Scientists postulated decades ago that deep-sea animals might use sound to (navigate) and communicate. But until now, no one had really tried to listen in.

That’s why marine ecologist Rodney Rountree, from the University of Massachusetts Amherst, decided to turn a few mp3 players into (waterproof), deep-sea recording devices. He and his colleagues attached one device to each of 100 crab traps, and sent them to the sea floor for 24 hours.

After dredging up the traps and listening to the recordings, the team discovered a multitude of deep-sea sounds, including 12 they could not (identify) and which had probably never been heard before.

Rountree wants to send down video cameras along with the recording devices, in order to identify which species are making these strange sounds. Just like a birder uses his eyes and his ears to study bird species, Rountree hopes that (eventually) ecologists will be able to use sound to locate and learn more about marine species.