Zebra Mussel Update - Little Boy 6/24/2026

Invasive Species

Little Boy Zebra Mussel Update - 6/24/2026

As promised, WLBCR Lakes Association wants to keep you informed about the zebra mussels (ZM) found near the Little Boy public access. The first ZM was found on May 26, 2026, on a PVC-style settling sampler by a longtime lake-property volunteer monitor. It was an adult, approximately 0.75 inches. A second ZM, approximately 0.625 inches long, was found on May 27, 2026, by DNR AIS staff on a native mussel near the public access, approx. 630 feet from the original report site. DNR designation as infested waters was publicly reported on June 6, 2026.

As Little Boy Lake is located upstream of Inguadona Lake and Leech Lake, which are both infested with ZM, Rice Lake was also listed due to its connected waters to Little Boy Lake, as it lies between Little Boy and Inguadona Lake. Because the ZM were not isolated, and the confirmed locations were spread a fairly good distance (about 630 feet), this is an indicator that they are most likely lake-wide. Due to the widespread assumption by the MN DNR, Little Boy does not qualify for treatment under current policies. Treatment permits are only issued for small, isolated populations. There are currently no known effective treatments. We will continue to look for opportunities that may help our lakes and others.

We are grateful for the strong support from our members and lake property owners who have volunteered to monitor 18 settling samplers from their docks in Wabedo, Little Boy, Cooper and Rice. Their help will improve our understanding of where ZM are present and how established they may be.

Once established, ZM populations grow quickly, reaching maturity in about 1 to 2 years, and can produce up to 700,000 offspring per square meter. Warm water temperatures, abundant food (phytoplankton), and stable substrates such as rocks, docks, and boat hulls support their growth.

ZM can attach to engine cooling intakes, hoses, strainers, and internal passages. Their microscopic larvae (veligers) can enter cooling system and grow into adults, blocking screens, hoses, and passages. This can cause engine overheating, reduced cooling efficiency, and potential catastrophic engine failure with an expensive repair or replacement.

Tips to protect yourself and water equipment:

- Keep boats and motors fully out of the water; tilt lower units as needed.
- Limit how long water equipment stays in the water, including paddleboats, canoes, and kayaks.
- Wear protective lake shoes and gloves when working with docks, lifts, and related equipment.
- If buying or selling a dock or lift, remember that Minnesota AIS law requires that it dry at least 21 days. ZM can settle inside hollow structural supports where they are difficult to see.
- Check shoreline for any potential ZM on washed-up vegetation, native clams or mussels, riprap, and the underside of rocks.
- If using lake water for irrigation, pull equipment out of the water when not in use.

It’s critical NOT to transport or spread ZM when traveling to another lake. See MN DNR infested waters list: infested-waters.xlsx

Courtesy decontamination stations are available nearby if watercraft cannot dry for 5 days before entering non-infested waters.

Cass County: Cass County MN - AIS Prevention and Management.
MN state DNR Decontamination Stations: Courtesy Decontamination Sites in Minnesota.

As of now, no ZM have been found in Wabedo or Cooper. We will continue testing for veligers (ZM larvae) in Wabedo, as we have done for the past 4 years, with results to date reported as “absent”. Cooper has no public access, which helps reduce risk. Other early detection monitoring efforts will continue, including settling samplers at both public accesses and Little Boy Resort, and rake throws to examine vegetation and invertebrates at the public accesses. AIS watercraft inspectors will continue to be scheduled at both Little Boy and Wabedo.

The long-term impact on our lakes remains uncertain. In the meantime, please watch for signs of ZM around your property, including on washed-up vegetation, under rocks, on native clams, and on watercraft equipment. If you find something suspicious, contact Cindy Gackle, 612-751-7921, or Bob Krahn, 763-350-1962.

We also want to keep other aquatic invasives out of our lakes, including Eurasian watermilfoil, starry stonewort, and spiny water fleas. Please continue to follow Minnesota AIS laws:

1. Clean watercraft, trailers, gear, and equipment to remove aquatic plants and prohibited invasive species.
2. Drain all water and leave drain plugs out during transport.
3. Dispose of unwanted bait in the trash. Never release bait, plants, or aquarium pets into Minnesota waters.
4. Dry docks, lifts, and rafts for 21 days before moving them from one waterbody to another.

Thank you,

WLBCR AIS Team

2025 Lake Access Surveys

During 2025, WLBCR hired PLM Lake and Land Management Corp to perform two surveys of our public boat access sites on Wabedo and Little Boy Lakes. With the threat of Aquatic Invasive Species throughout the state of Minnesota, these surveys are intended to search areas where the highest likelihood of newly discovered AIS may be found. Additionally, an inventory of all species within the designated search areas were recorded.

Based on the searches, Wabedo and Little Boy Lakes were determined to not have any new high priority invasive species that were observed.

With the threat of Aquatic Invasive Species throughout the state of Minnesota, these surveys are intended to search areas where the highest likelihood of newly discovered AIS may be found. Two surveys of public boat access sites for the Wabedo, Little Boy, Cooper, and Rice Lakes Association were conducted on June 24th and September 2nd, 2025.

Wabedo and Little Boy Lakes appear healthy and support many different and thriving native species. Water clarity was favorable and conducive for surveying. It is PLM’s recommendation that the Wabedo Little Boy, Cooper, and Rice Lakes Association continue educating residents of the lakes and guests to the area about the importance of maintaining clean and dry equipment to help mitigate the spread of invasive species and to continue surveying the areas of greatest concern.

Click here to read entire report

Zebra Mussels in Wabedo Lake?

