There is the potential for a massive fish kill in many Minnesota lakes this winter.  The problem is too much snow on lake ice -- which prevents sunlight from reaching underwater plant life which gives fish oxygen.  The D-N-R is using aerators where the snow cover is heaviest to create open water so fish can get oxygen.  The D-N-R's Sean Sisler says if heavy snows continue this winter, the fish kill could reach serious levels on some lakes -- especially in southern Minnesota where the snowpack is deepest.