Global warming
puts coral in peril
A worst-case scenario has
By Rohan Sullivan
coral extinct by 2100 if conditions
don't improve
Associated PressSYDNEY -- Global warming is causing a damaging condition known as coral bleaching to strike the world's reefs more often and with greater intensity than ever before, scientists and environmentalists said today.
If the current rate of climate change continues, "coral reefs could be eliminated from most areas of the world by 2100," said Professor Ove Hoegh-Guldberg, author of a report released by Greenpeace Australia.
Scientists say coral bleaching struck reefs across the globe in 1998. The term describes a condition that occurs when coral becomes stressed and expels the microscopic plants that give them their vibrant color.
Devastating coral bleaching was recorded last year in many regions including Australia, India's Bay of Bengal, the Gulf of Thailand, Florida and the Seychelles islands off East Africa.
Industrial pollution and the El Nino weather pattern are believed to be among the causes.
The report said that at the current rate of global warming, the occurrence of coral bleaching would increase in frequency and intensity until it became an annual circumstance all over the world by 2070.
Reefs can recover from bleaching, but not if it occurs that frequently, said Hoegh-Guldberg, a marine biologist with the University of Sydney.
"The loss of these fragile ecosystems would cost billions of dollars in lost revenue from tourism and fishing industries, as well as damage to coastal regions that are currently protected by the coral reefs that line most tropical coastlines," he said.
Coral reefs, some of which are still alive after 2.5 million years, consist of thousands of small organisms and a coating formed by a single-cell plant that gives off the coral's distinctive bright colors. They are home to a fourth of all marine fish species, scientists say.
A study released last month by the World Resources Institute said that nearly 60 percent of the Earth's living coral reefs are threatened by human activity, including coastal development, overfishing and inland pollution.
Richard Kenchington, the executive director of the Great Barrier Reef Marine Park Authority, said the predictions in the report were feasible, but appeared to be a worst-case scenario.
"It's right to sound the alarm, but it is very important that we get better data so we can scale the extent of that alarm," Kenchington told Australian Broadcasting Corp. radio.
An international symposium hosted by the authority last year concluded that coral bleaching and "coral mortality" occurred with unprecedented frequency in 1998, and was likely to increase.
Highly sensitive corals can live only in water between 64 degrees and 86 degrees, and bleaching can be triggered by a temperature increase of just 1.8 degrees above the maximum, Hoegh-Guldberg said.
The 1,200-mile Great Barrier Reef is the largest complex of coral reefs and islands in the world, comprising more than 2,600 individual reefs and 300 islands off Australia's east coast.
It generates $975 million a year in tourism revenue.
