Navy sonar all but ruled out as cause of orca’s death

Exercises done by HMCS Ottawa far from where whale washed up

This orca, identified as L112, washed up on the shore  in Washington state in February, days after HMCS Ottawa  used sonar in an exercise in Canadian waters.

This orca, identified as L112, washed up on the shore in Washington state in February, days after HMCS Ottawa used sonar in an exercise in Canadian waters.

The Royal Canadian Navy is likely off the hook in connection with the death of an orca that washed up on a Washington state beach in February, say U.S. officials.

The National Oceanic and Atmospheric Administration continues to investigate why the three-year-old killer whale, known as L112, was found battered and bruised in Long Beach, Wash. on Feb. 11.

The orca had lived with a pod of 86 endangered southern resident killer whales.

Environmentalists immediately pointed fingers at the Royal Canadian Navy’s HMCS Ottawa, which used sonar and detonated two underwater charges during anti-submarine training in the Strait of Juan de Fuca off Vancouver Island, Feb. 6.

Marine biologists say certain sonar frequencies can interrupt whales’ navigation and communication.

Though all possible causes of death, including sonar, can’t be ruled out at this stage in the investigation, U.S. officials say the animal, which likely died between Feb. 7 and 9, washed up near the mouth of the Columbia River, about 322 kilometres from Canadian waters – a great distance from where the frigate was sailing.

“It is unlikely in the extreme it died in Canadian waters and drifted south,” said Brian Gorman, the administration’s spokesperson.

“The prevailing winds and currents are all from the south to the north, and it’s virtually impossible it could have died north of Long Beach and drifted south.”

In a statement, Rear Admiral Nigel Greenwood, commander of Maritime Forces Pacific, said, “HMCS Ottawa followed the (navy’s) Marine Mammal Mitigation Policy prior to and during the period when they were using ships’ sonar, and prior to deploying the small charges. There were no reports, nor indications of marine mammals in the area.”

Testing on tissue samples taken from L112 is now underway. The first wave of results are expected in the next three weeks.

However, testing doesn’t always pinpoint cause of death, Gorman cautioned.

“It is not uncommon, even with a fresh carcass and a thorough investigation and a thorough necropsy, for (investigators) to not make a definitive conclusion. This isn’t like television,” he said. “We may never know why this animal died.”

To help further its investigation, the National Oceanic and Atmospheric Administration contacted the Royal Canadian Navy through the U.S. Navy, seeking details about its activities.

“When you start an investigation like this you don’t shut off any avenues,” Gorman said.

“It might have been sonar, it might have been some kind of explosion, (the orca) might have been struck by a fishing boat, it might have been caught in a net. There are dozens of different possibilities and you can’t dismiss any of those until you have reason to dismiss one or more of them.”

emccracken@vicnews.com

Victoria News