MI DNR Says Fish Kills May Be Common During Spring Thaw

Don't be alarmed if you see dead fish and other animals during the spring thaw.

With spring just around the corner, the Michigan Department of Natural Resources says that it may be more likely to see dead fish and other aquatic animals this year. Don't be alarmed, this is normal. The DNR is reminding Michiganders that the winter conditions commonly cause fish, turtles, frogs, and more to die.

Winterkill is the most common type of fish kill...As the season changes, it can be particularly common in shallow lakes, ponds, streams and canals. These kills are localized and typically do not affect the overall health of the fish populations or fishing quality...said Gary Whelan, DNR Fisheries Division research manager.

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The most common areas for this to happen are shallow lakes along with canals in urban areas. These fish and aquatic life normally die during late winter and go unnoticed until about a month after the ice melts from the lakes. Rapid temperature changes in the spring also play a factor if it is unseasonably warm. The rapid changes in temperatures cause stress and sometimes mortality of aquatic life.

Winterkill begins with distressed fish gasping for air at holes in the ice and often ends with large numbers of dead fish that bloat as the water warms," "Dead fish and other aquatic life may appear fuzzy because of secondary infection by fungus, but the fungus was not the cause of death. The fish actually suffocated from a lack of dissolved oxygen from decaying plants and other dead aquatic animals under the ice...said Whelan. 

To learn more about fish kills in Michigan, click here. 

Source: Michigan Department of Natural Resources