A United Effort: Whitefish Lake Community Steps Up To Address AIS

Posted on by akowalsk@uwsp.edu

By Eric Olson, Director, Extension Lakes

“Lake residents didn’t panic when EWM was found in Whitefish Lake, instead they rallied.”
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Underwater image looking up from the bottom at tall plants stretching to the top of a clear lake on a sunny day.

Whitefish Lake in Douglas County has long been a destination for people seeking the perfect lake from nearby Duluth and the Twin Cities. Whitefish is both deep (over 100 feet) and clear (Secchi depths between 20 and 30 feet). The cold deep waters of the lake support a healthy population of cisco as well as several rare and endangered plants. The Whitefish Lake Conservation Organization (WILCO) has been working for over 50 years to protect the lake and its unique plant and fish communities.

Protecting What Matters Most
WILCO was among the “early adopters” of the Clean Boats, Clean Waters watercraft inspection program. In a typical summer, volunteers and hired students connect with over 1,000 boaters and anglers, sharing AIS prevention steps as they come and go. Thanks to such diligence, Whitefish Lake has been largely free of aquatic invasive species (AIS)—with the exception of the 2019 discovery of mystery snails. While mystery snails have less extreme impacts on waters than other AIS, WILCO has proactively worked to manage their population by removing 13,000 pounds of snails in the last three years!

With such a major focus on preventing and managing AIS, WILCO leadership was disheartened when Department of Natural Resources (DNR) biologists discovered populations of Eurasian watermilfoil (EWM) near the public boat launch late last summer. The DNR’s plant survey was part of a directed lakes study, building on an extensive history of ecological monitoring at Whitefish Lake. Rather than resignation or panic, WILCO leadership is drawing on what is known about EWM to develop a strategic response.

Community Strong
In their recent newsletter, WILCO reports they will use their mystery snails experience to focus on manual removal of EWM by SCUBA divers this spring, when the plants are more easily identified and handled. They also encourage landowners to maintain the healthy native plants already found in the lake, as EWM can more easily spread on a disturbed lake bottom. WILCO leaders cautioned their members that complete eradication of the invasive plant is not a realistic expectation, but that monitoring and manual removal can help minimize the plant’s impact on the lake.

See video of Whitefish Lake’s snail removal efforts on diver Ryan Marshik’s YouTube channel.