Spotting a grey whale in Vancouver isn't a good thing
You might have been lucky enough to have spotted a whale in and around the Vancouver area this year, with many Vancouverites reporting whale sightings — even in highly urbanized areas like Kits Beach.
While this is good news on a couple of fronts, as it points to a rebound in humpback whales and transient killer whales, it’s a much sadder story for grey whales.
According to Andrew Trites, a professor at the University of British Columbia’s Institute for the Oceans and Fisheries, grey whales are actually swimming close to Vancouver “in a desperate attempt to refuel their emaciated bodies.”
This means that the grey whale that many Vancouverites spotted in late April and May isn’t necessarily the happy story we might have hoped for.
“Several grey whales have washed up dead along the coast, likely from starvation, and unfortunately, we’re likely to see more deaths in the years ahead,” Trites said in a press release.
What’s happening to grey whales?
In the summer and fall, grey whales feed near Alaska on amphipods, which are small seafloor crustaceans.
These amphipods depend on nutrients from algae that grow on and beneath the Arctic sea ice.
All grey whales need to eat enough to sustain themselves on their 20,000-kilometre round-trip migration to Mexico. Pregnant females, in particular, need a lot of food, not only during their pregnancy but also after they give birth to nurse their calves and bring them from tropical waters to the Arctic.
Trites said that in a recent UBC study, they found pregnant females need 1,600 to 1,900 kilograms of food per day to support fetal growth and store enough energy to make milk while traveling, after giving birth.
When they’re back in their Arctic feeding grounds, lactating females still need to eat 1,300 to 1,600 kilograms per day for another three to four months.
“However, climate change is reducing sea ice, which in turn decreases the algae that sustain the amphipods that grey whales depend on,” said Trites.
What about the good news?
While grey whales are struggling, the Salish Sea has seen the resurgence of both transient killer whales and humpback whales.
Another UBC study showed that transient killer whales are seen in the Salish Sea for more than two-thirds of the year, on average.
Taryn Scarff, who conducted a study as part of her Zoology Master’s degree at UBC, said that they found that orcas are regularly hunting in the Strait of Georgia, North Island Waters and harbours in Vancouver and Victoria.
“The recovery of seal and sea lion populations has created what amounts to a year-round buffet,” she said in the press release.
“Seals and sea lions were heavily culled until the 1970s, but protections allowed their numbers to recover — and the killer whales followed.”
Meanwhile, humpback whale populations bounced back after most commercial whaling for them ended in the North Pacific in the mid-1960s.
“Large numbers now return to B.C. waters each summer to feed on krill, herring, and other prey,” said Trites.
“Recovery has been driven mainly by protections from whaling, but conservation measures such as improved fisheries management and efforts to reduce entanglements, underwater noise and ship strikes have also supported their return,” he added.
In the past, humpback whales occupied B.C. waters. But just three years of commercial whaling from 1907 to 1910 wiped them out from the region.
“There were no whales left to pass on knowledge of feeding grounds to the next generation, so it has taken roughly a century for humpbacks to rediscover parts of their former range,” said Trites.