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Resilience of Central Pacific Corals to Repeated Heat Stress Events

Paper Reviewed
Donner, S.D. and Carilli, J. 2019. Resilience of Central Pacific reefs subject to frequent heat stress and human disturbance. Scientific Reports 9: 3484, DOI: 10.1038/s41598-019-40150-3.

What are the chances that coral reefs are going to experience widespread bleaching-related mortality in the future due to global warming? Climate alarmists claim it is very high, yet a recent study by Donner and Carilli (2019) suggests far more optimism.

Focusing their attention on the reefs of the central Gilbert Islands of the Republic of Kiribati, the two researchers analyzed nine years of survey data over the period 2004-2012, alongside a series of remote-sensing variables "along gradients of climate variability and human disturbance in the region to evaluate the drives of coral community response to, and recovery from, multiple heat stress events."

So what did their analysis reveal?

Over the nine-year record there were two El Niño-induced warming events (2004/05 and 2009/10) where the Gilbert Islands' reefs experienced temperature stress. Surprisingly, despite "despite similar levels of heat stress," fewer corals bleached during the 2009/10 El Niño than the 2004/05 El Niño. Additionally, Donner and Carilli report that "benthic cover data further illustrat[ed] the limited effect of the 2009-2010 heat stress event, relative to the 2004-2005 event.

In consequence of the above findings, the scientists conclude that corals of the Gilbert Islands "showed evidence of acclimation to heat stress." And if these findings hold for coral reefs elsewhere -- and there is growing evidence that they do (see Coral Reef Responses to Temperature Stress: Recovery and Resilience in our Subject Index) -- perhaps we ought not be so concerned about predictions of their future demise due to global warming!

Posted 22 May 2019