Sonar Suspected in Porpoise Deaths

Thursday, May 15, 2003
NAVAL STATION EVERETT -- Whale watchers on Whidbey Island found a dead harbor porpoise near Admiralty Head Tuesday, and nearby residents were searching for another dead porpoise Wednesday, raising concerns that the recent deaths of marine mammals in Puget Sound could have been caused by the sonar of the Everett-based USS Shoup.

The Shoup, a guided missile destroyer with a crew of roughly 380, is one of the Navy's newest warships. It was launched in November 2000 and commissioned in Seattle in June .

Residents were still searching late Wednesday for the second dead harbor porpoise, which had been reported stranded near West Beach, west of Oak Harbor.

Susan Berta, a member of the Whidbey-based Orca Network, said the harbor porpoise found in Fort Casey State Park on Whidbey Island was bleeding from its eye and blowhole.

All told, 10 porpoises have been found stranded in the last week, Berta said, and the number is raising red flags.

"A few washing up, that happens. But there seems to be something going on," Berta said.

Reports that the destroyer had been using its sonar as it traveled between Vancouver Island and San Juan Island on May 5 have fueled speculation that the midrange tactical sonar used by the warship played a role in the strandings.

A Navy spokeswoman, however, said there isn't any evidence to suggest the Shoup's sonar contributed to the porpoise deaths.

Sonar is a system that transmits sound waves and registers reflected vibrations to find underwater objects or depths.

The Navy is concerned about how sound effects marine mammals, said Navy Cmdr. Karen Sellers of Navy Region Northwest, and experts will review the event and consult with the National Marine Fisheries Service.

Sellers said the Shoup was on an exercise near San Juan Island on May 5, and used its sonar for training to detect submarines and mines.

The ship's instruments and lookouts didn't find any nearby marine mammals, but the ship stopped using its sonar after Canadian authorities contacted the ship to report complaints about the sonar from small boats nearby.

Necropsies will be conducted on the porpoises to determine why they died, Sellers said in a statement.

"The Navy's marine mammal experts are reviewing the available information about this event and are consulting with the appropriate agencies, including the National Marine Fisheries Service," Sellers said.

Ken Balcomb, executive director and senior scientist for the Center for Whale Research in Friday Harbor, saw the reaction of marine mammals, including killer whales, a minke whale and Dall's porpoises, when the Shoup passed through Haro Strait between San Juan Island and Vancouver.

The marine mammals started swimming away quickly to escape. And killer whales started to hug the shore in what appeared to be an effort to escape the sounds of the sonar, he said.

If the porpoise deaths are attributed to Navy sonar, it would be the first time in Puget Sound that sonar has been linked to the stranding of marine mammals, Balcomb said.

In past years, the same type of sonar has been the cause of marine mammal deaths near Greece, the Bahamas and the Canary Islands.

Examinations of the porpoises, including a forensic examination of bleeding patterns from acoustic pressure trauma, would be needed before the mammal deaths could be blamed on the Shoup's sonar.

"Right now, we're just dealing with an amazing amount of circumstantial evidence," Balcomb said.

"I don't think all those porpoises are related to the Shoup. I think it's also unlikely that none of them are," he said.

The Shoup has been undergoing testing at sea in recent months. In mid-March, the ship's Evolved Sea Sparrow Missile air defense system was successfully tested near Point Mugu, Calif.

Balcomb said the National Marine Fisheries Service has four porpoises it can examine, but he didn't immediately know when test results would be available.

By Brian Kelly