The Michigan Department of Natural Resources says many fish and other living things in waterways will have a difficult time making it through this brutal winter.

The D.N.R. says this will become evident when snow and ice starts to melt. For example they say groups of dead fish in ponds, rivers and lakes will be likely.

Researchers say there's a reason why this occurs. They say with such think ice cover in many places aquatic plants that produce dissolved oxygen will often die. When that happens living things in the water that rely on that oxygen will find it tougher to be able to survive. Officials have a name for this: Winterkill.