Eurasian watermilfoil was accidentally introduced to North America from Europe and reached the Midwest sometime between 1950 and 1980. The leafy aquatic plant is spread primarily by boats but also by water birds. The plant forms thick underwater strands of tangled stems and vast mats of vegetation at the surface. It can crowd out native plants, and in shallow areas interfere with boating, fishing and swimming. It may become entangled in boat propellers, or attach to keels and rudders of sailboats. Stems can become lodged among any watercraft apparatus or sports equipment that moves through the water, especially boat trailers. A single segment of stem and leaves broken off a plant can take root and form a new colony.
The mussels were discovered in the Great Lakes in 1988 and believed to have been brought in the ballast water of freighters. Adult zebra mussels are 1/4 to 1 1/2 inches long and have D-shaped shells with alternating yellow and brownish colored stripes. Female zebra mussels can produce 100,000- 500,000 eggs per year. Mussels attach to boats, nets, docks, swim platforms and boat lifts, and can be moved on any of those objects. They also can attach to aquatic plants, and microscopic larvae can be carried in water in bait buckets, bilges or other water moved from an infested lake or river. Water between 140 and 160 degrees can kill zebra mussels after about five seconds. Letting watercraft sit and dry for at least five days will also kill any zebra mussels.
Wisconsin: Boaters are required to drain all water from boats, containers and fishing equipment when leaving state waters or entering the state over land. The state also requires boaters to inspect the vessel and remove any attached aquatic plants or animals before launching or after removing the boat from the water. In most cases, fishing minnows used in the state must be purchased in Wisconsin. Fines can run up to $767 for first offenses.
Minnesota: Boaters are required to have boat plugs open or removed when transporting watercraft. After leaving a body of water, they are required to drain any bilges, live wells and bait containers. Any visible vegetation needs to be removed from the boat, trailer and vehicle. The DNR also recommends debris and mud be removed. Violating the state’s aquatic invasive species regulations can result in either a civil or criminal penalty. Fines start at $100 and go up to $500.