U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2012–3100

May 2017, ver. 1.1

The National Nonindigenous Aquatic Species Database

The U.S. Geological Survey (USGS) 

Nonindigenous Aquatic Species (NAS) Program 

maintains a database that monitors, records, and 

analyzes sightings of nonindigenous aquatic plant 

and animal species throughout the United States. The 

program is based at the USGS Wetland and Aquatic 

Research Center in Gainesville, Florida. 

The initiative to maintain scientific information 

on nationwide occurrences of nonindigenous aquatic 

species began with the Aquatic Nuisance Species 

Task Force, created by Congress in 1990 to provide 

timely information to natural resource managers. Since 

then, the NAS database has been a clearinghouse of 

information for confirmed sightings of nonindigenous, 

also known as nonnative, aquatic species throughout 

the Nation. The database is used to produce email 

alerts, maps, summary graphs, publications, and 

other information products to support natural 

resource managers. 

The NAS Database in a Nutshell

The NAS database includes records of aquatic 

plants and animals occurring outside of their native 

range. It is freely accessible online (http://nas.er.usgs.

gov), and users can query the database to view 

current species distributions.

The NAS database encompasses aquatic 

ecosystems (wetlands, lakes, rivers, estuaries, 

and coastlines) throughout the United States and 

its territories. As of February 2017, the database 

contains records for 1,271 species dating back to 

1850, and new records are continuously added 

by NAS Program staff. The database also offers a 

searchable reference database on nonindigenous 

aquatic species, informational profiles on individual 

species, distribution maps, and new location notices. 

Maps produced from 

the database are 

widely used in 

scientific talks, 

publications, 

web pages, 

and news 

outlets. 

Management and Policy Uses

Risk Analysis

•	 The U.S. Army Corps of Engineers used the NAS database 

to examine the risk of nonindigenous species introduction 

across watershed connections to help prioritize which 

connections to sever and which to monitor. 

•	 The U.S. Fish and Wildlife Service uses the database as 

input data for their models to produce ecological risk 

screening summaries.

•	 The U.S. Forest Service used the database to identify 

infested source waters, thereby lowering the risk of 

unintentionally spreading nonindigenous species while 

airdropping water drawn from natural sources, such as lakes 

and ponds, to fight fires. 

Monitoring and Prevention

•	 Data and alerts are used by natural resource agencies to 

determine where to focus monitoring efforts. 

•	 Federal and nongovernmental partners have prepared field 

guides for early detection of invasive marine fishes. 

•	 Ecological modelers use NAS data in predictive modeling to 

show possible distributions of species in future invasions. 

•	 South Carolina State planners used pathway analysis to 

determine where to direct their public education to help 

decrease new invasions.

Management and Planning

•	 Occurrence data supports national assessments of aquatic 

invasions and regional management of nonindigenous 

aquatic species.

•	 Reports from NAS have been used to document range 

expansion of invasive species throughout a region of 

concern.

Federal Policymaking

•	 Data and reports from NAS have been used to make 

decisions about Lacey Act listings.

•	 NAS provides information for Congressional testimonies.

ISSN 2327-6916 (print) ISSN 2327-6932 (online)

 https://doi.org/10.3133/fs20123100
NAS Specimen Records

Each specimen record documents a nonindigenous aquatic species in a particular 

location at a point in time. The specimen may not have survived or reproduced after the 

sighting; however, the record provides documentation of the event, allowing researchers 

to analyze trends and pathways in introductions. All specimen records include the 

location, date, and identity of the nonindigenous aquatic species. Other details, such as 

museum specimens (if the organism was collected) or herbarium vouchers are available 

for some records. To the extent possible, the database includes the best available 

information on the population status of each species, documenting whether it has 

failed or established a self-sustaining wild population. The database also distinguishes 

between native transplants (that is, species native to the United States that are moved to 

a different region) and exotics, which are species that originate from other countries.

Records are compiled from published materials, such as books, journal articles, 

and technical reports, as well as records and reports from Federal and State fish and 

wildlife agencies, museum holdings, and university researchers. Anglers, boaters, 

divers, and other members of the general public also submit reports of sightings.

To ensure the integrity of the data, the identity and reported location of each 

species are verified by NAS Program staff before each new specimen record is entered 

into the database. Supporting documentation like collection information, photographs, 

supporting academic literature or other documentation are attached

to the specimen record (fig. 1).

Queries and Searches

Users can perform text-based searches by genus, species, 

or common name, or browse all occurrences within a broader 

taxonomic group, such as frogs, mammals, or fishes (fig. 2). 

Specimen records can also be queried according to geographic 

criteria, including

• State,

• County,

• Major drainage area–2-digit Hydrologic Unit Code (HUC),

• Drainage–6-digit HUC,

• Watershed–8-digit HUC.

Using advanced text searches, users can filter results 

by additional criteria, including year, freshwater or marine 

environments, introduction pathway, and species origin. 

Additionally, users now have the ability to perform searches 

(including spatially enabled queries) directly from the database’s 

point map interface.

Assessing Trends in Introduction

The NAS database offers summary graphs and charts 

(figs. 3 and 4) that display key facts and trends, such as origins 

of nonindigenous aquatic species, as well as pathways and 

environments where they have been introduced. The graphs 

can include all species in the United States or can be displayed 

by taxonomic group (fishes, mollusks, crustaceans, reptiles, 

amphibians, and plants). Graphs can also summarize information 

across the entire United States or by individual State. 

