An aggressive invasive aquatic plant that can take over other species’ habitats in Maine’s lakes has been found for the first time in Hancock County.
Officials recently determined a plant sample collected at Alamoosook Lake in Orland last summer was the invasive variable watermilfoil, raising concerns about potential spread in the area.
The fast-growing plant that lives along the shoreline can, when left unchecked, interfere with boating and swimming, cause property values to decline and colonize native plants’ habitats.
The extent of the infestation in Alamoosook is unknown but state officials and other organizations are working to root out the plant before it gets a firm hold in the 997 acre lake.
The Maine Department of Environmental Protection plans to begin surveying the lake for the watermilfoil later this year and will remove the plant by hand, said John McPhedran, a biologist with the state’s invasive aquatic species program.
This particular species is one of the most prevalent invasive aquatic plants in Maine. First found in Sebago Lake in the 1970s, the variable watermilfoil can choke out other plant life, especially in shallow areas.
“They tend to grow and dominate habitat,” McPhedran said.
The best chance for a successful removal of the plant is by pulling it out before it spreads.
“Finding the plant early when it’s not widespread provides a window of opportunity to manage and remove whatever is growing there,” McPhedran said. “We’re hoping it’s confined to a small area.”
Katie Greenman, a member of the Alamoosook Lake Association Board of Directors, hoped that the infestation was in its early stages and said it’s a major concern to local communities and the surrounding watershed.
The association, Lake Stewards of Maine, DEP, Hancock County Lakes Association and other groups in the area are all pitching in to try to eradicate the plant before it gets too far along.
“Mitigation of advanced infestations would present a major financial burden to the community,” Greenman wrote in a notice to surrounding towns.
Alamoosook Lake is popular with fishermen and boaters. It’s also home to the first federal fish hatchery in the US and has a large alewife run.
The plant is often spread lake-by-lake through boats or other human activities. A plant can be stuck in a propeller or hanging from a trailer and then taken to a non-infested body of water.
Once it starts growing in a lake or pond, it can also spread further downstream naturally, or via bird feces — putting other Hancock County waters potentially in danger, according to McPhedran.
Variable waterfoil is confirmed to be in about 30 lakes and ponds in Maine and has been eradicated in about five. Its only reported presence in Hancock County is in Alamoosook Lake. There is also one infested lake Down East.
Officials say one of the best ways to prevent the spread of these and other invasive aquatic plants is for boaters to inspect their boats after a day on the water. Spending just a few minutes by looking for any plants left clinging to boats can cut down on the chances of transporting invasive species to new lakes.
“Any lake is at risk,” McPhedran said. “We really need to do our part to help stop spreading these plants around.”
Correction: An earlier version of this story used a featured photo of a type of milfoil that was not the type that was found in Alamoosook Lake.