other normal paraffins." (Dr Grassle

T6142). Mr Cowell, quoting ZoBell (1971) added that "polycyclic

aromatics are produced in very large amounts in the sea by

phytoplankton." (T10920)

2 .6.38 In consequence of this large scale production of

natural hydrocarbons, which one estimate quoted by Professor

Clark (T3781) puts at "3 tons of aliphatic and aromatic hydro

carbons per square kilometre of ocean per annum", animals

which feed on plants or on their remains in sedimentary mater

ial almost invariably contain some plant-produced hydrocarbons.

The copepod Rhincalanus nasutus takes up heneicosahexane and

"accumulates it when maintained in cultures of appropriate

algae in the laboratory, though other related copepods in

similar cultures do not. The same compound has been isolated

in oysters, herring and the liver of basking shark (Professor

Clark, T3773), while Dr Blumer (Exhibit 297) found evidence for the passage along a food chain of hydrocarbons of biologi

cal origin by identifying the compounds found in the liver of

the basking shark Cetorhinus maximus with those found in the

copepods Calanus hyperboreus and C. finmarchicus on which it

had been feeding.

(b) Animals

2.6.39 It would appear from evidence given that some animals at least, like plants, are capable of synthesizing hydrocarbons,

often using precursor materials derived from plants. Dr Blumer

(Exhibit 297) instanced the synthesis of squalene in the liver

of the basking shark and Dr Grassle (T6383) cited experiments by Blumer, Mullin and Thomas (Exhibit 306) which suggest that some copepods may synthesize pristane from plant derived phytol.

(ill) Pollutant hydrocarbons 2.6.40 Pollutant hydrocarbons have been found in the bodies

of a variety of marine organisms, and instances were given in

evidence of animals that have been seen to ingest oil in the various states of droplet suspension in sea water, as oil/

water emulsions in sediments, and when present on rocks as a

semi-solid coating of weathered oil. Freegarde, Hatchard and

Parker, in a paper (Exhibit 362) which was referred to in the evidence of Dr Connell (T7176-81), Mr Mansfield (T7201) and

Mr Keith (T12056), observed the capture and ingestion of drop

419

lets of Kuwait oil by barnacle larvae and the copepod Calanus

finmarchicus in experimental laboratory cultures. The addition

of a fluorescent dye to the oil enabled it to be traced in its

passage through the gut of these animals and its expulsion with

the faeces. No mention was made of its occurrence in other

parts of the body. Professor Clark (T3696) cited reports of

limpets (Patella) rasping partially hardened oil from the sur

faces of intertidal rocks. According to Dr Nelson-Smith (Exhi

bit 365) some, and perhaps all of the ingested oil is subse

quently expelled with the faeces.

2.6.41 The contamination by pollutant oils of oysters,

scallops and other molluscan shellfish was referred to in the

evidence of Dr St Amant (T3974 et seq), Mr Stanphill (T4646),

Dr Halstead (T7320 et seq), Dr Grassle (T6123 et seq), Mr

Cowell (T11019-21) and Professor Clark (T3770-4) among other

witnesses; and a suspected contamination of mullet by petro

leum hydrocarbons in the Brisbane River was discussed by Mr

Harrison (T5734-5) and Dr Connell (T7071 et seq) . In none of these cases was entry of oil observed but one or other of two

criteria were used in demonstration of its presence.

2.6.42 Dr St Amant (T3974) said "... that a serious taste and odour problem developed when oyster beds become contamina

ted with oil based muds" and that "Oysters will purge them

selves of an oily taste if removed to uncontaminated areas ..." (T3975-6) The tainting of oysters when oil is present and, as

Dr St Amant's evidence would seem to indicate, its absence in oysters from uncontaminated waters, strongly suggests that

tainting is due to pollutant hydrocarbons absorbed on to the

surface of the animal or retained within its body.

2.6.43 Tainting is not however of itself unequivocally demon strative of the presence of pollutant oil compounds. Mr Harri

son noted that "tainted fish have been picked up in the river system at Noosa where there is no industry and not many people"

(T5735), and Dr Connell said that tainted mullet had been taken

at many places along the Queensland coast, and he instanced Tin

Can Bay, Tewantin, Caloundra, Pine Rivers, Sandgate, Luggage

Point, Wynnum and the Brisbane River as localities from which

tainted fish had been sent to him for analysis. (T7075) The

main points he made when questioned on his statement (Exhibit

316) were that only some fish - the percentage was not known

to him - from these localities are tainted (T7O83) and that in

every case the unpleasant taste or odour was due to kerosene like substances.(T7082) When asked "whether these were

naturally occurring hydrocarbons ... or whether they were the

result of some sort of spillage" Dr Connell answered "I do not know." (T7094)

2.6.44 The conclusion we draw from these few observations is

that natural hydrocarbons may be, but are not proven to be, a

cause of tainting, but that petroleum hydrocarbons can, with out question, cause tainting.

(iv) Persistence of pollutant hydrocarbons in

organisms

2.6.45 The subject of the persistence and possible accumu lation of pollutant hydrocarbons within the bodies of marine organisms was referred to in the statements of several witnes

ses. It was evident that very few quantitative estimations had been made and that the principal sources of information derive from the work of Dr Max Blumer and his associates of the Wood's Hole Oceanographic Institution, Massachusetts. Quantitative

data and commentaries bearing on the contamination of oysters and scallops following the massive release of No. 2 diesel fuel

from the wreck of the barge 'Florida' in Buzzard's Bay, Massa

chusetts are reported in Exhibits 72, 238, 290 and 532. A study by Dr M. Erhardt on 'Petroleum hydrocarbons in oysters from Galveston Bay, Texas (Exhibit 540), though admitted late

in the hearings and not subjected to critical examination, was also taken into consideration by the Commission.

2.6.46 Dr Blumer was not available to give evidence. The

experimental procedures used and the conclusions drawn by Dr

Blumer and his associates were, therefore, examined mainly

through the evidence of Dr Grassle (T6138 et seq) who had par

ticipated in the study (Exhibit 238) which most directly and

fully reports the data and experimental procedures on which the

authors' conclusions were based.

Shellfish of Buzzard's Bay, Massachusetts

(i) General

2.6.47 Blumer, Souza and Sass explain the circumstances which led them to examine the contamination of oysters and scallops

by the No. 2 diesel fuel oil spilled into Buzzard's Bay follow

ing the wreck of the barge 'Florida' off Fasset's Point, West

Falmouth on 16 September 1969 in the following words (Exhibit

72, p. 2):

"Some of the productive shellfish beds upstream from

the affected areas had remained viable; however, they were

closed to the taking of oysters and scallops because of possible

contamination. On September 25, 1969, taste tests suggested

that shellfish could be taken safely and the areas were re

opened. However, commercial exploitation yielded scallops with objectional "oily" taste; this led again to a closing of the

shellfish areas on September 27, 1969. At that time a joint

effort between the Town of Falmouth (In the person of Mr G. Souza, Shellfish Warden) "and this laboratory" (The Wood's Hole Oceanographic Institution) "was initiated to determine the

possible pollution of oysters and scallops by this accident

and to advise on further closing or re-opening of the shellfish areas. Scallops (Aequipecten irradians) were collected in West

Falmouth Harbour on November 4 and oysters (Crassostrea virgin- ica) in Wild Harbour River on November 12 ... For comparison, uncontaminated oysters were collected on the same date from

Waquoit Bay on the South Shore of Cape Cod, Massachusetts" -

Waquoit Bay was said not to have been affected by the spill.

(Exhibit 238 p .22)

422

2.6.48 Only In the case of oysters were animals from both

contaminated and uncontaminated sources analysed for the total

quantity and composition of their hydrocarbons; and in these

animals only were successive analyses made with the passage

of time and under controlled conditions of keeping. Because

the experiments on scallops were limited to an examination of

the hydrocarbons present at the time they were collected, they

do not bear so directly as do the oyster experiments on the

subject of the persistence of hydrocarbons in animals.

(ii) Scallops

2.6.49 The hydrocarbon assays of scallops were of somewhat limited value. In the first place the animals examined were

all taken from the contaminated sediments of West Falmouth

Harbour and no hydrocarbon measurements were made of controls

from uncontaminated sediments by which to determine the levels

of pollutant oil present in the animals over and above the

levels of hydrocarbons of natural origin which would be present

in both contaminated and uncontaminated sediments for, as

Blumer et al remarked in Exhibit 72 at p .9, there is a "serious problem in tracing hydrocarbon pollution through the environ

ment since pollutants are always accompanied by natural hydro

carbons." Secondly, the scallop assays were limited to an examination of the hydrocarbons present at the time the ani

mals were collected. The data on scallops are not therefore

informative of the extent to which hydrocarbons may persist in

the tissues when animals are kept in clean water. A further difference in the character of the hydrocarbon assays on scal

lops as compared with those on oysters is that, in scallops, only the adductor muscles were analysed, a circumstance which,

while more exactly identifying the tissues in which hydrocar bon accumulation may occur, makes it impossible to compare

the total hydrocarbon carrying capacity of the oysters and scallops examined during the course of the experiments.

2.6.50 Data given in Table 1 of Exhibit 72, and Table 3 of

Exhibit 238 summarise the essential features of these collec

tions. Table 1 was subject to a correction entered at T6151 to

read "oysters" instead of "scallops" in respect of samples 5

and 6.

(iii) Oysters

2.6.51 The nature of the experiments as related in Exhibits

72 and 238 are as follows.

In all, 33 animals were used. Ten were taken from

the oil polluted area of the Wild Harbour River and 23 from

Waquoit Bay.

The 10 oysters from the Wild Harbour River were col

lected on 12 November, 1969, 57 days after the 'Florida' spill.

The soft parts of 7 of these oysters were analysed gravimetri

cally for their total hydrocarbon content and a small portion of the oyster tissues were used for chromatographic identifi cation of the constituent components of the oil. (Dr Grassle,

T6l42) The 3 remaining oysters "were removed to clean labora tory tanks on November 12, 1969 "and were maintained there for

either 72 or l80 days. ("Exhibit 238 p. 19) One oyster was analy sed gravimetrically and by chromatography after 72 days, the re

maining 2 after 180 days. The oysters within the three sam

ples subjected to zero, 72 and l80 days of cleansing had an

average wet weight of 15-7 g, 17-0 g and 16.5 g respectively

and an average hydrocarbon content of 6.9 mgm, 12.6 mgm and 3·8

mgm per 100 g wet weight.

The 23 Waquoit Bay oysters were divided into two lots

of 11 and 12 animals each of which was analysed as a batch on

the day they were collected. The batch of 11 oysters averaged 8.3 g wet weight and a hydrocarbon content of 0.55 mgm/100 g ; the batch of 12 animals were on average 3-0 g wet weight and

with 0.23 mgm/100 g of hydrocarbons. The purpose of the experi

ments was to test the ability of oysters to incorporate within their bodies hydrocarbons drawn from polluted waters, and sec

ondly to determine the extent to which oil, once incorporated,

may persist in the tissues.

(a) Incorporation of oil

2.6.52 Evidence of the uptake by oysters of No. 2 fuel oil

contained in contaminated sediments was based on data derived from the following experiments.

Twelve days after the accident, sediments in Wild

Harbour Basin were analysed chromatographically and compared

with the chromatographs of the original No. 2 fuel oil involv

ed in the accident. Figures 3A and 3B of Exhibit 72 illustra te the composition of fresh oil and the oil of 12 day age

recovered from the sediments. Blumer, Souza and Sass say of the two chromatograms that:

"The similarity ... is striking. The carbon number

range, boiling point distribution and relative contribution of

different isomers is nearly identical. The major difference is a general decrease of the low molecular weight hydrocarbons

in the oil recovered from the sediment; these hydrocarbons

are more readily soluble and should be depleted in an oil that has been in contact with sea water for an appreciable length of time. Conversely, these hydrocarbons are the most immedi

ately toxic fraction of the oil and their dissolution may be

responsible in part for the lethal effect of the oil on the

faunas." (Exhibit 72 p. 5) Later analyses of Wild Harbour River sediments from three different localities (Station II, IV and V) in December 1969 and May 1970 were reported by Blumer, et al, in Exhibit

238, p. 15, as showing "in December ... evidence of consider able biodegradation but only a minimal further change ...

between December 1969 and May 1970." They add that "The slow rate of degradation during these five months suggests that the

principal alteration of the oil has occured before it was in

corporated into the sediments" and that "heavily polluted regions retain their oil content and may remain a source of

relatively undegraded oil ... for a long time after the initial

accident." (Exhibit 238 p. 15 and 16)

2.6.53 Against this background of sediments demonstrably

polluted with No. 2 fuel oil, and which Blumer and his co

workers claim, we think with justification, to be only slowly

changed by dissolution and biodegradation in the more heavily

contaminated sediments, Blumer Souza and Sass examined the

hydrocarbons from the oysters taken in Wild Harbour River on

November 12, 1969 two months after the accident. In referring to the chromatogram illustrated in fig. 4B of Exhibit 72 they

say (p. 7) that the hydrocarbons "extend from C12 to about C23

and show the same general features as the No. 2 fuel oil and

the oil recovered from the sediments." They add, however, that

in the chromatogram spectrum below heptadecane (C17) there is a

decrease in the relative peak heights of hydrocarbons of lower

carbon number and they make this comment:

"The progressive alteration, in the same direction as

already observed in the oil from the sediments is not unexpected

though the extent of the change is remarkable. Compared to the

oil within the sediments which is protected from further solu

bilization, the oil now in the shellfish may have been exposed

to the sea water for a much longer time, for instance on top of

the sediments, in the water column or in the shellfish itself."

(Exhibit 72 p. 7)

2.6.54 The nature and significance of the compositional characteristics of oil retained for long periods within the body of the oyster received little attention in cross-examination.

At T6370 Mr Bennett touched briefly on this point in asking Dr Grassle to explain the different chromatogram spectra of oil

taken from the unpolluted oysters of Waquoit Bay and the animals

taken from polluted sediments.

Q. "What do you say that contrast shows?" A. "What it shows is that the oysters in Waquoit Bay do not contain the component of No. 2 fuel oil

and at least part of the components of No. 2 fuel

oil are retained unchanged in the oysters from the

polluted area and it is this background area which

is predominantly the aromatic hydrocarbons."

(b) Persistence of oil

2.6.55 Dr Blumer and his associates say "Oysters that were

removed from the polluted area and were maintained in clean

water for as long as 6 months retained the oil without change

in composition or quantity. Thus, once contaminated, shellfish

cannot cleanse themselves of oil pollution." (Exhibit 238 p .25)

This statement was rigorously questioned during the cross

examination of Dr Grassle. Dr Grassle was asked how he equat

ed no change with the reported sequence of 6.9, 12.6 and 3.8

mg/100 g hydrocarbon content of the 7, 1 and 2 oysters series,

maintained respectively for zero, 72 and l80 days in fresh

water (see paragraph 2.6 .51)·

2.6.56 The following questions and answers draw attention to the main points brought out in evidence:

T.63^7 Q- "How do you get the 12.6 after it

has been in fresh water for 72 days?" A. "For some reason or other this oyster

must have picked up more oil from the

environment."

T.6351 Q. "And in regard to two other oysters only it continued for a further 108

days and the hydrocarbon content was less than all the others and quite appreciably less?" A. "Yes." Q. "On that evidence ... there is no

proof ... is there, that the oyster

does not in time rid itself of the

hydrocarbon?" A. "That is true. It does not prove that it does not lose hydrocarbon at

a very slow rate." Q. "The object of the experiments ... in so far as they relate to the three oysters ... was to show that

after immersal in clean water for

427

a substantial period ... the hydro

carbon content was comparatively

speaking, very substantial?"

A. "That is correct."

T.6352 Q. "That being so, when the oysters

were taken out of the polluted

environment and before being

placed into the clean water why

was their hydrocarbon content not

then taken to make the experiment

more meaningful?"

A. "You cannot take a hydrocarbon

content of the same oysters you are keeping in the tanks. You

cannot because you have to kill

the animal to take the hydro

carbon content."

2.6.57 In a paper delivered at a Food and Agriculture

Organisation (FAO) conference in Rome in December 1970 (Exhibit

290) Dr Blumer said at p .2:

"We have demonstrated that hydrocarbons that are ingested by marine organisms pass through

the wall of the gut and become part of the

lipid pool,"

and he then quoted as source material for this statement the oyster experiments described by Blumer, Sousa, and Sass 1970

(Exhibit 72).

The analyses which were made of the hydrocarbon

content of the oysters collected from Wild Harbour and sub sequently maintained in clean water did not of themselves prove this decisively. It will be recalled that Blumer et al (Exhibit

72 pp. 2 - 3 ) analysed the entire soft tissues of the oysters,

including the gut. The animals had however been kept in clean

water for either 72 or 180 days (Exhibit 238 p .19) by which time as the authors say "If the oil were localized solely within the

428

digestive tract of the shellfish, elimination would be poss

ible..." p.19. If this possibility be allowed the analyses are

indeed indicative of the passage of oil into other tissues of

the oysters and of their retention within the tissues for a

period following evacuation of the gut, but they do not estab lish the sites of oil retention.

2.6.58 The possible sites of retention of hydrocarbons

within the tissues of oysters were not in fact made known in

evidence, though Blumer et al found in the adductor muscles of

contaminated scallops hydrocarbons which they identified as

originating from the No. 2 fuel oil spilled from the barge

'Florida' Exhibit 72 Table 1; Exhibit 238 Table 3). The

covering letter of Exhibit 72 states: "The authors show that

oil from this spill has been incorporated into scallops and

oysters and has destroyed their value. Several months after

the accident these pollutants are still present in the tissues of the affected animals ..."

2.6.59 It was also noted by Dr Connell at T7085 that mullet tainted with a kerosene-like substance, when analysed for the constituent hydrocarbons present in different regions of the musculature of the fish, showed "a highly significant correla

tion between the proportion of fats (as ether solubles) and the

proportion of volatile hydrocarbons ..." Dr Blumer's claim that hydrocarbons which pass through the gut wall of marine

organisms become part of the lipid pool is therefore in some measure supported by this circumstantial evidence.

(h) Transfer of hydrocarbons through the

food web

2.6.60 It is stated by Dr Blumer in Exhibit 290 (p.2) that hydrocarbons contained within food organisms can be transferred

"to predators, thus they spread throughout the marine food web

in a manner similar to that of other persistent chemicals,

e .g., DDT (Blumer, Souza and Sass, 1970; Blumer, 1967; Blumer

et al, 1969)."

429

2.6.61 The general pattern of organic production in the sea

was explained by Professor Connell, T563; Dr Talbot, T948-9,

957-63;· Professor Stephenson T20.63-70; Mr Harrison, T5725 and

Sir Maurice Yonge, T9275, among other witnesses.

2.6.62 Plants, termed primary producers, depend for their

growth and energy requirements on carbon dioxide, oxygen and a

range of nutrient materials dissolved in sea water and on

photosynthetic processes, involving the utilization through

chlorophyll and other photosynthetic pigments, of the energy of

sunlight for the conversion of simply constructed materials

into the complex molecular systems of protoplasm. Grazing

animals, as secondary producers, feed on the plants and may in

turn be eaten by carnivores which themselves may be eaten and

provide food for other predators in a sequence which Professor

Stephenson described as primary, secondary and tertiary con

sumers (T2070).

2.6.63 The essence of the food chain, more aptly called a food web, for the pathways of conversion are rarely along pre

determined lines, is that the biomass of production diminishes

at each successive stage of food conversion, partly because the

supply of food must be in excess of the requirements of the consumers if they are not themselves to diminish in number, and

partly because each conversion falls short of a 100% efficiency. The nature of this pyramid of biomass was explained by Dr Talbot

at T988. A further consequence of the food web is that materials contained in food organisms are ingested by the organisms that

consume them. Of the three papers quoted by Dr Blumer as evidence of the passage of hydrocarbons in this manner one,

Blumer et al 1969,did not figure as an Exhibit and was not con sidered in evidence. The 1970 paper (Exhibit 72) reports at

p.8 the presence in oysters from the uncontaminated Waquoit Bay

of a hydrocarbon mixture strongly resembling the hydrocarbons

in the diatom Rhizoselenia setigera a winter diatom in this

area; and Blumer, 1970 (Exhibit 297) describes the occurrence of pristane and other hydrocarbon components in the digestive

tract and liver of a small basking shark which contained

within its gut numerous copepods of the species Calanus hyper-

boreus and C. finmarehicus which are themselves rich in pristane.

