As the Gulf of St. Lawrence warms, whales are switching up the menu and may be sharing lunch

In a 28‑year study of tissues from fin, minke and humpback whales in the Gulf of St. Lawrence, researchers from the Maurice Lamontagne Institute found that Arctic krill, once primary prey, has become scarce. As a result, fin and minke whales are shifting to forage fish—capelin, mackerel and herring—which are the main diet of humpbacks. Isotope analysis of carbon and nitrogen shows the three species are eating the same fish but at different times or depths, indicating resource partitioning. Lead author Charlotte Tessier‑Larivière reported the findings in a 2025 Frontiers in Marine Science paper, posted Jan 23 2026. The shift highlights whales’ adaptive capacity amid climate‑driven prey changes.