ABSTRACT
The earliest and most extensive legislation that established laws for prevention and control of nonindigenous and invasive (nuisance) species in the United States was for protection of crops and livestock. Federal legislation to protect aquatic ecosystems was absent until the late-twentieth century, and federal policies most often took a “benign neglect” approach, sometimes even encouraging introductions of new species in attempts to make natural ecosystems more responsive to human needs. Policies against species introductions were rare and primarily reactive to individual species that became nuisances after they were established. Each new species invasion was treated as a separate event. The discovery of the zebra mussel (Dreissena polymorpha) in 1988 led to recognition that aquatic invasions were also a problem. While discoveries of nonindigenous species raised concerns prior to the late-1980s, it was the discovery of the zebra mussel that catalyzed awareness and rapid policy changes, including establishment of new regulations at many
levels of government across the Unites States and Canada. In the United States, the centerpiece of legislation was the Nonindigenous Aquatic Nuisance Prevention and Control Act, passed in 1990 and reauthorized and expanded as the National Invasive Species Act in 1996. It included legislative mandates for prevention (emphasizing ballast water), zebra mussel control, and other actions such as ecosystem surveys. It established the Aquatic Nuisance Species Task Force to encourage a coordinated federal approach and provided for establishment of regional panels; ultimately, it provided the impetus for Executive Order 13112, which resulted in the rst comprehensive national plan for managing all invasive species in the United States. Although little additional progress was made after 1996 through 2011, the policy changes started in 1990 established aquatic invasive species as recognized national problems with regional and local implications. The legislation of the 1990s led to growth of sustained federal and state programs that continue to respond to new introductions while working toward preventing future introductions.
