Washington
11 July 2008
Experts say one-third of the oceans' coral reefs face extinction by themiddle of the century if nothing is done to save them. The reefs arehome to a vast array of sea creatures, which experts say would also beendangered by the loss of the reefs. VOA's Jessica Berman reports.
Agroup of thirty nine leading coral experts from around the worldsounded the alarm in the first-ever global assessment of coral reefs.
Corals are tiny sea creatures that lay their skeletons down to form large reefs that have been built over millions of years.
KentCarpenter of Old Dominion University in Virginia led the study,published this week in the journal Science, on the threat to theworld's coral reefs, which are produced in tropical and sub-tropicalseas in coastal waters.
Carpenter says steps must be taken now to reduce greenhouse gas emissions and stop over-fishing and pollution of the oceans.
"Ifwe do not do those things, then, at the current level of how things aregoing, we will probably lose our coral reefs by the middle of thiscentury," Carpenter said. "So, 2050 is the date that many peopleare predicting that coral reefs will cease to exist."
Carpenter says, as ocean temperatures rise, corals throw off algae attached to them that are essential for their survival.
"Normally,when you see a coral, it's tan or green or some colorful color," hesaid. "But when they expel their algae inside of them, then they becomewhite. And this is a phenomenon known as bleaching. Anotherconsequence of higher temperatures is increased disease, and this cancause mass die off."
Carpenter says the coral reefs at greatest risk of extinction are the most common - the branching or staghorn coral.
According to the report, the Caribbean has the greatest number of threatened coral species.
Thereport also lists corals within the Pacific's Indo-Malay-PhilippineArchipelago as threatened because of large concentrations of people.
Experts say more than 25 percent of marine species depend upon the reefs for their survival.
Carpenter says humans also depend upon coral reefs.
"Theyare important for food and important for other types of livelihoods," he said. "So, if we lose the ecosystems, we lose not only thebiodiversity, but we also lose the capability of people to obtainincome and food from coral reefs."
However, Carpenter says heand other marine biologists believe the coral reefs can be rescuedthrough targeted conservation efforts and a reduction in greenhouse gasemissions.
Earlier this week, a U.S. government report saidnearly half of coral reefs in U.S. government territory are in poor orfair condition.