Study: killer whales at elevated risk for serious immune-system, reproductive issues

HALIFAX — A new study says persistent organic pollutants in waters off Canada’s East Coast are putting killer whales at an elevated risk of serious immune-system and reproductive problems.

The study led by McGill University scientists, which looked at levels of polychlorinated biphenyls, or PCBs, and organochlorine pesticides in skin samples collected from six species of whales and dolphins, found that killer whales show “dangerously high” levels of toxic chemicals.

The samples collected south of Newfoundland between 2015 and 2022 showed that humpback, minke and fin whales, as well as dolphins, had lower levels of persistent pollutants than killer whales.

Lead researcher Anaïs Remili says toxins attach themselves to fatty issue, putting whales and dolphins at risk because of their blubber.

She says killer whales are particularly vulnerable because toxins amplify as they move up the food chain and killer whales are apex predators.

Though their use has long been banned in Canada, the chemicals linger in both the environment and living tissue, and in aquatic ecosystems carnivorous marine species are more likely to be exposed.

This report by The Canadian Press was first published Nov. 7, 2024.

Cassidy McMackon, The Canadian Press