Navy Seeks to Test Sonar; Some Fear Effect on Whales

The U.S. Navy is asking to be exempted from a federal law that forbids the harassment or killing of whales as it begins exercises with a powerful new sonar designed to hunt for super-quiet submarines.

The controversial sonar system, designed to blast swaths of ocean with low-frequency sound waves, will be the subject of protests today in Los Angeles and then a public hearing.

The hearing will be the first of three to be held across the nation by the National Marine Fisheries Service since government scientists confirmed that a different Navy sonar was probably responsible for the mass stranding of beaked whales in the Bahamas in March 2000.

Necropsies showed that six whales died from hemorrhaging around the brain and ear bones--presumably from intense internal vibrations caused by bursts of mid-frequency sound waves.

Environmentalists have pounced on that case as proof that high-power sonar systems can disorient and kill whales and other sea mammals.

“It is undeniable evidence of just how dangerous and unpredictable intense sound can be in the ocean,” said Joel Reynolds, senior attorney for the Natural Resources Defense Council. “We simply cannot afford to play Russian roulette with our oceans.”

He and others fear that whale strandings will become more common if the Navy conducts peacetime exercises across 80% of the world’s oceans with its new high-intensity, low-frequency sonar.

But Navy scientists say such fears are unfounded. The deaths in the Bahamas were linked to a mid-frequency sonar that has been around since World War II. It would be wrong, the Navy and fisheries service say, to assume that a low-frequency sonar system could result in the same tragedy--if operated with proper precautions.

“Damage attributable to one sonar doesn’t mean that all sonars are harmful,” said Roger Gentry, coordinator of acoustic teams for the fisheries service. “Because of technical differences and anatomical differences in animals, you must parse out the effects.”

The Navy is trying to persuade the fisheries service that the low-frequency active sonar can be operated safely, without posing significant danger to whales or other sea creatures.

Joe Johnson, a Navy sonar engineer in charge of environmental studies on low-frequency sonar, said the Navy is seeking an exemption from the Marine Mammal Protection Act because of its concern about violating the law’s ban on harassing whales--not the ban on whale deaths.

“There is no doubt that there will be some harassment of marine mammals,” Johnson said. “We have a very loud sonar system.”

To avoid more significant harm, Navy officials promise to use shipboard observers and fish-finding sonar to make sure no marine mammals or sea turtles are within a kilometer of a sonar broadcast. Should a whale come too close, the sonar would be shut off, they say.

Four boats with the Navy’s Surveillance Towed Array Sensor System would operate low-frequency sonar at least 12 miles offshore. That way, for instance, they would remain out of the way of the annual migration of gray whales along the California coast, the Navy said.

Some Areas Would Be Off Limits

The sonar vessels would remain even farther off the Eastern Seaboard to stay clear of the range of the Atlantic’s endangered northern right whale. The Navy says it will not deploy the sonar in waters near Antarctica where whales from across the Southern Hemisphere converge and in whale habitat around the Hawaiian Islands and off the west coast of Costa Rica.

The Navy has spent $350 million and a decade of research to develop the low-frequency active sonar to detect newer, quieter submarines. Planners fear that such a vessel from hostile nations such as China, North Korea or Iraq could launch a terrorist attack on a U.S. ship without having been detected by “passive” listening systems.

Active sonar could be compared to a floodlight, sending a sound-wave burst to “light up” enemy submarines with an echo. Low-frequency sound has long wavelengths, which make it capable of traveling great distances through water before stopping.

Each ship dangles 18 underwater loudspeakers on a cable hundreds of feet below the surface. They will generate sound up to 215 decibels--about the volume experienced by a person standing next to a fighter jet during takeoff.

The sound should dissipate to below 180 decibels within a kilometer--which the Navy calculates should be safe for whales. But the calculation of what decibel level causes physiological damage has created a loud, and divisive, debate among marine researchers.

“Friends have stopped talking to us,” said Kenneth Balcomb, director of the Center for Whale Research in Friday Harbor, Wash. “We’re getting a bit of character assassination.”

Balcomb was outside his home on Abaco Island, Bahamas, on March 15, 2000, when a 16-foot Cuvier’s beaked whale became stranded in shallow water. With some help, he managed to push the 2-ton animal back into deeper water.

Soon he found a total of 16 whales--two minke whales and the rest beaked whales--stranded over a 200-mile area. All this occurred immediately after a day of Navy sonar exercises in the area.

Although a similar mass stranding had occurred in Greece, this time a marine mammal researcher had fresh samples. Balcomb collected the whale heads and sent them to the Harvard Medical School for CT scans.

The research concluded that the loud sounds caused a “resonance phenomenon” in the air cavities of the whales’ heads. The sound vibrations were literally “tearing apart delicate tissues around the brain and ears,” he said, leading to hemorrhage and death.

Even more disturbing to him, he said, is that since that day he has not seen any of the 35 photo-identified Cuvier’s beaked whales he has studied for a decade.

“These guys were here all months of the year for 10 years,” Balcomb said. “They’re gone. The Navy killed them.”

Emotions always run high on the subject of whales, perhaps the most beloved ocean creatures. Today, scientists and celebrities will rally to save the animals.

Actor Pierce Brosnan will join activists and a video presentation of Jean-Michel Cousteau to kick off a day of events that will culminate in the public hearing at the Renaissance Hotel near Los Angeles International Airport at 6 p.m.

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Sonar Controversy

The Navy says a $350-million sonar system will allow it to detect the undersea presence of a growing number of submarines deployed by potentially hostile nations. But environmentalists say the system will harm whales and other sea life. How the system works:

1. Ship extends cable with speakers attached into ocean.

2. Speakers send out sounds at up to 215 dB.*

3. Sound waves bounce off submarine; reflected sound is picked up by microphones designed for water.

*Decibel levels in air are not equal to decibel levels underwater. Sound with an intensity of 215 dB in water equals an intensity of 155 dB in air.

160 dB is equal to standing next to a fighter jet at takeoff.

Sources: U.S. Navy, Silent Oceans Project, Natural Resources Defense Council