Ecologists Capture First Deep-Sea Fish Noises

ScienceDaily (Jan. 26, 2012) — University of Massachusetts Amherst fish biologists have published one of the first studies of deep-sea fish sounds in more than 50 years, collected from the sea floor about 2,237 feet (682 meters) below the North Atlantic. With recording technology now more affordable, Rodney Rountree, Francis Juanes and colleagues 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.

Though little is known at present about the significance of sounds made by deep-sea fishes, Rountree and Juanes say that if, as their pilot study suggests, these tend to be low-amplitude, then man-made noise in the oceans may turn out to be a particular problem for some important species.

Their paper appears in the new book, "Effects of Noise on Aquatic Life," from Springer Science+Business Media in its "Advances in Experimental Medicine and Biology" series. It compiles papers from an international workshop in Ireland in 2010.

Using hydrophones deployed by fishermen during normal fishing operations, Rountree, Juanes and colleagues obtained a 24-hour recording in Welkers Canyon south of Georges Bank that yielded "a wealth of biological sounds" including sounds of fin, humpback and pilot whales, dolphins and examples of at least 12 other unique and unidentified sounds they attribute to other whales or fish.

Their new paper includes graphics showing the number of these grunts, drumming and duck-like calls recorded per minute by time of day, plus peak volume and frequencies of various noises. Some of the sounds exhibited strong temporal patterns, for example fin whale and dolphin sounds dominated the recording and peaked at night.

Continued:  http://www.sciencedaily.com/releases/2012/01/120126142908.htm