2.6.64 Whilst these observations are indicative of the

transfer of naturally synthesized hydrocarbons at two stages

of the food chain they were not designed to test whether the

hydrocarbons so derived would persist in the animal which had

acquired them. Dr Grassle at T638O however quoted a paper by

Blumer, Mullin and Thomas "Pristane in the marine environment"

which was later (at T6540) tendered by Mr Connolly as Exhibit

306 in which assays of pristane were made in the copepod

Calanus hyperboreus kept in filtered sea water and therefore

unable to synthesise further pristane from food sources.

Assays were made at approximately 4 day intervals over a

period of 86 days in all. Although the lipids of the animals were notably depleted the pristane content rose slightly over the period, a surprising circumstance which the authors are

inclined to ascribe to the very slow cumulative conversion

into pristane of a precursor, phytol which had been stored when the animals were feeding and the retention of the pristane

as a buoyancy material of great adaptive advantage to the

animal.

2.6.65 These observations though of interest in indicating

some aspects of the biochemical transformations of natural hydrocarbons in organisms, shed little light on the fate of

pollutant hydrocarbons in their passage from one organism to

another. No convincing evidence was received on this import ant topic. Thus, while pollutant hydrocarbons may spread through a food web, such spread is not at present satisfactor ily proven. The significant depletion over a period of months

of pollutant oils held in oyster tissues puts them however, in a different category from the so-called persistent pollutants

such as DDT, mercury and lead with which Dr Blumer associated them. The truly persistent pollutants as Mr Cowell, at T11010

said "can be present after an accident for 50 to 100 years.

(i) Health hazards

2.6.66 Dr Blumer in a paper delivered in Rome in 1970

(Exhibit 290) when speaking of the cancer hazards of oil put his case as follows:-"The higher boiling crude oil fractions are

rich in multiring aromatic compounds. It

was at one time thought that only a few of

these compounds, mainly 3,4 - benzopyrene,

were capable of inducing cancer. As R.A.

Dean (1968) of the British Petroleum

Company stated 'no 3,4 - benzopyrene has been detected in any crude oil ... it there

fore seems that the risk to the health of

a member of the public by spillage of oil at

sea is probably far less than that which he

normally encounters by eating the food he

enjoys.' However, already at the time when

this statement was made, carcinogenic fractions

containing 1,2- benzanthracene and alkyl

. benzanthracenes had been isolated by Carruthers,

Stewart and Watkins (1967) and it was known that 'biological tests have shown that the extracts obtained from high-boiling fractions of Kuwait

oil ... are carcinogenic' ... We now know that a far wider range of polynuclear aromatic

compounds- than benzopyrene and benzanthracene

are potent tumour initiators ... and all oil products containing hydrocarbons boiling between

300°C and 500°C should be viewed as potential

cancer inducers. "

2.6.67 Professor Clark at T3781, while agreeing that "fract

ions of crude oil include carcinogenic compounds and (that) it

would be wrong to dismiss out of hand Blumer's claim that spilled oil is permanently incorporated into food organisms and 432

transmitted through the food web although the evidence for this

is tenuous" added the following note of caution; "However, the

mere existence of carcinogenic compounds in food materials is

not a sufficient cause for alarm or corrective action. Some

realism must be provided by assessing how great a public health

risk oil pollution constitutes and setting this alongside other

public health risks. This is difficult in view of the scanty

information available. Furthermore, the chemical induction of cancer requires prolonged exposure often at a high level, in

order to increase the statistical incidence of the disease.

One has only to consider how many years were required to

establish beyond doubt a connexion between cigarette smoking

and lung cancer to appreciate the difficulty of assessing the danger to public health in these circumstances."

2.6.68 It was pointed out by Mr Cowell, Professor Clark,

Dr Grassle, among other witnesses that carcinogenic hydro

carbons are in any event, normally present in the sea as

natural products. Mr Cowell quoting Dr ZoBell, a world

authority on this subject, said at T10920 that ZoBell 1971 shows "that polycyclic aromatics are produced in very large amounts

in the sea by phytoplankton" and that "in relation to the

natural sources of polycyclic aromatics the possible contribu

tion from crude oil spilt on the sea would be very small indeed;" their concentration in crude oils "is a very small number of

parts per million ..." By contrast "3-^ benzopyrene which has been associated with carcinogenic effects in experiments is produced in very large amounts in smoked foods ..." Mr Cowell

considered that the many sources of carcinogenic substances

to which man is normally exposed together with the fact that "the amounts of these materials that are produced naturally are very high ..." argues "a very high inbuilt resistance to

them." (T10922)

2.6.69 Mr Jeffery, QC, recalling that the possible health

hazards of hydrocarbon carcinogens had been brought to the

attention of the Commission most forcibly through a reading of

433

Exhibit 290 which was the Blumer paper at the Rome Convention,

particularly pp. 3 - 4 under the heading 'Oil and Cancer', the

relevant passages of which have been quoted in paragraph 2.6.66

supra questioned Dr Grassle as follows (T6513):-"Doctor, Dr Blumer was there propounding

the proposition that all crude oils and

oil products are potentially cancer

inducers, was not he? ... Yes."

"The laboratory evidence to support that

relates particularly to the application

of concentrated dosages of various hydro

carbons to laboratory animals? ...

Various concentrations, yes."

"The subject of cancer is one which

naturally excites considerable public

alarm does not it? ... I think so, yes." "Certainly there would be no well based

scientific reason for sounding an alarm

of that sort, would there?... Which sort?"

"That there is a known threat of carcino

genesis in public consumers of fish as a

consequence of petroleum activities in the

Great Barrier Reef? ... No, there would be

no cause - just to make sure I have your sentence right - there is no reason to

raise such an alarm."

i)3^

PART 7 - GAS LEAKS AND THEIR ECOLOGICAL EFFECTS

Statistics

2.7.1 The statistics of gas leaks have been dealt with in

paragraphs 1.2.2 and 1 .3·5 et seq.

Nature of gas leaks

2.7.2 Dr Chapman a Petroleum Geologist and Senior Lecturer

in the University of Queensland said that "...petroleum gas is

in fact a mixture of gases of different molecular weight and number of carbon atoms" and he added that "...some gases could

have ... liquids with them ... . "(1353^1) "A normal petroleum gas" he said "is mostly methane, CH^ and that is the most

soluble of the range ... up to butane ... C^H-^ ." (T3535) He

was, however, of the opinion that "Petroleum gas is virtually

insoluble in sea water at surface temperatures and pressures

and is not therefore a potential pollutant ..." (T3998), particularly because "The passage of gas through a column of

sea water ... is so rapid" (T3507), though he entered a note

of caution about accepting figures based on conventionally accepted values in saying "I do not believe any measurements

have been made on the solubility of a gas in sea water under these conditions." (T3536)

The question arose in evidence as to whether some petroleum gases might contain, in addition to hydrocarbons, -

other substances of known toxicity. Mr Chapman said "Some

petroleum gases have hydrogen sulphide in them and hydrogen sulphide is soluble in water, more soluble than petroleum gas is;" (T3507) and Dr D. W. Connell, a Senior Research Scientist

with the Australian Wine Research Institute, Adelaide, quoting a passage from MacRoberts and Legatski "The Chemistry of

Petroleum Hydrocarbons, Vol. I (195*0 "said "... there are many reported instances where nitrogen and carbon dioxide have

been present as major constituents of natural gas.

435

Similarly, hydrogen sulphide concentrations of as high as 12 to

15 per cent have been reported." He knew of no information "...

on the effects of hydrogen sulphide on coral or other Great

Barrier Reef species of marine animals", though it had been

shown in respect of fishes "... found in and around the waters

of the United Kingdom ... that for stickleback, trout and carp

a very low number of parts per million of hydrogen sulphide can

constitute a lethal limit and this may vary from one part per

million in the case of trout to 8 to 12 parts per million in

the case of carp." (T7043)

Their effects

2.7- 3 Speaking of the effects of gas blowouts on marine

life, Mr Keith, at T5506 said "... there is no record that

these caused any damage to the environment", and Mr H.W.J.

Stewart, Petroleum Engineer for the Department of Mines of the

State of Queensland instanced three gas blowouts in the North

Sea fields of several days to four months duration in respect of which "There was no evidence that the gas caused any damage

to marine life." (T4429-30) Whether the observations were of

more than a casual nature was not however stated.

2.7- 4 It would appear from the evidence before the

Commission that, with one possible qualification - the presence

of hydrogen sulphide - gas blowouts do not present a serious

danger to marine animals. The absence of any substantial data

on the toxic effects of the emitted gases, of their concentra

tion in solution in the neighbourhood of a blowout and of

adequate biological surveys of possible damage within the

affected areas, makes it prudent however to regard consequential

damage as within the realm of possibility. For in this context it must be recalled that evidence has been given that "Within

each series of hydrocarbons the smaller molecules are more

toxic than the larger." (T10908)

2.7.5 Gas emissions do not lead, as does oil, to sub stantial sea surface layering of oil damaging to birds and

436

other diving or surface-breaking animals. Their effects, if

any, are more likely to be shown on swimming and planktonic

species, though the small molecular weight of the gas con

stituents and their susceptibility to biodegradation might be

expected to make gas pollution less persistent than pollution

caused by liquid hydrocarbons of higher carbon numbers.

PART 8 - REMEDIAL MEASURES

(a) Introduction

2.8.1 When oil is spilled at sea, the hazards to which it

gives rise and which are a major cause of public concern are,

on the one hand, the damage it may do to marine eco-systems and,

on the other, the disfiguring and amenity insult effects it

causes when stranded along the seaboard of mainlands and

islands.

The protective and remedial measures that have been

used with varying degrees of success in reducing or removing

massive or small scale spills of oil are reviewed in the

Answer to TR4 at paragraphs 4.4.2 et seq. They include

mechanical devices for arresting or containing a flow of oil,

(e.g ., booms and tents); methods facilitating its collection

and removal (e.g ., pumps, skimmers, absorbents and gelling agents); removal from the surface by burning or sinking; and

the dispersal of slicks by oil dispersants. In the context of TR2, which is concerned with the effects of remedial measures

on the preservation of marine eco-systems, the use of oil dis

persants has a particular relevance for, unlike mechanical

methods which add nothing that is biologically deleterious to the environment or are capable of influencing the toxic

potentialities of oil, dispersants are chemically active liquid mixtures which may, as the evidence later to be presented shows,

be in themselves toxic or by their interactions with oil enhance

its toxicity.

(b) Oil dispersants: Toxicity

(i) General

2.8.2 Dr Grassle, at T6l82, said, "The toxic, solvent-based

detergents which did so much damage in the clean-up after the

'Torrey Canyon' accident are presently only in limited use.

However, so called "non-toxic dispersants" have been developed.

The term "non-toxic" is misleading; these chemicals may be

non-toxic to a limited number of quite often resistant test

organisms but they are rarely tested in their effects upon a

very wide spectrum of marine organisms including their juvenile

forms, preferably in their normal habitat."

(ii) Toxicity tests and toxicity grading

2.8.3 It is nevertheless convenient to have some method by which to grade different types of dispersants in terms of

their comparative toxicity within the limited range of the

organisms that have been tested. A method of assay which

Professor Clark, at T3672, said had led to the acceptance of

an internationally recognised grading is based on LC50

determinations obtained in the following way.

A sufficiently large number of individuals of a

selected test organism are subjected for a chosen period of

time (usually 24 hours) to varying concentrations in sea water of the dispersant to be assayed. The minimum (threshold)

concentration, measured in parts per million, required to kill 50% of the sample is then recorded as its LC50 value. The

scale to which Professor Clark referred is as follows:-"practically non- acute toxicity threshold

toxic (LC50) above 10,000 ppm.

slightly toxic threshold 1,000 - 10,000

ppm.

moderately toxic threshold 100 - 1000 ppm.

toxic threshold 1 - 100 ppm.

very toxic threshold below 1 ppm."

On this scale, and in respect of the limited number of

organisms tested, the older dispersants are almost all 1 toxic' while the newer ones are only 'slightly toxic'." (T36?2)

Figures illustrative of the LC50 values and toxicity ratings of different types of dispersants were presented by several .

439

witnesses (e.g. Professor Clark, T3672-79; Mr Norrie, T6037 anc

Mr Cowell, T10966) and were most extensively quoted and conven

iently assembled by Mr Stanphill (T4635-53). The test organisms

included a few species of plants and a much wider range of

animals, for example several species of fish, Crustacea and

molluscs.

The value of these laboratory tests is that they

provide a reasonably accurate measure of the toxicity of dis

persants of differing composition substantiating, by the assays

that have been made, that the older, kerosene-based mixtures

are in the 'toxic1 category and newer, water-based chemicals

and some chemicals based on selective kerosene cuts (Mr Cowell,

T10906) are within the 'slightly toxic' range. They have also

shown that organisms of different kinds, age and size and at

different stages in their life history exhibit wide variations

of sensitivity under identical time/concentration exposures

to the toxic materials.

(iii) Toxicity of dispersants under field conditions

General 2.8.4 The laboratory tests and the grades of toxicity

established thereby are howeVer for various reasons, including

methods of application and rates of dilution, only generally

indicative of the nature and extent of the damage that will be caused to living organisms when dispersants are used under

field conditions.

Mr Stanphill explained at T4630-1 that petroleum

(kerosene) based dispersants are most effective in clearing oil

when applied neat whereas water-based mixtures are best used

diluted in water. The impact of neat kerosene-based dispersants on the rocky shores of south west England following the deposi

tion of oil from the wrecked tanker 1Torrey Canyon' was conceded by Professor Clark, who was not opposed to this method of shore

cleaning when "public presure to have clean beaches for

recreation ... demands first attention," (T3891) to have "resulted in biological damage" (T3612) which he later said

was evidenced "in the almost total death of gastropods, bivalves,

440

barnacles, crabs, worms etc. , and damage to Intertidal algae."

(T3698) But this extensive damage, which was corroborated by

Professor Connell (T517) and Dr Straughan (T5622 - 3), was due,

in Professor Clark's opinion, to an incorrect use of the

dispersants. He explained that "In beach cleaning the

recommended practice is to spray dispersant ahead of a rising

tide or to wash down a sprayed beach with high pressure fire

hoses. Under crisis conditions during the clean-up after the

'Torrey Canyon' spill, these precautions were not always

observed and instead neat dispersant was simply tipped on to''

the beach and left." (T3698) "Properly applied, toxic dis

persants cause little obvious damage on beaches or in the sea." (T3612)

It cannot however be overlooked that, even when a

dispersant is properly applied according to the recommended practice outlined by Professor Clark, it will in the course

of its dilution remain for a time above the threshold level of toxicity. For a 'toxic' dispersant of 1 - 100 ppm LC50 6 4

threshold a 10 - 10 dilution must be achieved before the non-lethal concentration is reached; and similar considera

tions hold, though with a lesser degree of hazard, to dis persants of a 1,000 - 10,000 ppm range and rated as 'slightly

toxic'. Mr Stanphill said of Corexit 7664, for example, that

the recommended practice was to spray the chemical as a 1 - 6% solution in sea water (T4624). This would mean that the dis

persant would require to be diluted by a factor of 10 - 600 to

fall below its threshold of LC50 toxicity.

Although these figures help little in defining the

extent and area of the damage imposed on marine organisms

under actual spill conditions by the dissemination of progress

ively diluted dispersants, they go far to explain two points on which the witnesses who ventured opinions on this question were in agreement. It was thought that while dispersants may with some justification be used in the open sea, they should

either not be used or used only under carefully controlled con ditions in shallow or enclosed waters where the protection of

marine life is the primary consideration.

Use in the open sea

2.8.5 In the open sea Mr Norrie said "The dispersant becomes

all too rapidly diluted in practice, and toxicity does not seem

to be a large problem at sea" (T6036) and Mr Cowell considered

that "Floating oil slicks are best dealt with before they can

come ashore even if the more toxic dispersants are used since

toxicity is related to dilution." (T10982) These opinions found

support in the statements of other witnesses who, however, added

reservations about the use of emulsifiers in coastal waters.

Thus: "Chemical dispersants may have an application in combat

ing oil spills in open sea areas where little damage can be done

to marine life and where the chemical can be rapidly diluted ...

R.G.J. Shelton, Scientific Officer with the UK Ministry of

Agriculture has noted that 1 toxic dispersants may be of value

in treating oil at sea, but should not be used in large

quantities in shallow coastal water'." (Dr D.W. Connell, T706l);

"The use of emulsifiers and detergents can be justified only

if they are employed well out from the littoral zone and if

local currents.send the emulsifier/oil mixture further out to

the open ocean. The use of detergents on beaches, littoral zones and harbours is more dangerous because, in making oil

miscible with water, the oil will spread into the sand..." (Mr Stanphill, T4569-70); "...some types of organic solvent

based dispersants can be toxic to marine life if certain

thresholds of dilution are exceeded. This potential toxicity lies in their use in excess in shallow or enclosed waters where such concentrations are likely to be exceeded. In open water

their toxic effect has been rated as negligible on larger fish

and where oil slicks have been extensively treated in such areas

no adverse effects have been noted on the fauna." (Mr Haskell,

T5905-6)

Use on shores and in near-shore waters 2.8.6 In support of the reservations entered by Mr Norrie,

Mr Cowell, Dr Connell, Mr Stanphill and Mr Haskell against the

use of dispersants in inshore waters, their employment in such

situations was opposed by a number of other witnesses for

442

reasons exemplified in the following statements.

Dr Grassle was of the opinion that "Detergents and

dispersants, while cosmetically effective, are especially

harmful since they introduce all the oil into the environ

ment ... The use of dispersants should be most strongly dis

couraged." (T6198) In situations where eco-systems which it

is desired to preserve are at risk, other witnesses were

equally disapproving of their use. Dr Straughan said "One

obviously does not want to use them on commercial shellfish

beds ... ." (T5654) Mr Biglane, who was called upon to advise

on the protection of some investigation sites of the Smithson

ian Tropical Research Centre on coral reefs following a spill

of bunker C and diesel oil from the tanker 'Witwater' which

went ashore in December 1968 in the Panama Zone," ... insisted

that they should not use dispersants, if they really wanted to protect that live coral reef." (T6708); and Mr Cowell said

"... it is not possible to clean a salt marsh or plants with dispersant; the penetration is 20 seconds and whatever you

do the damage is very rapid indeed." (T10958) When asked "That would be true of a mangrove area?" he answered "I think

it is true of a mangrove area, anywhere where you are dealing with a vascular land type plant. It is quite wrong to use dispersants and if you use dispersants they are completely

ineffective." (T10959)

(iv) Toxicity of dispersants to corals

2.8.7 The point has earlier been made (paragraph 2.8.3) that the toxicity of a dispersant as indicated by the des

cription given to it (for example, 'toxic', 'moderately toxic', 'practically non-toxic') and the thresholds of concentration applicable to these terms are valid only in respect of the

organisms used in making the assays.

2.8.8 It is therefore important to emphasise that, with

the exception of the two series of experiments now to be des cribed, the Commission was not made aware of any tests that

have been made on any of the great variety of organisms which

443

in the several stages of their life history occur in the plank

ton, the nekton, in association with coral reefs on the shores

of the mainland and islands, or on or within the sea floor

sediments of the GBRP.

2.8.9 The tests referred to were undertaken by Dr John B.

Lewis (Exhibit 338) and Professor S.H. Chuang. Professor

Chuang carried out three separate experiments using in each

instance a solution of the dispersant Chemkleen in a 250 ppm

concentration in 2 litres of sea water with dispersant free water as controls. In the first experiment three specimens of

the solitary coral Pungia actiniformis each 8-12 cm in dia

meter and partly emergent in a depth of some 2 cm of water were

exposed for three hours to the dispersant treatment at 2J°C.

Fresh sea water was then added to the container to remove the

dispersant and the corals placed in clean water for examination.

Although the control animals were "... viable and appeared healthy", all the treated corals were dead and binocular exami

nation showed the tentacles to be perforated in places.

