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. Noise pollution is a serious problem for cetaceans, which can be disoriented by man-made sounds and end up on beaches, but less is understood about how it affects fish.
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.
Juanes says some fish use special "sonic muscles" to produce some sounds, and different sounds have different meanings or functions. Many are believed to be related to reproductive behavior. Some fish use a "sound map" for orientation in their immediate environment and may even use sound waves returning from distant beaches to help them navigate over longer distances. "There is a fascinating acoustic soundscape out there just waiting to be explored."
Rountree has made some of these recordings available for download here.
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.