A public boat ramp at the south end of Messalonskee Lake in Belgrade has become the focus of a statewide debate over how best to stem the spread of invasive species in Maine. Leaving the ramp, boaters enter a marsh infested with variable leaf water milfoil, a fast-growing aquatic weed that has invaded several acres of the long lake north of Augusta. Boaters spread the milfoil around the lake and, if they don’t carefully clean their boat, take some with them to the next lake they visit.

The Department of Environmental Protection this year will spend close to $600,000 on milfoil control. The Department of Inland Fisheries and Wildlife will spend another $400,000. The money comes from stickers boaters must buy to launch their boats in Maine. The stickers come with lengthy instructions about checking for and removing milfoil.

Lakefront property owners want the state to close the public boat launch. State officials are hesitant to do this because, they fear, it would set a bad precedent of putting public water bodies off-limits to the public. There are two other boat launches on the lake, although neither is paved and both are smaller than the state-owned ramp. Still, it is hard to see how closing one boat ramp will solve the problem unless the infested areas of the lake are also closed to boat traffic, something the state could do.

Everyone who uses lakes and ponds in Maine – fishermen, boaters or lakefront camp owners who see their property values decline as the weed spreads – has a lot to lose if invasive aquatic plants are not kept in check. Maine is in a better position than most other states. It has found only two of the 11 known invasive aquatic plant species that have arrived in the United States. Variable leaf milfoil has been found in 15 lakes and ponds and hydrilla, an even worse invader, has only been documented in Pickerel Pond in York. Maine has more than 6,000 lakes and ponds so there is the potential for much more damage.

The state is right to stress education through signs and brochures that warn of the plants’ dangers. But, education isn’t enough.

Boat-wash stations have been set up at some ramps. Not everyone uses them. Hundreds of volunteer inspectors have been trained and stationed at dozens of boat launches, mostly in southern Maine. Not everyone agrees to have their boat inspected, however, and there is no way that milfoil inspectors can be placed on every boat launch on every lake. The state now plans to station a paid inspector at the Messalonskee boat launch every weekend this summer.

While all of this is helpful, if they truly want to keep milfoil and other invasive species out of the rest of Maine’s waterbodies, the state and lake associations must get even more serious about the problem. One way to ensure that Messalonskee does not pose a threat to nearby lakes is to temporarily close it to boat access and hire people to pull up all the milfoil. State officials will say this is impractical and will cost too much. But no one has come up with an estimate for how much it will cost. Will it cost more than the revenue lost from lakes that no longer attract fishermen and boaters from other states? Could a group of eager college students do it in a summer? No one knows because it hasn’t been seriously discussed.

Maine should start with this question: Does it want to be known as the state that made a half-hearted effort to eradicate milfoil and failed or as the state that attacked it aggressively and, maybe, succeeded?