Coral Reefs Absorb 97 Percent of the Energy From Waves Headed Toward Shore

This finding applies to reefs around the world

Waves breaking on a coral reef in Hawaii. Photo: Bill Schildge/Design Pics/Corbis

It's no secret that natural structures such as coral reefs, sand dunes and mangroves help protect water-front communities from the impacts of waves, storm surge and even tsunamis. A group of researchers decided to home in on coral reefs, however, to see just how significant their universal role is in breaking waves. And they found that coral reefs absorb a whopping average of 97 percent of wave energy—nearly all of it.  

The team looked at coral reefs from all over the world, by performing a meta-analysis of 27 peer-reviewed scientific studies that focused on individual reefs. Those studies, they explain, examined everything from pleasantly breezy conditions to hurricane-force winds. 

After the researchers crunched the numbers, they said they were shocked at the extent to which the reefs absorb that wave energy. "It is a huge reduction," lead author Fiorenza Micheli said in a statement. "The majority of wave energy is lost on the reef crest."

She added that that means coral reefs' effectiveness is on par with that of man-made structures built to shield coasts by dissipating wave energy. Where those two methods differ, however, is in cost. Artificial structures run about $19,800 per meter to build, she said, whereas coral reef restoration project add up to about $1,300 per meter. That's not to mention their other benefits, including "support of biodiversity, improved water quality, and support of fisheries and tourism," Micheli added. 

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