(T15571-3)

2.8.10 A second experiment tested six corals, five being

specimens of Fungia repanda and one F. paumotensis. The dura tion of the treatment was 2h hours. Professor Chuang said that

all the specimens were alive at the conclusion of the test but

those exposed to the dispersant showed "... visible signs of

damage." He thought that their survival may have been due to

their being of different species to the animals used in the

first experiment or to the more limited period of their expo

sure. (T15573-4)

2.8.11 In a third and final experiment two specimens of

Fungia repanda in a depth of 1.0-1.5 cm of water and partly

emergent were exposed for 1 hour to the 250 ppm dispersant in sea water solution. At this time and 8 hours later, of the two

corals examined while in clean sea water one was healthy, the

other showed abnormal swelling of the tissues over the septa.

(T15574-5)

2.8.12 The toxicity rating of Chemkleen was not made known

in evidence and in any event the short exposure times of Pro

fessor Chuang's experiments were not comparable with the cus

tomary 24 hour period of an LC 50 test. The most that the

experiments show are that for these corals, of which one spe cies (F. actiniformis) is commonly found in Australian waters

the animals were killed or suffered damage at a concentration

of dispersant of a type which approximates to a 1 toxic' or

'moderately toxic 1 rating.

2.8.13 Dr Lewis' experiments were described by Professor

Clark at T3685-6. The following account which includes some

details of the experimental processes is however drawn direct

ly from Exhibit 338.

"Four species of corals collected on reefs on the

west coast of Barbados were selected for testing. Porites porites (Pallas) Agaricia agaricites (L), and Favia fragum (Esper) are all shallow water species ... Madracis asperula

(Milne-Edwards & Haime) is a deeper water form." None is recorded as an Australasian species in Exhi

bits 2-, 3, 4 and 541 (Maxwell, Gillett and McNeill, Keith Gil-

lett and Isobel Bennett respectively.) A number of colonies of all four species were tested

in varying concentrations (10, 50, 100, 200, 500, 1000 ppm) of

'Corexit' dispersant in 350 cc of sea water in finger bowls,

at 20-24°C. Each container was sealed to prevent evaporation of the dispersant. An equivalent number of clean sea water

controls were used for comparison.

Healthy animals in the controls would feed on live

plankton, expand their tentacles and withdraw them at the touch

of a probe. Colonies of the dispersant treated animals which

did not show these responses were considered to be unhealthy.

Concentrations at which after 24 hours at least 50%

of the organisms were affected in all or some of these ways and

on occasions additionally by an abnormal extrusion of septal

filaments were (in ppm) Madracis, 50; Porites, 100; Pavia and

Agaricia, 500. After a 2A hour exposure the corals were trans

ferred to clean sea water. In the following 24 hours Porites

and Madracis showed little recovery, Favia and Agaricia showed

almost complete recovery.

2.8.14 'Corexit' is customarily graded as a 'practically

non-toxic' dispersant and in the Lewis experiments none of the

corals was killed at concentrations well below the 10,000 ppm

LG 50 threshold of acute (lethal) toxicity. It is however im

portant to note as an indication of the sub-lethal effects

which may be shown well below the lethal level that all four

species were demonstrably damaged at levels well below the

threshold value of acute toxicity.

2.8.15 Evidence was given that the damage that may be wrought

on marine eco-systems by the use of dispersants may not be due

solely to the toxicity of the dispersants but be compounded by

an enhanced toxicity of the treated oils during the process of their dispersion and emulsification. Professor Clark said that

the enhanced toxicity of oil/dispersant mixtures "... has been

shown by Griffiths (1970) -even for the supposedly low toxicity dispersants Corexit and Dispersol. Using intertidal winkles, Littorina littorea, he found that the time for death of half the

test animals (TD 50) was markedly reduced when these dispersants

were added at the recommended dilution of 10 : 1 to weathered

oil floating on water in a simulated tidal cycle." (T3679) Mr Stanphill quoted other experiments involving two species of

fish carried out on behalf of the Esso Research and Engineering

Company by the Institute of Marine Science, Miami University

and the Department of Natural Resources, State of Michigan,

which confirmed a substantial lowering of the threshold of toxi

city of Corexit 7664 when presented in a Corexit/oil mixture

(T4673, 4640); and Mr Biglane agreed that when a dispersant is

mixed with oil "... you get a higher level of toxicity from

the combined pollutants." (T6768) Mr Stanphill, when asked

"whether the addition of the Corexit made the oil more avail

able to organisms" agreed that it would (T4640), and Dr

Grassle said that "Instead of removing the oil, dispersants

push the oil actively into the marine environment; because of

the finer degree of dispersion, the immediately toxic fraction dissolves rapidly and reaches a higher concentration in the

sea than it would if natural dispersal were allowed."

(T6l82 A) The subject was not further elaborated in evidence.

(d) Conclusion

2.8.16 We conclude that the use of dispersants in all mar

ine situations other than in the open sea is at best a calcula

ted risk when the preservation of eco-systems is the primary

consideration. The hazards arise less from the intrinsic

toxicity of dispersants themselves than from the enhanced

toxicity of oil when present in oil/dispersant mixtures.

(e) Other remedial measures

2.8.17 Among the many methods for dealing with spilled oil that were brought to the notice of the Commission and for

which some success was claimed, two - the use of oil absorb

ents and of gelling agents - are not in themselves remedial, but serve to facilitate the mechanical handling and removal of oil. These methods are reviewed in paragraphs 4.4.75-79· In this Part, some comments are added on the possible toxicity or

other harmful effects of the materials used. ( i )

(i) Absorbents

2.8.18 Absorbents that have been used for trapping drifting

oil include natural products such as straw and hay, and syn thetic materials such a polyurethane, that are virtually inso

luble in water, chemically inert and non-toxic. Any reserva

tions on their use as oil absorbents rest solely on the possi-

bility that they may add to the environment objectionable oil-

contaminated debris should they become dispersed or be other

wise difficult of collection as was, for example, windblown

straw at Santa Barbara. (Dr Straughan, T5631)

(ii) Gelling agents

2.8.19 Mr Haskell described oil-gelling agents as chemicals

which reduce the surface tension of the oil-water interface so

causing the oil to become more cohesive and congealed. (T5946,

5949) They are liquids which Mr Mansfield said can be spread from aircraft or boats. One gelling agent (Shell Herder) was

applied in this way, in Mr Biglane1s opinion with "moderate suc

cess" (T6792), following blowouts at Chevron C platform in

February 1970 and at Baker platform block 26 in December 1970

in the Louisiana off-shore oil field. (T5178, T6982) According to Mr Biglane there are a number of commer

cially manufactured gelling agents (T6792), though Shell Herder

was the only example referred to by name. Mr Gusey said that

Shell Herder is a patented product and he did not know its com

position. (T5182) Mr Mansfield, quoting a paper by E.A. Mils

and J.P. Frazer (Exhibit 321) and other sources, believed that the oil-congealing properties probably derive from the presence

of long-chain alcohols (T7269) or other long chain compounds of

a related type. (T7283) Tests referred to in Exhibit 321 had

indicated that "the chemicals utilised are harmless to the eco

logy." (T7272)

(iii) Sinking agents

2.8.20 Dr D.W. Connell noted at T7061 that "Sinking oil by

the use of high density agents such as talc, chalk, cement dust,

has been carried out with some success, particularly during the 'Torrey Canyon' disaster." On this occasion "It was effective

on well weathered oil off the west coast of Brittany ... when

the French used a mixture of common chalk and sodium stearate.

They claimed to have sunk 20,000 barrels of oil." (Mr Stewart,

T4415/6) "The weighting agent used in some fine grained mater

448

ial of moderate density which has been treated with a sub

stance , such as stearic acid, to attract oil and repel water.

The sinking agent is blown dry on to the slick or sprayed on

as a slurry and, where necessary, mixed with the oil."

(Mr Haskell, T5910) The reasons put forward for using sinking

agents are that they remove oil from the surface of the sea

where it may be carried on to shore lines, and reduce the hazards to birds or other animals which alight on or break

through the sea surface. The objections to the use of sink

ing agents to which Mr Cowell (T10982-3), Dr Grassle (T6183,

6l88) Mr Stewart (T4415-6), Dr D.W. Connell (T706l) and other

witnesses referred, are that the sunken oil may settle on the

sea floor as smothering masses which are not readily dispersed by biodegradation and other means. However, in a large scale

test, undertaken off the coast of Holland in 1970 in the

presence of invited observers, the sinking of 100 tons of

crude oil with treated wet sand was effected "in less than 45 minutes and was, as far as all the experts could judge, at

least 95 per cent effective ... Divers were sent down to the

sea bed to investigate the oil. They reported that it was like a non-continuous fluffy cover which moved easily when

disturbed but sank immediately it settled. Observations were

maintained for up to six weeks after the test. At first a fair amount of oil rose to the surface ... but it soon dis persed over a wide area ... The combination of fresh sea water, wave action, oxidation and microbial attack soon clears

it away." (Mr Haskell, T5913)

2.8.21 In paragraph 4.4.60 a reference is made to an article in Exhibit 365 entitled "The Problem of Oil Pollution of the Sea" and the Commission concludes that "It is obvious that the conditions in many parts of the GBRP would make the

use of sinking agents and of toxic solvent emulsifiers very undesirable", and a recommendation against their use except

in special circumstances and then only with the approval of the Designated Authority is contained in paragraph 4.4.61.

The Commission would however add that the results of Mr

Haskell's test suggests that the use of sinking agents in the GBRP should be included in the various subjects for research

and experiment to which reference has been made in the

Appendix to the Principal Introduction.

450

PART 9 - OIL AND ITS PROBABLE EFFECTS ON THE

MARINE LIFE OF THE GBRP - CONSIDERATIONS PRELIMINARY TO PART 10

(a) Introduction - Both Australian and overseas experiments

and incidents are included

2.9.1 Of the three categories of substances of potential hazard to the marine life of the Province (oils, gas and che

mical substances used as remedial measures) the probable

effects of which the Commission is required to examine in

giving answer to TR2, gas emissions and remedial measures will be only briefly mentioned in these preliminary considerations

bearing on the answers to be given in Part 10.

Gas leaks, for reasons earlier given in TR2 Part 7

are considered to pose little hazard to marine life, save for

possible limited and strictly localised effects. Dispersants,

are on the other hand regarded by the Commission (paragraphs 2.8.7 et seq) to be in themselves and in oil dispersant mix

tures sufficiently toxic to marine organisms to justify a

recommendation that they be not used in the GBRP except under a few special circumstances defined in TR4 (paragraph 4.4.52) and then only with the permission of the Designated Authority.

In its consideration of the effects of crude oils on

the organisms and eco-systems of the Province the difficulties

which face the Commission are immense because of the few pres ently existing and well substantiated data available to assist

the answer. However, in respect of some of the subjects to be

discussed in this Part, the view is taken that information

drawn from world experience as presented in the foregoing Parts contains within it a sufficient generality of scientific truth and universality of application to make it suitable, with

due consideration of the special conditions which obtain within

the GBRP, for useful and legitimate predictions to be made of the way in which phenomena that have been studied in other

places may be displayed in the different regions of the GBRP.

This type of extrapolation is not however justifiable

when considering the probable effects of freshly spilled crude

oils of at present unknown composition on the organisms and

eco-systems of the Province. Individual species of plants and

animals, and to a lesser extent individuals within a species

vary so greatly and unpredictably in their sensitivity to toxic

hydrocarbons that it is impossible, without direct trial, to

equate the responses of any of the organisms which occur within

the tropical and subtropical waters of the GBRP with the res

ponses of temperate water organisms of a like zoological or

botanical relationship which have often been better studied.

The answers to be given in Part 10 will therefore require con

sideration to be given to the material given in this present

Part including details of the few and not always convincing

short-term experiments that were reported in evidence designed

to test the effects of crude oils on corals and other organisms

of the GBRP and of other coral reef areas overseas in which

GBRP species occur.

(b) Probable types of GBRP oils 2.9.2 This subject is briefly referred to in paragraph

PI.5.12.

It was the opinion of the witnesses who gave evidence

on this topic (Mr Woods, T894; Mr Ericson, T1201; Mr Allen, T1336-7) that the most likely type of oils to occur in the area

of the GBRP would be similar to existing Australian commercial

crudes which contain (a) a high proportion (44-55%) of gasolene, kerosene and diesel oil components

(b) low proportions of furnace oil and lubricating

stocks

T1336, Mr Keith T12059) However, no witness was prepared to dismiss the poss

ibility that other types of (for example heavier) crudes might

be found in the GBRP, because different types of oil are some

times found overseas in close proximity to one another (para

graph 3 · 3 - -4) and even at different horizons within a drilled well (ibid).

2.9.3 Physical properties of oils of importance in deter

mining the nature and behaviour of oil when spilled on the sea

surface include their specific gravity, viscosity, pour point, volatility, and their capacity for solution and the formation

of oil/water emulsions. These properties are defined, quanti

fied in respect of a number of oils of overseas and Australian

origin, and their significance in determining the behaviour of

spilt oil discussed in general terms in paragraphs 2.1.3-4 and 2.2.1-18 supra.

2.9-4 In respect of known Australian oils the evidence reviewed in these earlier paragraphs suggests that the follow

ing consequences might be expected if oils of these types were

to be spilled into the waters of the GBRP.

(i) The oils having specific gravities ranging

from 0.797-0.834 would initially float on

the sea surface. (T12059) (II) Spreading would occur. The gravity forces

generated by the mass of the oil would, as in all liquids, tend to be dissipated by spreading and thinning of the oil to the

point where surface tension forces at the

perimeter of the slick counteract the dimin ishing gravity forces. According to the evi

dence received, all oils appear to contain

surfactant (i.e. surface tension reducing)

substances. (paragraph 2.1.4 (ii) supra).

The quantity and nature of the surfacants present in Australian oils were not however

made known.

453

The viscosity of the oil - the resistance to

flow - is a further important factor in deter

mining the eventual thickness of an oil film

and the rate of spreading. The viscosities of

known Australian oils 1.85 - 3·3 centistokes at 100°F are relatively low compared with all

but two of the eleven overseas oils for which

figures were given (2.07 and 2.71, and 5 ·66 -

26,200 centistokes at comparable temperatures.)

(T12059) Viscosity diminishes with increase in

temperature and in warm waters spreading of sur

face borne oil would be expected to occur more

rapidly than in temperate and cold seas.

The 'pour point' of an oil was defined in evi

dence as "the temperature at which the crude

ceases to flow under given conditions." (T12046)

This physical property which, when operative,

tends to oppose the tendency of a slick to spread is considered to derive mainly from the

presence in oil of paraffinic waxes. The pour

point approximates to the temperature of solid

ification of the waxes and the onset of a con

sequential tendency of the oil to congeal and be

resistant to flow. Australian oils of the east

ern side of the continent have pour points rang

ing from 30° - 65°F- The water temperatures of the GBRP waters range, according to latitude,

from about 20° to more than 30°C (68° to 86°F).

If the wax content of any oils that may be found

in the Province tend towards the Minas rather than the Australian composition some congealing

could occur, but this prediction must be regard ed more as a possibility than a probability.

On the basis of these predictions, oil of GBRP

origin, if spilled within the sea area of the

Province, might be expected to spread rapidly

to form thin films. It appears, however,

that this generalisation may apply only

to the early stages of a spill when the

oil comes into contact with clean water.

If oil is already present, oil of later

discharge spreads less readily and, especially if it becomes emulsified by

the admission of water to form water-

in oil "mousse", may persist on the

surface as a substantially thicker

layer (T?l85).

(d) Evaporation of oils at sea

2.9.5 Evaporation of oil is a factor of especial signific ance and importance in promoting changes in the hydrocarbon component composition of oils during the process of aging (or

weathering) of oil at sea. The hydrocarbons which escape

into the air by evaporation are permanently removed from the marine environment and, in so far as the evaporated components are toxic to marine organisms the total toxicity of the oil is

proportionately reduced.

2.9.6 The opinion expressed by several witnesses (e.g.

Professor Clark T3609; Dr Grassle T6147-8; Mr Mansfield T7195 - 9; and Mr Keith (T12048) that evaporation from an oil slick mainly depletes the lower boiling point components was not

contested and it was explained that this differential evapor ation is due primarily to the smaller molecular size and

greater mobility of the lower boiling point hydrocarbons

possessing a small number of carbon and hydrogen atoms. It

was further stated that the rate of evaporation depends additionally, amongst other factors later to be mentioned, on the temperature within the oil and at its surface.

2.9.7 In respect of the influence of temperature on evapor

ation rates the Commission was informed in a statement tender

ed by Mr K. H. Deasy, Chief Chemist of the Mining and Secondary

Industries Section of the Queensland State Government Chemical

Laboratory, Brisbane on the penultimate day of the Commission's

hearings as Exhibit 548 that "It is universally accepted in the

physical sciences and has been borne out by my own observations,

that the rates of such processes as evaporation, dissolution

and chemical reactions generally, double or even treble for

each increase of ten degrees Celsius in the temperature of the

system under study."

2.9.8 It proved impossible to make arrangements for the

examination of Mr Deasy or other expert witnesses on the sub

stance of this statement which, taken at its face value, would

appear to imply that evaporation of oil in the GBRP, particular

ly in view of the expected low viscosity and consequent thin

filming of Australian oil, might be substantially more rapid

than with heavier oils spilled in more temperate seas.

2.9.9 The Commission enquired further on the possible sig

nificance of Mr Deasy's statement in regard to evaporation rates

of hydrocarbons at different temperatures from outside sources. Two physical chemists were independently consulted. Each made

calculations of the vapour pressure - indicative in an open

system of evaporation rates - of three hydrocarbons of differ ing carbon number and molecular weight, namely n-hexane (CgH^j

n-decane (C2.oH22 ^ and n-eicosane (C2oH42 ^ at different temperat ures. Their calculations showed that for a rise of temperature

from 15°C to 25°C the rates of evaporation of the compounds

named would rise by a factor of 1.57, 2.07 and 4.17 respectively. Taken as a rough approximation, these figures confirm the

increase in evaporation rate for a 10°C rise in temperature

claimed in Mr Deasy's statement. The figures indicate moreover that for the more readily evaporable compounds of low carbon

number a factor of two may be accepted as a near approximation.

2.9.10 In the light of Mr Mansfield's evidence earlier reported (paragraph 2.2) the arguments advanced and the figures

given in the foregoing paragraph cannot be taken to apply,

456

without further consideration of the factors involved, to

the rates of evaporation and the effects of temperature on

evaporation rate of individual hydrocarbons when present in

the complex mixture of a crude oil exposed to the air on the

surface of the sea. Mr Mansfield said that, under these con

ditions, account must be taken of such factors as the vis cosity of the oil, the thickness of the oil slick, the temper

ature within the oil and at the surface, and wind speed. Low

viscosity, thin filming of oil, high surface temperature and strong winds promote evaporation and increase the rate of loss of hydrocarbons to the atmosphere.

2.9.11 The Commission was given to understand that some knowledge of the nature and quantity of these and other

factors would be necessary in order to determine the evapora

tion rates of individual hydrocarbons from a particular oil in a particular place, and that no such study had as yet been

attempted. It is however justifiable to make a rough estimate of the rate at which an untested oil may evaporate, when the

general nature of the evaporation-promoting factors are known

or can be predicted with some confidence, from a knowledge of the rate at which some other oil, for which the relevant

factors have been quantified, has in fact evaporated when

spilled at sea.

2.9.12 A comparison of this kind of the 'Torrey Canyon'

(Kuwait) oil spilled in the English Channel in March 1967 with an Australian oil of the Moonie/Kingfish/Halibut type deemed to be spilled in the waters of the GBRP gives the

following contrasting statistics.

'Torrey Canyon' oil: Viscosity (100°F), 10 centistokes; temperature, 9 - 10 C;

Slicks "thick"; Volatile components (to

450°F B.P.), 32.1%.

The volatile components were said to

have been lost in 3 - ^ days (Mr Norrie

T6019) ·

457

The Chairman does not construe the evidence in

this way - see answer to TR3 paragraph 3-4.11

Sub-paragraph (n) (iii) thereof.

