Study suggests sonar doesn't harm fish

BALTIMORE, July 9 (UPI) -- A U.S. study suggests high powered sonar, such as used by Navy ships, does not harm fish.

University of Maryland researchers studied rainbow trout housed in an experimental tank at the U.S. Navy Sonar Test Facility in Seneca Lake, N.Y.

Led by biology Professor Arthur Popper and research associate Michele Halvorsen, the scientists found exposure to high intensity, low frequency, sonar did not kill the rainbow trout, nor did it damage their auditory systems, other than for a small and presumably temporary decline in hearing sensitivity.

But Popper cautioned the finding should not be extrapolated to other fish species or the effects of other sound sources.

He said there is considerable concern that human-produced (anthropogenic) sounds added to the environment could have damaging effects on marine life. While much of the interest has focused on marine mammals, such as dolphins and whales, there is growing interest in the effects of such sounds on fish.

"The effects of sound on fish could potentially include increased stress, damage to organs, the circulatory and nervous systems," said Popper.

The study is reported in the July issue of the Journal of the Acoustical Society of America.