No whales were detected by a Royal Canadian Navy warship when it used sonar during an anti-submarine exercise off the southern coast of Victoria last week, the ship’s captain says.
HMCS Ottawa crewmembers were capping off a week at sea on Feb. 6 when they used the ship’s sonar to practise hunting for submarines closer to shore.
The underwater sound waves were said to be heard as far as San Juan Island, prompting environmentalists and whale advocates to raise concerns that the sonar could impact the health of marine mammals.
Endangered southern resident killer whales frequent the area between Victoria, Vancouver and Seattle during the summer, though occasionally during the winter months.
The controversy around the navy’s use of sonar arose just days before the federal Court of Appeal released its judgement Feb. 9 to uphold a 2011 ruling that the Department of Fisheries and Oceans is legally bound to protect the critical habitat of killer whales.
Part of Washington State waters are also designated by the U.S. government as critical habitat.
Protecting marine animals from sound goes part and parcel with these designations and regulations.
“If the animals are close and the sounds are loud then it could interrupt communication. It could interrupt navigation,” said Anna Hall, captain with Prince of Whales Whale Watching and an independent zoologist based in Metchosin.
But every precaution was taken to ensure no marine mammals were within 4,000 yards – or more than three kilometres – of the ship, said Cmdr. Scott Van Will, commanding officer of HMCS Ottawa.
The crew listened for 30 minutes before actively using sonar to ensure there no marine mammals were in the vicinity. Sonar was used, at various strengths, for almost two hours, he said.
“As well, the lookouts will be looking out making sure they don’t see anything visually,” Van Will said.
In doing so the vessel followed a Canadian Forces marine mammal mitigation policy, which, since 2008, has governed the use of sonar by Canadian military vessels and aircraft, he said.
The policy is an order to immediately turn off sonar if a marine mammal is detected within 4,000 yards.
“If it’s causing (marine mammals) discomfort, then they’ll usually make noise and then we’ll hear that and then we’ll check to see how far away that is, and cease if it’s within a zone that we call our mitigation avoidance zone,” Van Will said.