Earthquake causes coral reefs to die
Published Friday, April 13, 2007 8:55AM EDT
BANGKOK, Thailand - A 2005 earthquake off the coast of Indonesia raised an island nearly four feet out of the water, causing one of the biggest coral die-offs recorded, scientists said Friday.
Researchers who surveyed the island of Simeulue in recent weeks found that the March 2005 quake had exposed most of the coral along its 190-mile-long coast.
"The scale of it was quite extraordinary," said Andrew Baird, who took part in the survey with scientists from the New York-based Wildlife Conservation Society. "Exposed corals were everywhere."
At some points along the coast, coral was visible from a few feet from the shore to a third of a mile out to sea. Coral reefs host many species of marine life.
"Some species suffered up to 100 percent loss at some sites," said Baird, of the Australian Research Council Centre of Excellence for Coral Reef.
More than 900 people were killed and tens of thousands left homeless by the 8.7-magnitude earthquake, which also struck two other islands off Sumatra -- Nias and Banyak. The quake came three months after the 2004 tsunami that left 230,000 people in a dozen Indian Ocean countries dead or missing.
Australian reef expert Clive Wilkinson, who did not take part in the survey, said the damage to the Simeuleu reefs was to be expected, given the uplift that occurred and the severity of the quake.
"This has been going on for million of years," Wilkinson said. "It's part of natural reef evolution. There are many islands in the Pacific that are actually uplifted coral reefs. It's just what happens to reefs."
Baird and his fellow researchers said the exposed reefs are largely lost and will become coastal forests.
Those just beneath the water's surface, however, are likely to grow back as long as local communities protect the small, fragile marine animals.
"The news from Simeulue is not all bad," Stuart Campbell, coordinator of the Wildlife Conservation Society's Indonesia Marine Program, said in a statement.
At many sites, the species most affected by the die-off are beginning to re-colonize reefs in shallow water.
"The reefs appear to be returning to what they looked like before the earthquake, although the process may take many years."
Baird said their findings should give hope to communities in the Solomon Islands, where concerns have been raised that an April 2 earthquake and tsunami might have damaged its reefs and in turn its diving industry.
"They shouldn't be worried about losing their dive industry. The fish they target to eat will still be there," Baird said.
"Everything still in the water will still be fine," he said. "Reefs can respond to these massive mortality events. They can power on through it as long as there is enough good reef out there."