Identification
European water chestnut is an invasive aquatic plant that prefers to grow in shallow, muddy bottom lakes, rivers, and ponds. Although it typically prefers shallower areas, European water chestnut can grow in water up to four meters deep because of its long stem. It has floating leaves that radiate from the central stem in a circular pattern. Leaves have serrated edges and are triangular in shape, giving them an appearance that is distinct from any native species. The chestnuts produced by the plant are hard and “woody” with sharp spines. The chestnuts do not resemble edible chestnuts that are used in cooking.
Impacts
European water chestnut can form extremely dense colonies that shade out the native vegetation growing below the floating leaves. This leads to a decrease in plant biodiversity and makes recreation like boating, swimming, fishing, and paddling nearly impossible. Decomposition of plant material in the water column reduces oxygen in the water which can harm fish and other aquatic animals. The chestnut seeds with their sharp points can be hazardous to people if stepped on.
European Water Chestnut in the Cataraqui Region
European water chestnut plants have been found in a few areas within the Cataraqui Region, such as along the coast of Wolf Island and in the Cataraqui River downstream of Kingston Mills. However, management efforts by Parks Canada, and Ducks Unlimited Canada have greatly reduced their numbers. To see up-to-date information on the distribution of European water chestnut, visit: European water chestnut (Trapa natans) - EDDMapS State Distribution - EDDMapS
If you think you have identified European water chestnut, call the invasive species hotline (1-800-563-7711) or report it using EDDMapS as soon as possible.