Lake County Aquatic Invasive Species

Spiny waterflea on fishing line

Aquatic invasive species (AIS) are threatening Minnesota waters. These non-native species harm fish populations, water quality and water recreation. Lake County is working to prevent the spread of harmful AIS within waterways of the region.

Lake County has and continues to engage youth education, citizen monitoring, and public outreach in the effort to prevent further or more robust AIS infestations in the Arrowhead region.

As of March 2015, rusty crayfish, spiny water flea, zebra mussels, and curly leaf pondweed have been found in some of the lakes and rivers in Lake County. In the summer of 2016, Lake County conducted a thorough survey of lakes and public accesses in the Lake Superior watershed. No new species were discovered. Additional invasive species have been found in Lake Superior, including rainbow smelt, mystery snails, Eurasian ruffe, and viral hemorrhagic septicemia (VHS). In 2017, Lake County conducted a thorough survey of lakes within the Rainy River watershed (and within the County). No new AIS infestations were found in 2017. Rusty crayfish were discovered by Lake County partners in Low Lake in St. Louis County. Although previously found in Lake Superior, there is a new infestation of Curly Leaf Pondweed at the Agate Bay public access as of 2017. Narrowleaf cattail, an invasive species without extensive management statewide, was also found at Lax Lake public access and in various ditches. Lake County has continued to monitor accesses through 2018 but has not found any new infestations. There is a suspected infestation of Bloody Red Shrimp (Hemimysis) in Agate Bay, but infestation must be confirmed with further testing.

In addition to surveying and monitoring, Lake County conducts watercraft inspections during the summer season at public access landings, part of a state-wide effort to bring watercraft users within compliance of Minnesota regulations on the transport of aquatic invasive species. In the summer of 2017, watercraft inspections took place at Fall Lake, along the Lake Superior corridor of Lake County including the Silver Bay Safe Harbor and Agate Bay accesses, and at scattered locations in Fall Lake Township near Ely, MN. Watercraft inspectors are certified as Level I Inspectors with the Minnesota Department of Natural Resources. Lake County has expanded watercraft inspection staffing in 2018 and focused staffing more on inland waters.

A number of additional outreach events occur each year related to AIS, including in-classroom presentations, a summer 4-H youth club called “Water Watchers,” and participation at local events through staffing an information booth (Bay Days, Heritage Days, Blueberry Festival, and Harvest Moon Festival). You can also see us in the St. Urho’s and Heritage Days Parades and occasionally at the Farmer’s Market in Ely and Finland for a crayfish boil.

Lake County’s AIS efforts are funded through a county tax bill, passed in 2014 at the Minnesota State Legislature, which provides funds for aquatic invasive species (AIS) prevention. Each year, $10 million is to be provided to Minnesota counties to support AIS prevention programs. AIS efforts in the county are coordinated by Lake County Soil and Water Conservation District (SWCD).

For more information about Lake County’s AIS program, contact the AIS Coordinator at or at the Lake SWCD Office at (218) 834-8370.