An increase in ocean temperatures that occurred 4,000 years ago triggered a collapse of coral reef systems in the eastern Pacific that lasted for about 2,500 years, according to a new study. In an analysis of 17-foot core samples taken from the frameworks of coral reefs off the Panama coast, scientists from the Florida Institute of 
Technology found that the reefs stopped growing during a period that coincided with the start of a period of dramatic swings in the El Nino-Southern Oscillation, including periods when ocean temperatures elevated significantly. They say this gap in growth also occurred in reef systems as far away as Japan and Australia. “For Pacific reefs to have collapsed for such a long time and over such a large geographic scale, they must have experienced a major climatic disturbance,” said Lauren Toth, a co-author of the study published in the journal Science. While the scientists said the results may foretell similar catastrophic events for reef systems worldwide as ocean temperatures rise as a consequence of climate change, they noted that it also suggests that coral systems may have the resilience to rebound if climate change is mitigated or reversed.
NOAA