Australian oil: Viscosity (100°F), 1.85 - 3 · 3

centistokes: temperature, 20 - 30°C; Slicks

predicted as "thin"; Volatile components

(to 450°P) 44 - 55.5%

2.9-13 The majority (the Chairman dissenting) consider that

assuming a doubling of the evaporation rate for each 10°C rise

of temperature and assuming also that winds in the GBRP are no

less strong than in the English Channel, an Australian oil in

the waters of the GBRP might be expected at a conservative est

imate to lose its more volatile (the most toxic) components -

half of the original oil by volume - in lh to 2 days. But

because of other factors favourable to evaporation such as high

concentrations of the compounds of low carbon number, low vis

cosity of the oil and the expected thinner filming of slicks,

the Australian oil might be expected to lose its volatile com

ponents more rapidly than this. Mr Mansfield's estimate, made

on theoretical grounds, was one day for depletion to half of

the original volume.

2.9.14 On the basis of the figures quoted above the oil would

be depleted of its lighter fractions after some 8 - 14 miles of travel in the most frequently occurring winds. Higher wind

speeds would carry the oil further but would evaporate it more

quickly. How much more quickly is not known, but evidence

given to the Commission suggests that wind speed is among the

more important factors favouring rapid evaporation.

The views of the Chairman on these matters are stated

in his dissent which appears in the answer to TR3.

(e) Exposure to oil of reefs, islands and coastlines 2.9.15 From the point of view of the questions asked in TR2 a

delineation of the geographical features of the Great Barrier

Reef Province which takes into account such matters as the

distribution, density, sizes and shapes of reefs in the diff

erent zones of the Province, and the differing physical char

acter and linear extent of shorelines with platforms of rock,

shingle, sand or mud is of lesser importance than an apprecia

tion of the extent to which these features may be vulnerable

to oil in its various states of surface slicks, solution or

suspension in the water, or when carried to the bottom and

incorporated in the sea floor sediments. The geographical

features of the Province have been described in the Principal

Introduction (paragraphs PI.4.1 to 32). We are here concerned

with the exposure and vulnerability to oil of some of the features there described.

(i) Emergent and submerged reefs 2.9.16 There are many reefs within the Province that are

always submerged. In the Australian Pilot (Exhibit 12) these

are usually referred to as shoals and their coralline nature is recognized in Dr Maxwell's naming of them as reefal shoals (Exhibit 2, p. 254). The many references in the Pilot show that these shoals may have from 1 foot to 10 fathoms or more

of water over them at the lowest tides. The Strip Map of the

Great Barrier Reef and Adjacent Islands (Sheets 1 - 3 ) which was prepared by the Survey Office, Department of Lands, Queens

land, as a reference map for the use of the Commission, shows

in some detail the distribution of reefs and shoals within the GBRP. Mr A.B. Yeates, Surveyor-General, Department of Lands

said that the Strip Maps included features visible in aerial

reconnaissance photographs down to a depth of "at least 30 feet" (T255) and he agreed that "The reefs that are marked on

the strip map are not limited to reefs that appear above the

surface ...". (T254)

2.9.17 Mr Yeates, when asked his opinion on "the proportion

of reefs which are submerged to those which do come above the

water line," said "I have no knowledge as to which reefs are

4 59

above or below water line except that normally a reef would be

above the water line." (T263) He thought It probable that

features shown by dotted lines were Indicative of permanently

submerged reefs or shoals. (T266) On this reading the grea

ter number of reefs shown with hatched edges on the Strip Map

would be exposed above the surface for a period at low water.

(11) Shelf edge reefs

2.9.18 Dr Maxwell at T218 said "... most of the reefs along

the shelf edge, the so-called outer barrier, tend to be lower

than the reefs back on the shelf. I do not believe that I have

ever seen a reef on the outer edge exposed. When we have been

on these reefs we have been In water depths of 2 to 3 feet.

The actual photographs I have of these reefs are all under

water." Dr Isobel Bennett In Exhibit 451 'The Great Barrier

Reef' describes their appearance and water cover In the follow

ing passages (pp. 37-38). "Only on a day of very calm weather

with an extremely low tide Is It advisable, or at all possible,

to venture on to such a reef. Careful navigation with a small

dinghy and outboard will enable one to negotiate the back region of the reef between the curved back ends. Here the

sandy bottom gradually shallows from the deeper waters of the

sea between the mainland and the reefs, and In water sloping

from about 3 fathoms to knee high, masses of coral 'rock', varied In size and form, some with curiously table-like struc

tures, are to be seen, each with a rock covering of living corals on their sides and upper surfaces. As one goes closer

towards the reef the coral growth becomes much denser.

"... The outer margin of the reef with its tremendous develop

ment of species is the most difficult to study since it is al most inaccessible ... On reefs where some fraction of this area

may be uncovered during the fortnightly period of the lower tides, it is sometimes possible to see the 'notched edge' of

the reef, which is much more clearly visible from the air. The

whole face along the windward edge of the reef may be 'toothed'

with deep grooves separated from one another by wide buttresses.

The sides of the grooves are covered with a wealth of encrust

ing species and provide, with their depth and incision back

into the face of the reef, a far greater amount of settling

space for the various reef faunas than would be possible

along a flat, unbroken area. As the tide ebbs water races

off the reef surface, cascading down the grooves as a wave

recedes in a swirl, of foam." And Mr Keith Gillett says of the

shelf edge reefs in the Swains Group at page 16 of his book

'The Australian Great Barrier Reef' (Exhibit 4) "the coral banks seldom completely uncover, even during the very low

spring tides."

2.9.19 The Australian Pilot Volume 4 (Fifth Edition)

Exhibit 12) comments in various passages on a drying at low

tides of some shelf edge reefs. Thus; at page 287, of Yonge reef which was visited by Dr Bennett, it says "The southern end of Yonge reef, which dries ..." and of Day reef in the

same area of the Northern barrier "Day reef which dries ...".

It was clear however from the evidence of observers who had actually landed on shelf edge reefs that if they dry at all, and it seems doubtful whether more than a proportion of them

do, their exposure is confined to small areas and is limited to a very short period of low water of some spring tides. Oil passing .over the reef would be unlikely to settle more than

momentarily on even the more exposed parts of the reef sur

face under the conditions of wave surge which normally pre vail at the shelf edge. On the other hand oil, newly spilled,

passing into solution or fine droplet dispersion, could be a

hazard to corals and other organisms covered by only a few

feet of water.

(ill) Reefs of the GBRP shelf 2.9.20 These include the many reefs of different form and size which lie between the shelf edge reefs and the shore line. Dr Maxwell said of their various forms that they "may

be assigned to one of 14 basic reef types. During its hist

ory of growth a reef may evolve from one type to another, or It

may combine two or more types to become a composite reef."

(T115) The shapes of reefs and their orientation to the cur

rents which mould their outline are important considerations In

tracing the evolution and relationships of the different types

but have a lesser relevance to the degree to which their sur

faces may be exposed to drifting oil. In this respect the ele vations of the various regions of the reef assume a greater

importance.

Dr Maxwell said that "... every organic reef is cha

racterised by 3 topographical elements which have been moulded

in various ways by organic growth, sediment deposition and sur

face erosion. These elements are the reef slope, reef rim and

reef flat. In addition to these basic elements other topo graphic features are variously developed, viz lagoon, back-

reef apron, ancillary reefs, banks, cays, boulder zones."

(T115) Descriptions of these features were given by Dr Maxwell

(T121-3), Dr Talbot (T978-80) and Professor Thompson (T656-6O). Except for some variations in nomenclature the descriptions were

consonant and that of Dr Maxwell will be followed.

Reef slope

2.9.21 The "Reef slope is the face of the reef from shelf

floor to reef rim. It varies in height from 16 to 32 fathoms for the majority of reefs although those of the near-shore zone

are much smaller. An average seaward slope approaches 30° ..."

and "is interrupted by a number of terraces ... . The lower

part of the slope carries a very sparse faunal cover ... .As

one progresses up the slope fauna become more prolific and from 30 feet to reef edge, coral is dominant. (T121) The "Reef front

is the highest part of the slope above the 2-fathom terrace. It includes the spur-and-groove structure-projecting walls of coral

and algae, separated by channels covered by reef debris ...

coral particularly Acropora is dominant." (T122)

462

Reef rim

2.9.22 The "Reef rim (or crest) is the highest part of the

reef and separates the reef slope from the reef flat ... It

varies considerably from reef to reef. In many cases it is

typified by the abundance of encrusting algae (Lithothamnion

and others) which form a hard, resistant surface. Small iso

lated colonies of branching coral are also abundant on some

rims. In most cases, the reef rim carries extensive boulder

and shingle deposits which add to its relief." (T123)

Reef flat

2.9.23 The "Reef flat is the main surface of the reef, be

hind the reef rim. Three zones may be recognized on the flat.

The zone of living coral and coral pools ("moat" of Yonge 1930)

varies in width from a few yards to five hundred yards. Algal

encrustation is common on the surface coral but in the pools

little encrustation is found. The dead coral zone lies to

leeward and is marked by an increase in dead coral, gravel and sand. Massive brain coral is common in this zone ... The sand flat merges leeward from the dead coral zone and, on the

larger platform reefs, is by far the major structural element ... Porites micro-atolls are common in this zone. Molluscs

and holothurians (Beche-de-mer) are also abundant." (T123)

(iv) Fringing reefs

2.9.24 In many parts of the GBRP fringing reefs border the

margins of the coastline and continental islands. Mr B. Cropp, who said "I have made regular skin diving trips to the Great

Barrier Reef since 1955 and for the past 10 years ... have spent an average of 3 months in each year on the Reef, cover

ing most of its length from Lady Musgrave on the southern ex tremity to Cooktown in the north" (T11740),when asked "Is the

coral on the fringing reef ... comparable with the coral out

on the true reef?" said "Yes and no. The coral on those frin ging reefs will tend to be more delicate, perhaps even piore

luxuriant but in little clumps here and there and over a wide

463

expanse." The fringing reefs "do not have the deep grottos,

the canyons and drop offs like the outer reef has, but indivi

dually some of these corals may be prettier ... because they

belong to the more delicate species; a great deal of soft

corals are in these shallows and ... are the prettier corals."

(TII8O6) Dr Isobel Bennett (Exhibit 451 p. 71) said of the

fringing reefs of the mainland coast in the north of Queensland

"... the coral growth there today is poorly developed except on

the outer margins of the reefs ... On the reef flat itself, al

though at first glance a place barren of all animal life, one

may find innumerable crustaceans and molluscs - in the pools,

among weed and under dead coral boulders." "The Near Shore

Reefs" says Dr Maxwell (Exhibit 2 pp.146-7) "exist in a vigor ous and changing environment. Wave action is augmented by

ground swell. In the mid-summer the zone is subjected to the

king tides ... leading to abnormally deep immersion and long

periods of excessive exposure and desiccation. The summer also

witnesses the heavy monsoonal rains ... resulting in reduced

surface salinities. These factors all act unfavourably on reef

growth and reflect ... the unusual constitution of their

faunas."

(f) Exposure of reefs at low tides 2.9.25 Dr Maxwell was asked at TI76 about the parts of a reef that are exposed at low tide. He said "The part of the reef

exposed at low tide is generally the reef rim and higher part of

the reef flat." He was of the opinion that 40-60% of shelf reef

surfaces would never be exposed. Professor Woodhead, speaking

of the reefs within the Swain's group, said that "At low spring

tides they would be exposed ..." but "At a neap tide such reefs as Heron Island are not exposed (T5249), and Professor Connell

considered that the living portions of corals on the reef flat

at Heron Island would be exposed, if at all, only on "very very

low tides." (T12266) He said that he had been there at very

low tides and could not remember seeing it happen. And accord

ing to the evidence of Professor Thomson, "... the depth of

water over the flats ... will vary tremendously from reef to

reef. In an old reef which has silted up, It might be only a

matter of Inches; In a younger reef I have seen channels bet

ween the outer and Inner flats at low tide which would still be three or four feet deep." (T646)

2.9.26 It is clear from the above description that there

are parts of the reef structure which remain below the water

level at all times and that only certain parts of the reef

ever emerge above the sea surface. (T235) By and largej in

summary of the evidence earlier reviewed, the shelf edge reefs

are emergent to a lesser degree and for a shorter time than

the shelf and fringing reefs. The maximum time of exposure to

air of the more emergent zones of the reef occurs at low water

of spring tides and is of the order of 1-2 hours.(Dr Maxwell, T236) On very low spring tides large areas of some reefs may

be exposed for periods of 2-4 hours. (Dr Maxwell T1625) The

most elevated region - the algal rim (reef crest) breaks the

surface "at low tide on most reefs, even if you are not deal

ing with spring tides. (T235) But not all parts of a reef are exposed even on the lowest tides. "I have never been on a

reef where I have actually seen the sand exposed but the tops

of the coral growths would come through and the tops of clams and other organisms." (Dr Maxwell T235) "The main faunal

development however ... is found in the depressed parts of the

reef surface which are rarely, if ever, exposed. Molluscs, echinoderms, crustaceans, marine worms and small coral colo nies occur on the exposed reef rim and parts of the sand flat

and these could be affected by oil." (Dr Maxwell T1625)

2.9.27 The water over the surfaces of reefs is, from the

descriptions earlier given, rarely still and the surges are often violent and confused. The water movements appear to be

most vigorous over reefs of the outer shelf edge but fairly

rapid currents also occur over the shelf reefs and fringing

reefs nearer to the coastline.

(g) Sea floor sediments: Benthic organisms

(i) Sediments

2.9.28 Information on the mineralogy, distribution and sedi

mentation of the sea floor materials within the GBRP came al

most entirely through the evidence of Dr Maxwell (T121 et seq;

T1612 et seq) and from descriptions in Dr Maxwell's 'Atlas of

the Great Barrier Reef' (Exhibit 2 Chapter 8). During the

course of his investigations Dr Maxwell examined between 5000

and 6000 samples. (T1681)

2.9-29 The 'Atlas' gives a synoptic account of the sedimen tary cover in the following words:

"In view of the enormous areal extent of the Great

Barrier Reef Province, of its range of bathymetric

and hydrologic conditions and of the geological diversity of the shelf and adjacent land mass, it

is not surprising to find wide variation in its

sedimentary cover. The Near North Shore Zone in cludes fine sandy, quartzose beaches, coarse sandy

and gravelly quartzose-feldspathic beaches, pebble

and boulder beaches, large intertidal mud flats and

extensive sand flats. Muds and muddy sands with

localised carbonate concentrations typify the Inner

Shelf while in places its eastern borders have com paratively mud-free sands. The Marginal Shelf where

maximum reef growth occurs is covered by fine, muddy carbonate sands. On the reef surfaces, carbonate

gravels and coarse sands are dominant over the reef

flat. Finer sands and silts are typical of the

lagoons, while boulder accumulations of widely varying magnitude and shingle banks occur on the reef crests or rims. The bases of the reef masses

are fringed with narrow zones of carbonate gravels and coarse sands. In addition to its diversity of

sediment type, the province is characterised by the

general abruptness of transition from one type to

another. Furthermore, the sediments are pre

dominantly detrital terrigenous and bioclastic

in origin. The contribution or inorganically

precipitated material, particularly carbonate, is negligible."

2.9.30 From the point of view of the questions asked in

TR2 the most important of the characterising features of sedi ments is their texture, that is to say the structure of the

deposit as defined by the sizes of its constituent particles

and the proportions in which the different sizes occur. Sedi ments of coarse texture, such as gravels and sands are less

closely packed than are fine-grained muds and silts; more

readily flushed by the passage of water through the particle

interspaces; and less liable, because of flushing, to be de prived of oxygen. As earlier noted, oil that is incorporated

into anaerobic muds is slow to biodegrade, but is less persis

tent when exposed to bacteria and other oil degrading organ

isms in the presence of oxygen.

2.9.31 Dr Maxwell (Exhibit 2, p. 197) classified the sedi ments of the GBRP into six types, viz. "... sand facies (less than 1% mud), slightly muddy sand facies (1 - 10% mud), muddy

sand facies (10 - 20% mud), sandy mud facies (40 - 80% mud), and mud (more than 80% mud)," adding that "The first two types

- sand and slightly muddy sand facies - are the most extensive

and together occupy more than half the total area of the pro

vince." Photographs in the 'Atlas' (Figures 145—147) show these two types of sediment to be coarse grained mixtures in which a 1 - 10% admission of mud would be unlikely to obstruct

the water channels of the inter-particle spaces sufficiently

to prevent irrigation.

2.9.32 By and large, the textural characteristics of the

sediments of the GBRP shelf over the greater part of the Pro

vince do not appear to be favourable to the long persistence

of oil that has been reported elsewhere in much finer deposits

such as the closely packed muds of Buzzard's Bay, Massachusetts.

The Chairman is doubtful whether the evidence supports this

conclusion.

(ii) Benthos

2.9· 33 Very little information was given to the Commission on the nature of the benthic organisms of the off-shore waters

of the GBRP. The responses of benthic animals to sunken oil

cannot, at the present level of knowledge, be predicted.

(h) The fauna and flora of the reef zones

(i) General

2.9.34 The following descriptions refer only to the more

general compositional characteristics of the fauna and flora of

coral reefs within the GBRP and to the more commonly occurring

organisms associated with the different reef zones described in

the previous Section. Detailed illustrated descriptions are

given in Dr Isobel Bennett, 'The Great Barrier Reef' (Exhibit

451), Dr Maxwell 'Atlas of the Great Barrier Reef' (Exhibit 2 K. Gillett and P. McNeill. 'The Great Barrier Reef and Adja

cent Isles' (Exhibit 3) and K. Gillett 'The Australian Great

Barrier Reef in Colour' (Exhibit 4).

2.9.35 Dr Talbot said at T938 "Coral reefs are perhaps the

most interesting of all marine living systems. They are inter

esting to the biologist mainly because they have a greater num

ber of species of animals and plants than any other marine

habitat but also because the sheer complexity of this number of

species interacting makes a total system more complex than any other. Sir Maurice Yonge voiced a similar opinion in saying "I think any marine biologist would agree that there is no eco

system quite so complex as a coral reef" (T9225) and Dr Endean extended the comparison to all eco-systems, aquatic and terres

trial: "I would think the diversity of species in the coral

reefs is only equalled by that of the tropical rain forests" .

(T13056) 468

2.9.36 Dr D.R. Stoddart, University Lecturer in Geography

in the University of Cambridge, England gave evidence on the

status of the Great Barrier Reef among the reefs of the world

and the problems of defining this status quantitatively. He

cited the work of Wells (1954) as showing that the greatest

number of genera of stony corals found anywhere in the world

is the East Indies - Marshall Islands region where some "70

genera out of a total possible number of rather more than 90"

are represented "... with the number decreasing along the Great

Barrier Reef from 50 in the north to about 20 in the south."

(T5793) He cautioned against making too much of these compar

isons for "many of the areas of known high diversity are those

where detailed work has been carried out, and vice versa ..." He instanced "Woodhead's collecting at Heron Island" which

"has revealed 54 genera and subgenera even at this very south

erly station (Woodhead and Webber,1969), and it is clear that similar intensive work is needed along the whole length of the barrier before meaningful statements can be made about latitu

dinal variations."

2.9.37 Nevertheless Professor Woodhead himself pointed to

the greater richness of the northern part of the Province in saying" I found about 70 genera and subgenera on the Papuan Barrier Reef in a week, diving and walking on reef flats ...

I am quite sure there must be many species which I missed ...

However, one nevertheless obtained a good index of the generic and subgeneric level - the highest number for anywhere in the

world, in fact - in one week." (T5307) Dr Talbot substantiated

this statement in saying "... the Indo-Australian region is

richer in species than any other tropical area of the globe" (T942) and Professor Stephenson, while acknowledging that "our

knowledge of diversity on the reef is woefully incomplete" said "some patterns are obvious. First, the richest faunas are in the north and they decline as we come southwards." (T2057)

2.9.38 The only other group in which numbers indicative of

469

species diversity in the GBRP and neighbouring reefal areas

were quoted were the fishes. Professor Thomson said "Over 1200

species of fishes have been recorded from the waters of the

Great Barrier Reef." (T629) Dr J.H. Choat, Lecturer in the University of Auckland, New Zealand, who had carried out re

search work on the ecology of reef fishes in Heron Island from

1963 to 1967, said that the fishes of the GBRP "are very close ly related to those found on central Pacific and Indian Ocean

reefs" but he was of the opinion that, because of the great

size of the GBRP it might contain "something in the order of 5000

species ... and will probably turn out to have the richest fish

fauna of any region on earth" (113146); and Professor Stephen

son told the Commission (T2057A) that "Two graduate students,

Woodland and Slack-Smith (1963) recorded 400 species from a single small cay - Heron Island. This is more than is known

from the entire area of the North Atlantic and associated

areas." Of 343 species collected at the neighbouring One Tree

Island Dr Talbot said (T977) that only 13% were found in all

zones of the reef and the outer reef zone has the greatest

number (61%).

