LEWISTON – State officials signaled Friday that they plan to step up enforcement to protect Maine’s lakes and ponds from invasive aquatic species.

“We’ve spent a couple of years educating folks they need to have those stickers and they need to do those inspections,” said Deputy Commissioner Paul Jacques of the Maine Department of Inland Fisheries and Wildlife.

“We’ve just been giving them friendly reminders and pats on the back, and maybe it’s time we take the next step, much like my father did, where the pat on the back turns into a little more direct and a little lower.”

Jacques was the keynote speaker at the fifth annual Maine Milfoil Summit, which was attended by about 200 people at the University of Southern Maine’s Lewiston-Auburn campus.

Diana Sanderson, who owns a camp on Pitcher Pond in Lincolnville and Northport, said she would share what she learned at the summit with members of the Pitcher Pond Association.

“It was so nice to hear Paul Jacques saying that prevention is the key,” Sanderson said. “That’s what we’ve been trying to get across to people.”

Anyone who transports an alien plant or places a contaminated boat in a lake faces a fine of $500 to $5,000.

According to the chief of the Maine Warden Service, Col. Tim Peabody, wardens checked 15,000 boats and 29,000 fishermen last year and issued just three warnings for transporting invasive plants and no summonses.

“My goal this summer is to continue to step up the enforcement on the transportation of plants,” Peabody said. “In other words, people leaving the boat ramp with plants on their boats, trailers, any parts of their vehicles, we need to start prosecuting those types of persons. I’m not sure how popular that’s going to be.”