Zebra mussels are a small, striped, fairly unassuming shellfish that have made their way into many Minnesota waterways. They can be found in the Mississippi River system, St. Croix River, in the Brainerd area and in Lake Mille Lacs. The problem with zebra mussels is they reproduce at a stunning rate, they kill native mussels, foul motors and beaches, and can wreak havoc on native fisheries and businesses that rely on fishing and tourism.
"Minnesota and other states east of us are at a crisis level as far as the zebra mussel goes," said South Dakota Game Fish and Parks Fisheries Program Administrator Dennis Unkenholz. "Recent discovery of zebra mussels in Nebraska indicates they are moving west".
These mussels cling onto anything hard, especially boat hulls and trailers, and can live out of water for quite a while. The immature stage of zebra mussels, called veligers, are very small and cannot be seen.
Boaters must disinfect bilges, live wells and anywhere water can accumulate in their boat. Even the water remaining in the boat motor can contain veligers.
"If you travel out of state with your boat and trailer, we are encouraging everyone to wash, disinfect, and inspect their rigs before putting it back in the water here," Unkenholz said.
Zebra mussels strip the water of plankton, allowing sunlight dependent plants and organisms to flourish. Many fisheries in Wisconsin and Michigan have been destroyed by the mussels. The sharp shelled mussels also wash up dead on the shore by the thousands, ruining beaches for miles. Zebra mussels can foul irrigation and municipal water intakes, however the most significant impact is the change in the biological community as a result of zebra mussel infestation.
"We really don't have the funding to monitor every boat landing in the state to make sure that these mussels, and other invasive species don't come across our borders. It is really up to each individual and it is critical that people take the time to do this," said Unkenholz.
Other invasive species such as curly pondweed and Eurasion Millfoil have found their way into South Dakota waterways, choking of marinas and large stretches of shoreline.
"The Hipple Lake area near Pierre is a perfect example of an invasive species taking over," Unkenholz said. "The curly pond weed takes over that fishery for two months and makes it impossible for boaters to get around without having it tangle up in motors and wrap around legs of swimmers and skiers. You can pretty much forget about fishing that area in the summer. It is choked off. So it can and does happen here."
Mussels, millfoil, curly pondweed, purple loostrife, and other invasive species such as the silver carp, spread quickly. Once it they are introduced to a water, it is nearly impossible to stop them from spreading.
"If you look at some historically wonderful fisheries in Michigan, they have been destroyed. You are talking about millions of dollars in industry related to fishing, that is gone. I don't want to see that happen here," said Unkenholz.
The 2006 South Dakota Fishing Handbook has a listing of carwashes throughout the state that are set up to handle the washing of boats.