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  BBC 8 Aug 07
Swifter decline for coral reefs

NewScientist.com 8 Aug 07
Coral reefs are vanishing faster than rainforests
Catherine Brahic

Yahoo News 7 Aug 07
Coral reefs dying faster than expected
 By Michael Casey, AP Environmental Writer

Coral reefs in much of the Pacific Ocean are dying faster than previously thought, according to a study released Wednesday, with the decline driven by climate change, disease and coastal development.

Researchers from the University of North Carolina in Chapel Hill found that coral coverage in the Indo-Pacific — an area stretching from Indonesia's Sumatra island to French Polynesia — dropped 20 percent in the past two decades.

About 600 square miles of reefs have disappeared since the 1960s, the study found, and the losses were just as bad in Australia's well-protected Great Barrier Reef as they were in poorly managed marine reserves in the Philippines.

"We found the loss of reef building corals was much more widespread and severe than previously thought," said John Bruno, who conducted the study along with Elizabeth Selig.

"Even the best managed reefs in the Indo-Pacific suffered significant coral loss over the past 20 years."

The study, which examined 6,000 surveys of more than 2,600 Indo-Pacific coral reefs done between 1968 and 2004, found the declines began earlier than previously estimated and mirror global trends.

The United Nations has found close to a third of the world's corals have disappeared, and 60 percent are expected to be lost by 2030.

The Indo-Pacific contains 75 percent of the world's coral reefs and provide a home for a wide range of marine plants and animals. They provide shelter for island communities and are key source of income, mostly from the benefits of fishing and tourism.

"Indo-Pacific reefs have played an important economic and cultural role in the region for hundreds of years and their continued decline could mean the loss of millions of dollars in fisheries and tourism," Selig said in a statement.

"It's like when everything in the forest is gone except for little twigs."

While the study didn't examine the cause of the decline, Bruno said he believed it was driven by a range of factors including warming waters due to climate change.

He also blamed storm damage, runoff from agriculture and industry, predators like fast-spreading crown-of-thorn starfish and diseases like White syndrome.

Bruno said the study demonstrated the need to better manage reefs and prevent threats such as overfishing, but acknowledged local measures would have little impact without a reduction of greenhouse gases.

"It is just one more example of the striking, far reaching effects of climate change and our behavior," Bruno said of the link between climate change and reef destruction.

"It is the folks in North Carolina driving their SUVs. It is their behavior that is having an effect way out in the Indo-Pacific."

Ove Hoegh-Guldberg, director of the Center for Marine Studies at The University of Queensland in Australia, said the study should put to rest any suggestion that reefs like the Great Barrier Reef are untouched by "human pressures."

"This is a solid study that produces mounds of evidence that suggests reefs are changing counter to the untested and ungrounded claims that it isn't happening," Hoegh-Guldberg, who was not involved in the study, said in an e-mail interview.

On the Net: Bruno's homepage: http://www.unc.edu/brunoj

BBC 8 Aug 07
Swifter decline for coral reefs

Coral reefs in the Pacific and Indian oceans are disappearing faster than had previously been thought, a scientific study has shown.

Nearly 1,554 sq km (600 sq miles) of reef have disappeared each year since the 1960s - twice the speed at which rainforest is being lost.

The corals are vanishing at a rate of 1% per year, a decline that has begun decades earlier than expected.

Details of the survey appear in the journal Plos One.

Historically, coral cover, a measure of reef health hovered around 50%. Today, only about 2% of reefs in the region looked at by the study have coral cover close to this historical level.

John Bruno and Elizabeth Selig from the University of North Carolina - Chapel Hill, US, and colleagues, looked at reefs in a large area of ocean stretching from western Indonesia, in the Indian Ocean, to French Polynesia, in the Pacific.

The Indo-Pacific region, comprising the Indian and Pacific oceans, contains 75% of the world's coral reefs.

The researchers analysed the results of some 6,000 surveys carried out on more than 2,600 reefs. The findings show that average coral cover declined from 40% in the early 1980s to about 20% by 2003.

Island impacts

One of the most surprising results was that there seemed to be little difference between reefs maintained by conservationists and those left unprotected.

Dr Bruno and Ms Selig argue that the consistent pattern of decline across the study region adds to mounting evidence that coral loss is a global phenomenon. This is probably due to large-scale processes such as climate change, they say.

This is likely to have a major impact on many island communities, which rely on the reefs for fisheries and tourism.

"The actions of people in Iowa, for example, have a big effect on people in small islands and throughout this whole Indo-Pacific region. It affects their livelihoods dramatically," Dr Bruno told the BBC.

"When corals died, there were some studies which showed how quickly the dive shops and the hotels closed down."

The UN says that a third of the world's coral reefs have already died. By 2030, that figure is predicted to be closer to 60%.

NewScientist.com 8 Aug 07
Coral reefs are vanishing faster than rainforests
Catherine Brahic

Coral reefs in the Indo-Pacific are disappearing twice as fast as tropical rainforests, say researchers.

They have completed the first comprehensive survey of coral reefs in this region, which is home to 75% of the world's reefs.

John Bruno and Elizabeth Selig of the University of North Carolina at Chapel Hill in the US compiled data from 6000 studies that between them tracked the fate of 2600 reefs in the Indo-Pacific between 1968 and 2004.

They used the extent to which reefs were covered by live coral as an indication of their health. "The corals themselves build their limestone foundation, so if the surface of the reef is not covered with live tissue that is continually secreting it, the reef can erode fairly quickly," explains Selig.

She and Bruno found that coral cover declined by 1% per year on average between 1968 and 2004. For comparison, tropical rainforests declined by 0.4% per year between 1990 and 1997 (Science, vol 297 p 999).

Steep decline

In the early 1980s about 40% of reefs were covered with live coral, but that number had halved by 2003. Today only 2% of Indo-Pacific reefs have the same amount of live coral as they did in the 1980s.

That's much less than expected, says Selig. She explains that it was generally thought that Indo-Pacific reefs were faring much better than Caribbean reefs, a bias she believes stems from the fact that Caribbean reefs have been studied more extensively. Caribbean reefs are declining by 1.5% a year (Science vol 301p 929).

The researchers found little difference between protected and unprotected reefs. "Well-managed reefs are definitely doing better in terms of fish population but not in terms of coral cover," Selig told New Scientist.

This uniformity has led Selig and Bruno to conclude that warming seas as a result of climate change are likely to be driving the rapid decline. Warmer oceans cause coral bleaching because higher temperatures kill their symbiotic algae. They also help diseases spread across reefs.

International effort

Selig and Bruno say local policies – for instance to limit harmful fishing methods and reduce continental run-off – can do much to help maintain the corals in the short-term, but long-term conservation will require an international effort to tackle global warming.

"There certainly are local problems that [reef] managers can and are addressing," says Bruno. "But there are problems that are happening at regional and global scales that no single manager, or even federal authority can cope with. Managers can't manage ocean temperatures."

In 2004, research led by Andrew Baker of Columbia University in New York, US, suggested that coral reefs might adapt to live in warmer oceans. Bruno says some reefs in their survey were recovering from previous damage – sometimes thanks to effective protection, sometimes independently of human intervention.

But overall the reefs do not appear to be adapting fast enough to stem their decline.

Baker believes more research is needed to explore whether anything can be done to boost corals' natural ability to adapt to change. “This might include attempts to inoculate the largest and oldest colonies on reefs with heat-tolerant symbiotic algae that might help them survive bleaching events,” he says.
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