MOUND (AP) — University of Minnesota-Duluth researchers are studying how shorter winters may increase the presence of harmful algae blooms and impact fishing.

The researchers worked with the U.S. Geological Survey and the University of Maryland to gather data from six lakes across Minnesota.

Researchers found that shorter, warmer winters mean more sunlight reaches the water. That jumpstarts algae production. That could mean more nutrients in the food chain but could also mean more toxic blue-green algae.

The harmful blooms can make humans sick and kill animals that drink the contaminated water.

Researchers are also examining how accurate satellite data is in determining the thickness of ice and snow cover.