Newborn killer whale J-46 swims with its mother in November 2009 in the Strait of Juan de Fuca, close to the area of B.C.'s coast that has the most underwater noise, according to a UBC biologist. (Courtesy of Mark Malleson)

A B.C. marine biologist wants his study of underwater noise to be used to protect whales off Canada's West Coast.

For the past three years, the University of British Columbia's Rob Williams has dropped microphones down to the ocean's floor to record the sounds made by whales.

But Williams has also picked up the noises made by the high number of ships and boats plying the waters from Alaska to southern B.C.

Endangered killer whales can be distracted from feeding and reproducing by excessive noise, Williams said.

'The more boats there are, the less time the whales spend feeding.'—Marine biologist Rob Williams

Nonetheless, he said he is encouraged by some of his findings.

"We've learned that there are some really noisy parts of the B.C. coast, but there are also some incredibly quiet places," said Williams.

"There may be some acoustic refuges here that could serve as quiet marine-protected areas or acoustic sanctuaries for whales."

The quietest part of the B.C. coast that Williams found is in Caamano Sound, near the northern port of Kitimat.

That could change if a proposed oil pipeline is built from Alberta to Kitimat, increasing ocean tanker traffic on the waters.

But that's where Enbridge is planning a major gas pipeline and port expansion for tankers.

Haro Strait noisiest

The waters that are the least quiet are in southern waters, between Victoria and Washington state's San Juan Island.

"Haro Strait is actually turning out to be the noisiest part of the coast," Williams said.

Haro Straight is a critical habitat for resident orcas, he said.

"Boat traffic is affecting the behaviour of killer whales," said Williams. "Specifically, it's affecting their foraging behaviour and the more boats there are, the less time the whales spend feeding."

Department of Fisheries and Oceans biologist Paul Cottrell said his department is also starting to collect its own underwater noise data.

"It's extremely important that we identify these potential threats that may be affecting [the killer whales'] recovery," Cottrell said.

With files from the CBC's Chad Pawson