The most recent major coral bleaching event occurred in 1998 as a result of the El Ni o weather phenomenon, which caused ocean temperatures to rise as much as 2 degrees Fahrenheit in some parts of the world. Studies show that 15 percent of the world's coral reefs were wiped out, Hodgson said, with as much as 95 percent mortality in areas of the Indian Ocean. While nearly a third of the reefs have recovered, Hodgson warns that other human threats such as overfishing and pollution are greatly contributing to coral reef declines throughout the world. Recovery efforts are difficult. Providing habitat for 25 percent of marine species, coral reefs are considered to be one of the most productive ecosystems on Earth.
Most reefs occur in poor countries.
If global warming predictions are correct, this event serves as a great warning. The Global Coral Reef Alliance is a coalition of action-oriented scientists, divers, environmentalists, and other individuals and organizations who are concerned about coral reefs. Visit ENN's special report Year of the Ocean . Reef Check is the largest international coral reef monitoring program involving recreational divers and marine scientists.