AP NEWS

Report: Fish species at risk from Lake Michigan warming

September 17, 2018

CHICAGO (AP) — Warmer and wetter climate in the Midwest could lead to the displacement of some cold water fish species in southern Lake Michigan and trigger die-offs in smaller inland lakes, according to a new report.

The research published last week by Purdue University found the Great Lakes are warming along with the atmosphere due to the proliferation of greenhouse gases, the Chicago Tribune reported.

The report on the impacts of climate change also determined summer surface water temperature in Lake Michigan has warmed about 3 degrees since 1980 and is projected to accelerate. Experts predict that water temperature will rise at least 1 degree a decade.

A hotter climate can create issues for some game fish such as trout and salmon, which rely on cold, oxygen-rich water. The warming of Lake Michigan is expected to reduce the amount of time that such fish spend in the southern basin, where the chances of catching these species are limited by the shallower and more tepid waters.

Most fish can’t survive in the lake’s open water since it’s so deep and cold, but warming will likely open up more habitat for the majority of fish, said Tomas Hook, a professor of fisheries and aquatic sciences at Purdue and director of the Illinois-Indiana Sea Grant.

It’s unclear if the fish will be able to find sufficient food in those new waters, Hook said.

Angler Carl Beutler of Westfield, Indiana, said fishermen are worried about the impact of long-term temperature shifts.

“Short-term, it will just reposition where the fish are at,” Beutler said. “Long-term, repercussions could be the destruction of spawning habitat, because they need a lower temperature to spawn. If the water temperatures increase, they are going to deteriorate before they even hatch.”

Inland lakes are also most at risk of increasing algae blooms, which would force cold water fish to occupy a shrinking area as water near the surface warms and oxygen levels drop near the lake bottom.

“They can’t really migrate much but up and down in the water column,” Hook said. “I would expect to see more die-offs in those types of systems. A lot of aquatic species don’t have the flexibility to migrate into new systems like terrestrial organisms do.”

___

Information from: Chicago Tribune, http://www.chicagotribune.com

AP RADIO
Update hourly