image: T063 Chainsaw breaching
Credit: Julia Adelsheim
If you’ve noticed more whales visiting local waters, you’re not imagining it: Vancouver’s gargantuan guests are here are here thanks to the season, great grub and conservation successes, researchers say.
A new study has confirmed transient killer whales are now seen in the Salish Sea for more than two-thirds of the year on average. And they are not alone. Humpback whales have rediscovered an ancestral feeding ground while grey whales are stopping by on their migration north.
Dr. Andrew Trites (AT), professor in UBC’s Institute for the Oceans and Fisheries (IOF), Taryn Scarff (TS), who conducted the study as part of her Zoology Master’s degree and Julia Adelsheim (JA), IOF alumna and whale biologist, discuss why we’re seeing this increase and how to keep our vast visiting whales safe.
What whales are people likely to see?
TS: We’re seeing more and more reports of transient killer whales travelling along the Vancouver shoreline. Based on sightings from 2016-2023, our study found orcas regularly visit the Strait of Georgia, North Island Waters and harbours in Vancouver and Victoria to hunt.
AS: We’ve also seen humpback whales. Historically, humpbacks were common in B.C. waters, but three years of commercial whaling from 1907 to 1910 eliminated all of them from this 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.
And lastly, we’re seeing grey whales visit, which is unusual — they’re usually seen along the outer coast of Vancouver Island.
Why are we seeing more whales than we used to?
JA: A lot of it is seasonal: this is when whales return to B.C. waters to feed after fasting in their winter breeding grounds and during migration. Baleen whales such as humpback and grey whales arrive in the Salish Sea focused on rebuilding their energy stores, feeding on the Pacific Northwest’s cold-water prey, which are rich in fats.
TS: For transient killer whales, the recovery of seal and sea lion populations has created what amounts to a year-round buffet. Seals and sea lions were heavily culled until the 1970s, but protections allowed their numbers to recover—and the killer whales followed. Today, transients are seen in the inside waters around Vancouver Island on roughly 250 days of the year, and about 70 per cent of the West Coast population regularly uses these waters.
AT: Humpback whales are another conservation success story. Their populations rebounded after most commercial humpback whaling 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. In winter, they migrate to breeding grounds in Hawaii and Mexico. 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.
Grey whales tell a different story. They feed near Alaska during the summer and fall on amphipods—tiny seafloor crustaceans that depend on nutrients from algae growing on and beneath Arctic sea ice. All gray whales must eat enough to fuel their 20,000‑kilometre round-trip migration to Mexico, but pregnant females need even more energy—to support their pregnancy, nurse calves born in warm tropical waters and bring them back to the Arctic.
In a recent study, we found pregnant females need 1,600 to 1,900 kg of prey per day to support fetal growth and store sufficient energy to produce milk while traveling after calving. Upon returning to their Arctic feeding grounds, lactating females require 1,300 to 1,600 kg of prey 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 grey whales depend on. As a result, some grey whales are stopping off in places like Vancouver in a desperate attempt to refuel their emaciated bodies. 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.
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What can people do to keep whales safe?
JA: The biggest thing is simple: give whales space and stay alert. If you’re on the water—whether it’s a boat, kayak or paddleboard—assume a whale could surface nearby. Slowing down and paying attention can make a huge difference in preventing collisions.
It’s also really important to follow the viewing-distance rules. Around southern B.C., vessels now need to stay at least 200 metres away from most killer whales and 1,000 metres from endangered southern resident killer whales, and at least 100 metres from other whales, 200 if they’re resting or with a calf. If you’re unsure, it’s always best to be conservative and keep your distance. The Marine Education & Research Society (MERS) has a free whale safe boating course online if you want to learn more about how to keep whales safe while on the water.
A good rule of thumb is: if you see a blow, go slow. Whales can change direction and surface unexpectedly, so giving them extra space helps keep everyone safe.
Journal
Marine Mammal Science