Scientific American (Science News): Coral reefs throughout the world face an array of threats: nutrient pollution, starfish predation and deadly bleaching that follows warmer sea temperatures. Yet they provide between $10,000 and $100,000 in economic benefits to nearby communities, according to one estimate, including everything from coastal protection from storm surges to better fishing. More than 75 percent of the world's reefs lie in the
"Global coral loss began earlier and is far more rapid and geographically extensive than we anticipated," says marine biologist John Bruno of the
…By 2003 coral cover had slid from 42 percent in the 1980s to an average of just 22 percent of each reef's surface area, the researchers report in PLoS One. The decline accelerated after 1995, with an average loss of more than 1,200 square miles, or 2 percent of the total of living reef per year—more than double the rate of rainforest loss in the 1990s. "Corals are dying worldwide for a number of reasons, particularly because of pest outbreaks (diseases and predators) but also due to climate change, nutrient pollution, destructive fishing practices and coastal development that can smother corals with sediment," Bruno says.
Reefs in other parts of the world face similar hurdles, but recent research has shown that even severely degraded corals can recover, given the opportunity. "Even on Caribbean reefs in
But Bruno says that can only be achieved if greenhouse emissions are reduced, dynamite and arsenic fishing is eliminated and other steps are taken to halt reef killers. Given the economic—and ecological—benefits such reefs provide, that may be a small sacrifice to make.