Loudspeakers that play sounds intended to attract fish are helping to bring dead coral reefs back to life, according to a paper published recently in Nature Communications. The paper’s authors said that they hope that their findings could lead to efforts undo much of the mass destruction of coral that has been taking place throughout the world’s oceans in recent decades.
In the paper, the researchers described placing underwater loudspeakers at locations in a zone of ocean water north of Australia. Each site was within a formerly vibrant coral reef that had largely died out.
The speakers played sounds associated with healthy, vibrant reefs; the researchers intended for fish to hear these recordings and flock to the sites to breed. Their plan worked: The sites that had the speakers saw 50% increases in both the numbers of fish and numbers of fish species.
New fish populations won’t directly create more coral, but they can encourage new coral growth as the fish clean reef surfaces and create more spaces for corals to grow, the researchers said. Andy Radford, a paper coauthor from the University of Bristol, said that efforts such as this one to boost fish populations can be important parts of larger initiatives to bring lost coral ecoysystems back to life.
“If combined with habitat restoration and other conservation measures, rebuilding fish communities in this manner might accelerate ecosystem recovery,” said Radford.
Ocean researchers have been concerned about coral health throughout the world’s oceans in the last few decades, due to widespread deaths of coral in many locales. The main driving force behind coral death is climate change: Ocean water becoming incresaingly acidic as it absorbs larger amounts of carbon dioxide from the atmosphere, according to researchers.