2.9.39 These comments on the great variety of species of

corals and fishes in the GBRP, the full diversity of which has

clearly not as yet been fully explored, a circumstance in part due, according to Professor Stephenson, to the shortage of competent taxonomists and the difficulty of getting collections

identified (T2056), apply equally to other groups of animals. These were not reported on in detail in the oral evidence but the Commission had the benefit of the excellent descriptions of

reef animals and of the general ecology of reefs contained in Dr Isobel Bennett's 'The Great Barrier Reef', W.G-H. Maxwell, 'Atlas of the Great Barrier Reef', K. Gillett and P. McNeill, 'The Great Barrier Reef and Adjacent Isles' and Keith Gillett,

'The Australian Great Barrier Reef' which were tendered as

Exhibits 451, 2, 3 and 4 respectively.

470

2.9.40 Of this great number of species in the GBRP many

are present in immense numbers of individuals. The Commission

on visits to Heron Island and Green Island were able to see

for themselves the forests of staghorn coral (Acropora spp.)

which project from the gulleys of the reef slope and provide

living space for multitudes of fish of many kinds. And even

on the more sparsely populated reef flats we were able to

observe many forms of coral and a variety of species of sea

snails, clams, starfishes, brittle stars, sea urchins, sea

cucumbers, worms and sponges among the larger and more con

spicuous animals. We would not, from our brief surveys, dis agree with Dr Maxwell that "on the surface of a reef you have

large areas of little coral growth." (T231) Nor would one of

us who worked over the Lodestone Reef off Townsville defer

from Dr Endean's judgement that the Townsville reefs, of which

he showed a film, are 80% covered by coral. (T13002) An

average coverage, according to Dr Endean, would be of the ord er of 40%. (T12938)

2.9.41 The different zones of a reef vary greatly both in

the nature and richness of the floras and faunas they support. A few of the more dominant species that are met with in pass

ing up the reef slope, over the reef crest into the flats and

channels which lie on the leeward side of the crest will be mentioned from descriptions given by Dr Maxwell (T121-7; 146

9), Professor Thomson (T626-9) and other witnesses supplemen ted by accounts given in Dr Bennett's book 'The Great Barrier

Reef'. (Exhibit 451)

(ii) Reef slope

2.9.42 The lower parts of the reef slope extending upwards from the shelf floor to depths of 50 to 60 feet have a sparse organic cover. Dr Maxwell said "Coral is represented by stun

ted growths of small massive species and short branching forms Non-calcareous green algae are common and occasional clumps of

Halimeda (a small bush like calcareous alga) are present.

Crinoids (sea lilies) and bryozoa (tufts and mats of colonial

animals) occur in small numbers." Upwards to about 12 feet

from the surface coral cover increases "with the large dish

shaped Acropora hyacinthus dominating the terraces ..." and

accompanied by the related species A. humilis and A. pulchra.

"Species of Montipora, Fungia and small to medium-sized brain

corals (Coeloria, Lobophyllla, Pavia, Goniastrea and Porites)

are well represented in this zone. Soft corals (particularly

Sarcophytum) also occur here." Encrusting calcareous algae

(Lithothamnia and related genera) and non-calcareous algae,

particularly the green Chlorodesmis are common. (T146-7) As

one progresses up the slope to the reef front, the highest part

of the slope "the fauna becomes more prolific." Many species

of Acropora are particularly abundant (T121-2) and "are to be

found in a magnificant array of form and colour." (Exhibit 451,

p. 67)

(ill) Reef rim

2.9.43 The crest, at its highest part the algal rim is pre

dominantly bright pinkish-mauve in colour and separates the reef slope from the reef flat· "In many cases it is typified by the

abundance of encrusting algae (Lithothamnia and others) which

form a hard resistant surface." In most cases, the reef rim carries extensive boulder and shingle deposits which add to its

relief." (Maxwell, T123) "Though this may appear as a very

barren region, with little or no animal life, the underside of large boulders will be found with enormous populations of minute

animals, either as single individuals or small colonies. Large

boulders, two or three feet high, will be seen to be covered

with oysters and barnacles . . . These boulders provide the only available rocky substrate at the right tidal level for these

particular animals and they are not found elsewhere on the reef

flat." (Exhibit 451, p.67) Encrusting algae and corals (Pavona,

Cyphastrea) coat the rocks, sea urchins which bore into the lime

stone (e.g. Echinometra mathael) and a wide variety of molluscs

inhabit this zone (Dr Maxwell, Tl48): and the list of species

was elaborated in greater detail by Professor Thomson.(T.628) 472

(iv) Reef flat:

2.9-44 Dr Maxwell said "Three zones may be recognised on the flat·"

Behind the crest "The zone of living coral and

coral pools ("moat" of Yonge 1930) varies in width from a few

yards to five hundred yards·"(T123) Here "dense populations

of Acropora, Pocillopora, and Seriatopor-a thrive in the protec tive lee of the algal rim and are nourished by the subdued surf and oceanic water that surges up the grooves and tunnels ben

eath the algal rim ... A common inhabitant of the coral Pool is

the black long-spined echinoid Dladema Setosa..." "The transition from the living coral to the dead coral zone is comparatively abrupt and is marked by a slight

increase in the amount of sand. The massive brain corals,'

Favia, Platygyra and Lobophyllia are generally most common in this transition region ... On many reefs the brain corals rise

above the level of the adjacent fauna and form a discontinuous belt of rounded clusters . "(Exhibit 2, p .115) Giant clams

(Tridacna) are frequently present in this zone.

The sand flat merges leeward from the dead coral zone and "typical of the sand flat are the micro-atolls of

Porltes, which are circular disc shaped colonies that grow out

radially, the older central parts dying and eroding to form a central lagoon in minature. The blue Heliopora and the grey

Goniopora also form micro-atolls. The sand flat supports in addition a varied fauna of burrowing molluscs "and other burro

wing animals such as gastropod snails and sea cucumbers" (Ex hibit 2, p.115). "Small fish, crabs, worms, shrimps are abun dant ."( Professor Thomson, T625)

(j) Oil and the marine life of the GBRP

(i) Oil on the sea surface Birds (and see paragraphs PI.6.176-184)

2.9.45 Although a number of witnesses referred to the very serious effects which oil pollution can have on bird life, the

witness who dealt most fully with the probable effects of oil

pollution on birds of the GBRP was Dr Kikkawa (T675 et seq,

T1903 ~ 1982) who paid particular attention in this context to

the distribution, habits, population size and reproductive

behaviour of the birds of the GBRP.

2.9.46 Dr Kikkawa listed some 230 species of birds resi dent within or migratory visitors to the GBRP (T16462 and

tables at T675-80). He said that "In considering possible

effects of oil pollution ... on the birds of the Great Barrier

Reef and its waters, it is necessary to have the basic infor

mation of local distribution, abundance and the pattern of

migration of birds within the area." He noted however that

"... only a few islands have been surveyed in the past" and

"The patterns of general and local movements are also little

known ..." (T1909) According to Dr Kikkawa "The most vulner able groups of birds to oil pollution in Australian waters are

probably the penguins, cormorants, gannets and shearwaters ...

If the current causes accumulation of oil on continental shores

of central and northern Queensland severe local mortality would occur in up to 10 species of herons, egrets and ibises, inclu

ding rare resident species and three species of ducks, particu

larly the Grey Teal in winter. During the summer months up to

30 species of migratory plovers and other waders will be affec

ted if oil stays on muddy shores. If oil stays in inshore waters the cormorants will be the most susceptible to pollu

tion." (T1909)

2.9.47 At sea Dr Kikkawa said "... Some workers believe that birds deliberately seek out oil because the water is calm

or they mistake it for an indication of the presence of food.

If they do, migrating shearwaters and feeding flocks of gannets

and terns would suffer considerable losses. These and other

behavioural aspects of oceanic birds in relation to oil pollu

tion are not understood." (T1910) "... Some terns dive into the water to obtain food; other terns come near the surface

and skim the water and obtain food from the surface of the water without diving. So depending on their habits, the way

they contact oil would differ" (T19HA) and "... the Wedge-

tailed Shearwater, which breeds in large numbers on many islands

of the Great Barrier Reef, may suffer great mortality in local

breeding populations if the pollution is prolonged, or in mig

ratory flocks up to several hundreds of thousands if they land

on oil. This species is absent from the region between June and September." (T1910)

2.9.48 Among GBRP birds which Dr Kikkawa said produce

few young are shearwaters and gannets (T1914) though the list

of birds with a slow replacement capacity would include "...

terns, gannets, frigate birds and most of the sea birds which

breed in the tropical islands ... they normally lay one or two eggs. If they lay two eggs, only one chick grows, so that in

one breeding season, if their breeding is successful, a pair brings up one chick." (T739)

2.9.49 Mr Helman, in his closing address made the follo

wing comment in summary of Dr Kikkawa's evidence.

"According to Dr Kikkawa there is some risk to individual birds, of a certain

limited number of species in the Great Barrier Reef area, but a careful exam

ination of the habits, likely reactions,

ability to be cleansed, reproductive rate and distribution of those species,

shows there is no significant risk to

them" (T16494-5)

2.9.50 The Commission, while respecting Mr Reiman's con

clusion, is mindful of Dr Kikkawa's expressed view that "... the birds we have in the Great Barrier Reef waters are the birds of the tropical ocean and we have not any evidence of

the type of damage that they may receive from a disaster of this type ..." (T1944) In the absence of a better knowledge

of the habits of many of these species, the Commission, while not regarding catastrophic damage of a lasting nature from oil

pollution as a definite probability, considers that in the light

475

of Dr Kikkawa's evidence some damaging effects are probable,

and damage endangering the status of a species at least pos sible ,

Turtles and sea snakes (see also paragraphs

PI.6 .212-3)

2.9-51 Amongst other animals which live all or a part of their lives at sea in GBRP waters and which require from time

to time to break surface to breathe in air are turtles and sea

snakes. Dr Isobel Bennett in Exhibit 451, p.62, says "Three

species of marine turtles are found in Barrier Reef waters.

The small Hawksbill, Eretmochelys imbricata ... the much larger Loggerhead turtle, Caretta caretta ... and the G r e e n Turtle,

Chelone mydas ... the most widely distributed of the marine

turtles ... (which) owing to the delicacy of its flesh has

suffered very severe predation by man." Several species of

sea snakes occur in the Province and "are quite common in the

more northern waters." (Exhibit 451, p .64)

No evidence was received on the probable effects of oil on

marine reptiles.

(ii) Oil in the sea

Plankton (and see paragraphs PI.6.151-161)

2.9.52 Little is known of the nature, distribution,

seasonal variations and productivity of the GBRP plankton.

The present paucity of knowledge drew from Professor Stephenson

the comment that "... the amount of work done on the Barrier Reef ... is I think a couple of papers published about 1930"

(T2067) and based on work which he later explained as having

been done "... in a localized area by the Yonge Expedition, and over most of the space we do not even know the seasonal

occurrence of dominant forms, much less the temporal and spat ial distinctiveness of such "communities" as might exist." The

papers referred to by Professor Stephenson were Reports of the

Great Barrier Reef Expedition of 19?-8-29 (Exhibit 182) relating

to plankton surveys at Low Isles, north of Cairns.

476

Phytoplankton

2.9.53 The plankton of the Province Includes both plants

and animals the latter comprising adult organisms (most of

them microscopic) and the larvae and other developmental stages

of corals and other organisms that live in the area. Professor Stephenson said of the phytoplankton, at T2064, "Planktonic

plants occur in reef waters as they do everywhere else in the sea, but we rarely see conspicuous spring outbursts (spring

outbursts are a characteristic feature of the algae of plankton

in high latitudes). In the warm waters of the reefs it appears

that .... there is never a high standing crop of producers, but

instead a high rate of production and turnover throughout the

year ..." Moreover, according to Dr Talbot, "A coral reef,

such as any lagoon system in the Great Barrier Reef, has rela tively little input or output of nutrients, and is largely a

closed system rapidly producing and cycling food." (T950)

Zooplankton

2.9.54 The zooplankton, almost all of which depends directly on planktonic plants for its food, appears to be similarly maintained at an even level of production over the

year for, "... the results at Low Isles seemed to indicate that the high temperature so increased metabolic rates allowing rapid development and replacement of planktonic -animals in

these tropical waters that, averaged over a year, the produc tion was comparably as much as that of the colder waters", and

would appear, like the phytoplankton, to be produced and main tained substantially as a closed system for "... biologists

working at Bikini Atoll discovered that many of the planktonic

animals found within the lagoon were not taken in the ocean

waters, except where there was a strong current flowing from a reef" (Dr Isobel Bennett, Exhibit 451, p .94). Professor

Woodhead also ascribed the closed system character of the reef

plankton to "... certain hydrographical features ... which in some instances help to contain the larvae and eggs near the

reef. At the same time, many are certainly lost to the ocean currents and swept away from the reefs ..." (T5388) Professor

477

Connell, quoting a literature source at T12164, said "Johnson

(1954) found that plankton was 2 to 4 times more abundant

within the lagoon than in the waters just outside the reef.

He attributed at least part of this concentration to the ebb

and flow of these counter-current patterns".

It was clear from the evidence given to the

Commission that little is known of the composition of the GBRP

plankton. Dr Grassle remarked that "... no one has studied

the planktonic larvae in the Great Barrier Reef. It is cer

tainly one of the top priorities for research." (T6440)

Difficulties arise partly from inadequacies of collection for

"Even collections taken just above corals known to be capable

of releasing larvae seldom catch any planulae..." Professor

Connell, T12161) and "In plankton tows taken several times a

month for a year at Low Isles planulae were caught only in

December, even though some species liberated planulae every

month in the laboratory (Russell and Colman 1934)", and partly from the difficulty of identifying planulae with the species

of coral which produce them (Professor Connell, T12158).

2.9.55 From observations made in areas other than the GBRP, Professor Connell said (T12157), "... most planulae soon

settle down, usually within the first two days. A very few

remain swimming longer, up to three weeks, or in one instance

two months" (Atoda, 1951,b) and Professor Woodhead, speaking of the length of their larval life, said of the varying periods

that they "... would be a matter of perhaps minutes or hours...

running to months" (T5275) · It was not denied that larvae

produced from organisms of a reef might, especially if they

have a long planktonic life, be carried beyond the confines of

a largely closed system (Dr Bennett, Exhibit 451, p .94;

Professor Woodhead, T5388) to aid in the regeneration from a distant source of reefs damaged by pollution or through natural

causes.

2.9.56 Nevertheless, the Commission was impressed by the

weight of evidence favouring the concept of the essentially

closed system of Individual reefs, and Is not disposed to

regard the plankton of reefal situations as being so readily

capable, if damaged by oil, of regeneration from external

sources as may be the case in the plankton of the open sea.

Freshly spilled oil could under these circumstances be damag

ing to the economy of a reef, if not by direct kill of adult

organisms, by removing - temporarily at least - important

sources of food and of juvenile reproductive stages. Massive

overlays of freshly spilled crude oil or the continuing

admission of oil in the smaller quantites of a chronic pollution

could kill plankton and affect, for a time at least, the

organisms which depend upon it. Weathered oil is considerably

less toxic, and in the protection of the plankton of reefs it

seems prudent to ensure that sites where spills may occur,

for example exploratory wells and production platforms, are

placed at a "safe distance" from reefs in order to allow sea

room for the weathering of drifting oil. (See answer to TR3)

(iii) Oil on shores and reefs

A . Experiments, both Australian and

overseas, with fresh and weather ed crude oils

Section (1) Corals

Introduction 2.9.57 Six separate and independently conducted series of

experiments designed to test the effects of oil on corals were reported to the Commission during the course of the

hearings of evidence. The scientists who undertook the experiments, the dates of the investigations and the places

in which they were carried out were as follows:- Mr E. M.

Grant, Fisheries Research Biologist, Queensland Department of

Primary Industries, Brisbane, February 1969, Moreton Bay, Brisbane, August/September 1971, Wistari Reef, and April 1972, Heron Island; Mr N. M. D. Haysom, Fisheries Biologist,

Queensland Department of Primary Industries, Brisbane, August/ September 1970, Fitzroy Reef, and October 1970, Moreton Bay;

Professor R. E. Johannes, Associate Professor of Zoology,

479

University of Athens, Georgia, USA in early 1971 in Hawaii,

and June 1971 at Eniwe.tok lagoon, northern Marshall Islands;

Mr E. A. Shinn, Senior Geologist with Shell Oil Company, New

Orleans, Louisiana in July 1971 at Key Largo, Florida; Dr

J. B. Lewis of the McGill University Montreal at unspecified

dates in 1971, in Barbados; and Professor S. H. Chuang,

Professor of Zoology, University of Singapore at an unspecified

date in 1971 or 1972 in Singapore. Except for Dr Lewis, whose experiments were described in Exhibit 338, all the scientists

concerned appeared as witnesses and were examined on their

experimental procedures and findings.

2.9.58 During the course of the experiments some 20 - 25

genera and a greater number of species of coral were put to

test, and crude oils of differing provenance and composition

were used. The conditions of experimentation varied in respect

of the corals examined; the concentrations of oil to which

the corals were subjected; the presentation of oil - either

by direct contact or in solution or emulsion; the full

immersion in sea water or part emergence into the air of the

corals under test; water temperature; degree of oxygenation

and other experimental conditions.

The Australian experiments

Mr Grant 2.9.59 Mr Grant, in aquarium experiments carried out at

the Fisheries Laboratory, Brisbane, in February 1969 (T10268 et seq), placed in each of three tanks (A, B and C) 30 x 12 x 15

inches high, and each containing 15 gallons of Moreton Bay

water two Turban Corals, Favia speciosa, of approximately 6 inches diameter. All three tanks were aerated. Three pints

of Moonie oil were poured gently on to the surface of the

water in tanks B and C to form an unbroken surface \ inch thick. To A, the control, no oil was added. The water level

in Tank B was maintained static; in tank C water was siphoned

out of and into the tank to simulate the ebb and flow of the

tide. At the lowest level of the water, oil was in contact with

the corals for about 5 minutes daily for 5 days (T10268 - 9).

"On the eighth day the crude oil was skimmed from the surface

of Tanks B and C and the corals maintained for a further 16

days. At the expiry of this time they were still alive and the experiment was concluded." (T10269)

Comments made in Mr Grant's statement and in

examination included reference to the oil concentration -25,000

ppm, and the discolouring of the seawater presumably by oil in solution or suspension.

2.9.60 In August/September 1971 Mr Grant carried out three

experiments on the effects of Moonie crude oil sprayed on to

water flowing over corals near the reef edge at the north

western extremity of Wisfcari Reef in the Capricorn Group.

(T10273) For the first experiment a small area about 12'

x 5' was pegged out. Between 08.10 and 09.10 hours on 31 August 10 gallons were sprayed continuously on water to the south side of the pegged area to form an oil slick with a

front of about 71 which was carried on a falling tide over and around the corals in the pegged area. The water cover

initially was about 1 inch. At the conclusion of the experiment on the falling tide, some corals, mainly staghorns had their tips protruding above the surface of the water.

Staghorns and Pocillopora within the pegged area responded by

secreting strands of mucus.(T10275) "The following day (1 September) all corals within the area appeared alive and healthy as they were three days later." On the fifth day "one colony, and possibly two had their uppermost tips whitened.

