U.S. marine biologists said that recordings of fish sounds 2,237 feet below the North Atlantic surface can shed new light on deep-sea life and ecosystems, UPI reported. Researchers at the University of Massachusetts Amherst are exploring the idea that many fish make sounds to communicate with each other, especially those that live in the perpetual dark of the deep ocean. They say their pilot study suggests these tend to be low-amplitude sounds, raising the possibility man-made noise in the oceans may turn out to be a particular problem for some important species, a university release reported Thursday. The researchers made a 24-hour recording that yielded "a wealth of biological sounds" including sounds of fin, humpback and pilot whales, dolphins, and at least 12 other unique and unidentified sounds they attribute to other whales or fish. "We think work to describe underwater sounds is extremely valuable," researcher Rodney Roundtree said. "The importance of sound in the ecology of both freshwater and marine systems is poorly understood." "If sound is important to these deep sea fishes, it's a whole area of ecology we need to know about."