Lack of oxygen killing fish

DULUTH, Minn. — Fish in tributaries to Big Sandy Lake are dying because of warm water and low oxygen levels, the Minnesota Department of Natural Resources reported today.

Crappies, perch and northern pike are dying, mostly in the streams flowing into the Aitkin County lake — namely the Big Sandy and Prairie rivers and in the areas of the lake nearby, said Rick Bruesewitz, Aitkin area fisheries supervisor for the DNR.

But there also have tullibee dying in the 6,000-acre lake itself, Bruesewitz said, and walleyes have perished in Davis Lake just upstream from Big Sandy.

The problem started with the massive rainfall and flood that inundated Aitkin County in June. That scrubbed wetlands and peatlands of organic matter that moved into the rivers, where microbes are breaking it down. Those microbes are using up all the oxygen and in some cases the tributaries “were nearly devoid of oxygen,’’ Bruesewitz said.

Tags: outdoors, news, fishing