Coral bleaching less likely in reefs used to temperature changes

How can reefs avoid coral bleaching as ocean temperatures rise? Practice, practice, practice, one new study suggests.

Coral reefs that weather frequent temperature changes can better withstand the conditions that cause bleaching, the international team of scientists discovered.

The researchers looked at 118 reefs around the world. Noting that some of the reefs showed only patchy bleaching, the team set out to see how sections that resisted coral bleaching differed from areas that could not.

They found that the areas that experienced frequent temperature changes were better able to survive warming events. Those that experienced more stable temperatures were more likely to fall to bleaching.

“Importantly, our results show that the resistance of corals to bleaching in areas of high-frequency temperature variability occurs in reef regions throughout the world,” co-author Dr. Gareth Williams of Bangor University said in a press release.

In some cases, the researchers found, reefs just a few hundred meters apart – or even just a few dozen – had different temperature conditions and different responses to warming events.

The study offers some hope for coral reefs, many of which have been damaged by bursts of warm water temperatures in recent years. It could also help scientists better understand how and why coral bleaching happens.

But that doesn’t mean people should let their guards down, the research team warned. Warming events that damage coral reefs have become more frequent, they said. This is an issue of global concern, they said, because reefs are so vital to shoreline protection, fisheries and other important parts of the ocean ecosystem.

“This positive news should not distract from the urgent need to reduce greenhouse gas emissions to protect coral reefs globally, but instead help guide strategic management actions in the inevitable interim,” Williams said.

The study has been published in the journal Nature Communications.

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By Kyla Cathey, Earth.com staff writer

Image credit: Paul Marshall