For the first time, Minnesota's 800,000 boaters will encounter mandatory roadside check stations this spring at which their vessels will be inspected for aquatic invasive species -- part of a statewide crackdown to slow the spread of exotic critters and plants.

Motorists towing boats will be told to pull into check stations staffed by Department of Natural Resources conservation officers and boat inspectors, the agency announced Friday. Boats that fail inspections will be sent to a nearby decontamination area to be high-pressure-washed with hot water.

But their owners won't get off clean. Those caught violating state laws against transporting zebra mussels, Eurasian water milfoil and other invaders can expect citations and fines instead of warnings, as in previous years. "We're done educating,'' said Jim Konrad, DNR enforcement chief. "If you get caught violating invasive species laws, you should expect a citation.'' Fines are $50 and up.