Aquatic Invasive Species (AIS) is a non-native aquatic species that invades ecosystems beyond their natural, historic range. They are spread either intentionally, someone dumping their aquarium contents into a lake, or unintentional by way of ships, fishing, hunting and boating, to name a few. Aquatic invasives might also be called exotics, nonindigenous or non-native. No matter what you call them, they are a growing problem.

A primary focus of the AIS program is invasive species prevention. There are coordinators located throughout the U.S. that work closely with public and private sectors to develop and implement AIS projects.

One way to prevent nonnative wildlife species from becoming invasive is to list them as an injurious species under the Lacey Act. This authorizes divisions of the Department of the Interior, such as U.S. Fish and Wildlife Service, to regulate or ban the importation or transportation of that animal or plant within the U.S.

Other preventive measures include Ecological Risk Screening Summaries, a process to characterize and prioritize the potential risk of invasiveness from species of wild animals and plants. The Aquatic Nuisance Species Task (ANS) Force, established by Congress and dedicated to preventing and controlling ANS.