There could be a way to save the world’s coral reefs - by playing the sounds of a healthy reef to attract fish, possibly kick-starting natural recovery processes.
Researchers working on Australia’s devastated Great Barrier Reef found that if they played the sounds of healthy reefs through loudspeakers, twice as many fish arrived.
The fish also stayed, compared to equivalent patches where there was no loudspeaker.
The experts now believe that the ‘acoustic environment’ could be a valuable tool in helping to restore damaged coral reefs.
The international research team was made up of scientists from the University of Exeter and University of Bristol, plus Australia's James Cook University and the Australian Institute of Marine Science.
Study lead author Tim Gordon, a PhD student at Exeter University, said: "Fish are crucial for coral reefs to function as healthy ecosystems.
"Boosting fish populations in this way could help to kick-start natural recovery processes, counteracting the damage we're seeing on many coral reefs around the world."
The new technique works by regenerating the sounds that are lost when reefs are quietened by degradation, according to the findings published in Nature Communications.
Senior author Professor Steve Simpson, also of Exeter University, explained: "Healthy coral reefs are remarkably noisy places - the crackle of snapping shrimp and the whoops and grunts of fish combine to form a dazzling biological soundscape.
"Juvenile fish home in on these sounds when they're looking for a place to settle.
"Reefs become ghostly quiet when they are degraded, as the shrimps and fish disappear, but by using loudspeakers to restore this lost soundscape, we can attract young fish back again."
Fish biologist Dr Mark Meekan, of the Australian Institute of Marine Science added: "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."
The study found that broadcasting healthy reef sound doubled the total number of fish arriving onto experimental patches of reef habitat, as well as increasing the number of species present by 50 per cent.
The researchers said that the diversity included species from all sections of the food web - herbivores, detritivores, planktivores and predatory piscivores.