Aquatic Invasive Species (AIS)

Aquatic Invasive Species are water-dwelling plants, fish, invertebrates, and microbes that are not native to Minnesota.  These species tend to propagate and spread rapidly, out competing native species, and negatively impacting the ecology, economic benefit, and recreational enjoyment of our waters.  More information on AIS can be found on the Minnesota DNR’s AIS website or the MN Aquatic Invasive Species Research Center (MAISRC) homepage.  The Districts AIS Program can be summarized in four categories: Watercraft Inspections, Decontaminations, AIS Education, & AIS Early Detection.

Watercraft Inspections

In an effort to stop the spread of AIS, North St. Louis Soil & Water Conservation District first implemented a watercraft inspection and decontamination program in 2016 on Lake Vermilion in partnership with the Vermilion Lake Association.  This program, generously funded by St. Louis County AIS Prevention Funds, has since grown.  From year to year the District now hires around 35 seasonal staff to perform over 20,000 watercraft inspections on upwards of 30 different lakes around the region.  The success of this program would not be possible without support from St. Louis County, Lake Soil & Water Conservation District, Koochiching County/SWCD, the many local governments and Lake Associations around the region, Resort Participants, and collaboration with the MNDNR and other Watercraft Inspection Programs from across the state.

Watercraft inspectors are trained by the MNDNR and are authorized to deny launch if a watercraft is contaminated with Aquatic Invasive Species.  As authorized agents of the MNDNR, watercraft inspections are required before entering and after exiting a body of water if an inspector is present (MN Statute 84D).


FREE decontamination services are provided around MN during the open water season (generally May thru September).  During a decontamination, MNDNR trained and certified staff will soak, flush, and/or spray off areas of boats/equipment that are at high risk of transporting AIS.  Hot water (120°F for 2 minutes, or 140°F for 10 seconds) will be used to kill AIS.  If attached foreign material cannot be removed by hand a high-pressure spray can be used to remove the material.  In general, decontaminations can take 10-30 minutes.  The District generally operates six units around northern St. Louis County.  Decontamination hours and locations around MN can be found HERE.

AIS Education

Minnesota has some of the most pristine waters and it is our job to keep them free of Aquatic Invasive Species.  The Districts goal is to educate as many people as possible about the risk of AIS and how simple actions can help prevent the spread of AIS.  Education starts at the public accesses with our Watercraft Inspectors who are trained to teach lake users about AIS and the importance of performing watercraft inspections. We also spread the word of AIS prevention through a number of informational booths and water-based events.  If you, your group, or your organization would like to learn more about AIS and AIS prevention feel free to contact the Districts AIS Program Coordinator to set something up!

AIS Early Detection

Using trained staff and volunteers the District continuously monitors lakes around the region to check for any undocumented cases of AIS and to verify the presence/absence of infestations.  Understanding the distribution of AIS in our area helps us adjust our prevention plan to reduce the risk of spreading the AIS any further.  Education and spread prevention are the most efficient and cost-effective way to protect our pristine waters, and understanding the current state of a lake/river helps us keep the public informed.  If you think you have uncovered a new infestation northern St. Louis County that is not already on the MNDNR infested waters list, please contact our AIS Program Coordinator to investigate.  The Coordinator can also be contacted if you are interested in volunteering as an early detector on your lake (training would be provided)!

How can you help Stop Aquatic Hitchhikers?

By following simple procedures each time you leave the water, you can stop aquatic hitchhikers.

  • CLEAN watercraft, trailer, motor, and water-related equipment. REMOVE visible aquatic plants, mussels, other animals, and mud before leaving any water access.
  • DRAIN water-related equipment (boat, ballast tanks, portable bait containers, motor) and drain bilge, livewell and baitwell by removing drain plugs before leaving a water access or shoreline property. Keep drain plugs out and water-draining devices open while transporting watercraft. It’s the law!
  • DRY watercraft for 5 days and boat lifts/docks for 21 days minimum before introduction into a new body of water. Micro plant particles, zebra mussel veligers, and other AIS can survive in small amounts of water and can be transported to new water bodies if not given the proper dry time.
  • DISPOSE of unwanted bait, including minnows, leeches, and worms, in the trash. It is illegal to release bait into a waterbody or release aquatic animals from one waterbody to another. If you want to keep your bait, you must refill the bait container with bottled or tap water.
  • Habitattitude – Adopt a conservation mentality. Protect our environment by not releasing unwanted fish and aquatic plants from your aquarium, backyard pond or water garden. If you have an undesirable aquatic plant or fish species in your aquarium or water garden, it is important not to release these plants or animals into the environment. They have the potential to create negative impacts on our natural environment.


Read on the latest research at Minnesota Aquatic Invasive Species Research Center! There are nearly three dozen AIS — about an equal number of plants, fishes, invertebrates, and microbes — that MAISRC currently considers high-risk for Minnesota and in need of research into their detection, prevention and control. Learn more about some of these priority species by watching the video below.


Answers to Common AIS Questions

  • AIS can be stopped! Humans are the most common contributor to spreading AIS, not waterfowl or any other animal.
    • The spread of AIS follows the highways not the flyways. There is no evidence or reliable research that shows the spread of AIS being caused by birds or any other land creatures.  Although there is evidence of most new infestations first discovered near boat launches.
  • Inspections DO lower the risk of AIS transfer.
    • A proper watercraft inspection usually takes less than 3 minutes and is the easiest way to be sure you are not spreading AIS. It is also the best way to make sure you are compliant with MN state laws, keeping you out of trouble with the MNDNR Conservation Officers!
  • Introducing a new invasive to a waterway only compounds issues.
    • There are many other aquatic invasive species on their way to Minnesota that can be more devastating than zebra mussels. Quagga mussels can out-compete zebra mussels for food and live in much deeper depths of water. Hydrilla is like milfoil on steroids. In addition, the impact of individual AIS becomes more complex with each invasive in a water body. Once a water body has one invasive, it becomes more important to keep any other AIS out.
  • Inspections are necessary between launches, even in non-infested waters.
    • It is impossible to know which lake may already be infested, therefore it is necessary to assume all water bodies may be infested. It can take 2-3 years after an infestation to discover a colony of mussels.
  • Decontamination is worth the time.
    • On average, ballast tank decontamination will take about 30 minutes. The outdrive (lower unit) of an engine will take about 10 minutes. Decontaminating an average boat without any tanks or live wells could take less than 30 minutes.
  • AIS is not in all the lakes; we can still protect much of Minnesota’s waters.
    • Many of our bodies of water remain free of any AIS, and it is our duty to keep it that way! For example, as of 2023 only 9 of the 738 lakes (1%) in St. Louis County are infested with zebra mussels.

Take the MNDNR Pledge to protect MN Waters!

North St. Louis Soil and Water Conservation District

505 3rd St N, Ste A,
Virginia, MN 55792
Office Hours: 8:30 - 4 Monday-Friday and by appointment

Upcoming Board Meetings

Wednesday, August 14th at 10:30 a.m.
This meeting will be held in-person at the SWCD office. A link is available to join virtually by contacting Anita at least 2 hours prior to the meeting. The public is welcome to attend.

View Meeting Schedule »
Minnesota Clean Air and Water Legacy Amendment