Invasive species are introduced organisms that become overpopulated and negatively impact their new environment. The LMAC is currently managing two invasive weeds in Lake Massapoag: variable milfoil and fanwort. Professional invasive weed surveys have been conducted yearly from 2016 - 2021. Maps of the weed surveys are available here.
Invasive weeds in the southern and western coves were treated with a herbicide in 2014. Because Lake Massapoag has an endangered flowering plant in some shoreline areas, we were required to lower the level of the lake 8 inches before herbicidal treatment, so that the endangered plant would not be affected. The lagoon, which lies south of the Community Center, was treated with a herbicide in 2018.
The town has also conducted annual diver-assisted suction harvesting (DASH) for weed control in the southern end of the lake, and in Fletcher’s Cove from 2017 through 2020.
Plans for 2022 DASH will be posted here when available.
Learn more about fanwort and variable milfoil here.
Native aquatic weeds have been spreading in the eastern end of the public swimming area at Veterans Memorial Beach. The 2021 survey shows they include waterweed, naiad spp., tapegrass, spikerush, and bladderwort. Plans for weed remediation for safety in the swimming area will be posted here.
Invasive Asian Clams
Asian clams were found in Lake Massapoag in 2014, eradicated by the hard work of Cliff Towner and Greg Meister, but have recently been seen on the shore in 2022.