Variable Leaf Milfoil (Myriophyllum heterophyllum, or VLM) was first discovered by a Courtesy Boat Inspector (CBI) on a boat leaving the Annabessacook Public Boat Launch in 2013. This led to a comprehensive survey that identified a VLM infestation in Annabessacook Lake.
VLM has been identified in Annabessacook, Jug Stream, Cobbossee Lake and Stream, Horseshoe Pond, and Pleasant Pond. Control methods include herbicide treatments, and manual removal by hand as well as Diver Assisted Suction Harvester (DASH).