Once waters begin to warm, a study finds, it's too late to adapt

By Tina Hesman Saey

Web edition: January 7, 2013
Print edition: February 9, 2013; Vol.183 #3 (p. 16)

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BEATING THE HEAT

Some forms of Acropora hyacinthus coral preempt the effects of warming waters by turning on genes that help them resist heat and stress.

Credit: Franco Banfi/Getty Images

Corals that can survive in warming ocean water may be genetically primed to sweat it out.

Studying reef-building Acropora hyacinthus corals from American Samoa’s Ofu Island, researchers from the Stanford University Hopkins Marine Station in Pacific Grove, Calif., found that the activity of hundreds of genes changed when both heat-sensitive and heat-tolerant corals were switched from 29.2° Celsius water to 32.9° C water. But even before getting into hot water, heat-tolerant corals had already turned on 60 genes designed to help combat heat and stress, the researchers report online January 7 in the Proceedings of the National Academy of Sciences.

Sensitive corals that bleach in the heat didn’t turn on those heat- and stress-beaters until after temperatures rose. It’s not clear if the heat-tolerant corals face long-term consequences from their constant vigilance against environmental stress. The finding may help researchers better predict how future climate change may affect coral populations.