"A major new survey of the world's coral reefs finds that they are in trouble. Big trouble.

Overfishing and local pollution continue to grow as threats, and the reefs' long-term existence is in doubt because the world's oceans are gradually getting warmer and more acidic because of human activity.

There's a lot at stake: Coral reefs are spectacular ecosystems, overflowing with diverse and colorful marine life. They're also the source of food and economic sustenance to half a billion people around the world.

'Currently, we find 75 percent of the world's reefs are threatened by a combination of local and global threats,' says Lauretta Burke, a senior author of the new report. 'By 2030, the percentage will rise to 90 percent. By 2050, virtually all reefs will be threatened,' she says."

Richard Harris reports for NPR's All Things Considered February 23, 2011. [2]