Experts warn of climate change impact on Great Lakes fish populations by 2030s

NORTHERN MICHIGAN,. (WPBN/WGTU) — - Despite a colder-than-average winter in the Great Lakes and across the country, some experts are observing a rapid growth in warming.

Donald Wubbles, an emeritus professor from the University of Illinois, conducted an assessment in 2025 on the impacts of warming. “The Great Lakes regions has warmed 2.5 degrees since 1901, nearly three degrees since 1951,” Wubbles said. “Since the last report, the Midwest has warmed another two-thirds as much as it did at that point, and so basically the warming is accelerating.”

Wubbles noted that warming is expected to impact the Great Lakes region as soon as the early 2030s, particularly in urban areas.

“We’re seeing more dangerous heat in the region,” he said. “For example, urban areas like Chicago may experience, well this is projecting, but may experience over 200 hours above 95 degrees by the 2030s, up from about 30 hours in recent years.”

Despite an increase in ice coverage on the Great Lakes this year, the future could be different.

“We’re seeing more declining ice cover,” Wubbles explained. “2024, which was an El Nino year, recorded the lowest winter ice cover on record in the Great Lakes, only about a 4.3% average maximum, 16% over the winter.”

This decline in ice cover could impact the fish population.

“Whitefish could disappear from parts of the Great Lake Michigan over the next five years, even if commercial fishing was to halt,” Wubbles said. “Part of that is because of less ice cover; there is an effect on the eggs—they’re affected by, they need that ice cover.”

Scott Heintzelman with the Central Lake Michigan Management Unit added that there might also be changes to the types of fish seen in the coming years.

“Depending on how resilient those systems are, you may see those shift to more warm water species over the next few decades, and you’ll see those cold water species no longer be able to exist in some of those systems,” Heintzelman said. “So I think we’ll see changes in what species and diversity we have.”