A study published Thursday says our coral reefs could be in danger. Toth and her co-writers say in the study that El Niño Southern Oscillation (ENSO) caused reef ecosystems in the tropical eastern pacific to collapse thousands of years ago, and pollution combined with global warming changes could now repeat the process. The sea temperature changes associated with El Niños are the main cause for the coral reefs dying off from bleaching.
Around 4000 years ago reef growth began to shut down. The collapse lasted about 2500 years. Scientists came to this conclusion after analyzing coral reefs on Panama’s Pacific coast. They inspected cross-sections of the reefs using radiocarbon dating and mass spectrometry techniques to find the “hiatus” in the reef’s growth, as it was described in the report. Coral reefs in Japan and Australia experienced similar hiatuses in growth. Scientists believe that the widespread distribution of the hiatus suggests that it was caused by historical changes in ENSO.
El Niño activity in recent years has devastated tropical reefs. And as our world grows warmer and warmer, the reefs are more and more likely to lapse into their hiatus state and die off. Pollution, and CO2 emissions especially, will hurt the reefs’ chances of survival. However, the study ends optimistically, suggesting that if the Pacific reefs were able to overcome thousands of years of stagnancy then perhaps they will be resilient again, but only if we cut down our pollution and over-fishing.