This followed a period of very low tides and cold winds (4 to 5 September) and similar damage appeared fairly generally over other areas examined. Eleven days after oiling "there

was no substantial change in the general appearance of the corals ... They were colourful ... Two colonies of Pocillopora had their uppermost tips encrusted with a brown filamentous alga ... I conclude that the discharge of 10 gallons of Moonie

crude ... apart from the immediate reactions stated above,

481

had no apparent effect on the corals ... ." (T10276)

2.9.61 In the second experiment (1 September) an area

measuring about 17 ft 8 inches by 7 feet was pegged. The area

contained a wide array of corals including staghorns, brain

corals and Pocillopora in addition to some clams and serpulid

worms.(T10279) On 2 September between 11.05 and 14.30 hours forty seven gallons of Moonie crude were sprayed by knapsack

sprayer to the side of the pegged site the oil being carried

over it in continuous thin film. Except for 2 minute rests

each half hour, spraying was continuous. The corals had

initially a water cover of about 1 inch on a falling tide. At

low water some corals were exposed, and at the end of the

experiment the tide had risen to 2 - 3 inches cover. At the beginning of the operation oil moved at a speed of about \

knot over the study area; the speed later declined to about l/7th knot.(T10282) During spraying some emergent and some

submerged corals exuded abundant mucus mats which were lifted

clear on the rising tide.

Next day Mr Grant reported "all corals, clams and

serpulid worms alive and normal-. (T10283) A similar report was was given after one and seven days following a further spray

ing of 35 gallons of Moonie crude.(TIO287)

2.9.62 Mr Grant's third and last experiment in the series

(8 September 1971) involved the enclosure of a small brain

coral within a "polycloth" screen fastened to six hexagonally disposed steel stakes driven into the surface of the reef but

with water free to pass under the "polycloth". The surface area of the container was about 6 sq.ft.(T10291). Some 21

hours after enclosure two gallons of Moonie oil were poured into the enclosure. Wave surge was sufficient to raise and

lower the water from a mean level of some 3' 3" and to disperse a substantial part of the oil into droplets. With

the falling tide the water level in the enclosure fell to about

6 inches at which time a further two gallons of oil were added.

At low tide the coral was at or slightly below water level .

(T10294) The screen was then removed. Then and some 15 hours

later Mr Grant said "the general appearance of the brain coral

was unchanged. It appeared quite normal and healthy as did

the surrounding area." (T10295)

On 16, 18 and 19 January 1972 Mr Grant revisited the

area and examined the corals studied in the September 1971

experiments. He said that there were no differences apparent

which could be attributed to the addition of oil. (T14200)

The corals within the experimental areas were photographed in colour in September 1971 and January 1972. Some 175 slides

(Exhibit 546) were projected for the benefit of the Commission

and were commented upon by Mr Grant. (T10301-49)

Possible damage short of death not recorded

2.9.63 Attention was drawn to some deviations in the experi

ments from the conditions of oil presentation attending acci

dental oil spills. The spraying of oil (Wistari: Experiments 1 and 2 ) may result in substantial losses through evaporation

of the lighter fractions of the Moonie oil used (T10277), and

it was admitted by Mr Grant that possible damage short of death was not recorded in observing macroscopically the res

ponses of corals to oil exposure. (T14229)

Change of colour after the experiments 2.9.64 The difference in colour of some corals before

(August 1971) and some time after exposure to oil (January 1972) as evidenced in the slides shown by Mr Grant, attracted extended attention and comment in cross-examination. (T14200-1)

Mr Grant accepted that colour variations were apparent in many instances but attributed them to such factors as variations in time of day, light intensity, water depth, water rippling, camera distance from subject and camera angle. (T14202 to

14252 various references) It was also suggested by Mr Grant at

T15523-4 that a piece of coral can change colour.

The Chairman has some difficulty in accepting Mr

Grants explanations for the white tips and the brown colour of

483

certain of the corals four months after the experiments as he

considers from his own interpretation of the photographs that

they are consistent with ill health, (and cf Mr Grant at T14245

and Mr Shinn at T10124)

2.9*65 In so far as the limited number of species put to test

by Mr Grant are concerned, namely one or two species of Acro-

pora, Pocillopora, Pungia and brain corals the conditions of

oil presentation to which he submitted them included direct

contact, intermittent contact, and emulsion and solution expo

sure, all of which adequately simulated the conditions of expo

sure that might normally be expected in oil spills. We see no

reason to differ from Mr Grant's appraisal of the tolerance of

the few species of coral tested in his experiments when he said

at T14221, "I conclude that at the actual time of application

of oil, some corals, but not all, are irritated to the extent of exuding mucus. However, again under the conditions of my

experiments, the corals survived what I take to be a rather

massive application of oil," nor - the Chairman however dissent

ing - would we differ substantially from the views he expressed

in the following questions and answers:

"Mr Grant, would you say that your experiments

and the results you obtained related only to short-term effects. Do you regard them as

short-term experiments or not? -- No, sir,

I do not think I do.

You do not regard them as short-term experiments?

Do you think it would be likely or unlikely that

they could be a reliable basis for general conclu

sions? -- Within the limits of the experiments,

yes. (T14252A)

What are those limits?

-- That the oil was applied for only two con secutive days.

In a running out tide?

-- On both a running out and ascending tide, yes.

484

In an area where the current was travelling at

about just under 3 miles an hour?

-- At the time of initial application I think that is correct.

At all events you do not agree that your experi ments relate only to short-term effects in a

limited area - or do you?

-- The effects, I think, Sir, are long-term. The area is certainly limited by the extent of being 17 ft 8 ins by 7 ft." (T14253)

The Chairman does not agree with Mr Grant. He

regards both the experiments and the effects as short term

within the meaning of that phrase as used by the CSIP.O when

advising the then Prime Minister in 1971 (see reference to the

Prime Minister's letter of 2nd June 1971 to the Chairman in paragraph PI.2.3)

Mr Haysom

2.9.66 Mr Haysom conducted two general groups of experiments.

(Exhibit 351, T10619-10727) In August and September 1970 at Fitzroy Reef, Capricorn Group four separate experiments were

carried out. (T10622) One involved pouring oil on to four discrete pools, each with a similar numerical and species assemblage of corals, with one pool of a similar faunal con

tent, as a control. The second involved the presentation of oil in plastic bins suspended from the stern of a launch and therefore subject to agitation. The third and fourth involved

the pouring of quantities of crude oil to be carried onto coral

by the tide. A single experiment carried out at Peel Island, Moreton Bay in late October 1970 involved the presentation of

Moonie crude and bunker oil to corals contained in sea water

within perforated plastic bins.

Mr Haysom said that these two series of five experi

ments were undertaken after Mr Grant's 1969 aquarium experi

ments on the effects of Moonie oil on turban corals (Pavia spj

had been completed: "we discussed how perhaps we could expand

h 85

these experiments somewhat to find out to a greater degree what

effects oil might have on corals. We discussed how we might go

about these experiments and decided perhaps some form of con

tainer anchored out in the reef area to keep oil enclosed so

that it comes in contact with the corals might be the most use

ful way ... . However, it would be rather difficult to arrange

such a structure ..." and it was decided to do experiments in

"natural enclosed pools ... or some form of bin which would be

easier to erect on the reef" or try "spilling oil in front of

the incoming tide and watching it wash across the corals on the

intertidal area." (TIO696)

2 .9.67 In the Fitzroy Reef experiments (first series) pools

containing corals and other organisms were submitted to oil

cover. Five discrete pools of surface area 1-2 square metres

each near the south-western end of Fitzroy Reef adjacent to the

reef rim were chosen. (T10628) The corals and other organisms

in pools 1-4 served as the test animals for the oil treated

samples. Pool 5, the unoiled control, was made up to include a coral content similar to 1-4. (T10717) The 'hard' (scleract-inian) corals in the pools were (1), 2 Favia sp.; (2) 2 Fungia

sp.; 3 Pocillopora sp., 1 Acropora cuneata; (3) 1 Fungia, 1 Acropora sp., 1 Acropora cuneata?, 1 Favia sp., 1 Seriatopora sp.; (4) 1 Fungia sp., 1 Seriatopora, 1 Acropora sp., 1 Acro

pora cuneata?, 1 Favia sp.; (5) 1 Fungia sp., 1 Seriatopora sp.,

1 Favia sp., 1 Acropora sp., 1 Acropora cuneata?, 1 Pocillopora

sp.

2.9.68 The experiments were carried out at the time of a spring tide. (T10711) Low water at Heron Island, 10 miles dis

tant from the area of experiment, was 15.46 hours on the day (19

August 1970) when oil was first added to a pool. The height of

the water in the pools at low water averaged about 6-7 inches;

at high tide they had a 2-3 foot cover. (T10634, IO636) Of

the corals in pool 1, Mr Haysom said that they were at all

times submerged (T10633), and, though this was not specifically

486

stated in evidence, the photographs which Mr Haysom showed to

the Commission indicated that cover was also maintained in

pools 2 and 3· Pool 4, however, "Completely drained out"

during the course of the experiment. (T10650)

2.9.69 The oil treatments of the pools were as follows. Oil

in quantity calculated to give a layer about 1 mm thick

(TIO685) was added to all the pools within half an hour or

less of the time of low water. (TIO633, 10644, 10649, 10650)

Pool 1 received fresh Moonie crude followed by 24 hour 'wea

thered' crude on the next low tide; pool 2 fresh Moonie oil;

pool 3 fresh Moonie oil; pool 4 'weathered' Moonie oil. The

pools and the overlying oil overflowed 2\ hours after low

water with the tidal rise. The corals in the pools were in spected on the day following the oiling of the pools, some

times at a period somewhat less than 24 hours.

2.9-70 In none of the experiments was any visible damage to

any of the corals detected by Mr Haysom. (TIO637, 10655, 10649, 10650)

2.9.71 The conditions of presentation of oil claimed for

these experiments were, in summary, (i) oil present as an over

lying but not contacting layer in which oil/coral contact would presumably be through solution or emulsification (ii) oil pre

sent as a layer equivalent to a "fairly massive contamination" a claim made by Mr Haysom (T10684) on the basis of a published statement (J. Wardley Smith) that "If the water surface is

heavily contaminated, the final thickness may be 1 millimetre or more." (T10684) As a reservation to these conclusions it

must be noted that the oil in the pools was not submitted to the water agitation that occurs in the open sea and which aids solution and emulsification. The second and more important

point to be noted is that the experiments were not designed to discover any toxic effects on corals other than lethal effects.

(T10721)

2.9.72 In the second series of the Fitzroy Reef experiments

the test area chosen was the outer rim of the Reef where the

number and variety of corals was much greater than in the pre

vious experiment. In each of two trials (TIO663, T10669) one

and a half litres of fresh Moonie oil were released on the

front of the incoming tide on the seaward side of a mixed com

munity of encrusting and stubby branched coral. "As the oil

was carried towards the crest, it fetched in succession on a

series of coral and Palythoa colonies, but was rapidly lifted

off with the rising level of the water. Some slight discharge

of mucus by some Acropora colonies was noted. No trace of this

spill was found when the area was re-examined 24 hours later."

(TIO663)

2.9.73 Special attention was paid in one of the trials to the drift of oil on to two small colonies of Favia and some small

twigs of Acropora when oil contacted them. "Within five min

utes the corals were seen to exude fine streams of mucus" and

"By the time the colonies were completely covered by the tide,

the Favia heads were completely clear of oil, but some oil drop

lets still adhered to the Acropora twigs." (TIO669)

2.9.74 In the third trial bunker oil was substituted for

Moonie crude. Five litres were released and "This oil adhered

much more persistently to the organisms with which it came into contact but, even so, within 15 minutes it was obvious that a large proportion of the oil was being sloughed off with the aid

of vigorous mucus production by the coral colonies" (T10666)

"The area of the spill was revisited 24 hours later when I observed that no oil was visible on living scleractinian coral

... though a few small traces were still attached to old dead

twigs." (TIO667)

2.9.75 The contacts of oil with corals in these trials were of

very short duration and no damage was reported. Rapidly con

ducted trials of this kind can be no more than indicative of

the purposes they are designed to serve, namely, in this

instance of the greater capacity of a viscous oil to adhere

for a while to corals more firmly than does a light crude; of

the greater tendency for oil to adhere to some species than to

others; and of the oil removing effects of the mucus secreted by corals.

2.9.76 The last of the series of experiments performed by

Mr Haysom at Fitzroy Reef involved the placing of a selection

of branched corals (Acropora spp. and Stvlophora) in plastic

bins some 40 cm high and with their sides perforated about 3

inches from the bottom of the bins with \ inch holes. (TIO656)

Three bins were suspended from the stern of a launch the depth of water level inside the bin being about 20 cm. 1 litre of

Moonie crude was run into two of the bins and 1 litre of

'weathered' Moonie oil into the other. An unperforated bin,

containing a similar selection of corals, was placed on deck as a 1 control'. The oil layer in the suspended bins was esti

mated to be about 8 mm. thick. The bins were left suspended

overnight and joggled sufficiently in a choppy sea to break

tips off some of the coral. The corals remained submerged

throughout the experiment though one bin lost half its water

content so that oil came within a few centimetres of the tip of some corals. (T10660) Inspection the following day led Mr Haysom to report all of them "as being alive and healthy

after the conclusion of the experiment." (T10659)

2.9.77 The main circumstances distinguishing the plastic bin

trials from Mr Haysom's pool and reef-surface exposures of

corals to oil were (i) the longer period of oil cover (but not contact) to which the test animals were subjected and (ii) the probability that the corals were exposed to high concentrations

of oil in solution and droplet emulsification. The design of

the experiments was however unnecessarily cumbersome and in several respects unsatisfactory. In particular, they did not

allow of the quantities of oil which escaped from the perfora

tions in the bins to be measured; the corals in the bins were

thrown about and damaged; and the ’control* conditions in the

unperforated bin were different from those in the perforated

oiled containers.

2.9-78 Mr Haysom's Peel Island experiments of October 1970

(TIO671 et seq) involved similar procedures but were intended

to be more testing of the capacity of corals to withstand ex

posure to oil in that there was to be direct contact of oil

with their surfaces over a period of some hours.

Basically they involved the use of three perforated

plastic bins with polystyrene flotation collars and tethered to

stakes on the flat foreshore of Peel Island. The scleractinian

corals placed in the bins were as follows:

Bin 1; 2 Pavia speciosa, 1 Flavia stelligera,

1 Acropora spicifera and 1 Turbinaria peltata.

Bin 2; 2 Pavia speciosa, 1 Acropora digitifera,

. 1 Cyphastrea serailla.

Bin 3; 2 Pavia speciosa, 1 Acropora digitifera.

One litre of Moonie crude was added to Bin 1; 1 litre

of bunker oil to Bin 2. Bin 3, unoiled, served as a control.

(TIO675) Mr Haysom estimated the thickness of the oil layer to

be about 8 mm. (TIO677) Oil was added about one hour before

low water and on the falling tide the oil layer sank to the

level of the corals. "... direct contact lasted for at least

three hours in the case of the lowermost portions of all the

colonies, and up to six hours in the case of the uppermost polyps of the A. spicifera colony, before the incoming tide

again submerged the polyps." (TIO678)

2.9-79 The experiments were started at 18.30 hours on the eve ning of 21 October and the first inspection of the corals was

made at 01.30 hours the next day by floodlighting the bins which

at high water had floated to the surface. A few traces of Moonie oil were present in Bin 1 and some slight mucus produc

tion by Acropora. The bunker oil in Bin 2 coated the inside

490

walls of the bln, water of which contained a heavy flocculent

discharge of mucus. (TIO679) At 06.15 on the third day

(October 23) the corals were removed to storage bins for

transfer to Brisbane. "All were alive and in good condition."

(TIO679) On arrival at Brisbane via Manly, where they were

placed in muddy harbour water, one specimen of Aeropora dlgi-

tifera from Bin 2, which had been transported in a leaky con tainer and had been exposed to air for an estimated 20-25

minutes had an abnormal smell and eventually died. (T10680)

The remaining corals, now under laboratory aeration, "were

examined at 0830 hours on 26th October 1970. The corals all appeared healthy ... They had been held a total of one week

from the time of application of the oils." (T10681)

2.9.80 Mr Haysom himself appropriately described the Peel

Island tests as a "sledgehammer type of treatment." (TIO687)

Certainly the corals were subjected to a variety of stresses

in addition to oil treatment. One colony of the nine which suffered oil treatment died, the remaining eight, drawn from

4 genera and 5 species, survived. The inspection made of them was however insufficiently detailed for the identification of possible tissue damage.

Summary and appraisal of the Australian experiments 2.9.81 Tests of the effects of oil on corals of the GBRP have been on branching corals of the genera Aeropora, Poeillo-

pora, Stylophora and Seriatopora and on species of more massive growth within the genera Favla, Fungia, Turbinaria, Montipora and Cyphastrea. All the corals that have been put to test live

in pools, channels or on the surfaces of the reef flat on the

leeward side of the reef rim; and all have either a very shal low water cover at low water of spring tides or may be exposed at least partially, for a short period of this time. They may

therefore be regarded as being potentially susceptible to con

tact or near contact with oil should a spill invade a reef.

Field and laboratory experiments carried out to test

the effects of oil provided both for contact and the near con tact of an oil film, the thickness of the oil film approximat

ing in the several experiments to thicknesses that might be

expected in an actual spill. In the experiments which provi

ded for contact, the period of contact was on occasions as long

as would be expected in a real oil spill situation. The simu

lation of near contact conditions is more difficult to achieve

in experiments, for the period of cover and the quantities of

oil that pass into solution in the open sea are dependent on

the size of the spill, the degree of wave action, sea turbu

lence and many other contributory factors which cannot be ex

actly replicated.

Of the many individual corals and coral colonies that

were put to test in the Australian experiments only one (a

specimen of Acropora digltifera) died and the circumstances of

its death (Haysom T10680) were such that oil could not with

certainty be implicated. Of the species of coral tested, the

few experiments which were done appeared therefore to show that

they have a surprising but nevertheless real capacity to survive

the kinds of oil contact and cover that might normally be expec

ted to be associated with an acute exposure to oil of limited

duration.

The reservations which must be entertained concerning

the effects of oil on corals lie in the as yet unexplored con

sequences of chronic exposure to oil and in the possible sub-

lethal effects which acute as well as chronic exposure to oil

may produce.

Although both Mr Grant and Mr Haysom reported on signs

of stress in corals short of death, notably in the production of copious mucus, tentacle retraction and tissue lesions no single

experiment or instance of microscopic tissue examination was

brought to the notice of the Commission whereby possible short

term damage to the tissues, or short and long term effects on

the feeding, growth and reproductive capacity of corals could

be revealed.

In so far as the Australian experiments are concerned

492

it is appropriate to point out that the total experience de

rives from the experiments of only two people - both skilled

biologists who conducted their experiments with care and pre

cision and who reported on them fully under intensive examina

tion. Nevertheless the address to the problem in Australia,

some twenty man/weeks in all, has been disappointingly small.

Other experiments (Mr A.E. Shinn, Professor S.H. Chuang, Professor R.E. Johannes, Dr J.B. Lewis).

(a) Mr Shinn

2.9-82 Mr Shinn, "employed as Research geologist by Shell Oil

Company" (T10107) described to the Commission "A short-term oil pollution experiment on semi-in-situ reef corals" (T10149)

which he had undertaken on July 23, 1971 at Key Largo, Florida.

"Three iron stakes were driven into the sea floor in 20 feet of water near a coral patch off Key Largo, Florida,

Branches of Acropora cervicornis collected from a few feet away but never removed from the water, were wired to the top of two

of the fixed stakes. An additional small colony of Porites porites was wired a few inches below the branch of Acropora

cervicornis. A small head of Montastrea annularis, Porites

asteroides and Agaricia agaricites were wired to the remaining stake. A clear polyethylene bag of approximately 10 gallon

capacity containing 5 to 6 gallons of sea water was placed over the stake holding the Acropora cervicornis and Porites porites and tied securely to prevent water circulation. "(T10159) Of the three coral-mounted stakes the last mentioned Acropora/

Porites preparation served as a control.

Over the other Acropora/Porltes stake was placed a similar bag containing a half gallon of Louisiana crude to 3

gallons of sea water. "In placing the bag in position, an

additional 1 to 3 gallons of water entered the bag ... the final ratio of oil and water exposed to the coral was between 1:6 and

1:12. Oil floated at the top of the bag and the upper tips of

the Acropora cervicornis were within a few centimetres of the oil-water contact throughout the two hours exposure and actually

H93

touched the pure crude several times during bag placement."

