Global warming study prompts wildlife concerns

March 29, 1994|By Knight-Ridder News Service

MONTEREY, Calif. -- The federal government wants to blast the Pacific Ocean with sonar in a global warming experiment that some fear will disrupt migrating whales, seals and sea lions -- or worse, deafen them.

Two high-powered sonar devices -- one inside the Monterey Bay National Marine Sanctuary off Point Sur, the other at Kauai, Hawaii -- would emit waves that critics say are 10 million times more intense than the level already known to cause gray whales to alter their course.

Ultimately, the Defense Department wants to place the transmitters in all the world's oceans as part of a decade-long project to measure whether the Earth -- more than 70 percent of which is covered by water -- is undergoing a rise in temperature.

"We want to give them the clear answers they need to make energy policy for the long term," said the project's deputy director, Andrew Forbes of the Scripps Institute of Oceanography in La Jolla.

The devices would emit 195-decibel sound waves in 20-minute bursts every four hours. Concerts at a coastal amphitheater aren't supposed to exceed 98 decibels.

Waves blasted from the device that would be placed on Sur Ridge, 25 miles offshore, would be measured in New Zealand. The premise of the experiment is that the speed of sound increases as water temperature becomes warmer.

Critics are upset that the experiment may go forward without determing the effect the bombardment will have on marine mammals that are protected by federal law.

Many types of whales, for instance, emit high-frequency sound waves to communicate and to hunt and stun prey. Nobody knows for sure whether the bombardment might damage their sensitive hearing.

"There has been no baseline data gathered," said Lindy Weilgart, a marine biologist who has studied acoustics relating to sperm whales at Dalhousie University in Canada. "It will be hard to document clear disturbances . . . since if whales are being deafened, they will show less and less disturbance from the sound over time."

Others are simply worried about adding more noise pollution to oceans already inundated with incessant sounds from supertankers, motorboats and offshore drilling. Constant loud noise, says Randy Raine-Reusch, a proponent of acoustic ecology, causes stress in all mammals.

He likened the sonar blasts to setting up a cannon outside someone's front door and exploding it regularly.

"Humankind is good at throwing garbage around," said Mr. Raine-Reusch, "and noise pollution is garbage. The noise garbage in the ocean is ankle-deep already. This will make it shoulder-high."

A two-year testing permit is being sought by the Scripps Institute, which is under contract with the Pentagon to conduct the Acoustic Thermometry of Ocean Climate project. The Point Sur site was chosen, project officials say, because the sound waves can be monitored at a nearby Navy tracking station.

It's also a good site to study the effect of sound waves on marine life, according to Professor Christopher Clark of Cornell University, for the same reason critics say it's the worst possible site. Mr. Clark, who will oversee the marine mammal tests for Scripps, has described coastal California as "particularly rich in marine mammals." It therefore "provides a unique opportunity to conduct basic research," he wrote on a marine mammal computer bulletin board that has carried hot debate on the project for a month.

"What can we say," Ms. Weilgart responded on the same bulletin board, "except that this statement rather blatantly exposes the priority of the marine mammal component of [the project]: to carry out research rather than to protect marine mammals."

If the permit is approved, the sonar device could be in place as early as May, said Dan Costa, a marine biology professor at the University of California-Santa Cruz who will coordinate the California studies for Mr. Clark.

The project researchers say the amount of potential suffering by marine mammals is minimal compared with what will happen if global warming is occurring. Food sources could disappear. Currents that cause water to flow from ocean to ocean could become still, making tropical oceans heat up. Melting arctic ice would flood coastal marshes.

"If we let the oceans warm up unchecked with the short-term goal of protecting marine mammals," Mr. Forbes of Scripps said, "it's a short-sighted point of view. Global warming could cause them far more harm. We won't get a global consensus on warming unless we measure."

If global warming is found, the problem then becomes persuading the public to act to stop the pollution that contributes to climatic change.

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