Toxic chemicals from oil spills, wildfire smoke found in B.C. killer whales

Toxic chemicals from oil spills and wildfire smoke have been detected in 12 killer whales off the B.C. coast — the first time such hydrocarbons have been studied in orcas in the province.

The dangerous substances were found in the muscle and liver samples of six Bigg’s killer whales and six southern resident killer whales, its endangered cousin.

The research published in Scientific Reports also detected the transfer of the chemicals from mother to fetus in the womb.

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Study co-author Juan José Alava, principal investigator of the Ocean Pollution Research Unit at the University of British Columbia, called the whales the “canaries in the coal mine.”

“They are telling us that our waters, our marine environment is contaminated by oil emissions and also fossil fuels — some of them coming from wildfires. That’s a reality,” he told Global News.

The samples were taken from whales that had died while stranded between 2006 and 2018, in partnership with the B.C. Ministry of Food and Agriculture and Fisheries and Oceans Canada. Researchers tested for 76 polycyclic aromatic hydrocarbons, and found some in every sample.

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Alava said whales are consuming the toxins through their diet — marine mammals for the Bigg’s killer whales and salmon for the southern residents. The wildfire smoke chemicals make their way into the water through the circulation of ashes, rainfall, runoff and more, he explained.

In the Bigg’s killer whales, researchers detected hydrocarbons that were mostly linked to forest fires and burning coal and vegetation, while in the southern residents, they found mostly those linked to oil spills and burning fossil fuels, like gasoline.

It could be due to their different habitats, with the southern residents swimming in more polluted urban waters around the Salish Sea, they said.

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While the team team didn’t study the internal toxicity level of their whale subjects, Alava said that the contaminants can accumulate. In high concentrations, they can be carcinogenic and impair the immune and reproductive systems.

The concentrations detected in the 12 whales were higher than in previously studied captive killer whales near Iceland, but lower than wild animals in the Gulf of California.

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He said the findings are especially critical as the southern resident killer whale population hovers around just 74 animals.

“The data that we produced just basically to support the risk management of pollution, is basically to inform policy decision-makers,” Alava explained. “Prevention is better than cure. Maybe this is a red flag, right?

“We believe we should really think very, very seriously to transition away from more fossil fuel consumption.”