The stench of rotting fish hangs over Grand Lake near Duluth, where the Duluth News Tribune reports that as many as 35,000 sunfish, crappies, walleyes, northern pike and largemouth bass have died.
Winterkill, brought on by low oxygen levels in lakes, is blamed for killing the fish, which have washed up in reed beds and the front yards of lakeshore residents.
Winterkill typically hits shallow lakes with lots of aquatic vegetation or high nutrient levels. Grand Lake, a 1,600-acre lake between Saginaw and Twig, is popular with anglers. Grand Lake is 24 feet at its deepest, but just 1 percent of the lake is deeper than 15 feet, according to the Minnesota Department of Natural Resources.
The lake has historically suffered some winterkill events, according to Dan Wilfond, fisheries specialist for the Minnesota Department of Natural Resources at French River, who said the last severe winterkill on Grand Lake was in 1955-56.
As a result of the winterkill, Wilfond said the DNR will stock the lake with 755,000 walleye fry (tiny, just hatched fish) each year from this year through 2016. This year's fry stocking likely will take place in a couple of weeks, Wilfond said.
"In our management plan, we said we would reintroduce walleye stocking in the event of a winterkill," he said.
The ECM Post Review reported that winterkill also struck North Center Lake in Center City. Chisago County Administrator Bruce Messelt said the county has collected about 12.5 tons of dead fish, mostly carp, out of the lake and transported them to a landfill in Mora.
“The critical thing is you get early ice, and heavy snow cover that shades the phytoplankton and algae, so they die, and they aren’t producing oxygen anymore,” said Roger Hugill, area fisheries manager with the Minnesota Department of Natural Resources, who added that this is the first recorded winterkill in North Center since the 1960s.
Earlier the Star Tribune reported that the long, cold and snowy winter has taken a toll on fish. The newspaper reported that two dozen lakes in central and southern Minnesota have suffered some winterkill because of low oxygen levels.
“I don’t think we’ve had this bad of a winter in 18 years," said Dave McCormick, assistant regional fisheries manager in St. Paul.
The newspaper said that other lakes where fish kills have occurred include Pelican and the north end of Maple Lake in Wright County; Little, Sunrise, Spider and north Goose lakes in Chisago County; Snail Lake in Ramsey County; Centerville Lake in Anoka County; and Long, North and South Stanchfield, Francis and Paul’s lakes in Isanti County.