Friday, May 4, 2001

question Navy research
on sonar effects

They say an incident in the
Bahamas proved sonar
harms whales

By Stephen Manning
Associated Press

SILVER SPRING, Md. >> A new Navy sonar system for tracking submarines drew fire yesterday from environmentalists who claim the resulting underwater din is disruptive to marine life and can fatally harm whales and dolphins.

In the last of a series of public hearings held by the National Marine Fisheries Service, environmentalists questioned research that the Navy says proves the sonar has little effect on marine life.

"There is strong evidence that these uses of sound have caused damage and death among marine mammals. There is no evidence to prove that it is not harmful," said Jean Michel Cousteau, son of ocean explorer Jacques Cousteau, in a letter read at the hearing.

The hearing was part of the Navy's application process for a Fisheries Service permit for the sonar and included testimony from several environmental groups. One activist brought a life-size Plexiglas dolphin with blood flowing from its ears to symbolize the damaging effects of sonar.

The hearing at the Fisheries Service headquarters follows two sessions held last month in Hawaii and Los Angeles.

Whale-lovers from Maui and the Big Island packed last month's public hearing to protest Navy use of low-frequency active sonar to search for quiet enemy submarines.

A permit would let the Navy deploy the sonar system, which will reach distances greater than conventional sonar.

Suspended from warships to depths of several hundred feet, the system emits sonar waves at frequencies of around 500 hertz, much lower than the 3,500 hertz that midrange sonar systems use. The longer wavelengths travel farther in water, allowing the sonar to "ping" faraway objects.

The Navy says it has extensively tested the system to determine if the low sound waves disrupt mating, feeding and migration patterns of four whale species. Whales rely on their own form of sonar to communicate, and larger species, including blue and gray whales, use frequencies similar to the special sonar.

The only discernible effect was that whales swam around the sonar source, said Joe Johnson, a program manager with the Navy's Submarine Warfare Division.

But environmentalists say some types of sonar can cause ear hemorrhages that disorient whales, leading to beachings. At least 16 whales beached themselves in the Bahamas last year while the Navy was conducting anti-submarine exercises with non-low-frequency active sonar.

Most who spoke at yesterday's meeting cited the Bahamas beaching and one that occurred in Greece after a 1996 NATO naval exercise as proof that all sonar is dangerous to marine mammals.

"This is a giant gamble, one that the Navy hopes won't kill large numbers of whales," said Judy Olmer of the Sierra Club. "But we just don't know enough about the long-term impact of this system."

Scientists say there is no direct evidence linking the Bahamas sonar use to the beaching.

"The public has determined it was the cause of this stranding, and have demanded that we use it as the basis of making our decision," said Roger Gentry, the Fisheries Service lead acoustician. "But scientifically, it is still a hypothesis."

However, the Navy tested low-frequency active sonar effects on whales to levels of only 155 decibels even though the Navy has deemed sounds as loud as 180 decibels to be safe for marine life.

The equipment will also be accompanied by a "fish-finder" sonar to search for marine mammals, Johnson said. If any come closer than a kilometer from the ship, where decibel levels are higher than 180, it will be turned off, Johnson said.

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