"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."