January 30, 2012
Ecologists Capture Sounds From The Deep Sea
Ecologists have captured 12 distinct sounds from deep sea fish at a depth of 2,237 feet below the North Atlantic.
The team was exploring the idea that many fish make sounds to communicate with each other, particularly those that live in the deep part of the ocean.
The University of Massachusetts scientists used hydrophones deployed by fisherman during normal fishing operations. They obtained 24-hours of recording in Welkders Canyon south of Georges Bank.
Some of the more familiar sounds included in their discovery were of humpback whales and dolphins. However, there was 12 other unique and unidentified sounds they attribute to other whales or fish.
The sounds included grunts, drumming and duck-like quacks throughout the recording. The team said some of the sounds showed patterns throughout different parts of the day.
"If sound is important to these deep sea fishes, it´s a whole area of ecology we need to know about," Rodney Rountree, who was involved in the research, said in a statement. "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."
The researchers hope to create a census of sounds and behavior observed from many different aquatic and marine habitats.
"We believe passive acoustic monitoring is an important tool in this study," Rountree said. "And, it doesn´t harm the fish or their habitat."
Passive acoustic studies differ from active acoustic studies in that during this type of study, researchers just sit and listen. During active acoustic studies, scientists bounce sound waves out and back.
Researcher Francis Juanes said some fish use special "sonic muscles" to produce sounds, which can have different meanings or functions.
He said many sounds are believed to be related to reproductive behavior, and some fish use a "sound map" for orientation.
"It´s not only that some fish make sounds, but we think the overall soundscape is interesting and important," Rountree said in a press release.
The scientists are also conducting passive acoustic surveys of sound in other habitats as well, such as freshwater ponds, rivers and streams.
The new research appears in the book, "Effects of Noise on Aquatic Life" in the "Advances of Experimental Medicine and Biology" series.
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