Coral sounds boost reef health, study shows

Researchers have discovered a novel method to help struggling coral reefs by using underwater speakers to play recordings of healthy corals. This approach could potentially restore vitality to degraded reefs.

A team led by Nadège Aoki from the Woods Hole Oceanographic Institution tested this technique off the coast of Saint John in the US Virgin Islands. By playing sounds of thriving corals through underwater speakers, they found that coral larvae were up to seven times more likely to settle on the reef. This finding was published in the journal *Royal Society Open Science*.

Aoki noted, "We’re hoping this may be something we can combine with other efforts to rejuvenate reefs. You could use speakers to attract not just coral larvae but also fish." Coral reefs have seen dramatic declines, with about half of the world's reef cover lost since the 1950s and species diversity plummeting by over 60%, largely due to climate change, overfishing, pollution, and habitat destruction.

Previous restoration attempts have included using steel frames to create breeding grounds. However, many of the world’s largest reefs continue to suffer from bleaching, a process where corals expel the algae living in their tissues.

In their experiment, Aoki and her colleagues installed speakers at three reefs and observed the settlement of larvae in rock-like ceramic containers. Only one site played the healthy coral sounds, while the other two served as controls: one was a degraded reef and the other a healthier one. They found that larvae were 1.7 to seven times more likely to settle near the speaker, with settlement rates decreasing with distance from the sound source.

The study suggests that acoustic enrichment could offer a promising tool for coral reef restoration. However, Aoki cautioned that it is not a panacea. "You have to be very thoughtful about applying this technology," she said. "It needs to be part of a broader strategy to ensure the corals' survival and growth."

University of Bristol marine biologist Steve Simpson, who has researched similar methods for two decades, emphasized the importance of such innovations. "Coral reefs are the first marine ecosystems we could lose to climate change, which means they are also the first we can save," he said. "If we can save reefs, we can save anything."

[Information sourced from Futurism, The Guardian]