He adds, "If sound is important to these deep sea fishes, it's a whole area of ecology we need to know about. One reason is that fishermen are exploring deeper and deeper water to make their catch, and we need to know such things as the baseline populations of food fish, their requirements for spawning, their essential habitat and other key aspects of their lives. We believe passive acoustic monitoring is an important tool in this study. And, it doesn't harm the fish or their habitat."
Unlike active acoustic studies that bounce sound waves out and back, passive acoustic studies involve just listening. Rountree and Juanes have been promoting underwater passive acoustic studies for more than a decade. They hope to create a census of sounds and behavior observed concomitant with sounds from many different aquatic and marine habitats.
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 adds, "It's not only that some fish make sounds, but we think the overall soundscape is interesting and important." This study was supported by MIT Sea Grant.
In addition to their deep-sea recording project, the researchers are conducting pioneering passive acoustic surveys of sound in many different habitats, such as freshwater ponds, rivers and streams and coastal estuaries of New England, as well as on the commercia
|Contact: Rodney Rountree|
University of Massachusetts at Amherst