An underwater loudspeaker on a coral reef attracts young fish. (Tim Gordon /University of Exeter/SWNS.COM)
Coral reefs, under threat from global warming, may be saved by attracting fish through music played underwater.
The bizarre theory has come from a new study that suggested putting underwater loudspeakers among the coral to attract fresh marine life.
It’s believed that ‘acoustic enrichment’ may be able to help reefs blighted by warming ocean temperatures.
University scientists from Exeter, Bristol and Australia’s James Cook University teamed with the Australian Institute of Marine Science to figure this out. They worked on Australia’s Great Barrier Reef and placed loudspeakers among patches of dead coral.
They found twice as many fish arrived – and stayed – compared to equivalent patches where no sound was played.
Tim Gordon, a PhD student at Exeter University, and the study’s lead author said: ‘Fish are crucial for coral reefs to function as healthy ecosystems. Boosting fish populations in this way could help to kickstart 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.
Different groups of fish provide different functions on coral reefs, meaning an abundant and diverse fish population is an important factor in maintaining a healthy ecosystem.
Study co-author Professor Andy Radford, of Bristol University, said: ‘Acoustic enrichment is a promising technique for management on a local basis. If combined with habitat restoration and other conservation measures, rebuilding fish communities in this manner might accelerate ecosystem recovery.
‘However, we still need to tackle a host of other threats including climate change, overfishing and water pollution in order to protect these fragile ecosystems.’
Mr Gordon added: ‘Whilst attracting more fish won’t save coral reefs on its own, new techniques like this give us more tools in the fight to save these precious and vulnerable ecosystems. From local management innovations to international political action, we need meaningful progress at all levels to paint a better future for reefs worldwide.’