By Bob Krahn (WLBCR Lake Association)

Aquatic Invasive Species (AIS)! The spread of Zebra Mussels and other AIS in our lakes and rivers is most commonly due to careless or insensitive boaters who forget, or simply refuse to properly clean, drain, dispose, and dry their equipment when moving from one body of water to another. Decontamination stations are strategically located to assist boaters in ensuring clean boats when moving between lakes (https://webapps15.dnr.state.mn.us/ais_decon_sites).

August 15, 2020 a fisherman and his pals did not thoroughly clean their boat and trailer before entering Wabedo Lake. According to the boat owner, he had launched at 5:00 AM, prior to the arrival of the Cass County Boat Inspector. At approximately 11:00 AM the boat owner returned to the landing to begin the process of trailering his boat. Coincidently, volunteers Bob Krahn and Dave Sohn were sampling aquatic plants at the landing as part of an AIS effort called Starry Trek. Prior to the trailer entering the water to load the boat, the Inspector noticed a large clump of aquatic plants near the axle of the trailer. Upon further inspection, a ¼” zebra mussel was found on the aquatic plants. The boat owner claimed several times that he only fished Wabedo therefore could not have transmitted the aquatic plants and the zebra mussel to this lake. It was only after the Inspector found two (2) adult zebra mussels attached to his boat that he admitted to fishing in an infested lake recently. The aquatic plants were bagged and taken for analysis to Levy Bergstrom, Cass County Resource Specialist, where it was noticed that the aquatic plants also contained approximately 20 juvenile zebra mussels. The sample was forwarded to Nicole Kovar, DNR AIS Specialist. Levy and Nicole have since been to the Wabedo landing sampling native vegetation types. The aquatic plants found on the trailer do not apparently occur in the part of Wabedo Lake near the boat landing, reinforcing the premise that the plants were imported from an infected lake. Minnesota law prohibits the transport of Aquatic Invasive Species. The offending boater may be subject to a fine.

A dive team will search the area around the Wabedo boat landing for evidence that a zebra mussel population exists. According to Nicole, zebra mussels may, or may not have been introduced into the lake during this event. It is possible that those in the vegetation sample and the two on the boat were the only invasive mussels carried by this boater. If, however, zebra mussels were introduced into the lake, it may be several years before they reach an observable density.

Property owners on Wabedo and the connecting lakes, along with non-resident users of the lakes, should be especially diligent in cleaning their equipment and watching for signs of infestation. If you observe any suspicious aquatic species, capture a sample in a sealable bag, take a photo, and note the specific location and time the sample was taken. Record any suspicious aquatic species you find, with location and date. Report your findings to Gina Kemper: 218-537-6100; gina.kemper@state.mn.us.

Wabedo and Little Boy Lakes, which are connected by a navigable channel, have 4 (four) trained AIS Detectors living on the lakes who sample vegetation at the public landings monthly to try to detect any AIS early and, hopefully, contain the spread of any species that are introduced. As the boating season nears its end for the year, boaters and property owners should carefully inspect their boats, docks, lifts, and fishing tackle for any possible infestations.

WLBCR Updated AIS Plan

On May 16, 2020 the WLBCR Lakes Association board approved an updated AIS Plan. The plan was updated on June 22, 2020 to include information on mystery snails and crusty crayfish. The plan acknowledges and follows the Cass County AIS Prevention and Management Plan as approved by the Cass County Board of Commissioners on 3/20/2020 and supports the Minnesota state law: Clean your watercraft, Drain all water, Dispose of unused bait. The plan identifies general strategies to be implemented to educate property owners and the public, in order to greatly reduce or prevent AIS from entering the lakes.

Learning Opportunities

The Minnesota Aquatic Invasive Species Research Center (MAISRC) has made available several webinars that may be of interest to you. The full list is available at: https://www.maisrc.umn.edu/ais-detectors/webinars

In the News

Zebra mussel genome has been identified by researchers at MAISRC (MN AIS Research Center) See StarTribune article of July 11, 2019: http://www.startribune.com/minnesota-scientists-map-genome-of-invasive-zebra-mussel/512555322/

MAISRC website: https://www.maisrc.umn.edu/zebramussel-research

Minnesota Infested Waters

The Minnesota Department of Natural Resources (DNR) regularly updates the state infested waters list, which includes Minnesota lakes and rivers containing certain aquatic invasive species. There is also a downloadable Excel spreadsheet, which is the most complete version of the infested waters list. Another resource is the EDDSMaps site which lists MN infested waters. EDDSMaps www.eddmaps.org/midwest/tools/infestedwaters/

Reporting a Suspected Invasive Species

If you suspect a new infestation of an aquatic invasive plant or animal, note the date, the exact location, and, if possible, take several photos and keep the specimen (a plastic bag is fine). You may contact:
- Cindy Gackle at 612-751-7921 or
- Bob Krahn at 763-350-1962.

If neither of those two are available be sure to contact the AIS specialist for our region:

- Gina Kemper, Northwest Regional DNR AIS Specialist: 218-537-6100; gina.kemper@state.mn.us

For More Information

MAISRC (MN AIS Research Center): www.maisrc.umn.edu
MN DNR EDDSMaps www.eddmaps.org/midwest/tools/infestedwaters/
MN Lakes & Rivers Advocates: http://mnlakesandrivers.org/
MN Sea Grant: http://www.seagrant.umn.edu/
Wildlife Forever: https://www.wildlifeforever.org/
Association of Cass County Lakes (ACCL): http://www.acclakes.org/

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