"A similar bag containing one ounce of crude to 3

gallons of water was placed over the stake holding Montastrea

annularis, Porites asteroides and Agaricia agaracites. Again

an additional 1 to 3 gallons of seawater entered the bag during

placement, bringing the ... oil-water ratio .. to somewhere be

tween 1:384 and 1:768. (T10151)

"In yet another test an in-situ 8 inch diameter head of Montastrea annularis was covered with a 16 inch clear lucite

dome approximately 3/4 filled with crude oil. Approximately

half of the coral was thus immersed in pure crude oil for two

hours. "All the experiments lasted for two hours." (T10151) Mr Shinn in reporting the effects of these immersions

or near-contacts of oil with corals, said "The extended polyps

of Acropora cervicornis retracted immediately upon contact with

the oil/water mixture. Polyps of the control corals, however,

remained extended throughout the experiment. Since the polyps

of Montastrea and Agaricia are retracted in daylight, it is

impossible to ascertain their initial reaction to oil. (T10151) Although the polyps of Acropora cervicornis remained

retracted for at least hour after the pollutant had been re

moved, Mr Shinn said that 24 hours later polyps of all the

species "were extended and appeared no different from those of

the control" And further: "After 13 days all the test corals

were still living and appeared to be as healthy as corals grow

ing on the nearby coral patch" None, including "Montastrea annularis, exposed directly to crude oil for two hours, showed the slightest damage." (T10152) The least convincing aspect of

Mr Shinn's evidence lay in the reasons he gave for not suspect

ing the slightest damage'. At T10175 he said that "If there had been any damage I would have expected to see some sloughed off tissue ... which we did not see." Under cross-examination how

ever his reply in answer to the question "... does sloughing, if it has occurred, always reveal itself to ... the naked eye?",

he replied: "I do not feel reasonably certain to answer that."

He added "I place my strongest evidence on the lack of encrust-

ing algae 13 days after the experiment." (T10176) Mr Shinn

said at T10174 that in his experience, the presence of en

crusting algae was an indication that the coral where they

settled was dead. (110174) The criteria by which damage short of death was assessed were not made known.

Singapore experiments

(b) Professor Chuang

2 .9.83 Professor S.H. Chuang, described laboratory experi ments which he had carried out in order to test the effects of crude oils on three species of mushroom corals (Pungia spp).

" Preliminary experiments were carried out on Pungia repanda, Pungia actiniformis, Pungia paumotensis after one day of acclimation to laboratory conditions. Pungia corals were chosen because they can be removed without mechanical damage

from the reef." (T15570) The corals were brought from the Salu and Sudong reef flats separately in polythene bags. (T15644)

Experiment 1: "Four aquaria were set up. One was the

control. Each of the other aquarie contained 2 litres of sea water at a temperature of 27 degrees and three Fungia actini

formis of 8-12 cm diameter. Aeration from a compressed air

outlet was provided and the aquaria were placed next to a win dow with diffuse sunlight coming through this. (The aquaria

were open to the ordinary atmosphere). To one experimental

aquarium was added 0.5 millilitres of BP crude oil, to another a similar quantity of Mobil crude oil and to the last a similar amount of Chemkleen. In each experimental aquarium the concen

tration of oil or Chemkleen amounted to 250 ppm." (T15571) The tests with the dispersant Chemkleen are described

in Part 8 (supra).

"After 3 hours fresh sea water was added into each aquarium to remove the oil ... and the animals left overnight. The effects of the addition of the two crude oils ... were generally the same. Pungia actiniformis have large and long

(up to 2 cm) tentacles. Some tentacles contracted soon after

the addition of the oil ... and remained contracted during the

course of the experiment. Small droplets of oil were found

trapped in the film of mucus on the oral surface. A thick

layer of mucus accumulated on the aboral surface of the corals.

All corals were dead with some tentacles damaged. The damage

to the tentacles was more pronounced in Mobil crude oil ...

than in BP crude oil. The corals in the control aquarium re

mained viable and appeared healthy." (T15572)

In later cross-examination Professor Chuang assented

to the following account of the procedures used in the experi

ment :

"... you put 2 litres of water into the aquarium, the

size of which you told us, you aerated the water both during

the experiment and afterwards; you put coral in, the upper por

tion of which was emergent from the water, you poured the oil

down the side of the aquarium so that is spread out as a film over the surface of the water and you did not at any time pour

the oil directly onto the coral? ... Yes." (115642) He agreed,

however, that a film of oil was pushed over the surfaces of the

corals by the succession of air bubbles used in aerating the shallow water layer of 2-3 cm depth in which the corals were

kept. (T15642-3) Professor Chuang, in recording damage suffered by the

corals after exposure to the BP and the Mobil crudes, noted

three changes of condition which in his view were symptomatic

of damage. The originally brownish colour of the flesh (main

tained in the controls) showed some fading, and there were seve

ral blotches of white due to perforation of the tissues

(T15573); the perforations which were inspected both with the naked eye and under a binocular microscope (T15572) were evident

in the tentacles (T15572), and in the extrusion of septal fila ments, normally contained in the control cavity of the coral,

through breakages in the damaged oral disc. (T15647) Death of the corals was judged in the following way:

"The coral has no heart so we cannot tell when it dies but

from the cilia current we can tell. That is the current which

496

the cilia generate ... When the cilia stop moving it is a sure

sign that they die." ( T15572) An additional sign of death or

of approaching death, noted by Professor Chuang was "the tend

ency of the water to become very cloudy ... because you get

bits of tissue coming off." ( T15572)

Experiment 2: "This experiment was carried out on

Fungia repanda, a species with smaller tentacles (one specimen .

turned out to be Fungia paumotensis after removal of the

flesh). Two and a half hours of direct contact between oil ...

and the oral surface of the corals was allowed. The tempera -

ture of the sea water was 25°C and the concentration of the crude was 250 ppm. Six corals were put into each aquarium ."

(T15573) Except for the shorter time of oil exposure in this

experiment and the use of a different species of coral the conditions of experimentation were as in experiment 1. Signs

of damage or of death were looked for immediately after the

conclusion of oil presentation and 8 hours later after the

animals had been in oil free sea water overnight. "After the addition of additional sea water to remove the crude ... the

corals were examined with a binocular. Some small oil droplets

were trapped on the thin mucus film of the oral surface of all the corals. More droplets were trapped in the exceedingly thick ( up to 3mm) mucus that formed on the aboral surface of the corals ... On the following day about half of the corals

in each aquarium ... showed signs of damage but the extent of this damage was not as extensive as in the previous experiment.

(T15574) Experiment 3 : In this experiment five or six Fungia

repanda were placed in each of two aquaria of twice the floor area of the containers of experiments 1 and 2. Two litres of sea water gave a water level of only about 1 cm. BP and Mobil crude were again used in 250 ppm concentration. The corals used "were smaller, younger ones, about 8 cm rather than 12 cm,

and had about the same amount of emergence as in the previous

experiments ( T15576). The time of contact with the oils was

1 hour ( T15575).

497

As in experiment 2, there were no deaths of coral.

After one hour's contact much mucus was produced, but except for

one small coral in the Mobil oil-treated tank which had "swell

ing along the septa" the animals appeared to be normal. There

were evidences of swollen septa eight hours later but "other

wise the coral seemed to look healthy." (T15575)

In summary of Professor Chuang's experiments a 3 hour

partial contact with a 250 ppm oil in sea water exposure caused

the death of all three of the Fungia aetinifomis put to test.

Exposures to fresh crude oil of one and of two and a half hours

duration of the 10 or 11 specimens of Fungia repanda did not

kill them but caused in almost all cases lesions of the soft

tissues.

2.9.84 After Professor Chuang had given evidence, Mr E.M.

Grant undertook a series of experiments to test the effects of

Moonie oil on mushroom corals at Heron Island on 17th April

1972. The experiments included as test animals Fungia actini-

formis (a species Professor Chuang had used) and F. fungites.

Mr Grant said "I chose the genus Fungia to attempt to replicate

the work of Professor Chuang." (T15978) The experimental con ditions were in Mr Grant's opinion chosen as more closely

approximating the natural habitat of mushroom corals than had

been provided by Professor Chuang, it being Mr Grant's view that

small shallow tank exposures would not be reproduced in nature. (T15984) Following presentations of oil comparable to those

used by Professor Chuang, Mr Grant's corals showed no signs of

the acute stress and eventual death suffered by the Singapore

animals.

(d) The Johannes experiments 2.9.85 Professor R.E. Johannes carried out two groups of ex

periments on the effects of oil on corals, the first at Hawaii

in early 1971; the second at Eniwetok Lagoon, northern Marshall

Islands in June 1971. The oils used were Santa Maria crude,

498

Alaska heavy crude, Murban crude, Iranian medium crude, and

low sulphur fuel oil (T4211). All were used In 250 ppm con

centrations each In an aquarium containing four litres of sea

water. The corals tested In the five aquaria and In a sixth

non-oiled control were three specimens each of 3-10 gm Porites

compressa, Montlpora verrucosa and Fungla scutaria.

In the first experiment the film of oil was not

allowed to come Into contact with the corals. After 2% hours

sea water was added to clear oil from the tank and the corals

then transferred to running sea water where they were examined

periodically under a binocular microscope for 25 days (T4212).

Signs sought were tearing or deterioration of the soft tissues

and unduly lengthy contraction of tentacles. No such signs were found (T4212).

In the second experiment oil was allowed to come Into

direct contact with the coral by siphoning out water until the

corals were partially exposed to air and the oil film. Wave motion was simulated by rocking the aquaria for a few minutes.

The water level was then raised and the corals removed Into

running sea water. (T4213) Oil adhered to an estimated 1% or less of the total surface and only briefly.

Professor Johannes summarised the results of these

experiments thus: "Of the total of 90 coral specimens used, only one died In 25 days, a specimen of Montlpora verrucosa exposed directly to Alaska heavy crude oil. Among the other corals (Including two other specimens of Montlpora verrucosa directly exposed to Alaska heavy crude) no visible changes

that we could attribute to oil were observed." (T4215) The cause of the one death was not known to Professor Johannes

(T4251)· The Enlwetok experiments Involved 22 species of corals

collected under water by hand or by chiselling them from the reef surface (T8659) · They were placed on trays which were

floated on the surface of the lagoon, a part of each coral

being In the water and a part In the air (T8649). 200 cc of

Santa Marla crude In a layer about 0.6 mm thick was poured

499

into the water around one of the trays. The other was used as

a control. (T8633) Slight wave action caused a gradual accu

mulation of oil on the corals which were left exposed at midday

for 1\ hours, one hour in full sun and half an hour with cloud

cover. The air and water temperatures were 29°C. "The corals

in both trays were replaced in 2 metres of water and observed

periodically for 4 weeks. Oil adhered with greatest affinity

to the branching corals of the genera Acropora and Pocillopora."

(T8634) "In the case of Pungia and Symphyllia both species

with large, fleshy polyps and abundant mucus, most of the oil

disappeared after submersion for a day. Amongst most of the

branching species (approximately 8 species of Acropora and 2

species of Pocillopora) some of the oil was still visible on

the corals four weeks later. Other species, members of the

genera Turbinaria, Pavia, Plesiastrea, Pavites, Psammocora,

Astreopora, Symphyllia, Montipora and Porites showed interme diate "affinities" for the oil." (T8636)

Professor Johannes said that the inspection of the

corals at the end of four weeks showed that "Complete break down of tissue occurred on the areas to which oil adhered in

patches of more than a few millimetres in diameter. Areas to

which the oil did not adhere did not appear to be visibly affected in any species. Macroscopic algae colonized the areas

of the skeleton over which the tissue had disintegrated. There

was no sign of recolonization of the affected areas by coral tissue." (T8637) It was Professor Johannes'recollection "that

about half the area to which oil adhered initially had oil on it after 24 hours and subsequently showed signs of damage" but

he agreed that "... at least half the area on which the oil had stayed for an hour and a half apparently was not affected"

(T8674) "None of the specimens was entirely killed ... and the

portions to which oil did not adhere appeared healthy." (T8639) In a note of caution on the interpretation to be

placed on the results of his experiments, Professor Johannes

said "This was a preliminary experiment squeezed in between

other activities which unavoidably had higher priority, so it

500

leaves many questions unanswered. It does enable us to say

that floating oil can kill coral tissue If It adheres when

corals are exposed to air. It remains to be established if

heating is the primary cause or perhaps only a contributory

factor to tissue death. An experiment was planned for evening hours when over^-heating would not be a significant factor, but time did not permit this." (T8640)

(e ) The Lewis experiments

2.9.86 The last of the series of experiments to come to the

notice of the Commission was submitted as Exhibit 338 in the form of pages from the Marine Pollution Bulletin. (T8121) It

concerned experiments carried out by Dr John B. Lewis at the

Bellairs Institute of McGill University, Barbados. The nature

of the experiments and the results drawn from them were refer red to only briefly in the evidence (Professor Johannes,

T4252-54) and they will therefore be only shortly summarised

in respect of their character and findings.

The purpose of the experiments was to test the effects of oil in solution on some responses of the corals Porites porites, Agaricea agaricites, Favia fragum and Madracis aspe-

rula to the presence of an oil supplied by General Crude Oil Co., Barbados. The oil in concentrations of 0, 10, 50, 100,

200, 500 and 1,000 ppm was presented on soaked filter paper to

corals in 350 cc containers which were sealed to prevent evap oration of volatile fractions. The signs of oil effects to be

observed were deviations of the normal extension of tentacles and of feeding and tactile responses. "Healthy, normal ...

(animals) would feed on live plankton, hold tentacles expanded and retract them at touch or probe. Without these signs the

colonies were considered unhealthy." (Exhibit 338) The expo

sures were for 24 hours. After this the corals were given two changes of fresh sea water and observed for recovery after 24

hours.

Abnormal responses were shown with concentrations of

oil of 100 ppm and above and in some cases recovery was not

501

complete after 24 hours though In every case a measure of re

turn to normality was shown. The controls at all times gave a

substantially higher percentage of normal responses than the

oil treated animals. An interesting observation was the deve

lopment of ruptures in the oral disc of corals Agaricia and

Pavia under conditions where no oil contacted the animals and

which were therefore presumably caused by damage due to oil in

solution.

Section 2 - Organisms other than corals

2.9·87 Although the effects of crude oils on organisms other

than corals have been extensively studied in other parts of the

world and mainly in temperate seas little is known of the ways

in which oil may affect the many kinds of plants and animals

which make up the complex eco-systems within the variety of

habitats to be found in the GBRP.

Such observations as have been made rest, in the main,

on notes made by Mr Grant and Mr Haysom on the responses to oil

contact or oil-on-water cover of a very few types of soft coral,

molluscs, polychaete worms, crustaceans and small fishes,

(rarely identified below the level of genera) during the course

of their coral testing experiments reported in paragraphs

2.9.59-63.

2.9.88 In a pegged out study area near the reef edge of Wis- tari Reef which he sprayed with 10 gallons of fresh Moonie

crude Mr Grant noted at T10275-6 that "One conspicuous clam at

the water surface remained expanded during and after the spray

ing" It was "agape and apparently healthy," and he further re

ported that "Serpulid worms within the pegged area were expan

ded and reactive to vibration and changes in light intensity." These behavioural reactions, Mr Grant explained at T10284-5, are characteristic of normal healthy tube-inhabiting worms of

this kind. Observations made on the following day and ten days

later confirmed the maintenance of the normal colour and behav

ioural responses of the animals; and in two further oil spray-

502

ing trials clams and serpulid worms present in the test areas

were reported as unharmed by the oil treatment. (T10279,

T10283) Photographs (colour slides 53, 54, 85 and 91 of

Exhibit 546) illustrating the clams and worms under test were

shown to the Commission and commented upon by Mr Grant at

T10313, 10314, 10321 and 10323.

2.9.89 Mr Haysom's Fitzroy Reef experiments of August/Sept

ember 1970 (ÎÎ0622-10650), which involved the pouring of fresh

or weathered Moonie oil on to pools of 1-2 square metre sur-

Î¦ face area to form a layer of about 1 mm thickness, (T10633, IO685) put to test a wider range of animals. These included,

in the oil treated pools 1-4, the following identified and un identified species.

Coelenterata: 1 soft coral (Xenia sp.)

Mollusca: Gastropods (Sea snails); 2 Monetaria annularis; 3 Vasum turbinellus; 6 Conomurex

luhuanus; 5 Trochus niloticus; 1 Virroco.nus ebraeus;

1 unidentified turbinid; and 1 unidentified cerithiid.

Rivalves: 1 unidentified oyster and 2 unidentified

juvenile clams (probably Tridacna fossor) Crustacea: 1 unidentified hermit crab and 1 unidenti

fied crab.

Echinodermata: 16 Holothuria leucospilata (sea

cucumbers).

Almost all of these animals were, at the time of appli

cation of the oil, covered by water and therefore not in

direct contact with the oil film. One of the clams, however, projected through the surface film and oil was for a time in

contact with its soft tissues, (T10654-5) and one Trochus was seen to break the surface of the oil. (TIO633) When the pools

were examined some 12-24 hours later (the periods varied,in respect of the different pools) about half of the more mobile

species of sea snails and crabs were missing from the pools but

503

those which remained were described in every instance as appa

rently unaffected by the oil. Mr Haysom's note on the species

in pool 3 will exemplify comments made at various places in his

evidence" ... all the organisms were apparently alive and un

affected. The clam reacted instantly to a poke from a stick by

contracting its adductor muscle ..." The pool was re-examined

again two weeks later (2 September 1970). "The Conomurex and

Trochus had disappeared but all other fauna appeared normal and

healthy." (T10649) The exposure to oil in each case, either

by direct contact or as an overlying film, had been of the

order of 2-2% hours. (T10633, 10689) w

2.9.90 In a separate series of Fitzroy Reef experiments,

selected species of animals were placed in sea water in perfor

ated plastic bins suspended from the stern of a launch. There

was added to the surface of the water fresh or weathered Moonie

oil in a layer estimated by Mr Haysom to be some 8 mm thick.

(TIO685) There were included with a variety of corals in three

oil treated bins the following animals:

Echinodermata: 6 unidentified crinoids (sea lilies)

Mollusca: 1 unidentified abalone (a sea snail) and 1 unidentified chiton (coat-of-

mail shell) 1 unidentified crab and 1 unidentified

alpheid prawn (pistol-prawn) 1 Dascyllus aruanus (a small 'humbug'

fish) and 1 unidentified gobioid fish.

One of the bins, which included in its contents the two

crustaceans, developed a leak overnight and lost about half its

water content. All animals were examined 24 hours after oil treatment. Mr Haysom reported that "All the organisms in the perforated bins were alive and appeared in the same condition as

when first placed in the bins ..." (TIO658A) and he showed

photographs (numbers 13 to 16 inclusive of Exhibit 351) in illu

stration of their condition. In a later comment he reported

however that the gobioid fish had escaped through the perfora-

Crustacea:

Fish:

504

tions in the bin and was not available for examination

(T10660), and that the crab and the prawn in the damaged bin

had both died. (T10661) Mr Haysom was unable to say whether

death had been due to the presence of oil or to some other cause.(T10661)

2.9.91 Two other trials conducted by Mr Haysom can be

briefly reported. One involved the flooding of lh litres of

fresh Moonie oil, and on another occasion of 5 litres of

bunker oil in front of an advancing tide in an area on the

south side of Fitzroy Reef on 1 September 1970. The area

supported "an extensive and prolific epi-rim coral fauna and numerous colonies of the colonial anemone Palythoa caesia"

(TIO663) The anemones suffered a brief contact with the oil which "was rapidly lifted off with the rising level of the

water". (TIO663) When examined 24 hours later " a few small patches (of oil) were still adhering to Palythoa colonies"

(TIO667) the colour of which (shown in photograph 23 of

Exhibit 351) appeared to be normal and to indicate a healthy condition. The second trial, of animals exposed to fresh Moonie oil and bunker oil in perforated bins tethered to the

shore off Peel Island in Moreton Bay, involved a contact or near contact of oil at low water with the colonies of the soft coral Xenia and one other unidentified soft coral.

These experiments, as earlier noted, resulted in the death of

one scleractinian coral (Acropora digitifera) but all other corals (including the soft corals) were reported by Mr Haysom

as healthy on examination 48 hours after exposure to oil.