Types of graphs currently available include

• Introductions over time,

• Introductions by taxonomic group,

• Introduction pathways,

• Native transplants versus exotics, and

• Continent of origin of exotic species.

Figure 1. The specimen record provides details 

about a single introduction of the black carp, 

including a map of where it was found. 

Figure 2. Text-based search for “arrowhead” as a common name 

returned these five plant species. From here, users can access a 

species profile and a point map showing sighting locations. 

Years

Up to 1900 Up to 1950 Up to 2000 Up to present

Exotic to the

United States

Native transplants

EXPLANATION

Number of species, cumulative

80

70

60

50

40

30

20

10

0

Figure 3. This bar graph shows the number of mollusk 

species introduced since 1850, and indicates the proportion 

of species that are exotic versus transplanted. 
laf17-0828_fig 04

47 (10.1%)

48 (10.3%)

66 (14.2%)

149 (32.1%)

42 (9.1%)

38 (8.2%)

17 (3.7%)

15 (3.2%)

10 (2.2%)

1 (0.2%)

4 (0.9%)

6 (1.3%)

8 (1.7%)

Aquarium release

Unknown

Pet release

Stocked

Hitch hiker

Aquaculture

Escaped captivity

Bait release

Canal

Dispersed

Released

Planted

Shipping

Released food fish

Released lab animals

Hybridized

EXPLANATION

Figure 4. Pie charts, such as this one for Florida, categorize 

occurrences of nonindigenous aquatic species by their 

introduction pathways. 

Species Distribution Maps

A point map is provided for each specimen showing the 

location of the record. Species maps are also provided for all 

reports for a given species to display the national distribution. 

In addition to text, State, and drainage queries, new spatial and 

multispecies queries have been created. Users can now query a 

specific area and see what species have been reported nearby. For 

example, they could see what has been found within 5 miles of 

their homes or in a specific park. The multispecies query can be 

used to show all species together on a single map. It also allows 

users to compare the distributions of two species, or map all species 

that share a common pathway. Some of the new functionality and 

tools present on the new map page are

•	 Direct spatial query (either within a circle or user-defined 

polygon) to find all records within a specified geographic 

area;

•	 Use of a taxonomic tree-based browser to add a species to 

a map;

•	 Color-coded display of multiple species on a single 

map, including native ranges (up to seven distinct 

species can be viewed simultaneously);

•	 New reference layers, including land cover, U.S. 

census information, Congressional districts, and 

climate data (with more to be added in the future);

•	 Highlighting individual records on the map to sort 

them to the top of the records page;

•	 Ability to save exact map layout (for example, search 

criteria, geographic area in map window, zoom level, 

base and reference layers) via a shareable URL; and

•	 Ability to download tabular data as a comma 

separated values file.
Animated Maps

Animated maps showing the spread of species can make 

quite an impression! Select any species and an animated 

map will reveal recorded observations over the years. These 

animations can be paused at any time, or set for a specific year.

Watch for New Introductions!

The NAS Alert System notifies registered users of new 

occurrences of nonindigenous species. These alerts are based on 

geographic area, species, or broad taxonomic categories.

•	 State Watches track sightings by State.

•	 Species Watches create single-species alerts.

•	 Group Watches include categories of fish, 

amphibians, reptiles, mollusk, crustaceans, and other 

taxonomic groups. 

To receive alerts, visit the NAS homepage (http://nas.er.usgs.gov)

to register.

Report Sightings!

The public plays a significant role by acting as “early 

detectors” of new appearances of nonindigenous species. A 

recent analysis of the NAS Alert System showed approximately 

two-thirds of the alerts generated between 2004 and 2011 came 

from personal communication through the NAS database’s 

volunteer reporting mechanism. Users can pinpoint the waters 

where a nonindigenous species was seen, report the geographic 

coordinates by using an online map or the program’s new mobile 

device app, and upload photographs for NAS Program staff to 

verify the species identity. Both the online tool and mobile device 

app have been effective for reporting new invasions. Reports can 

be submitted online at http://www.usgs.gov/STOPANS.

Learn more and download the NAS mobile app for Android and 

iOS at https://nas.er.usgs.gov/mobilesightingreport.aspx.

Partnerships

The NAS Program works closely with State agencies and 

develops special tools with partnerships, such as integrated 

reporting and custom views of the NAS database. Through 

partnerships, NAS offers custom, regional views of the database 

that allow managers to focus on a specific area of interest. 

One example of this is the National Oceanic and Atmospheric 

Administration Great Lakes Aquatic Nonindigenous Species 

Information System. NAS is a member of the Global Invasive 

Species Information Network and Global Biodiversity 

Information Facility, and provides data to these larger networks 

as well as to other invasive species databases. Data analysis, 

time series maps, and detailed regional maps can be designed 

for special projects. Potential partners can contact NAS for more 

information about custom maps and other tools.

For More Information

Pam Fuller, Biologist/NAS Program Leader

USGS Wetland and Aquatic Research Center

7920 NW 71st Street

Gainesville, FL 32653

Phone: 352-264-3481

Email: pfuller@usgs.gov 

Visit NAS online at: http://nas.er.usgs.gov

Suggested Citation:

Neilson, M.E., and Fuller, P.L., 2017, The National Nonindigenous Aquatic Species Database (ver. 1.1): U.S. Geological 

Survey Fact Sheet 2012-3100, 4 p., https://doi.org/10.3133/

fs20123100.