Evidence of the dire condition of coral reefs around the world is being presented in abundance at the 12th International Coral Reef Symposium that got underway yesterday in Cairns, Australia. And scientists are calling for action to stop the losses: More than 2500 marine researchers and managers at the conference and around the world have signed a Consensus Statement on Climate Change and Coral Reefs that calls on "all governments to ensure the future of coral reefs, through global action to reduce the emissions of carbon dioxide and other greenhouse gases, and via improved local protection of coral reefs."
The need for action is self-evident to the community. "The huge declines in live coral cover that people have been talking about are real and increasingly well documented," Jeremy Jackson, professor emeritus of oceanography at Scripps Institution of Oceanography in San Diego, California, said at a press briefing. He noted that in the Caribbean, live coral cover has declined from 50% to 60% of reefs in the early 1970s, to around 5% to 10% today. Even on Australia's Great Barrier Reef, probably the world's most well-protected, live coral cover has decreased from 40% of the area to 20% over the last 50 years.
The causes are well known: overfishing, habitat destruction, sedimentation, pollution, and, increasingly, climate change. Warmer ocean waters mean increased bleaching; and the oceans are becoming more acidic, which weakens coral skeletons. "There are no climate skeptics among coral reef scientists or coral reef managers because we've been measuring the impact of climate change since about the 1980s," said Terry Hughes, who studies the links between reefs and local communities at James Cook University in Townsville, Australia.
Addressing climate change will take time. Meanwhile, there is hope in local action. "We know from observation and experience that in places where protective actions have been taken, the coral reefs are in better shape," Jackson said. Protecting reefs from human activities makes them more resilient to bleaching and naturally occurring disruptions such as typhoons and will buy time "while we come to grips with the (world's) carbon dioxide addiction," said Stephen Palumbi, a marine biologist at Stanford University in Palo Alto, California.
The scientists banded together because "a statement from a single scientist may not be enough to generate the political and leadership changes we need for saving coral reefs," Palumbi said. He and a small group of like-minded researchers started work on the statement 2 years ago in anticipation of having it adopted at the symposium. Of course, "the statement is just the beginning," he said, adding that the 2500 signing scientists need to engage political and community leaders "to help us by taking on the science and turning it into political action."