Winter ice cover on the Great Lakes is unpredictable from year to year. For example, two years ago, 92.5% of the Great Lakes were covered with ice, but in 2012, just 12.9% of the lakes froze over. Why does this matter? Because ice cover affects everything from the length of the shipping season to ice fishing. And speaking of fish, they care too. For example, in the shallow waters where whitefish spawn in early winter, ice cover protects whitefish eggs from destructive wind and wave action, so more ice is good for them. Snow on top of the ice matters too. Listen to our podcast and find out why.