Date: Fri, 12 Apr, 1996
Orca defenders criticize plans for noise tests off San Juans
by Danny Westneat
(Seatttle Times staff reporter)

A team of scientists plans to broadcast loud, high-pitched sounds from underwater speakers this summer in the San Juan Islands, in part to test whether noise harms or disorients killer whales and other sea mammals. The scientists say the pulses of noise, the loudest of which would have the same sound intensity as a jet taking off, likely would not seriously hurt the roughly 100 killer whales, or orcas, that inhabit north Puget Sound waters in June or July.

But critics contend the scientists actually have no idea whether the noise will cause temporary or permanent hearing loss in whales, and that the scientists' own proposal concedes the monthlong study may alter behavior patterns of whales swimming up to 4 miles away.

The scientists proposing the study are from Woods Hole (Mass.) Oceanographic Institution and the Massachusetts Institute of Technology. They plan the sound pulses primarily to study the chemical and physical properties of a marine "front," where salt water and fresh water meet and first begin to mix. Patrick Miller, a researcher from Woods Hole, says that most of the noise won't be any louder than that emitted by a fish-finding sonar device. The sound probably can't damage a whale's hearing even temporarily unless the whale "nudges directly up against the sound source, which is virtually impossible," he said.

In total, the experiments should be less disruptive - and maybe even less noisy - than the 50 or more whale-watching boats that follow the whale pods every day, the researchers say. But broadcasting sounds into prime orca habitat to see if the whales are bothered is "a bit like pouring poison into a river to see if it's toxic to fish," said Paul Spong, a scientist at OrcaLab, a research group that studies killer whales at Vancouver Island.

The research, sponsored by the U.S. Navy, will also use two 6-foot-long underwater robots to analyze water characteristics. The testing area is in Haro Strait, a key waterway for orcas as well as for porpoises, seals and other mammals, which rely on hearing to feed and navigate.
"This is like a main highway for the orcas," said Peter Hamilton of Lifeforce, a Vancouver, B.C., ecology group.
"Nobody knows how harmful these sounds may be to them. They say the animals can just swim away, but this place is vital to where they travel and live."

Though it is extremely unlikely the noises will severely injure or kill a marine mammal, the research could force some mammals, particularly whales, temporarily away from their preferred habitat, according to a review by the National Marine Fisheries Service. The loudest underwater pulsed "ping" will be about 195 decibels, equivalent to about 135 decibels on land, or the approximate sound intensity of a nearby jet engine as heard by the human ear. An outboard motor issues a sound intensity of about 170 decibels underwater, Miller said. The sounds will be broadcast at high frequencies, in some cases out of the range of human hearing but certainly detectable by many marine mammals, the scientists say.

The fisheries agency has announced it intends to grant the researchers a permit to do the experiments because the area in question is only a small fraction of orca habitat in Puget Sound. Further, the researchers have agreed to let an independent panel of four Northwest scientists monitor the work and shut it down if it appears the noise is directly harming sea life. Sound to a marine mammal is like vision to humans, said Dan Costa, a professor of biology at the University of California-Santa Cruz, but the scientific community doesn't understand much more than that about it.
"If somebody's shining a spotlight, is it going to be a problem for you to see? It depends on how bright it is and whether it's shining in your face, and the same is probably true for a whale confronted by a loud sound," he said.

A whale or porpoise traveling close enough to a loud, directed sound may experience sensations ranging from pain to annoyance to nothing at all, Costa said. If it hears the sound and doesn't like it, the mammal typically will respond by swimming somewhere else, said Costa, who has been studying the effect of low-frequency noise blasts on sea mammals in California.
"But the answer is, we don't really know what it does to them," he said.
"We do know there is so much more noise in the ocean from boats than there is from researchers that if these animals are really that sensitive, then we have an incredible problem on our hands."

A plan announced two years ago to study ocean temperatures by broadcasting sound pulses across the Pacific Ocean from California caused a storm of controversy. Since then, oceanographers who routinely use sound waves to measure things in the water have faced scrutiny over whether their work harassed marine mammals.

After delaying the project for more than a year and finally agreeing to move the sound emitter away from a marine sanctuary off San Francisco, scientists in the California study began in December to broadcast low-frequency sounds that can be detected as far away as Alaska. Mammals don't appear to be bothered and certainly have not fled the area, but it's too soon to tell whether the noise is having any subtle effects on swimming patterns or other behaviors, Costa said.

Miller, one of the scientists proposing the local study, said he grew up, in part, on San Juan Island and wants to do the noise experiments to help protect the region's marine life, not hurt it. Only by testing whether moderate-to-loud underwater sound harms marine mammals can society begin to discuss whether boats, ferries or other noise-makers should be restricted from crucial areas, he said.

Other scientists agree.

"All those little boats tooling around with their outboard motors are far more disruptive to these animals than our sound emitters," said Bob Spindel, head of the University of Washington's Applied Physics Laboratory and part of the California project team. "And they don't even need a permit."

How to comment The National Marine Fisheries Service has proposed granting scientists a permit to broadcast underwater sounds that may affect orcas and other marine mammals in the San Juan Islands. To comment, write to:

Chief, Marine Mammal Division,
Office of Protected Resources,
National Marine Fisheries Service,
1315 East-West Highway,
Silver Spring, Md. 20910-3225.
Comment period ends April 29


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