Minnesota conservation officials will take new steps in 2012 to stop the spread of invasive species. Department of Natural Resources officials say they will conduct random road checks for the first time ever in order to stop species from hitchhiking on trailers, boats and other vehicles. They will also buy 20 decontamination units to put at waters infested with zebra mussels. Boaters would have to use the units before they leave a boat landing. The state has three such units so far on lakes with zebra mussels. The agency also plans to hire 150 more watercraft inspectors to work at boat launches to educate boaters and point out potential problems. The announcements came at the agency’s annual roundtable convention for outdoors activists on Friday.