The National Invasive Species Act (NISA) is a United States federal law intended to prevent invasive species from entering inland waters through ballast water carried by ships. NISA reauthorized and amended a previous measure, the Non-indigenous Aquatic Nuisance Prevention and Control Act of 1990 (NANPCA). Organisms targeted by NISA are categorized as aquatic nuisance species, including in particular zebra mussels and Eurasian ruffe. To extend upon NANPCA, NISA authorizes regulation of ballast water, a key factor in the spread of aquatic invasive species; funding for prevention and control research; regional involvement with the Aquatic Nuisance Species Task Force; and education and technical assistance programs to promote compliance with the new regulations. NISA also includes specific actions for certain geographical locations, such as the Great Lakes, Chesapeake Bay, the Gulf of Mexico, and San Francisco Bay. Environmental issue NISA directly addresses problems associated with nonindigenous species, with special attention on aquatic nuisance species in the Great Lakes. In the proper conditions, nonindigenous species can out-compete indigenous species by dominating resources or spreading diseases or parasites. These disruptions can lead to a loss of biodiversity and as a result, ecosystems and economies are greatly affected. Below are a few descriptions of nonindigenous species that are mentioned in NISA. Zebra mussels In 1988 zebra mussels (Dreissena polymorpha) were found in Lake Erie, and soon after they spread to all the Great Lakes. Since then, zebra mussels can still be found in each of the Great Lakes, as well as throughout the major navigable rivers in the eastern part of the United States (including the Hudson, St. Lawrence, and Niagara Rivers). Recent reports have revealed that this species has dispersed as far as California. A native of southern Russia, the zebra mussel most likely made its way to North America through the release of ballast water from cargo ships traveling from the Black Sea to the Great Lakes. After its introduction there, it was carried through the lakes and connected waterways via recreational and commercial traffic. A large part of the zebra mussel's ability to disperse has to do with its travel flexibility. In the larval stage, zebra mussels can float along passively. In the adult stage, zebra mussels can attach themselves to boats very well. Overland dispersal can be achieved, too, because these mussels can survive dry conditions for several days. This was most likely the way that they were introduced to California: