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Deep Sea Mining. -

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Most volcanic activity happens not on land, but kilometres down in the deep ocean. Geological
research has revealed that underwater volcanoes, or hydrothermal vents, are rich in metals like
copper, zinc, silver and gold at concentrations that make them commercially attractive to miners.
But, they are also colonised by exotic life-forms and scientists believe the vents may have been
the location where life originated. Mark Horstman takes a look at a mining project that is set to
commence operations in the deep waters off Papua New Guinea.

NARRATION

You may not get to see an eruption very often, but we live on a volcanic planet where they happen
all the time. Most volcanic activity happens not on land but kilometres underwater in the deep
ocean covering two thirds of the earth's surface. Wow! Holy Moly. This is a story about volcanic
hot springs called hydrothermal vents. Told by two explorers from different scientific view points.
One a geologist.

Dr Chris Yeats

There's ones about dinosaurs and ones are live volcanos. And I'm one of the volcano loving ones. So
it was, it's great for me.

NARRATION

And the other a biologist.

Professor Cindy Lee Van Dover

The roots of, of the tree of life as we know it right now, the deepest roots we know of come from
hot springs.

NARRATION

And both have undertaken research in deep sea vents with a daring plan to mine them. In 1990 Cindy
Lee Van Dover became the first woman to pilot the US submersible ALVIN. Routinely diving to depths
greater than two thousand metres she's explored nearly all of the world's hydrothermal vent fields.
Chains of them occur along fault lines, like the Pacific Rim of Fire and the Mid Atlantic Ridge.

Professor Cindy Lee Van Dover

Even after a hundred dives, like I've made, there's a sense of anticipation of not knowing what
you're going to see when the flood lights come on.

NARRATION

Here's how hydrothermal vents work. Under incredible pressure sea water pushes into fractures, is
rapidly heated, picks up chemicals as it reacts with the hot rock and gushes out of the sea floor
at scalding temperatures. What was once plain sea water is now hydrothermal vent fluid.

Professor Cindy Lee Van Dover

What's special about these environments is that it's this wonderful mixture of vent fluid and cold
sea water with chemicals that microbes can use to make new organic material. So it sets up a food
web. And once you have that food web set up then species can come in and use it.

NARRATION

This dark, toxic unstable environment supports an amazing array of bacteria, snails, muscles and
crabs. In the Eastern Pacific giant tube worms grow to two metres in just a couple of years.

Professor Cindy Lee Van Dover

They have no mouth, they have no gut - how do they make a living? This is a giant animal on the sea
floor. Where is, where is it getting its nutrition. And the answer is that they have bacteria that
live inside of them.

NARRATION

With their symbiotic microbes the animals crowding around deep sea vents aren't the only ones
seeking out plumes of sulphide minerals. So do geologist.

Dr Chris Yeats

That's a really, really nice black smoker. And that's, yeah that's about as black as you get.

Mark Horstman

How big would something like this be?

Dr Chris Yeats

Oh that's probably one and a half to two metres in height.

NARRATION

But they come a lot bigger than that.

Dr Chris Yeats

That's enormous. That's absolutely enormous.

NARRATION

That's Chris Yeats you can hear in the submersible at a depth of more than sixteen hundred metres
exploring a vent field and collecting samples of chimneys, like this one.

Dr Chris Yeats

This central cavity here would have been full of very hot water. Um, you're talking about stuff
which is two hundred and fifty or three hundred degrees centigrade. And pumping very rapidly, it,
it may well have been a black smoker with black smoke coming out of the top of it. And you sort of
get a very sharp temperature grade in between, three hundred degrees here, and three degrees out
here.

NARRATION

As the hot acidic chemical laden fluid hits the cold sea water the metal sulphides drop out a
solution to grow a chimney. But when the fluids are really hot to form a huge plume of particles
that looks like black smoke.

Professor Cindy Lee Van Dover

You come on a black smoker and it's like being in an industrial landscape. They can be really quite
tall structures in some places, thirty metres tall.

Dr Chris Yeats

You're sitting on the side of an active volcano, there's this constant earthquake, these structures
are quite fragile. They're constantly changing and evolving. Collapsing, starting, finishing.

