Rising temperatures in a Southcentral Alaska river are driving a noticeable change in the behavior of invasive northern pike. As the water warms, these predators are eating more, raising concerns about the future of native fish such as salmon.

Researchers led by the University of Alaska Fairbanks examined the stomach contents of northern pike collected by the U.S. Fish and Wildlife Service in the Deshka River during the summers of 2021 and 2022. They compared those findings with samples taken from pike in the same river about ten years earlier.

Their analysis showed that pike across all age groups increased their fish consumption as temperatures rose.…