Nonindigenous Aquatic Species Database and Website (NAS)

Science Center Objects

Nonindigenous - non-native - species threaten biodiversity, but the distribution of these species is not well-known. The Nonindigenous Aquatic Species (NAS) database tracks occurrence data on non-native aquatic plant and animal species throughout the United States, and provides the public with species profiles, distribution maps, and online/real-time queries for state/hydrologic basin- specific species. 

Nonindigenous Aquatic Species Database and Website (NAS)

Nonindigenous Aquatic Species (NAS) database tracks non-native aquatic plants and animals in the United States. 

The Science Issue and Relevance: Nonindigenous species are ranked second only to habitat loss in the agents that threaten native biodiversity; however, the geographic distribution of many of these organisms is poorly understood. As new taxa are introduced and the range of those previously established continues to increase, precise tracking of their status and distribution is imperative for decision making and resource management.

The Nonindigenous Aquatic Species (NAS) database ( functions as a central repository and clearinghouse for spatially referenced occurrence data on non-native aquatic species from across the country. It contains locality information on more than 1100 species introduced as early as 1850 and focuses on freshwater animal invasions. Taxa include foreign species as well as those native to North America that have been transported outside of their historic range. The web site provides species profiles, distribution maps, and online/real-time queries to obtain lists of species according to state or hydrologic basin of interest. USGS staff may be contacted for specific data, custom products and reports.

The NAS Alert System is a component of the program that notifies registered users by email when a species reaches a new area.  All alerts are archived on the website and are searchable.

NAS Species Occurrence map example

An example of species occurence data from NAS 

Methodology for Addressing the Issue: Locality data are obtained from many sources including the literature, state, federal, and local monitoring programs, museum accessions, on-line databases, professional communications, and on-line public reporting. Before inclusion into the database, records are critically reviewed then geographically referenced.

Data are plotted in real-time on distribution maps for each species, including geographic accuracy and population status. New occurrences at the national, state, county, or hydrologic basin level are disseminated through the NAS Alert System, the web site, and Twitter. Informational factsheets summarizing basic biology, ecology, native and non-native distributions, current status, and impacts are available for most species in the database.  

The NAS database is used by agency and academic researchers to examine patterns, pathways, and vectors of introductions; describe temporal and spatial rates of introductions of individual species, taxonomic groups, or within geographic areas; and in predictive modeling of potential areas of colonization.

Future Steps: Occurrence data for nonindigenous aquatic species will continue to be added to the database, through examination of museum collection records, critical review of scientific literature, partnerships with other federal, state, and local government agencies, academia, and reports submitted through the NAS web site. Data collection efforts will focus on high resolution, fine-scale (temporally and spatially) data. Species profiles will be continually updated incorporating new information on distribution or impacts. Predictive models of potential distributions of species will be generated in collaboration with USGS researchers at the Fort Collins Science Center. Environmental layers (e.g., climate, hydrology) will be incorporated into species’ distribution maps to help visualize past and potential future areas of spread. We will continue to generate publications describing general patterns of aquatic species introductions, as well as works targeting specific taxonomic groups or geographic regions.

The NAS database will continue to feed into larger distributed databases such as Global Biodiversity Information Facility (GBIF), NISbase, Global Invasive Species Information Network (GISIN), and Biodiversity Information Serving Our Nation (BISON).

Related Projects: NISbase, Asian Tiger Shrimp genetics, Smithsonian Environmental Research Center’s National Exotic Marine and Estuarine Species Information System