Indonesian Earthquake Killed Vast Coral Reefs

BOGOR, Java, Indonesia, April 12, 2007 (ENS) - A massive death of corals resulting from an earthquake off Aceh, Indonesia on March 28, 2005 was just discovered by scientists two years after the upheaval. They found that an entire island heaved more than a meter upwards, exposing and killing corals in unprecedented numbers.

Last month, scientists from the Wildlife Conservation Society's Indonesia Program and the Australian Research Council Centre of Excellence for Coral Reef Studies, ARCCoERS, first investigated the condition of coral reefs off the province of Aceh on the island of Sumatra.

In surveys that covered 35 sites along 600 kilometers (372 miles) of coastline, the scientists documented, for the first time, the effects of earthquake uplift on coral reefs.

Dr. Stuart Campbell, coordinator of the Wildlife Conservation Society Indonesia Marine Program says, "This is a story of mass mortality on a scale rarely observed. In contrast to other threats like coral bleaching, none of the corals uplifted by the earthquake have survived."

The entire island of Simeulue, with a perimeter of 300 kilometers (186 miles), was raised up to 1.2 meters (3.9 feet) following the March 2005 earthquake, exposing most of the coral reefs which ringed the island.

Researcher finds an uprooted coral reef on the island of Simeulue, Indonesia. (Photo courtesyWildlife Conservation Society)
Dr. Andrew Baird of ARCCoERS says, "Amazingly, the uplifted corals are so well preserved we could still identify each species, despite these colonies having been exposed for two years. Some species suffered up to 100 percent loss at some sites, and different species now dominate the shallow reef."

"This is a unique opportunity to document a process that occurs maybe once a century and promises to provide new insights into coral recovery processes that until now we could only explore on fossil reefs" says Baird.

Campbell adds, "The news from Simeulue is not all bad. At many sites, the worst affected species are beginning to re-colonize the shallow reef areas. The reefs appear to be returning to what they looked like before the earthquake, although the process may take many years.

"The challenge now is to work with local communities and government agencies to protect these reefs to ensure the recovery process continues," he says.

The team found coral reefs ranging from diverse assemblages of branching corals in sheltered waters to vast areas of table corals inhabiting surf zones.

The team also documented, for the first time in Indonesia, extensive damage to reefs caused by the crown-of-thorn starfish, a coral predator that has devastated reefs in Australia and other parts of the world.

Crown-of-thorn starfish and a recently eaten coral (Photo courtesy ARCCoERS)
"Finding the starfish damage is particularly important," says Baird. "Most observers would attribute damage on this scale to more common reef threats in Indonesia such as cyanide fishing or bleaching.

"People monitoring Indonesian corals reefs now have another threat to watch out for, and not all reef damage should be immediately attributed to human influences," he says.

Many other reefs in the area continue to be damaged by destructive fishing including bombing and the use of cyanide although these practices are now illegal in Indonesia.

Dr. Campbell says, "While reef condition in southwestern Aceh is generally poor, we have found some reefs in excellent condition as well as and evidence of recovery at damaged sites."

Campbell and Baird are hopeful that coral reefs in this remote region can return to their previous condition and provide local communities with the resources they need to prosper.

The scientists say recovery would be enhanced by management that encourages sustainable uses of these ecosystems and the protection of critical habitats and species.

The Wildlife Conservation Society is based at New York's Bronx Zoo. Its Indonesia program is headquartered at Bogor, Java.

The Australian Research Council Centre of Excellence for Coral Reef Studies, supported by the government of Australia, is based at James Cook University in Townsville, Queensland adjacent to the Great Barrier Reef.