Threats:
Dense water chestnut growth can be impenetrable and can easily choke out
the water bodies in which it invades, outcompeting native vegetation,
reducing oxygen levels which may increase the potential for fish kills,
and providing little value to waterfowl. Dense infestations of water
chestnut make swimming, boating, and other recreational activities
nearly impossible. Its sharp spiny fruits wash ashore and can be
hazardous, inflicting painful wounds to those who step on them.
Distribution: Water chestnut's native range is Europe, Asia, and
Africa. First introduced into the northeastern United States in the late
1800s, water chestnut currently infests waterbodies in Vermont New York,
and Massachusetts. Maryland and Virginia used to have populations of
water chestnut but management activities were successful in eradicating
the plant In Vermont water chestnut was first reported in southern Lake
Champlain in the 1940s. More than 300 acres of southern Lake Champlain
are infested; the northernmost population in the lake is found in McNeil
Cove in Charlotte. Populations have also been found in five additional
Vermont waterbodies in the Lake Champlain Basin.
Control: Because water chestnut is an annual plant effective
control can be achieved if seed formation is prevented. Herbicides and
mechanical removal methods have been used. Mechanical harvesting and
cutting, and handpulling are the methods currently being used in Vermont
to manage this species.
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