UPDATE: DNR Confirms Finding Two Larval Zebra Mussels In Lake Winnibigoshish

The Department of Natural Resources said this afternoon that two microscopic, larval-stage zebra mussels have been found in Lake Winnibigoshish in northern Minnesota.

Located in Cass and Itasca counties, 58,544-acre Winnibigoshish is the fourth-largest lake in Minnesota.

In a news release, the DNR said fisheries crews collected water samples from Winnie and other large lakes throughout last summer as part of a statewide program examining aquatic systems. During a recent examination, two larval zebra mussels, called “veligers,” were found in a sample collected in mid-July near the middle of Winnibigoshish.

“Although no adult zebra mussels were found, it is prudent and proactive to list Winnibigoshish Lake as infested,” Rich Rezanka, DNR invasive species specialist, said in a statement. “The size of the lake may delay locating an adult population, but the presence of veligers suggests there is likely a reproducing population in the lake. This listing will allow recreationists and other resource partners to be aware of the finding and take additional precautions to prevent inadvertent spread to other lakes.”

Winnie is part of the Mississippi River watershed. Connected waters include:

Cut Foot Sioux Lake.
Egg Lake.
First River Lake.
Little Cut Foot Lake.
Little Winnibigoshish Lake.
Pigeon River from the Pigeon Dam Lake’s dam to Lake Winnibigoshish.
Rabbits Lake.
Ravens Flowage, which includes an unnamed creek from Township 146, Range 29, Section 3 to Township 146, Range 29, Section 11 and Raven Creek.
Raven Lake.
Sugar Lake.
Third River downstream of Highway 33.
Third River Flowage, which is part of Lake Winnibigoshish.
Mississippi River from the Knutson Dam downstream to Little Winnibigoshish.

Further sampling will continue next spring and summer, including additional plankton tows, dives, shoreline searches, and coordination with resource partners on the lake and downstream waters to monitor for zebra mussels. The DNR is working cooperatively with the Leech Lake Band of Ojibwe on this veliger finding, the agency said.