Orcas appear in Vancouver Harbour from time to time and often delight residents who catch a glimpse of them. But marine experts say three whales spotted there last week are unlike any previously recorded in B.C. waters.

The whales, which have been seen over several days swimming between Lions Gate Bridge and the Second Narrows Bridge, appear to belong to an Alaska population, according to Fisheries and Oceans Canada (DFO).

The department says its scientists are now studying the animals, which it says have never been “previously documented” in the province, to better understand their behaviour.

“We will be able to share more once our whale experts have completed their assessment of the available information,” the federal institution said in a statement. 

A DFO science team from Nanaimo, B.C., has been on the water observing the whales as part of that assessment.

Rare appearance in Vancouver Harbour

Jared Towers, executive director of Bay Cetology, says about 99.5 per cent of the time, orcas photographed in Vancouver Harbour are well-known whales, most commonly transient orcas, also known as Bigg’s killer whales.

Those whales inhabit the coastal waters and feed primarily on marine mammals, particularly coastal seals and sea lions, and are closely tracked by researchers.

But the three orcas spotted recently don’t belong to the population of Bigg’s killer whales, which Towers said means they are genetically distinct and have different DNA and vocalizations.

“Every killer whale looks unique, just like people,” Towers said. “By taking photographs of their dorsal fins, their saddle patches and the white eye patch behind the eye, we can recognize individuals and track them over time.”

He says many whales seen in B.C. waters have been documented through photo identification for decades.

“It’s quite rare for whales that have never been photographed before in B.C. to show up,” Towers said.

He says researchers have been able to match the three whales with a single previous sighting near Anchorage, Alaska, about 1,200 nautical miles away, recorded almost a year ago.

Signs they may be oceanic whales

Experts say it isn’t clear as to what might have prompted the whales to travel all the way to Vancouver but one clue to where they may have come from lies in distinctive scars near their dorsal fins.

Josh McInnes, a marine mammal researcher at the University of British Columbia, says one of the whales spotted had a circular bite mark on the grey saddle patch behind their fins.

Those marks, he says, are believed to come from cookie-cutter sharks, which live far offshore in deep, open waters.

“Killer whales that we see with these marks primarily occur in open-ocean habitats,” McInnes said.

UBC researchers have catalogued more than 150 oceanic killer whales off the outer coasts of California, Oregon and B.C., but sightings close to shore are extremely rare.

“We’ve never seen them this far into coastal waters,” McInnes said.

Still, other experts say it’s too early to say exactly which population the animals belong to.

“I think it would be really interesting if they were oceanic killer whales,” said Aly Kohlman, a marine naturalist based in Nanaimo, B.C. “But as far as which population they belong to, we need a lot more time with them before we can actually say for sure.”

Psychologically trapped in the harbour?

The whales were first observed last week in Burrard Inlet and for about the last four days, have been spending much of that time in the busy harbour.

Marine naturalist Kohlman says that behaviour is unusual.

“With wild transient killer whales, we don’t typically see them spend extended periods of time in one given area,” she said. “They’re constantly on the move.”

She says the whales may have become “psychologically trapped” in the waterways, which are busy with cargo ships, ferries, recreational boats, sea bus and sea plane traffic moving through the inlet.

“These whales are just not used to this sort of chaotic harbor … they’re not physically trapped there, but maybe they’re scared.”

Researchers say there haven’t been any sightings as of Monday evening but it isn’t confirmed if they have left.  

Researchers are urging people who photograph the whales to upload images to Finwave.io, which helps researchers identify individual orcas.

But experts stress that the animals should be given plenty of room.

Under Canada’s Marine Mammal Regulations, vessels must stay at least 400 metres away from killer whales in southern B.C. coastal waters.