GRAND REPIDS, MICHIGAN (DRES) – Most Michigan residents love the state because it goes through all four seasons. But the transition from winter to spring has some drawbacks.
The Michigan Department of Natural Resources reminds residents that the spring thaw could find many dead animals on waterways.
Gary Whelan, head of the DNR Department of Fisheries Researchsays Michigan’s winter conditions can be harsh for many fish and other creatures, including turtles, frogs and toads.
“Winterkill is the most common type of fish killing,” Whelan said in a release. “As the season changes it can be especially common in shallow lakes, ponds, streams and canals.”
However, these killings do not usually have a long-term impact on our ecosystems.
“These killings are localized and usually do not affect the general condition of the fish population or the quality of fishing,” Whelan said.
Two ecosystems are more likely to observe winter killings: shallow lakes and ponds with excess aquatic vegetation and canals in urban areas.
In shallow water, if too much vegetation or algae grows, they will naturally be destroyed in the winter.
According to Resource Lake and Wisconsin Ponds, bacteria from these dead plants will absorb oxygen from the water, depriving other wildlife of the oxygen they need to survive. Because ice and snow usually build up throughout the winter, these plants stop producing oxygen, creating more stress for fish.
In cities, pollution can cause big problems in the winter. Chemicals from icing and road salt, especially chloride, can upset the natural balance of waterways. Killing fish occurs more often near urban areas because they are more likely to see higher concentrations of chemical runoff.
Whelan says fish and other animals usually only die later in the winter, but you may not notice this right away.
“Winterkill starts with painful fish catching air in holes in the ice, and often ends with lots of dead fish that swell when the water heats up,” Whelan said.
Often still lifes will look fuzzy because the fungus has begun to feed on them, but the fungus rarely causes death.
If you notice a potential fish death, the DNR is urging people to report it. You can contact the department Eyes in the fieldincluding exact location and detailed observations.