In a study led by Lauren T. Toth at Florida Institute of Technology published in the journal, Science, coral reef ecosystems in the tropical eastern Pacific “collapsed for 2500 years, representing as much as 40% of their history, beginning about 4000 years ago.” A series of powerful El Nino events, which include periods of significantly warmer ocean temperature every three to seven years, coincided with the 2,500-year period of coral decline. This was followed by a cycle of La Nina events characterized by much cooler water, beginning 3,200 to 3,800 years ago. Corals recovered during the millenia since but now face a return to extreme weather conditions like those that wiped them out, due to climate change impacts.
Researchers shared the implications for today’s coral reefs with the New York Times:
“Even conservative models of climate change predict a return to extreme weather conditions,” said the lead author, Richard B. Aronson, a professor of biology at the Florida Institute of Technology. “This means that reefs could shut down. The hopeful part is that these reefs did prove to be resilient 1,500 years ago. Reefs today could recover, but only if we get a handle on the greenhouse gases causing climate change. Local conditions would have to improve, too,” Dr. Aronson added. “Coral mining is also a threat, ship grounding, overfishing.”…More at Observatory: Coral Rebounded From Hostile Climate Millenniums Ago, Study Suggests (New York Times)