A recent surge of grey whale deaths off the B.C. coast has researchers concerned.
The Department of Fisheries and Oceans (DFO) responded to four dead whales off the west coast of Vancouver Island in 10 days.
DFO marine mammals co-ordinator Paul Cottrell said three necropsies were performed with the help of Huu-ay-aht, Kyuquot/Cheklesaht, and W̱SÃNEÄ First Nations.
“Two are severely emaciated. Theyâre basically a bag of bones, really sad to see that kind of body condition,” Cottrell said.
On April 8, a grey whale was found dead near Barkley Sound and a second dead grey whale was discovered on April 9 near Kyuquot. The next day another grey whale was found floating in Barkley Sound. The fourth grey whale was discovered off Sidney on April 17.
“Some of the worst animals I’ve ever seen,” Cottrell said.
A total of five grey whales have been found dead in B.C. waters this year, and researchers believe a dramatic decline in available prey in their Arctic feeding grounds is to blame for the deaths.
“Last year, feeding in the Bering and Chukchi Seas was really not a great year for grey whales,” Cottrell said.
John Calambokidis, a research biologist at Cascadia Research Collective, said 13 dead grey whales have been found dead this year off Washington state.
Calambokidis said dead whales are being found “at a rate that has surprised us.”
The Marine Mammal Center and the California Academy of Sciences confirmed eight grey whale deaths in the San Francisco Bay Area so far this year.
“Never have they come at this pace this early, so we’re really worried about where this is headed,” Calambokidis said.
Grey whales primarily feed on benthic amphipods, small crustaceans found in the bottom sediment.
“There has been documentation of declines in those benthic amphipod populations, but all of that is also complicated by the fact that the most dramatic changes in the Arctic ecosystem have been this progressive overall loss in ice cover,” Calambokidis said.
The grey whale population has been dwindling, estimated at just under 13,000.
“That was less than half what it had been 10 years previous, so a greater than 50 per cent decline in 10 years is alarming,” Calambokidis said.
Back in 2019, there was a significant spike with 216 grey whales found dead.
“It was declared an unusual mortality event. We actually declared that over in 2023,” Calambokidis said.
This year could surpass the worst year in B.C. when 11 dead grey whales were discovered in 2019, according to Cottrell.
“We could be in for a worse year than the worst year that we’ve had,” Cottrell said.
There are also concerns about the calf production rate as the females are not healthy enough to have babies, he said.
“[Itâs] the lowest calf production on record, in recent history, so that doesn’t bode well,” Cottrell said.
Last year, 158 grey whales were found dead, four of them in Canadian waters.
Both Cottrell and Calambokidis expect the number of deaths to continue rising as the whales migrate through to June.
“We’re only a very small portion of the way through that,” Calambokidis said.
Wendy Szaniszlo, a DFO marine mammal technician on Vancouver Island, saw a group of grey whales off Barkley Sound on April 17.
“It looked like almost two-thirds of them were very skinny,” Szaniszlo said. “Their scapula or shoulder blades were protruding.”
She thinks more research would help the population as “there is very little known about grey whales in B.C.”
“Without knowing what prey types are important to them and what habitat is important to them, it’s going to make it really hard to try to protect,” Szaniszlo said.
She encourages anyone on the water to give grey whales lots of space and report any dying whales to DFO immediately.
Cottrell said necropsies are important to find out exactly what is going on and rule out pathogens.
“It’s important to really pay attention when we have this migrating species that covers great distances and feeds on small critters, it can be a real indication of things to come,” Cottrell said.
