Oil Tankers Pose Serious Risk to Under-Studied Minke Whales Off B.C. Coast, New Research Shows

A small, shy whale, may be one of the rarest marine mammals along the coast of B.C., but remarkably little is known about minke whales and the threats they face in the north-east Pacific, according to Jared Towers, research director with the Marine Education and Research Society.

Seldom-seen minke whales – unlike the splashier and much-studied killer whales and humpbacks found in B.C. waters – have no special protection, either in Canada or the U.S, and, according to a recent study published in the Journal of Cetacean Research and Management, more research is needed.

Information is essential if minkes are to be protected from hazards such as oil spills and vessel strikes, Towers said.

Numbers in B.C are likely to be about 388, with another 478 animals off the Washington, Oregon and California coast, Towers said.

“The numbers are really much less than expected…Their numbers are probably much less than the number of killer whales,” he said.

It is probable that minke numbers were previously believed to be higher because of re-sights, especially as minkes tend to return to the same feeding areas year after year.

“But no one knows enough about the stock structure in B.C.,” said Towers, who with a team of scientists, has identified individual animals through photo-ID, acoustic studies and darts that collect small samples of genetic material.

“We don’t see them on a regular basis. They are not as gregarious as orcas. They are elusive and solitary,” he said.

As minkes tend to hang out in shallow feeding areas around Hecate Strait, Broughton Archipelago and Juan de Fuca Strait, the risk of ship strikes and oil spills is high, so concern is growing that, if the Enbridge Northern Gateway pipeline to Kitimat and twinning of the Kinder Morgan pipeline to Burnaby proceed, the resulting increase in tankers could spell disaster for the tiny B.C. minke population.

As DeSmog Canada recently reported, a Department and Fisheries and Oceans analysis pointed to severe deficiencies in Kinder Morgan’s assessment of oil tanker threats to baleen whale populations.

“Of course, if there was an oil spill, just like the porpoises and killer whales and every other animal, the minke whales would suffer, but, because their populations are so low, it could really hurt them,” said Towers, reiterating that those threats make it essential that scientists discover as much as possible about their habits and movements.

The recent study found that, although a few animals stay in B.C. waters year-round, others are regularly seen in some areas of the Salish Sea from April through October and then many animals migrate south over long distances, possibly to Hawaii or Mexico.

The research was not based on tracking the secretive minkes to their winter locations, but by looking at the wounds their bodies accumulate while they are away.

Scientists found that, each year, animals would return to B.C. waters with fresh wounds made by cookie-cutter sharks, which are found only in tropical waters. Some whales also carried commensal barnacles – another species found further south.

“It is clear that common minke whales found in the eastern North Pacific range over a large geographical area,” says the study, adding that research to help determine migration routes and winter destinations is needed to help understand population structures.

Minkes are among the smallest of the baleen whales, growing to about nine metres and weighing about 10 tons. They feed on forage fish such as herring and sandlance.

Almost a decade ago, the Committee on the Status of Endangered Wildlife in Canada, in a risk assessment of north east Pacific minkes, concluded threats were not severe enough to cause concern.

But Towers would like to see the species listed as data deficient while there is a concentrated effort to learn more about the elusive whales before they face additional perils – whether from tankers, increased vessel traffic or pollution.

Image Credit: Tom Benson via Flickr