More boat inspectors have gone on patrolling Minnesota lakes and rivers to help stop the spread of invasive species such as zebra mussels.

Authorities have said they are going to be more aggressive regarding issuing fines to violators as they try to change boater behavior. The Star Tribune has reported that counties have also been beefing up inspections because of the $10 million in state funds.

Greg Salo, of the Department of Natural Resources' enforcement division, said 148 conservation officers of the state have been out issuing tickets over the holiday weekend. He mentioned that 17% of the boaters stopped at checkpoints, disobeying rules.

Salo said in the first few years, they tried to focus on education; it's a type of culture change for people. He added that but now they have reached to the point, they have understood that in order to get the rest of the public to change, they have to take a stronger approach.

Over 500 Minnesota rivers, lakes and wetlands have been listed as infested, including more than 200 with zebra mussels, which though can clarify water but at the same time can clog motors and hurt swimmers with their sharp shells.

There came a change in the law in 2010, since then boaters have to remove the drain plug before transporting a boat. They also must remove weeds and drain water from bait buckets and livewells, or would have to pay a $100 to $150 fine. Transportation of zebra mussels results in a $500 fine.

Salo said, "It's really simple - just pull your plug and clean your boat; it takes less than five minutes to do that. It only takes one boat to infect a lake".