LITTLE FALLS -- We are coming off Minnesota's 6th coldest winter in 120 years, and it could mean additional winter fish kill in some Minnesota lakes.

Eric Altena is the DNR Area Fisheries Manager in Little Falls. He says it's normal to have some winter fish kill, especially in some shallower lakes in southwestern Minnesota. Altena says thick ice and heavy snowpack can reduce the oxygen levels in the lakes.

Altena says, "Typically lakes achieve a common temperature throughout, especially in the wintertime when the water is actually a little warmer toward the bottom.  They have good oxygen content with the colder water.  As the winter progresses and you have less light transmission and still the high nutrient levels, the oxygen gets used up."

Lakes in central and northern Minnesota are generally deeper and can sustain the necessary oxygen levels for fish survival.

Walleye and bass are the most susceptible species to winter kill.