NARRATION

To biologists the discovery of more than five hundred previously unknown species living on deep sea
vents makes them cradles of biodiversity.

Professor Cindy Lee Van Dover

I could take you tomorrow to a place where we'd find a new hydrothermal vent that would almost
certainly have dozens, if not hundreds of new species.

NARRATION

To geologists vent fields are the birth place of giant ore bodies with grades of copper and zinc
many times higher than those found on land. And that's got the attention of mining companies.

Dr Chris Yeats

This is the Bigpela Chimney, it's the biggest chimney ever dredged on the sea floor, and I'm
sitting down near the base here and, and the fluid would have been gushing up from the bottom
towards the top.

Mark Horstman

So it's extinct now? That's why it's all filled in, but it's full of minerals like gold, silver,
zinc. Is it worth mining?

Dr Chris Yeats

Oh certainly worth mining.

NARRATION

This chimney comes from a vast hydrothermal vent field deep in volcanically active Bismarck Sea off
Papua New Guinea. And it's here that a company called Nautilus Minerals is planning Solwara One,
the world's first open cut mine for copper and gold on the sea floor.

Dr Chris Yeats

The amount of metal value you gain from, from mining something like Solwara One is the kind of
metal you'd gain from mining something ten or fifteen times the size on land. So potentially
they're a very efficient way of mining.

NARRATION

Here's the plan. On the sea floor at one point six kilometres deep three remote control robotic
miners crush the chimneys and grind up the sulphide deposits, which along with everything living on
them are sucked up by a giant vacuum cleaner to a ship on the surface. The slurry is filtered and
the waste sent back down the pipe to the seabed where it's released. Over a period of eighteen
months two million tonnes of ore would be mined from the vent field and shipped to nearby Rabaul.

Mark Horstman

During the time I was making this story Nautilus Minerals declined my invitation for an interview
and announced a joint venture with the PNG Government to start mining within the next few years.

Dr Chris Yeats

The activities that Nautilus are proposing are something like ploughing a field or raking your
garden, that you're, you're, you're stirring up the environment but you're not fundamentally
changing it.

Professor Cindy Lee Van Dover

We don't know when you scrape away five thousand years of deposit, what influence did that five
thousand years of deposit have on the fluid chemistry and the kinds of animals that might be able
to colonise it.

NARRATION

After mining it's likely that vent structures will reform and animals will recolonise. But the
question is, how long does it take?

Professor Cindy Lee Van Dover

What interests us as scientists is that here's a question we just don't know the answer to. And if
mining, if extraction of metal, metals on the seabed takes place we'd like to know what happens and
how quickly the animals come back.

NARRATION

If Nautilus Minerals is successful it could spark a gold rush of sea floor mining in International
Waters without knowing how to restore the habitats after mining.

Professor Cindy Lee Van Dover

There's nobody who's an expert in that. No expert exists right now who has any idea how to tackle
that. I'd love to know that a hundred years from now people would look back and say, 'That's the
generation that got it right'.

Topics: Nature

Reporter: Mark Horstman

Producer: Mark Horstman

Researcher: Mark Horstman

Camera: Karl Miethe

Additional Camera:

Duke University Media Services, North Carolina USA

Sound: Carsten Frederiksen

Editor: Chris Spurr

Story Contacts

Dr Chris Yeats

Research Program Leader - Mineral System Science

CSIRO Earth Science & Resource Engineering

Kensington WA

Prof Cindy Lee Van Dover

Harvey Smith Professor of Biological Oceanography

Director, Duke University Marine Laboratory

Duke University

Beaufort, North Carolina USA

Related Info

"The Promise and Perils of Seafloor Mining" (WHOI, 2009)

"Tighten regulations on deepsea mining" (Cindy Lee Van Dover in Nature, 2011)

Nautilus Minerals Solwara 1 project

Map of deepsea mining tenements in Bismarck Sea, PNG

"New Ireland rejects deepsea mining agreement": PNG Mine Watch, 3 June 2011

"The near future of the deep seafloor ecosystems" (2008)

Centre for Marine Environmental Sciences, University of Bremen