Spike in Vancouver whale sightings a sign of the 'new normal'
Many Vancouverites have reported whale sightings in and around Vancouver in recent weeks — a sign of a remarkable recovery after many of their populations experienced a sharp decline in the 20th century.
For example, locals have filmed transient orca pods swimming under the Lions Gate Bridge, and a humpback whale was spotted in North Vancouver’s Deep Cove.
Andrew Trites, a UBC professor and the director of the marine mammal research unit, said that this time of year is when both humpback and grey whales migrate from southern waters up north to spend the summer feeding.
He said this relatively recent resurgence of marine life is “normal, but it’s also part of the new normal.”
Back when he moved to B.C. in 1980, he didn’t recall seeing a single whale in the area and likened the area to a desert.
“I was not going to see them walking around Stanley Park,” he said.
What happened to the whale populations?
The Salish Sea had a population of humpback whales until the early 1900s, but every last one of them was killed by hunters.
“And it took them a hundred years to come back,” Trites said.
Humpback whaling ended in the 1960s, which has allowed the Pacific population to recover. In 1997, “Big Mama,” who has since become a well-known phenomenon, finally returned to the Salish Sea and has come back nearly every year since, introducing her calves to the area.
Further, transient killer whale populations have rebounded following Canada’s ban on culling seals and sea lions on the West Coast in the 1970s. These killer whales eat seals and sea lions, and so once those populations started recovering, they had more food.
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Trites likened the resurgence of these whale populations to that of putting money into a bank account with compound interest — the growth seems slow at first as you slowly add in money, but all of a sudden it will start to increase quickly.
“We’ve been saving for this return of whales, and I’d say the savings account started about 20 years ago. But it’s only in the most recent years that we suddenly see the compound interest really exploding.”
He added that the Salish Sea is home to white-sided dolphins, harbour porpoises, Dall’s porpoises, seals, and sea lions.
Today, the Salish Sea is far from resembling a desert in terms of the life it holds.
“We gave nature a chance, and look how well it’s responded,” said Trites. “To me, the Salish Sea, it’s our Serengeti. It’s one of the most incredible wildlife preserves.”
But it isn’t all good news
While people have also spotted a grey whale feeding near Kits Beach, False Creek, and Stanley Park, this isn’t a good sign for the species.
Grey whales are migratory animals that are now swimming back to the Arctic to feed after spending the winter in Mexico. But it is very unusual for grey whales to swim into English Bay, and Trites said they are doing so “out of desperation.”
“Some of those whales are starving, and some of them are stopping to feed,” he said. “It’s unusual. They don’t come in here usually, but if they’re short of food, we start to see them showing up in places we don’t see them normally.”
The grey whales are unfamiliar with the Vancouver area, and Trites said they are trying to figure out if it’s a good place to feed.
Typically, these animals consume enough food in the summer and early fall to last them the entire year.
Grey whales feed by diving to the bottom of the ocean in the Arctic, taking a mouthful of mud, and filtering out amphipods — tiny shrimp-like creatures. To last through the winter, they need to consume a lot: a large adult has to eat a minimum of 1,000 kilograms per day for months, and a pregnant female will need between 1,600 and 1,900 kilograms per day.
This year, some of those grey whales didn’t store enough energy before swimming south last fall.
Trites said that while researchers don’t know for sure what has happened to the grey whale’s food, they think it is likely a climate change effect.
Sea ice “kick-starts” the growing season of algae on the bottom side of sea ice. As the ice melts, the algae drifts to the bottom to feed the amphipods.
“And with less ice, there’s going to be less algae to feed the amphipods, and so less overall for the grey whales to consume,” he said. “That’s the best explanation. But the population has done just horribly. It’s declined from the peak of about 27,000 in 2016 — that’s only 10 years ago — to now about 13,000.”