If you discover dead fish or other aquatic animals as the ice and snow thaws out this spring, just know -- it’s totally normal, according to the Michigan DNR. “Winterkill is the most common type of fish kill,” said Gary Whelan, DNR Fisheries Division research manager. That’s because the dead fish and other aquatic life are temporarily preserved by the cold water. “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.”Dissolved oxygen is required by fish and all other forms of aquatic life.