In new research published in the Journal of Applied Ecology, Australian scientists amplified the natural sounds of the sea via underwater speakers, inducing baby oysters to swim toward desirable locations for regrowing oyster reefs. Thousands more larvae swam to those locations than to control areas to settle on bare rocks. Oyster reef restoration in Australia and globally is viewed as a way to re-establish healthy ecosystems. Shellfish filter and clean large volumes of water as they feed, and shell piles provide habitat for fish.

Many marine animals use sound to communicate over long distances, because it can carry more information than sight or smell underwater. Healthy reefs emit crackles and pops from shrimp and fish as they feed, and that makes oyster larvae aware of a healthy habitat for them to settle on a rock and begin growing their shell.

The researchers recorded sounds from the healthy Port Noarlunga Reef and played them underwater near two large reef restoration sites offshore from Adelaide and the Yorke Peninsula. They attracted up to 17,000 more oysters per square meter to these sites and close to four times more large oysters grew in the test areas over the next five months, further accelerating habitat growth.