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Ocean of Noise

The Navy's expanded sonar testing operations add to underwater cacophony for sensitive marine life

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'No Cause to Worry'

The $20 million a year the Navy spends on marine mammal research funds both military and nonmilitary scientists, including researchers at Scripps, Woods Hole in Massachusetts, and Cascadia. Some of this science helps the Navy estimate how many marine mammals might be affected by its operations. For the Hawaii-Southern California area, the number of possible exposures during a year is estimated at 2.8 million; this is not the number of animals, but the number of exposures to sound. Some individual animals may be exposed more than once to sound that the NMFS dubs "level B harassment."

"The emphasis is on the use of the term 'potential impact,'" says Johnson, explaining there are no mortalities expected from sonar, and that the modeling used does not factor in the mitigations such as powering down the sonar, which is done at under 1,000 yards, or turning off the sonar, which is done at under 200 yards.

But the numbers have people upset. Organizers in Mendocino and Humboldt counties, protesters in Oregon and politicians including Sen. Dianne Feinstein and congressmen Mike Thompson and Henry Waxman have demanded better protections for marine mammals.

These demands delayed, but did not stop, the permits.

Residents of the North Coast "have no cause to worry," explains Johnson. "Very little Navy activity occurs off the coasts of Humboldt and Mendocino. Most training is in Southern California, where ships group and deploy as teams." The northern waters are mainly for transit to more concentrated activities at Puget Sound, where typically a small number of sonar-equipped ships are ported. In Mendocino and Humboldt waters, according to Johnson, passing Navy ships travel "quite a ways offshore to avoid shipping lanes, usually beyond the line of sight." As these ships are in transit, there is occasional sonar training. How that sonar will impact North Coast marine mammals appears uncertain, given the relative lack of data.

"There's only so much we know about marine mammals," says Johnson. "But research by the Navy and outside organizations is continuing. It's challenging to do the studies on wild animals, because they move."

As part of ongoing research, the Navy recorded over 10,000 hours of passive acoustic data—human noise and animal vocalizations—over the past year, from two bottom-mounted buoys off the coast of Washington. These data will be analyzed at Scripps. Non-Navy researchers who want a network of hydrophones for less invasive study claim the Navy blocks collaborative efforts in the name of national security—and that trumps environmental protections.

But animal advocates push on. "There's too much noise in the oceans now," says Marcie Keever, of Friends of the Earth. "And these animals can't cover their ears."

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