13 Jul 2012

International Coral Reef Symposium comes to a close

5:17 pm on 13 July 2012

The International Coral Reef Symposium came to a close in Cairns on Friday with a major focus on the damage being done to reefs by climate change.

The Symposium is the worlds largest conference on coral reefs, this year it was attended by more than two thousand of the world's top marine scientists from 80 countries.

The message from the symposium was stark, coral reefs around the world are in rapid decline.

Up to 30 percent of the world's reefs are already severely degraded and without immediate action many more may be lost .

In his presentation to the symposium the director of Marine Science at Queensland University, John Pandolfi, said the biggest threat to reef life is climate change.

"There's a lot of evidence from the geological past that tells us that global warming and ocean acidification together have been responsible for a whole lot of reef degradation and reef crisis, they have played a role in some mass extinction events in the earth's history. We do know that corals and reefs have had tremendous resistance to climate change over the geological past, no matter how hard they've been knocked down they've generally managed to return. But what is different today is the rate of climate change. We are as yet unable to identify any periods in earth history where the rates of CO2 rise are comparable to that of today."

Peter Doherty, from the Australian Institute of Marine Science, says climate change gradually degrades reefs through ocean acidification, sea level rise and temperature increases.

But he says one of the dramatic threats it brings is more frequent and powerful storms.

Cyclones can be particularly catastrophic, winds of hundreds of kilometres an hour. Cyclone Yassi in 2011 went across the centre of the great barrier reef, we had a swell of up to nine metres in the Great Barrier Reef lagoon which is almost unprecedented. When the winds had abated and the cyclone had passed then they leave a tremendous swath of broken coral on all the reefs within a hundred kilometres or more of their centre.

So in an attempt an attempt to capture the attention of global decision makers the convenor of the symposium, Terry Hughes, says more than two and a half thousand scientists signed a consensus statement, urging immediate action on climate change.

That's a very unprecedented thing for the science community to do and it basically reflects our concern about the global trajectory of coral reefs. We're calling on governments around the world to improve the way that coral reefs are managed.

Bob Richmond from the International Society of Reef Studies says although Pacific nations contribute the least to greenhouse gas emissions they stand to lose the most, due to their reliance on reefs for ecological, economic and cultural purposes.

In the case of Palau it's a world wide diving destination. If you run the numbers it generates over three million dollars a year in dives alone, not counting hotel stays, food purchase locally, airline tickets and all the other things that go with it. There's really nothing else that Palau has that can generate that amount of revenue in a sustainable manner.

However Stephen Palumbi from Stanford University says small communities can do their part to protect their reefs by fighting overfishing and pollution locally.

By changing the local stressors it allows coral reef communities to become more healthy, more vibrant, to grow better and then have enough excess energy to fight off global climate change for a little while longer. It's a way to buy time. It's a way to keep those ecosystems going for as long as possible, providing the benefits that they provide the people for as long as possible while we come to grips with the carbon dioxide addiction that the rest of the world has.

And Geoff Jones from James Cook University has discovered protecting small reefs can also provide a boost for local fishermen.

Professor Jones says fish born in small reserves around reefs make up about half of all the juveniles in unprotected areas and could boost the total number of adult fish available to catch by as much as 50 percent.

The reserves that we have been looking at down in the Kepple Islands are not big reserves. One of them is only about 800 meters across and it's still having an effect . The benefits are local too so the same community that's setting up a reserve will be the one that benefits in terms of the boost to the fishery.

Professor Jones says this is good news for small Pacific nations because it can sometimes be difficult to protect a large area from fishing.