A necropsy will be performed Friday on a dead humpback whale that floated up under the containment net of a Mainstream Canada salmon farm north of Tofino on Wednesday.
The whale, believed to be a pre-adult female, about 7.6 metres long, seems to have drifted into the Ross Pass farm site and could have been dead for up to a week, Mainstream spokeswoman Laurie Jensen said.
As it decomposed, gases could have raised the carcass to the surface, she said.
“It is highly unusual. Some of these guys have been working out there for 20 years or more and they have never seen anything like it,” Jensen said. “It’s even more strange as no whales have been seen in the vicinity of the farm for months.”
Fisheries and Oceans Canada, with the help of Rod Palme from Strawberry Island Marine Research Society, removed the whale from the farm to a nearby beach. The necropsy will be performed by veterinarians from Vancouver Aquarium.
“It is a mystery what happened to her,” Palme said.
The whale showed no sign of trauma and did not seem to have been thrashing about or have been entangled in the net, as there were no lacerations, he said.
“All sorts of theories are being thrown out there and we’re trying to find something to make sense,” said Palme, who is hoping at least partial answers will be provided by the necropsy.
Containment nets at the Ross Pass farm were inspected by divers two days before the dead whale was found, and it is unlikely that they would not have noticed the carcass if it had been there then, Jensen said.
Fernando Villarroel, Mainstream Canada managing director, said the incident is very unusual.
“[It] was an unfortunate surprise for the staff who discovered it,” he said.
“We are working with DFO and Strawberry Island Marine Research Society to understand what happened, and will make all resources available to find answers.”
Humpback whales, once the most common whale on the B.C. coast, almost disappeared near the end of the 20th century after decades of whaling. They were declared endangered in 1960, but started reappearing off the west coast of Vancouver Island in the 1990s.
It is now estimated there are about 20,000 humpbacks in the North Pacific. Between 200 and 400 are seen off the coast of Vancouver Island.