The northern coast of Jamaica once served as the backdrop for scenes in the James Bond thriller No Time to Die. But today, beneath those same turquoise waves, a real-life mission is unfolding: the race to save a dying coral reef from collapse.
However, the tools a team of divers are carrying to the seafloor are not what you would expect to find in a marine biologist’s kit. They are installing waterproof speakers at the bottom of the ocean, and the man leading the team is not a scientist.
“It’s very different from everything I did before,” says Marco Barotti, an artist from Italy.
Five years ago, Barotti began creating sculptures based on 3D scans of coral. He was inspired by emerging research suggesting that sound could be the key to reviving struggling reefs. “Sound has always been at the core of my work, but never at this level,” he explains.
The soundtrack of the sea
To the human ear, the underwater world might seem pretty quiet, but a healthy reef is actually a cacophony of noise. It’s a biological symphony of snapping shrimp, grunting fish, and shifting currents. A dying reef is eerily silent.
“If a reef is alive with sound, it’s most likely to stay alive, right? And repopulate. And when reefs degrade, they grow silent,” Barotti says.
Fish and tiny coral organisms use sound to navigate the vast oceans and find a home, so the logic is simple: if you bring the noise back, the marine life will follow. The project uses “underwater boomboxes” that play recorded sounds of a healthy reef for 14 hours a day, powered by solar panels floating on the surface.
The Great Barrier Reef study
A study published in the journal Nature demonstrated the power of what is known as “acoustic enrichment.” Researchers at the Great Barrier Reef found that playing healthy reef sounds lured fish to degraded areas, doubling the total fish population in just six weeks. Not only did more fish arrive, but the diversity of species increased by 50%, a critical factor for long-term reef resilience.
Reefs cover just 1% of the ocean floor but support 25% of all marine life. They are the bedrock of our food supply and serve as a natural barrier, protecting coastal property from the worst of catastrophic storms. Since 1950, the world has lost approximately half of its coral reefs due to overfishing, pollution, and the climate crisis.
The root of the crisis is our planet-warming pollution. As we burn fossil fuels, we release carbon dioxide that acts like a heat-trapping blanket around the Earth. The ocean has been forced to absorb about 90% of that excess heat.
This leads to “marine heatwaves” – prolonged periods of abnormally high sea temperatures that are essentially the oceanic equivalent of a wildfire. A record marine heatwave in 2023 turned Caribbean waters into a “hot tub,” causing corals to expel the colorful algae living in their tissues. This process, known as bleaching, leaves the coral white, starving, and vulnerable to disease.
Lee-Ann Rando, a second-generation scuba diving instructor, has witnessed this decline first-hand. “It’s getting quieter,” she says. “It’s really sad to say that I’ve seen the degradation a lot in the past 10 years.”
Rando captured footage of herself swimming through ghostly white, bleached reefs in 2023. “You just feel hopeless,” she says. “You feel like, ‘Am I ever gonna see this again?’”
‘Coral matchmaking’
The sound project is designed to support the work of the local Alligator Head Foundation. Dexter Dean Colquhoun, the foundation’s head of research, says the idea resonated with him immediately. “I’m a musician. I play piano, so I know the importance and the power of sound.”
He says the acoustic approach is a vital addition to his organization’s conservation toolkit. “It fits right into what we’re trying to do, which is to restore the reefs using as many methods as possible.”
While the speakers play the “hits” of a healthy reef, researcher Bethany Dean is workingIn the lab, she grows coral fragments and experiments with assisted breeding, acting like a “coral matchmaker” to help the organisms reproduce in a warming world where natural reproduction is struggling.
“We’re looking at how to bring these eggs and sperm together so that successful reproduction can actually happen,” Dean says.
Eventually, these lab-grown coral fragments are attached to Barotti’s underwater sculptures. The result is a blend of science and art that could help replace silence with the sounds of a thriving ecosystem.
“You’ve got to stay hopeful, right?” says Rando. “I think there is hope. There are threads of it.”
Climate Central is an independent group of scientists and communicators who research and report the facts about our changing climate and how it affects people’s lives.
Frequently Asked Questions
Here is a list of FAQs about using underwater speakers to help revive coral reefs written in a natural conversational tone
BeginnerLevel Questions
1 Wait are divers really playing music to coral reefs
Yes but its not music like a pop song Divers play natural sounds of a healthy reeflike the crackling of shrimp and fish callsto attract baby coral and fish to dead or dying areas
2 How does playing sounds help a dying reef
Healthy reefs are noisy When a reef is damaged it gets quiet By playing those natural sounds underwater we trick baby coral larvae and fish into thinking the area is safe and lively so they settle there and start rebuilding the reef
3 What exactly are the sounds of the sea that they play
Its mostly the snapping of pistol shrimp the grunts of fish and the general crackling and popping of a bustling healthy ecosystem These sounds travel far underwater
4 Does this work on all types of coral
Research shows it works best on brooding corals that release larvae that settle quickly Its less effective for spawning corals that release eggs and sperm into the current Scientists are still testing which species respond best
5 Is this a replacement for cleaning up pollution or stopping climate change
No not at all This is a BandAid or a tool to help recovery It wont fix warming oceans or pollution but it can help a reef bounce back faster while we work on the bigger problems
AdvancedLevel Questions
6 How do divers set up the speakers without scaring the existing wildlife
They usually anchor small lowfrequency speakers on the seafloor They start the volume low and gradually increase it to mimic natural levels Most fish are curious not scared because the sounds mimic their natural environment
7 What kind of speaker can survive saltwater and pressure
They use specialized underwater speakers that are sealed in corrosionproof housings They are powered by surface boats or battery packs lowered to the reef
8 Can playing sound attract invasive species or predators
Yes thats a risk Scientists carefully choose sounds from the
