The Sounds Of Living Coral Reefs Are Breathtaking And Important

Simple recordings could help us save these incredible, threatened ecosystems

Coral reef in Virgin Islands

Coral reef in Virgin Islands

OLYMPUS DIGITAL CAMERA NOAA/Flickr CC by 2.0

Two new studies from the Woods Hole Oceanographic Institute show that the best way to help these reefs might be by listening to them. Literally. Audio recordings of reefs in the Virgin Islands show that just like on land the sea is a pretty noisy place to be.

One study published in Marine Ecology Progress Series found that a single low-frequency recorder might be enough to monitor the populations of fish and other aquatic life living on a reef. The small instrument could be deployed at reefs all over the world, recording information about what kinds of sea life are living at these locations, recording the sounds of fish swimming and feeding, and the snap-crackle-pop of shrimp. You can listen to the sounds of a reef here.

And the sounds of a reef filled with shrimp here (which sounds a little bit like adding milk to Rice Krispies cereal).

"It's a pretty exciting result that we found, because many reefs are difficult to access and it is very expensive to monitor them in traditional ways," co-author of the studies Max Kaplan said in a press release.

The research on sounds not only gives scientists a remote snapshot of the vitality of the reefs, it could also be used to build reefs up after they've died. One of the serious threats facing reefs today is bleaching, the slow death of corals after a change in the water (usually temperature related) kills off symbiotic algae, leaving the corals to die.

"If you want to restore a reef that has bleached, you could potentially broadcast some of these sounds and attract the larvae you want to bring back," co-author of the studies Aran Mooney said.

In another study published in Marine Pollution Bulletin the researchers found that those same sounds emitted from coral reefs might be in peril, due to other noisy animals in the sea. Particularly, humans and our boats.

The study found that small boats were the source of a lot of noise underwater, and more worryingly, the frequency of the noise from boats is about the same as the frequency of noises from fish. The similarity in noises "might be an important impediment for fish that don't produce very loud sounds and don't hear all that well," Mooney said.

The researchers will be expanding their work to Hawaii, where they will monitor 8 sites for 15 months.