LANSING, MI— The Department of Natural Resources says you may see dead fish or other aquatic animals as winter melts into spring.
When ice and snow cover reduce the daylight that reaches water depths, plants stop producing oxygen, and many die. Bacteria use the remaining oxygen in the water to decompose dead plants on the lake bottom. With available oxygen reduced, more aquatic animals die and start to break down, speeding up the rate that oxygen is used for decomposition. That further decreases dissolved oxygen levels in the water, creating a cycle of increased winterkill.
Fish and other aquatic life that die in late winter may not be noticed until well after the ice leaves lakes, as the cold water may temporarily preserve them.
