GRAND RAPIDS, Mich. (WOOD) — The Michigan Department of Natural Resources has seen more reports of fish kills than usual this spring.

Fish kills are natural cycle of Michigan’s water life, with the winter kill producing the most visible impact, explained Brian Gunderman, a unit manager with the DNR.

“We have natural fish kills in southern Michigan every year,” he said. “Usually, the most common type is winter kill when we have prolonged ice cover and the oxygen supply dwindles. A lot of the years, when the ice melts off, we see dead fish.”

Shallow bodies of water with a lot of aquatic vegetation are more prone to fish kills because they use up more oxygen during the winter months.

Gunderman said the quick spring warmup and dramatic change in water temperatures also stressed fish this year.

“Rapidly changing water temperatures is very stressful for fish,” he said. “They’re cold-blooded organisms so their body temperature changes with the surrounding water temperatures. They’re used to a more gradual warmup in spring and we went from snowing to 80 degrees.”

Gunderman said the public should not be worried. However, if they notice red blotches on the dead fish or discolored water surrounding the area effected, these may be signs of an outbreak of viral hemorrhagic septicemia, or VHS, an invasive virus that was first found in the Great Lakes region in 2005 and can kill all sorts of fish.

The public can report fish and other aquatic animal kills through the DNR’s website.