Fisherman holding fish
Walleye fish are in hot water as temperatures rise. (Photo: Courtesy of Leisure Outdoor Adventures and Jeff Andersen)

Walleye fisherman often say walleye are the tastiest fish in the world. And they’ve always been plentiful in Wisconsin’s North Country.

Vander Zanden: “This area of northern Wisconsin contains about 900 lakes. These are separate lakes, and each one of them – 900 of them – have a walleye population.”

Jake Vander Zanden is with the University of Wisconsin-Madison. He says walleye populations are shrinking in many of these lakes.

One reason is that people catch so many each year. But global warming is also a concern. Walleye prefer cold water, so rising temperatures may be contributing to their decline. And warmer water is more hospitable to bass.

Vander Zanden: “These warm water fish, not surprisingly, are doing a lot better. And those warm water fish could be predators or competitors with walleye. And there’s only so many resources that go around in these lakes. So they’re sort of like a new player in these lakes that’s crowding out walleye in a way.”

Scientists are trying to learn more about how global warming is affecting walleye populations and how to support these native fish.

For now, Wisconsin stocks the lakes with hatchery-raised walleye so people can still go out and catch their next big fish.

Reporting credit: ChavoBart Digital Media.

Samantha Harrington

Samantha Harrington, director of audience experience for Yale Climate Connections, is a journalist and graphic designer with a background in digital media and entrepreneurship. Sam is especially interested...