Navy, Eco-Group Settle on Sonar in Hawaii Whale Area

Maryann Mott
for National Geographic News

July 10, 2006

In compliance with an out-of-court settlement with an environmental
group, the U.S Navy began using mid-frequency sonar yesterday during
training exercises off Hawaii.

A U.S. district court judge had issued a temporary retraining order on July 3 forbidding the use of powerful sonar during the Hawaii excercises. But the Navy later agreed to a number of whale-protection measures in consultation with the Natural Resources Defense Council (NRDC), which had filed the lawsuit that had resulted in the restraining order.

The Navy agreed to use intense sonar sparingly, to add additional whale spotters on every vessel during drills, to steer clear of a vast new protected area, and to publicize a hotline for reporting marine-mammal incidents related to the international war games now taking place.

In exchange, NRDC withdrew its lawsuit.

"We can protect our national security and also protect the wildlife that shares the ocean," said NRDC spokesperson Daniel Hinerfeld.

"They are not mutually exclusive activities. It just requires a little bit of care and planning."

The group says mid-frequency sonar has been linked to mass strandings and deaths of marine species around the world.

After a similar naval exercise off Hawaii in 2004, a mass stranding of 150 melon-headed whales occurred. A federal investigation concluded that mid-frequency sonar was likely a contributing factor.

Scanning the Seas

Mid-frequency sonar equipment emits high-decibel sound waves across tens or even hundreds of miles of ocean to reveal objects underwater.

The U.S. Navy says the technology has become more important to national security in recent years, as other countries have acquired quieter submarines.

Rear Adm. James Symonds, the Navy's director of environmental readiness, believes it's critically important to use active sonar during the exercises, which take place until the end of this month.

"We want to ensure that the U.S. Navy and its partner navies get the benefit of this opportunity to train in anti-submarine warfare," he said.

This year about 19,000 service men and women from eight countries are participating in the Navy's Rim of the Pacific exercise, the world's largest international maritime training event.

Monumental Buffer

The agreement between the Navy and the NRDC, reached on Friday, also prevents the use of sonar within 25 nautical miles (29 miles/46 kilometers) of the new Northwestern Hawaiian Island Marine National Monument.

(See photos of animals in the new Hawaiian marine monument.)

The monument includes a 1,200-mile-long (1,930-kilometer-long) chain of relatively undisturbed island and coral-reef habitat that is home to more than 7,000 species.

This was an important victory, Hinerfeld says, because it underscores "the schizophrenic approach of the federal government."

He says that two weeks after the U.S. government identified the area as delicate, significant, and worth protecting, the Department of Defense issued an exemption allowing the Navy to blast it with powerful sonar.

"We need to have a coherent policy about protecting the oceans against this very dangerous technology," he said.

Navy spokesperson Capt. Jill Votaw countered that sonar exercises were never scheduled to take place in or near the monument.

Powerful Sound

Mid-frequency sonar used during training exercises can emit continuous sound well above 235 decibels—an intensity roughly comparable to a rocket blastoff, according to NRDC.

That's a problem for marine mammals and other aquatic animals, say experts, since sound is their primary means of learning about their habitat, communicating, and navigating.

Before the exercises began, the Navy agreed to an extensive list of safety measures suggested by the U.S. National Oceanic and Atmospheric Administration's National Marine Fisheries Service.

Those safety measures include:

• training all participants in marine-mammal awareness;
• using infrared light to detect mammals during low-visibility conditions; and
• setting the sonar at the lowest level, except during short periods of time

NRDC has another lawsuit pending against the Navy over its general use of mid-frequency sonar. About 160 ships in the Navy's fleet are equipped with mid-frequency sonar, but military officials say it's only turned on during training and maintenance activities.

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