Speed Reads

It wasn't all bad

Researchers find a new tool in coral reef restoration: underwater speakers

Coral reefs are surprisingly noisy places, but when they are degraded, they become "ghostly quiet." The lack of noise deters fish populations from settling in the dying reef, scientists say, further contributing to the decline.

In an effort to return life to the many reefs ravaged by climate change, researchers from the U.K. and Australia installed underwater speakers in a section of Australia's Great Barrier Reef. They projected the sounds of a healthy reef into a dying one, and diverse fish species from across the food chain flocked to the noise.

The study was led by Tim Gordon, a marine biologist at University of Exeter, and was published late November in Nature Communications. It concluded that ailing reefs fitted with speakers had twice as many fish as compared to dying reefs where no sounds were played. But the fish are just one part of the restoration, says fish biologist Mark Meekan.

"Of course, attracting fish to a dead reef won't bring it back to life automatically, but recovery is underpinned by fish that clean the reef and create space for corals to regrow," Meekan says.

"Acoustic enrichment," as the researchers are calling the method, combined with habitat restoration and conservation measures, could help accelerate the ecosystem and restore coral reefs.