Fri, July 06, 2012
WASHINGTON, July 5 (Xinhua) -- Climate change drove coral reefs in eastern Pacific to a total ecosystem collapse for 2,500 years, according to a paper to be published Friday in the journal Science.
The reef shutdown, which began 4,000 years ago, corresponds to a period of dramatic swings in the El Nino-Southern Oscillation (ENSO).
"As humans continue to pump greenhouse gases into the atmosphere, the climate is once again on the threshold of a new regime, with dire consequences for reef ecosystems unless we get control of climate change," said coauthor Richard Aronson, a biology professor at the Florida Institute of Technology (FIT).
The research team drove 17-foot, small-bore aluminum pipes deep into the dead frameworks of coral reefs along the Pacific coast of Panama and pulled out cross-sections of the reefs.
By analyzing the corals in the cores, they were able to reconstruct the history of the reefs over the past 6,000 years.
"We were shocked to find that 2,500 years of reef growth were missing from the frameworks," said lead author Lauren Toth. "That gap represents the collapse of reef ecosystems for 40 percent of their total history."
When Toth and Aronson examined reef records from other studies across the Pacific, they discovered the same gap in reefs as far away as Australia and Japan.
They linked the coral-reef collapse to changes in ENSO, which is the climate cycle responsible for the weather conditions every few years known as El Nino and La Nina events.
The timing of the shutdown in reef growth corresponds to a period of wild swings in ENSO.
