top of page

AIS Information

Aquatic invasive Species (AIS) are species that are not native to Minnesota but have been introduced into our lakes and rivers. AIS cause economic or environmental harm or harm to human health. AIS includes both aquatic plant and aquatic animal species. 

Those that currently pose the greatest threat to Minnesota waters are:

Starry Stonewort - The latest invasive species to be found in Minnesota, Starry stonewort is a grass-like form of algae that are not native to North America. The plant was first confirmed in Minnesota in Lake Koronis in late August of 2015. Plant fragments were probably brought into the state on a trailered watercraft from infested waters in another state. Starry stonewort can interfere with recreational and other uses of lakes where it can produce dense mats at the water's surface. These mats are similar to, but can be more extensive then, those produced by native vegetation. Dense starry stonewort mats may displace native aquatic plants

Zebra Mussels - small, fingernail-sized animals that attach to solid surfaces in water. Adults are 1/4 to 1 1/2 inches long and have D-shaped shells with alternating yellow and brownish colored stripes.  They may attach to motors and clog water intakes. Their shells are sharp can cause cuts and scrapes when people come in contact with them. Zebra mussels filter plankton from the water which can increase water clarity in the short-term, but over the long-term this can lead to denser and deeper lake weed growth and impact fishing by reducing food available for larval fish.


Eurasian Watermilfoil - typically has 12 to 21 pairs of leaflets. The native northern watermilfoil, with which it is often confused, usually has 5 to 9 pairs.  In nutrient-rich lakes, like Rice Lake, it can form thick underwater growth and thick mats of vegetation on the water's surface. In shallow areas, it can interfere with boating, fishing, and swimming. It can also crowd out important native aquatic plants.


Bighead and Silver Carp - large filter feeding fish that can weigh up to 110 pounds for bighead carp and 60 pounds for silver carp.  They are voracious feeders that eat huge amounts of plankton and detritus. They compete for food with native species including larval fishes and some adult fish. Silver carp can jump up to 10 feet out of the water when disturbed by sounds of watercraft , often jumping into boats and can injure boaters, personal watercraft operators, and water skiers.

For more information, checkout the DNR website or the University of Minnesota Aquatic Invasive Species Research Center (MAISRC) website.

What You Can Do

The spread of AIS can be prevented if boaters perform the AIS activities required in Minnesota State Statutes. It is the personal responsibility of watercraft operators to properly:

  • CLEAN all visible aquatic plants, zebra mussels, and other prohibited invasive species from watercraft, trailers, and water-related equipment before leaving any water access or shoreland.


  • 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.


  • DISPOSE of unwanted bait, including minnows, leeches, and worms, in the trash. It is illegal to release live bait into a waterbody or release aquatic animals from one waterbody to another. If you want to keep your live bait, you must refill the bait container with bottled or tap water.

You may not...

  • Transport aquatic plants, water, or prohibited invasive species such as zebra mussels or Eurasian watermilfoil.

  • Dump live bait into state waters, on shore, or on the ground.

  • Launch, or attempt to place, watercraft, trailers or equipment with aquatic plants, zebra mussels, or prohibited invasive species into any state waters.

  • Everyone who uses Minnesota lakes and rivers has a responsibility to stop the spread of AIS from one body of water to another.  Don't be part of the problem, be part of the solution.  

bottom of page