Saturday, April 19, 2008

Navy says whale deaths not caused by sonar


After a half-dozen whales washed ashore dead on South Coast beaches last fall, there were many theories about possible causes, and one of them was sonar testing by the U.S. Navy.
Navy officials denied any wrong doing and yesterday, Rear Adm. Larry Rice, director of the Navy’s Environmental Readiness Division, told a crowd of about 50 people at the Santa Barbara Maritime Museum why that’s the case.
Rice said the Navy actively uses sonar for about 700 hours each the year, but even when they are not using sonar, whales and other sea life wash ashore.
He said the Navy funnels $18 million to private institutions each year to research the impacts of sonar on marine mammals, the result of which simply doesn’t support claims that sonar is killing marine life.
When and if the science does say this, Rice said the Navy would change its ways.
“The Navy’s going to live by the science,” he said. “If the science shows Navy sonar is hurting animals we’re going to change the way we do business.”
But that’s not to say sonar doesn’t affect marine mammals, and could contribute to deaths if used improperly.
Years ago, Rice said Navy sonar testing off the coasts of five different countries contributed to the deaths of a number of beaked whales. In these instances, he said a “perfect storm” of events spurred the deaths. These events included the use of sonar over a prolonged period of time (a practice he said is no longer used), several ships using sonar at once and underwater conditions, such as deep water with “box canyon-like” conditions.
In order to avoid harming marine life, Rice said the Navy abandoned such practices.
Rice showed a chart that diagramed the behavior of a whale when sonar is being used and when it’s not.
The whale, which was stuck with a suction-cup monitoring device, was shown diving to a depth of about one kilometer before returning quickly to the surface.
With sonar, the whale bottomed out at about the same depth, then zigzagged to the surface much slower, as if attempting to get away from the sonar.
Easter Moorman, a spokeswoman for the Santa Barbara Museum of Natural History, which performs about 30 necropsies on marine mammals each year, said this chart fascinated her because it clearly showed the difference in the whale’s behavior with and without sonar.
In another chart, Rice showed a diagram filled with red dots that represented the location of a number of whales scattered over an area of several hundred square miles. When the sonar was in use, the whales either fled the area or moved to the outskirts where they couldn’t hear the noise.
So the Navy and Rice acknowledge sonar testing does impact marine life, but argue that over the past 40 years of sonar testing off the shores of California, very few marine mammal deaths have been linked to sonar.
Of the 3,500 marine mammal strandings that occur on U.S. beaches each year, Rice said less than one-fourth of 1 percent are linked to sonar testing.
That’s a far cry from the more than 600,000 marine mammals killed each year by commercial fishing, he said.
But some aren’t buying the Navy’s take on the sonar situation.
At least four lawsuits have been filed alleging Navy sonar use harms marine mammals. One of the lawsuits was filed by the California Coastal Commission in March 2007, and accused the Navy of endangering sea turtles and other marine animals by refusing to discontinue the “harmful impacts associated with use of undersea sonar during training exercises.”
In a news release announcing the lawsuit, the Coastal Commission said it had approved certain forms of sonar testing, but only if a number of conditions were met. When the Navy refused, the lawsuit was filed.
Those conditions were to uphold seasonal restrictions to avoid grey whale migratory routes; conduct thirty minutes of marine mammal surveys before testing beings; avoid areas with high numbers of whales and dolphins; use larger safety zones when marine mammals are in the vicinity of testing activities and lower sound levels during times of low visibility.
“The Commission understands the important national security implications of the Navy’s training exercises,” said Coastal Commission Chairman, Partick Kruer of San Diego, who added that’s why the commission approved certain types of sonar training. “By refusing to cooperate with us, they are challenging the jurisdiction of the entire Commission and undermining the Coastal Act and federal coastal protection laws that apply to all coastal states. That has implications way beyond this case.”
As far as Moorman can tell, the majority of the dead whales washing ashore near Santa Barbara are not the result of sonar testing.
“You have to be very careful not to draw those conclusions right away,” she said. “Whether or not [sonar] is lethal, we don’t’ know that.”
She did say it was helpful and informative to hear the Navy’s take on the sonar issues because it’s one that is rarely told.
“Having the information from the other side of the line is important,” she said.
Paul Collins, a curator at the Santa Barbara Museum of Natural History, said it’s common for about 25 to 30 marine mammals to wash ashore each year between Ventura and San Luis Obispo County. He said this number has spiked on occasion, but only when levels of domoic acid are high.
Otherwise, he said sonar or not, marine mammals are dying.
In the case of three blue whales in the Santa Barbara Channel last year, it was an instance of bad luck.
Collins said all three were struck by ships, likely while they were feeding on krill in the shipping lanes. He said whales normally feed on krill at lower depths, but for whatever reason, the krill were found closer to the surface last year and as a result, whales were hit.
“They were in the wrong place at the wrong time,” he said.

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