While these species often find their way to US ports on the seaboard and in the Great Lakes on international cargo ships, they are then often spread to inland waters by recreational boaters who are unaware of the dangers they pose. Zebra mussels, hydrilla, Eurasian milfoil, water shestnuts, piny waterfleas, and Asian clams are just a handful of the thousands of such species that have
established themselves in the waters of the District over the years.
As FSO-MS of the Bridge Flotilla (Crown Point NY/VT), I have made the detection, reporting, and, where possible,
eradication of these species a priority. In particular, I am battling the spread of Trapa natans (water chestnut) in upstate New York and Vermont.
Unlike the similarly-named water chestnuts found in the supermarket, this plant has no natural enemies and no food value. It spreads rapidly in rosettes of leaves on the water surface.
Top, New water chestnut infestation at Rockford, New York.
Bottom, Pulled water chestnuts showing unripe seeds.