Why it matters: Coral reefs are an integral part of marine life and sustain it by providing shelter and habitat to various organisms. They also supply and recycle nutrients as well as enable a thriving fish population, along with other species, for a healthy and diverse ecosystem. However, the rise in average water temperatures due to climate change has resulted in more frequent and prolonged "coral bleaching" events that damage their health, causing fish and other marine species to abandon them, a chain of events which scientists are now trying to reverse by blasting sound through underwater speakers near dying coral reefs to make them sound healthy again.
One important part of the incredibly complex ocean life is the interdependency of coral reefs and their surrounding habitat, which, like many other things in nature, has suffered from the consequences of climate change.
In a bid to revive this delicate ecosystem, scientists from the UK and Australia conducted a study that involved using speakers underwater near damaged coral reefs to make them sound healthy and attract fish, potentially kick-starting the natural recovery process of coral reefs and their dependent life forms.
The location for this experiment was the Great Barrier Reef in the Coral Sea, found alongside the east coast of Queensland, Australia. The site is noted to have the largest coral reef system in the world that's 1,500 miles (2,300 km) long and spans an area of nearly 133,000 sq mi (344,400 sq km).
A team of scientists from the UK and Australia teamed up to use underwater loudspeakers to try and entice fish back to dead coral reefs and potentially help them recover.
"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 hone in on these sounds when they're looking for a place to settle," said Steve Simpson, study co-author and a professor at the University of Exeter, UK.
By using loudspeakers to replicate such sounds, patches of dead coral reefs were found to attract twice as many fish, compared to places where no sounds were played. These returning fish, says lead author, Tim Gordon, could help in the recovery of this ecosystem by giving "those degraded patches of coral a chance of new life."
"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," he noted.
"Of course, attracting fish to a dead reef won't bring it back to life automatically," said Mark Meekan, of the Australian Institute of Marine Science, but that the recovery process relies on fish that clean the reef to make space for corals to regrow.
Bristol University's Andy Radford commented on "acoustic enrichment" as a promising technique for "management on a local basis." which if combined with "habitat restoration and other conservation measures" could rebuild fish communities and accelerate ecosystem recovery, alongside the need to tackle existing threats like climate change, overfishing and water pollution.