(T10681)

2.9.92 No other observations deriving from experiments on

the effect of oil on adult marine organisms of the GBRP other than scleractinian corals were reported to the Commission.

Mr Bryson however made an interesting comment suggestive of

a deleterious effect of oil in the recruitment of new

populations of animals. Mr Bryson described himself as an

505

oyster farmer working on a 13 acre oyster lease at Horseshoe

Bay off the northern shore of Magnetic Island,Townsville.

(T13538) Oyster spat used for restocking of his lays were

obtained by suspending fibro plates in the sea and allowing

the larval oysters to settle on them. He said, at T13587,

"I have found on neap tides that the oyster throws its spat and

it takes about a week to a fortnight to settle." The spat, he

said, settles "only in certain times, in October and November;

sometimes depending on the wind, September, October or March

or April" ... "I have fibro plates out to get the spat. On

gathering these fibro plates I have found some of them have

been covered by oil and suchlike. This, having been formed,

no spat has formed on these plates" ... "if I have oil around

at the time I am depending on the spat fall and it gets on to

my plates, that means I am out of production for the next year."

Conclusions

2.9.93 The observations reported in the foregoing paragraphs

vividly reveal the limitations of present experimentally based

knowledge of the effects of oil on GBRP organisms. They rest

on the reports of three witnesses, and relate to little more than a dozen species drawn from the five groups of the

coelenterates, molluscs, Crustacea, echinoderms and fishes. It is not possible to draw general conclusions from them, but they

appear to be indicative of the ability of the majority of the animals tested to survive applications of oil which simulate

oil spills of very limited periods of cover. They give no

information however on possible sublethal effects on the

organisms that were exposed to oil. Nor, save for Mr Bryson's observation, do they reveal possible developmental or behaviour

al disturbances which may affect the recruitment of new populat

ions and which are among the many factors affecting the dependencies implicit in the maintenance and functioning of the

complex eco-systems of reefal waters.

506

B. Oil spills including overseas spills in coral

reef areas

Section (1) - Massive spills - effects on corals

2.9.94 Reports on the consequential effects of oil spilled

from tankers or as a result of shore handling and processing

activities were brought to the notice of the Commission in

respect of three tanker spills; 'Argea Prima', Puerto Rico, 16 July, 1962; 1Witwater1, Panama Zone, 13 December 1968; and

1 Oceanic Grandeur', Torres Straits, 3 March, 1970; and three

localities or regions where oil terminals are sited in the

neighbourhood of reefs, namely Singapore, the Persian Gulf , and

the Gulfs of Aqaba and Suez. The Commission did not receive

evidence on the effects of the tanker 'General Colocotronis' spill off Eleuthera in the Bahamas.

The ecological situations and the communities associated with them that are referred to in these accounts

are coral reefs, the open sea plankton and shore lines,

including mangrove areas.

'Argea Prima1

2.9.95 The 1Argea Prima' ran aground on reefs off Guayanilla Harbour on the south shore of Puerto Rico. In an endeavour to refloat the vessel some 10,000 tons of crude oil were discharg ed into the sea (T4229)· A short paper "The effects of an oil

spill on the shore of Guanica, Puerto Rico" by Manuel Diaz - Piferrer, Institute of Marine Biology, University of Puerto Rico, which was read into the transcript by Professor Johannes

at T4229-31 contains the following passage: "Offshore coral reefs to the west also received a heavy blanket of thick oil."

The damage was said to be "most extensive." A reference thereto is made in paragraph 2.5.28 supra. It appeared,

however, that the effects on corals were not investigated, for Professor Johannes informed the Commission at T4240-40A that

though "... I wrote to two people in Puerto Rico to find out

what they knew about it ... I got the impression from the

507

correspondence I received that these people had heard that the

oil had covered an off-shore reef but I was unable to find any

evidence that anybody had actually gone out and investigated

this."

'Witwater'

2.9*96 The 'Witwater' spill was reported to the Commission in

Exhibit 259, a paper by Klaus Rutzler and Wolfgang Sterrer "Oil

Pollution: Damage observed in tropical communities along the

Atlantic seaboard of Panama." The authors dived over the reef

some two months after the wreck of the tanker. They say in

respect of the coral reefs "The reefs seemed to be the least

affected communities of all. Shallow coral patches, consisting

mainly of Porites furcata, P .asteroides, Siderastrea radians,

Millepora complanata ( a hydrocoral) and associated organisms

showed no ill effects at the time of the survey. This can be

explained by the fact that these corals were subtidal and did

not come into direct contact with the oil, which is mainly

confined to the air-water interface. Further, due to high winds, water level at low tide was higher than usual; some of

the corals observed would probably be partly exposed during

very low tides, but they were not exposed or affected by oil

during this period." (pp.222-3)

'Oceanic Grandeur'

2.9-97 Some consequences of the wreck of the tanker 'Oceanic

Grandeur' on March 3,1970 in the main inter-ocean steamer

channel to the north-east of Thursday Island, Torres Straits

were reported in detail by Mr E.M. Grant (T2472 et seq and

T12848 et seq) and Mr D.J. Tranter (T7514 et seq ). Each independently visited shores on nearby islands where approaching

slicks had been reported to locate and to examine areas where

oil had stranded. The heaviest infestations were found on the

sandy beaches of Thursday Island and Horn Island. (Mr Grant

T12870; and Mr Tranter T7542). Mr Grant was of the opinion

that living coral was sparse in the vicinity of the wrecked

508

tanker and said "It is necessary to go eastward a

considerable distance before coral reefs of any substantial

size are found." (T2472) His report makes no reference to

any living coral having been oiled or adversely affected.

Mr Tranter however noted the occurrence of a fringing reef

on Twin Island only 3 miles from the anchored tanker, and

only 7 miles from where it was supposed to have been holed.

"A landing was made on Twin Island at low tide to inspect

its fringing coral reef and shores for oil or detergent

pollution ... No trace of oil was to be found on either

shore or coral reef. The situation was entirely normal.

Many corals and other marine animals were seen in the sub-

tidal and inter-tidal shallows and all appeared to be

healthy(T7519-20) Mr Tranter was doubtful whether any

oil had reached Twin Island which lies to the north-east of the place where the tanker grounded. "No oil was washed up

on any of the several inhabited islands to the north and north-east of the tanker (Department of Native Affairs communication). It therefore seemed that any oil that had

been spilt must have been carried either to the west or the east ...".(T7516) There is, in short, no evidence from the observations of Mr Grant and Mr Tranter that oil from the

'Oceanic Grandeur' came in contact with corals.

2.9.98 In the light of these findings it is necessary to refer to the damage reported by Mr R Cantley who described himself as a freelance journalist who had spent some years

in the Torres Strait area.(T13684) Mr Cantley visited the area of the wreck on the day following the initial oil spill but

found at that time "no effect at all" on the corals within the area.(T13713) Three months after the spill in June 1970, he returned to the area and saw" ... reefs, especially the reefs of Cape York and Albany Island but all reefs showing

signs of great deterioration with lack of colour in corals, great discharge of mucus which is the protective device of

corals." (T13717) About January 1972 he again revisited the

509

area and he said that he observed in totally submerged areas"

... 100 per cent devastation in areas as large as hundreds of

acres".(T13719)

As a result of this evidence Mr B Goldman of the

Australian Museum Sydney and Mr R.G. Pearson and Mr G.M.J.

French from the Fisheries Branch of the Queensland Department

of Primary Industries visited Torres Strait and inspected the

areas which had been marked on a map by Mr Cantley as being

those in which he had reported that there had been "total

destruction". (T13927) After that inspection they gave

evidence (T15738-15820; T15824-15893-15930) on the conditions

of reefs in the. area to .which Mr Cantley had referred, but which the

they were unable to relate in all cases precisely with the

localities in which Mr Cantley had reported the most extensive

damage.

In the result, it can be said that their evidence did

not support Mr Cantley1s claims.

2.9.99 The Commission notes that Mr Cantley's explanations

of the cause of the damage to which he referred seems to contain

inconsistencies.

Thus in his original written statement which became

Exhibit 416 at page 2, he said:

"That the effect of oil spillage in coral environ

ments and waters contained by the Great Barrier Reef

can cause catastrophic imbalance ... with continuing deleterious effects on interacting eco-systems, I

have proved with my own experiments and checking on

the once fertile reefs on the Somerset influence

north of Cape York which suffered from the massive

spillage of oil from the holed oil tanker Oceanic

Grandeur1 in March of 1970 ..." During his evidence, however, he said at T13922:-

"I have blamed detergents for the death of viable

corals on these reefs ... I never, never said oil

would kill coral, no-one can say that yet because

510

the research has not been done on it." (T13922)

Later again however, (TI3928) he referred to the

damage as having been caused by oil and detergent.

Conclusion

2.9.100 In summary, none of the three incidents involving

large spills of oil in areas neighbouring coral reefs has

yielded well substantiated evidence of damage by oil to reefs.

It must however be noted that in the Oceanic Grandeur' spill, no oil was found on any reef in the area;

that the 'Witwater1 oil was considered as unlikely to have

contacted coral on the reef surveyed by Rutzler and Sterrer;

and that the Puerto Rico reefs suspected as having received a cover of oil were not, so the Commission was informed,

surveyed for possible damage.

In the result, such evidence unfortunately seems â¢to offer little assistance one way or the other.

Section (2) Chronic spills:Effects on corals overseas The oil spills remaining to be examined concern

chronic spills - recurring low level releases.

Singapore:

2.9.101 Dr Maxwell said, at TI667, "Singapore is an island of 2245.5 square miles, fringed on the south by a shallow shelf (mostly less than 10 fathoms) occupying an area of 220

square miles. The shelf edge is more than 500 miles distant (to the east and north-west). Situated on this shallow shelf are 44 small islands and 70 reefs (28 fringing reefs and 42 platform reefs), mostly on the western half of the shelf area.

Surface area of reefs approximates 7 square miles. The natural environment does not appear to be one favourable for luxuriant

reef growth because of the shallow sea, the great distance

from the shelf edge and open sea, the turbid water which has

511

a high sediment suspension and the low wave activity resulting

from the protection afforded by the surrounding land areas of

Malaya and Indonesia. In spite of these factors, reefs with

a limited variety of coral species (remarkably few Acropora)

and a high density of plant growth (particularly Enhalus

acoroides or sea tape grass) are surviving. Past tidal streams

(lh to 2\ knots), particularly from the west, tend to compensate for the less favourable factors by causing effective exchange

of water."

2.9.102 "In 1892, oil storage facilities were built in Pulau

Bukum (one of the islands in the central part of the reef zone)

and Singapore imported its first major cargo of oil - 20,000

barrels of Russian oil. In 1925, the storage facilities were

greatly extended and in 1961 a large refinery was built on the

island Pulau Bukum in the middle of this reef zone. Its

current through put is 120,000 barrels per day and by the end

of 1970 this rate will have increased to 235,000 barrels per

day. Two other refineries operate on the coastal region less

than three miles from the reef zone and a fourth is under

construction on an island within the reef zone. By the end of

1969, Singapore's refining capacity was 200,000 barrels per day (i.e. approximately 1/3 of Australia's total) and predicted

capacity by 1971 is 365,000 barrels per day. Singapore is now

the largest refining and bunkering port in the Far East. In

terms of general cargo as well as oil, it represents the fifth largest port in the world. Between 20,000 and 30,000 ships

use the port facilities each year (Singapore Government

information pamphlet).

2.9.103 "All of the crude oil is brought into Singapore by tanker and the anchorage area for tankers (prior to berthing at

the refineries) is approximately 8 square miles of sea between

the reef zone and the south-west coast of Singapore Island.

During my survey of the Singapore shelf, a minimum of five

large tankers were discharging oil into the main refinery

512

continuously. More than five tankers were normally at anchor

awaiting their turn to use the refinery berths, while others

serviced the smaller refineries and oil storage depots.

During the Japanese invasion of Singapore,the main storage

terminals on Pulau Bukum and other islands were sabotaged

by the retreating allied forces (by fire and explosion),

consequently releasing substantial quantities of oil in the

reef zone. Since that period, I have been unable to locate

records of any major oil spill in the region. However, oil

slicks and grease lumps are not uncommon on the sea, and I have photographs of small occurrences on the margin of Pesek

Reef. These may have originated from the refineries or the

tankers or from normal cargo vessels which pass through the area.

Whatever their origin, it is clear that the Singapore marine area represents an oil-influenced environment

which has probably been subjected to at least one major influx

of oil (during the demolition of the storage terminals in 19*11) and to minor but frequent pollution from oil that has escaped

from some of the 20,000 to 30,000 vessels which use the port and anchorage facilities each year."(T1668)

2.9.104 Professor Chuang expanded this information in quoting figures from the Port of Singapore Authority Report and Accounts,

1970. The figures showed a roughly 50% increase in the arrivals and departures of ships of 75 n.r.t. and over in Singapore

roads from 1966 to 1970, and in 1970 the passage of coasters

of smaller size outnumbered the larger vessels. "For the first time in 1970 21 giant tankers of more than 200,000 dwt. were handled off Pulau Bukum. Mineral oil loaded and discharged at Port of Singapore wharves and in the roads rose from less

than 20 million freight tons in 1966 to 32.5 million freight tons in 1970." (T15562)

2.9.105 Professor Chuang did not offer an opinion on the

extent to which the increased volume of traffic and of

513

refining activities had added to the oil pollution of

Singapore waters. He considered however that "spillage in

various degrees from these refineries is inevitable"(TI5563)

and in a reference to the spills from ships he was of the opinio

that the smaller vessels "which are usually less well maintained

than ocean-going vessels, may pollute the sea more than these

large vessels." He added that "A source of constant pollution

in the harbour area is the large number of still smaller craft,

such as bumboats, lighters with inboard engines, bunkering

lighters and others .... Many of these vessels pumped bilge

water into the sea even in broad daylight." (115562-3)

2.9.106 The question as to whether or not oil pollution in

Singapore Harbour and its environs has caused an impoverishment

of the coral fauna in comparison with unpolluted areas, either

by reducing the number of species or the number of individuals

within the several species, was not satisfactorily resolved

through the evidence given by Dr Maxwell, Professor Chuang, and Dr Serene ( Exhibits 484,485 and 486) on the fauna of this area.

The difficulties met with in attempting to resolve this problem

derive mainly from the absence of good historical records of

species present in particular situations before the onset of

oil pollution, and in relating present conditions of species diversity and total biomass of the living coral to particular

causal conditions.

2.9.107 On the first point Professor Chuang said, in quoting

at T15595 from a letter he had written to Dr Weatherley of the

Australian National University (Exhibit 485) that "historically Dana (1846) Brueggemann (1878) Brooks (1893) Verrill(1902) and

others described altogether about 39 species of Acropora of which only 15 are available today including 6 species not

recorded by previous authors." In this letter he referred to

three possible reasons for the discrepancies, namely -(1) "Presumably some specimens from the older

collections could have come from places

514

other than Singapore and the adjacent

southern islands;

(2) the recent collection was incomplete and not

thorough enough; and

(3) that presumably there could have been a

gradual depletion of the staghorn corals

during the last one and a half centuries."

(T15595)

Whatever the basis for Porfessor Chuang's presumptions, the

doubtful locations of origin of the historical collections

makes speculation on possible changes in the fauna of

individual reefs from oil pollution or other causes

unprofitable without the benefit of a more accurate series

of "before and after" surveys. Support for this view was given in a letter from Dr R. Serene, a biologist and UNESCO

official living in Singapore to Mr B.F.L. Crommelin,

Commonwealth Crown Solicitor's Office (Exhibit 484) in which

he said "The statement of Professor W.G.H. Maxwell that "the

Singapore reefs have survived" is correct. The extent of the

survival still has to be evaluated. I do not think that data exists for such an evaluation. What was the coral reef in Singapore fifty years ago in regard to what it is today is

questionable."

2.9.108 Professor Chuang gave evidence at T15545 to the

following effect:

"The geographical distribution shows an increase in the number of coral species of the sublittoral slopes from Labrador (on Singapore Island) south

wards to Raffles Lighthouse. Actually there is also an increase in the number of speciments of each species southwards. One exception is Sultan

Shoal at the western end of the port limit where

the corals are few and dying.

More coral specimens and more coral species occur

on exposed reef flats the farther these flats are

515

from the south coast of Singapore. On reef

flats near Raffles Lighthouse the exposed

corals are richer in species in places more

exposed to strong tidal currents than in

others where the current is weak."

and earlier he had said(T15536):-"I attribute the gradual decline of corals

in both quantity and number of species on

the reef flats of Singapore and the various

little islands to the south as due to increased

pollution including oil pollution. The most

prolific reef flats as far as corals and organisms

associated with them are concerned are those of Pulau

Senang, P.Pawai, P.Sudong,etc. far away from

Singapore harbour and the oil installations

(bunkering and storing services)."

2.9.109 At T15548-50A he provided tables of species found in

five localities along this line which confirmed and gave detailed expression to his statements. Dr R. Serene was of a

similar opinion when stating in a letter (Exhibit 484) "there

are still a lot of coral reefs around Singapore including some

within the Harbour area." These reefs were, however, graded as "relatively poor" and "It is obvious that the corals are

much more developed on islands close to oceanic waters like

Raffles Lighthouse and Hasbourg Lighthouse."

2.9-110 Possible reasons for the diminishing richness of the

reefs towards and in Singapore Harbour were discussed by

Professor Chuang at T15563-5· He listed sediment loaded turbid water, sewage, toxic industrial effluents, fresh water

kills, and oil pollution as factors unfavourable to coral maintenance and growth. Sedimentation, he regarded as a

particularly serious problem. The presence of areas of "soft

or quite soft mud" on the sea bed led to the stirring up of

sediment "when ocean-going steamer propellers revolve in the

516

Eastern Roads of the Singapore Harbour." (T15556-7)

Dr Serene, too said that "The main limitations to the corals

on surrounding Singapore islands seems to be related to the

turbidity of water and the consequent silting ... the

turbidity apart from flooding during the rainy season is

limited to a few hours in relation to the tidal currents.

In Singapore the turbidity created by the propellers of the ships must be added. Every ship passing nearby a coral reef

is creating waves of turbid waters which increase the silting."

2.9· Ill Dr Maxwell said at T1668 "I found no dead reefs in this region and no indication of dying reefs."

2.9. 112 However, Professor Chuang said of the corals and the fauna associated with them in Singapore and in the Malay

Peninsula, on which he had been working since December 1950, "My records indicate that even in the space of 21 years there have been changes in the fauna which I attribute partly

to oil pollution and partly to the increased sewage and drainage outflow ... of the enlarging city of Singapore and

the budding small industries."(Exhibit 485) He contrasted, in this respect, 38 species (listed by name) occurring on

"reefs at Pulau Serang, P.Pawai, P.Sudong etc., far away from Singapore and the oil installations" with 13 species

taken in 1961 from"the reef flat of Pulau Hautu (less than 1 English mile from Pulau Bukum, where Shell Oil Refinery is)" and where "Today several of these have disappeared." Under later cross-examination (T15620-22) Professor Chuang amended

the 13 species to the number 16 and said that by "several"

he meant 3 or 4.

2.9. 113 A further example of a suspected reduction in number

of species in recent years was given by Professor Chuang in respect of the reef flat of Tanjong Berlayar at the western

end of Keppel Harbour, the deep water harbour of Singapore.

"On this reef flat in 1957 there were about 30 different

517

species of corals, some of which were of large size. About

6-10 years ago, a jetty with pipeline for supplying oil to

ships was built on the reef flat. Today there are only 8

species of reef flat corals found ... there were about 20

sponges in 1957; today there are 3·" (Exhibit 485)

2.9.114 Dr Maxwell, when recalled to give evidence on the

observations of Professor Chuang and Dr Serene (T15650-15730)

questioned the validity of the comparisons made of the numbers

of species of coral in the different areas in that it had not

been made clear whether the areas and zones in the different

places had been ,of comparable size or variety of situations.

He admitted however that he had not visited the Tanjong

Berlayar area and he accepted Professor Chuang's assessment of

the recent impoverishment but he did not regard the area as a coral reef in the usually accepted sense of the term. (T15664)

2.9.115 The Commission considers that Professor Chuang's

evidence does indicate a recent impoverishment of the coral

fauna in this and other areas. The possible causal factors

such as increased sedimentation and water turbidity

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