As Asian carp, zebra mussels and other invasive species invade our waters, the reality of Minnesota's long tradition of carefree boating is coming to an end. The state is ramping up its defenses by stopping drivers at mandatory roadside checks, doubling fines and increasing a fleet of boat decontamination units.

Got aquatic weeds hanging off your boat or trailer? The fine goes from $50 up to $100 on July 1. The DNR says it'll have 140 inspectors out checking compliance with the boating laws meant to limit the spread of invasive species such as zebra mussels and Eurasian watermilfoil.

The Department of Natural Resources says there's hope that a chemical might help stop the spread of the invasive aquatic species that is fast spreading in Minnesota lakes. The DNR treated Rose Lake in Otter Tail County last fall, and two divers who scoured the lake this week did not find any zebra mussels.

Property owners on three Carver County lakes are suing Minnesota DNR Commissioner Tom Landwehr. They argue that it's up to the state agency to develop an approach that will stop the spread of invasive zebra mussels. And they say Commissioner Landwehr has failed in that duty.

Several lake associations in Carver County wanted to force the DNR to set up a boat inspection station to keep the invasive mussels from spreading to new lakes. But the court agreed with the DNR, which says it is only authorized to set up the stations at boat launches.

Tougher laws aimed to prevent the spread of aquatic invasive species, like zebra mussels and spiny waterfleas, go into effect Sunday, July 1 -- doubling fines for Minnesota boaters who are caught violating the rules. The Department of Natural Resources says about 20 percent of boaters are not taking the basic precautions to comply with the laws. The new fines range from $100 to $500 dollars.