LULU GARCIA-NAVARRO, HOST:
What you're listening to is the soundtrack of the Great Barrier Reef in Australia - a healthy section of the reef. And here's the sound from where the coral has died.
No, there's nothing wrong with your ears. It is the sound of silence. No sound means that fish that have just hatched and are looking for a home swim away from dead coral areas and go elsewhere to settle. Since fish can help jump-start a fledgling ecosystem, marine biologist Tim Gordon wanted to try luring them to an abandoned reef with sound. Here he explains his PhD thesis.
(SOUNDBITE OF ARCHIVED RECORDING)
TIM GORDON: Clownfish whoop, and cod grunt. And parrotfish crunch their way through coral as they graze. And sea urchins scrape, and shrimp snap their claws. And together, that makes a symphony of reef noise that can be heard from miles away.
GARCIA-NAVARRO: Gordon and his colleagues at the University of Exeter set up underwater speakers and played sounds they recorded from healthy coral areas. And guess what? It worked. The number of fish increased by 50%. Of course, it won't fix the coral reef crisis, but it could play a part. And it's proof that fish know what real estate agents know - location, location, location.
(SOUNDBITE OF THOMAS NEWMAN'S "WOW") Transcript provided by NPR, Copyright NPR.