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World's marine parks 'may not save corals'

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Media Release ARC Centre of Excellence for Coral Reef Studies

World's marine parks 'may not save corals'

August 27, 2008 - Embargoed till 8AM AEST.

Many of the world’s “no take” zones are in the wrong places and far too small to protect vulnerable coral reefs from the worst impacts of climate change, an international team of scientists warned today.

The team, which includes Nick Graham and Dr Shaun Wilson of the ARC Centre of Excellence for Coral Reef Studies, Australia, and colleagues from Newcastle University and the Wildlife Conservation Society, write in a leading scientific journal that urgent action is needed to prevent the collapse of this important marine ecosystem under climate change.

They warn that many existing “no take areas” (NTAs) in the Indian Ocean and around the world, while effective in protecting local fish, may not be much help in enabling reefs to recover from major coral bleaching events caused by ocean warming.

The research, published in the journal PLoS ONE, is the largest study of its kind ever carried out, covering 66 sites in seven countries in the Indian Ocean and spanning over a decade.

Many of these no-take areas were set up in the late 1960s and early 1970s to protect fish, before climate change and its impact on corals became a major issue, the researchers say. Several of the no-take areas are small, and are surrounded by areas of sea which are heavily fished or otherwise exploited.

These existing zones should not be removed, but new areas are needed in the right places to enable corals to recover from the mass die-offs caused by rising temperatures.

“When you have a major disturbance like bleaching, it can affect a huge area of the reef,” explains Shaun Wilson. “If you have extensive reserve systems, then the chances are much higher they will contain small areas within that escape bleaching which can help to recharge the reef as a whole.

Dr Wilson added that Australia’s approach on the Great Barrier Reef, where a third of the total area is protected by n—take or ‘green’ zones was a

model for how to protect large reef systems under climate change. “The Great Barrier Reef Marine Park Authority have put a lot of effort into determining exactly where these protected zones should be located to give the reef the best over chance of recovery from bleaching events,” he says.

Lead author Nick Graham, who joins CoECRS next month, says “New protected zones need to focus on areas identified as escaping or recovering well from climate change impacts. But a major focus needs to be shifted towards increasing the resilience of the system as a whole - that means reducing as many other locally derived threats as possible.

“Coral dies when it is put under stress so what we need to be doing is reducing the direct human impact - such as over-fishing, pollution and sedimentation - across the whole area. By removing all these other stresses we are giving the coral the best chance of surviving and recovering from any changes in temperature that may occur as a result of global warming.”

The team has investigated the long-term impact of a major coral die-off across the Indian Ocean caused by warmer waters in 1998. They have tracked declines in coral cover, reef structural complexity, fish species richness and the abundance of various feeding and size groups of reef fish across the Indian Ocean.

“These changes are substantial for some groups, and indicate that little insurance is offered by current small-scale NTA management across the region,” they say.

“We detected declines in fish species richness across the western Indian Ocean in response to loss of live coral cover….the one main exception is Mombasa Marine National Park, Kenya, where species richness and fish density have increased owing to management action.”

The 1998 bleaching event had - and is still having - extensive impacts across the western Indian Ocean. “Geography seems to be a key determinant in the ability of reefs to absorb and recover from such large-scale disturbances and this should be considered for other regions likely to suffer similar large-scale disturbances in the future,” the team says.

More information: Nick Graham, CoeCRS and Newcastle University (UK), +44 191 222 5091, +44 191 273 2183 or +44 7906135431 Shaun Wilson, COECRS and JCU, +61 (0)7 4781 6067 Jenny Lappin, CoECRS, + 61-(0)7 4781 4222 Jim O’Brien, James Cook University Media Office, 61-(0)7 4781 4822