Monitoring and detection play a crucial role in preventing new introductions from becoming established in U.S. waters. Many states, particularly those that have developed State ANS Management Plans, have monitoring programs in place for early detection of aquatic invasive species of concern. The Task Force has conducted ecological surveys to establish base-line data and to document ANS and their impacts in a number of systems, including: the Great Lakes and Upper Hudson River; Valdez Harbor in Prince William Sound, and Cook Inlet in Alaska; the Delaware Bay; Coos Bay, Oregon; Pearl Harbor, Hawaii; San Francisco Bay and the Inland Delta; Florida’s Fresh Water Systems; Chesapeake Bay; Sacramento-San Joaquin Delta, and most recently the Lower Columbia River in Washington and Oregon. In the Pearl Harbor Study 22% of the species collected or observed were introduced or cryptogenic (of uncertain origin). The San Francisco Bay study identified 212 introduced species, and an additional 123 species that were cryptogenic. The Columbia River survey found that most of the nonindigenous species found in San Francisco Bay are also in the Columbia River.

Early Detection and Rapid Response plans also play an important role in prevention. The Western Regional Panel has developed a model early detection and rapid response plan. Many states also have generic and species-specific rapid response plans in place or under development. The Task Force recommends such plans be included in updates of existing state management plans and that all new plans include a rapid response component

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