BELGRADE – A muddy boat ramp at the south end of Messalonskee Lake is at the center of a debate over what steps should be taken to stop the spread of invasive aquatic plants in Maine.

The Route 27 ramp is at the edge of a marsh infested with variable leaf water milfoil, a fast-growing aquatic weed that has overwhelmed acres of water.

Many fear the highly used public launch is a ticking time bomb threatening other lakes in the region. Others feel that closing the ramp would undermine Maine’s tradition of open access to its lakes and rivers.

A week ago, fears that fragments of milfoil will accidentally be dragged away prompted Maine’s Congress of Lake Associations to ask the state to close the ramp until it no longer poses a danger.

The state has never closed a boat ramp because of the presence of an invasive plant, so whatever happens at Messalonskee Lake will set precedent, said Mark Latti, spokesman for Maine’s Department of Inland Fisheries and Wildlife.

“Whenever we’re restricting access, or whenever there’s a chance of restricting access, it’s certainly something that we want to do very carefully,” Latti said.

The decision on whether to close the Route 27 ramp will be made by the commissioners of the fisheries and environmental protection departments, Roland “Danny” Martin and Dawn Gallagher, respectively, in consultation with Conservation Commissioner Patrick McGowan.

Three weeks ago, the three commissioners and Col. Tim Peabody, head of the Maine Warden Service, met in Belgrade with members of area lake associations, legislators and municipal officials to discuss closing the ramp.

Lake association members attending the session tried to emphasize that they do not want to limit access to Messalonskee Lake, said Michael Little, executive director of the Belgrade Regional Conservation Alliance.

“Nobody’s trying to deny access,” Little said. “Messalonskee’s got two other boat launches, one of which, granted, is not very good, but by closing one you’re not closing off public access to the lake.”

Caroline Feely of the Messalonskee Lake-Snow Pond Association said much of the impetus for closing the ramp comes from a survey last year that showed 42 percent of boats coming out of the water carried plant fragments. Of those plants, 80 percent were believed to be variable leaf water milfoil.

“We need to have controlled access to that ramp, or none at all,” Feely said.

But others like Heath Morris, president of the Maine BASS Federation, oppose shutting down any boat launches.

“Education is the key to protecting lakes from milfoil, not shutting down boat launches, and not surface use restrictions,” Morris said.

But those who favor closing the southern ramp note that only one accidental transfer of milfoil on a boat motor or trailer could set off a disastrous infestation elsewhere.

Despite such arguments, some foresee legal challenges if the ramp is closed and believe the issue will be decided by the courts.

Paul Jacques, deputy commissioner of fisheries and wildlife, said precedents set in the case could have far-reaching implications.

The three commissioners have not set a date for their decision, but John McPhedran of the environmental protection department said he believes it will be made soon.