Harmful exotic species

Harmful exotics pose a threat to Minnesota waters, native plants and animals, and water-based recreation, including fishing.

Currently, these harmful exotics and disease exist in Minnesota forests, lakes, and rivers. They could easily spread—and new species could enter from other states—if citizens who use state waters don’t take the necessary steps to prevent the spread of harmful exotic species.

Earthworms: Earthworms in Minnesota have been introduced from Europe. They are harmful to forests because they eat the leaf litter (duff layer) resulting in the elimination of seedlings, ferns, wildflowers, and ground-dwelling animals. Help save the forests by disposing of unwanted bait in the trash.

Eurasian watermilfoil: In shallow waters, this aquatic plant can interfere with water recreation, and its floating surface mats can crowd out important native plants. Fragments clinging to boats and trailers can spread the prolific plant from one water body to another.

Round Goby: This small bottom-dwelling fish from Europe can displace native bottom-dwelling fish and is a nuisance for anglers. It poses a threat to fisheries in the Great Lakes, where it has already entered, and in inland fisheries.

Ruffe: This small perch-like fish, native to Europe, is very abundant in the Duluth harbor. It displaces several native fish species and is a nuisance for anglers. Ruffe can be accidentally transported in bait buckets and livewells.

Spiny Water Flea: These tiny (less than 3/8”) animals, abundant in Lake Superior, can be a nuisance to anglers.

Zebra mussel: This small (1/4” to 1-1/2”) mussel from Asia displaces native mussels, disrupts lake ecosystems, and clogs industrial equipment. Zebra mussels attach to boats, aquatic plants, and objects placed in the water. The tiny larvae can be accidentally transported in livewells and bait buckets.

Fish Diseases: Diseases, such as largemouth bass virus and heterosporis, can harm game fish populations. These diseases can be moved from one lake to another in the water. Help prevent the spread or introduction of these diseases by draining water from livewells, bilges, and bait containers before transporting boats and equipment.

Exotic Species Laws
(prohibitions and restrictions)
Transportation, Launching, and Bait Harvest

It is unlawful to:
• transport aquatic plants, ruffe, round goby, zebra mussels, or other prohibited exotic species (see list below) on public roads;

• transport infested water (including in livewells and bait containers) from infested waters;

• transport live crayfish to other waters or to use them as bait in waters other than where they were taken;

• launch a watercraft with aquatic plants, zebra mussels, or prohibited exotic species attached;

• harvest minnows, frogs, or any other wild animals from infested waters for bait, except for personal use from waters that are designated as infested waters solely because they contain Eurasian watermilfoil, and for commercial use by permit. Minnows harvested for personal use from infested waters may only be used in that water body. A person cannot transport these minnows or the water to another water body.

• Nets and other equipment used in infested waters for commercial fishing must be dried for ten days or frozen for two days before using in noninfested waters;

• Water from infested waters may not be used to transport live fish.

• The addition of bleach to live wells helps prevent the spread of heterosporis.

Prohibited Exotic Species
Aquatic plants in Minnesota waters: curly-leaf pondweed, Eurasian watermilfoil, flowering rush, and purple loosestrife.

Aquatic plants not known to be in Minnesota waters: African oxygen weed, aquarium watermoss or giant salvinia, Australian stonecrop, European frog-bit, hydrilla, Indian swampweed, water aloe or water soldiers, and water chestnut.

Fish in Minnesota waters: grass carp, round goby, ruffe, sea lamprey, white perch.

Fish not known to be in Minnesota waters: bighead carp, black carp, rudd, silver carp, zander.

This entry was posted in Morrison County Record. Bookmark the permalink.