Warming waters raise toxic algae levels in Arctic whales

By Daniel Cusick | 07/18/2025 01:26 PM EDT

A new study found that neurotoxins in whales pose risks to Native whale-hunting communities.

A child poses in front of a whale after a whale hunt near Barrow, Alaska.

A child poses in front of a bowhead whale following a hunt near Barrow, Alaska, in October 2014. A new study raises concerns about neurotoxins in such whales. Gregory Bull/AP

Arctic whales are ingesting higher levels of toxic algae as warming waters create more suitable conditions for microorganisms to thrive, according to newly published NOAA research. That poses risks for those who hunt and consume the whales.

The study, published in Nature, found that “potent neurotoxins” that can cause serious illness and death in humans are increasingly present in fecal samples from bowhead whales that live in Arctic and sub-Arctic waters, including areas with sea-ice coverage.

Researchers affiliated with NOAA’s Northwest Fisheries Science Center found the prevalence and concentrations of two forms of toxins produced by algae — domoic acid and saxitoxin — in whale feces “increased significantly” between 2004 and 2022, a period of rapid warming in the Arctic that continues today.

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“This is like a sleeping giant awakening,” Kathi Lefebvre, a research scientist at NOAA Fisheries’ Northwest Fisheries Science Center and the study’s lead author, said in a release. “These are new risks that were previously unknown.”

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