The news for coral reefs just got worse. Today, 75% of the world's coral reefs are threatened, a new report says, an increase from 58%  a decade ago. Local pressures, in particular overfishing, destructive fishing, and pollution from nearby land-based human activity, are paramount, but global warming has caused increased bleaching and ocean acidification, which makes it harder for corals to grow, compounding the problems, the World Resources Institute (WRI) and 24 other organizations concluded in "Reefs at Risk Revisited ," an update of a 1998 report . This news is worse than even a 2008 assessment, "Status of the Coral Reefs of the World: 2008 ," which concluded that 46% of reefs were healthy and not under any predictable threat. "Threats have gone from worrisome to dire," Jane Lubchenco, administrator for the U.S. National Oceanic and Atmospheric Administration said at the briefing in Washington, D.C., about the report.
With the help of satellite data, the new analysis looked at reefs on a much finer scale than did the effort in 1998, with a 64 times greater resolution.
It evaluated how the 275 million people who live close to reefs will fare if these predictions come true. It concluded that, given the status quo, more than 90% of reefs will be at risk by 2030 and virtually all reefs will be threatened by 2050. Haiti, Indonesia, and the Philippines are among the most vulnerable countries because local communities depend so heavily on reefs for their food and livelihood.
To slow the decline of reefs, the report called for more effective marine protected areas, particularly in populated areas. About 27% of reefs are in parks and reserves, but only 6% of those are effective, it concluded. It also pointed out that when local threats from fishing, pollution, and so forth diminish, reefs can rebound. But, noted Nancy Knowlton of the Smithsonian Institution National Museum of Natural History in Washington, D.C., "If we do want to have reefs around by 2050, we are going to have to do something about carbon dioxide" to slow global warming and acidification.
Added Lubchenco: "We have a chance to reverse the decline of coral reefs, but the window of opportunity is finite."