Southern Resident killer whales not getting enough food: study

An endangered species of whale found off the west coast hasn’t been getting enough food since 2018, a new study out of UBC has found.

According to the research, the Southern Resident killer whale population — which is currently about 73 cetaceans as of October 2021 — has “been in an energy deficit, averaged across spring, summer and fall, for six of the last 40 years.”

Three of those years, the study says, came in the most recent of the study — 2018 to 2020.

“With the Southern Resident population at such a low level, there’s a sense of urgency to this kind of research,” said lead author Fanny Couture, a doctoral student at the Institute for the Oceans and Fisheries (IOF) and Ocean Wise.

Two Southern Resident Killer whales are seen swimming in the open water, a baby swimming closely along with them. You can see the orcas' iconic white eye patch, as well as their dorsal fins poking out of the water

“Both killer whales and Chinook salmon, the Southern Resident’s main prey, are important, iconic species for the west coast of Canada. Studying what is happening to the population may help offer solutions, both for the southern residents and potentially other killer whale populations in the future.”

Couture says the decline in Chinook numbers could be attributed to climate change and susceptibility to disease, as well as number of other factors.

The research shows the whales average energy intake is about 17 per cent less than it should be.

“The years where Southern Residents were in an energy deficit are also years where other studies report lower population growth rate and higher mortality rates for the killer whales,” explained co-author Dr. Villy Christensen, a professor at the IOF.


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While previous research projected that Southern Resident whales could switch to other salmon species when their primary food source has seen decline, researchers say “the dire situation” these whales are facing “may call for a reduction in the catch of larger Chinook salmon.”

“This could include promoting fishing techniques that increase the survival of larger fish,” they note.

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