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.