The infestation of invasive aquatic plants in New England’s lakes and ponds is the biggest threat to our waters and could cost millions of dollars in reduced property taxes, removal expenses and lost tourism dollars. Heavy plant growth causes entanglement of boats and motors in thick weed beds, causes problems for fishermen, and represents a nuisance and potential danger to swimmers.

Recreationalists who enjoy the waters the most are the most likely cause of the spread of milfoil. The plant can break apart easily due to wave action caused by boaters, swimmers, fishermen and other animals. Once these fragments settle to the bottom of the water, they take over and will grow to the surface of the water.

Invasive aquatic plants are introduced plants that have adapted to living in, on, or next to water, and that can grow either submerged or partially submerged in water. Aquatic nuisance species (ANS) are nonindigenous species that threaten the diversity or abundance of native species, the ecological stability of infested waters, and/or any commercial, agricultural, aquacultural, or recreational activities dependent on such waters.

Invasives that can be found in New England include:

Brazilian Waterweed (Egeria densa)
Brittle Water Nymph (Najas minor)
Curly Pondweed (Potamogeton crispus)
Didymo (Didymosphenia geminata)
Eurasian Watermilfoil (Myriophyllum spicatum)
Floating water hyacinth (Eichhornia crassipes)
Hydrilla (Hydrilla verticillata)
Variable Leaf Milfoil (Myriophyllum heterophyllum)
Water Chestnut (Trapa natans)