Nusa Dua, Indonesia More than a quarter of the world's coral reefs have been destroyed by pollution and global warming, experts said Monday, warning that unless urgent measures are taken, most of the remaining reefs could be dead in 20 years.
In some of the worst-hit areas, such as the Maldives and Seychelles islands in the Indian Ocean, up to 90 percent of coral reefs have been killed over the past two years due to rises in water temperature.
Coral reefs play a crucial role as an anchor for most marine ecosystems, and their loss would place thousands of species of fish and other marine life at risk of extinction.
Addressing 1,500 delegates from 52 countries at the Ninth International Coral Reef Symposium on the island of Bali, researchers warned that governments must urgently reverse global warming trends, cut pollution and crack down on overfishing.
But the most serious and immediate threat to the world's reefs is global warming, which causes a damaging condition known as coral bleaching. This occurs when higher water temperatures heat up the coral, causing them to expel the microscopic plants that give them their vibrant color. If the coral is not cooled, it dies.
Oceanographers say the El Nieather pattern two years ago, which led water temperatures to rise by up to six degrees, did enormous damage to the coral reefs, some of which had been alive for up to 2.5 million years.