Aquatic Nuisance Species in the Northeast

To learn more about invasive species threatening the northeast, and to create your own field guide, click on the “Online Guide to ANS” link on the lefthand menu.

The waters of northeastern North America are being transformed by invasive aquatic plants, fish, invertebrates, and other organisms from around the world. These plants and animals, which may be introduced both intentionally and accidentally, can irrevocably alter our native ecosystems. While they may be benign in their own native habitat, once “invaders” are established in a new ecosystem where their common predators do not exist, they can harm native species by eating their food, preying on them, transmitting diseases to which native species have no defense, or (like many invasive aquatic plants), simply outgrowing them. Not all non-native species cause serious problems, but some do, disrupting entire ecosystems by destroying habitat and altering food chains. These plants and animals are known as aquatic nuisance species or ANS. ANS not only threaten the natural environment, they also cause serious economic damage. Each year in North America, federal, state, and provincial governments, utilities, and businesses spend billions of dollars attempting to prevent, control or slow the spread of these plants and animals. Recreational activities are negatively affected when invasive plants choke fishing, boating, and swimming areas, and human health can also be threatened, as some aquatic nuisance species carry disease or parasites.