This dataset contains information on all snakehead fishes found in the United States. It is a subset of a larger database, the Nonindigenous Aquatic Species Database (NAS). This information resource is an established central repository for spatially referenced biogeographic accounts of introduced aquatic species. The NAS website provides scientific reports, online/real-time queries, spatial data sets, distribution maps, fact sheets, and general information.

This dataset contains information on the Bullseye Snakehead fish found only in southeastern Florida. It is a subset of a larger database, the Nonindigenous Aquatic Species Database (NAS). This information resource is an established central repository for spatially referenced biogeographic accounts of introduced aquatic species. The NAS website provides scientific reports, online/real-time queries, spatial data sets, distribution maps, fact sheets, and general information.

Data described herein was collected by USGS personnel and the project funded by USGS. Northern snakehead specimens were collected from the Potomac River and its tributaries by regional natural resource management agencies in the course of their field investigations working with this priority invasive aquatic species. Specimens were provided to USGS for the purpose of conducting health related assessments of northern snakehead in the region, with approximately 90 specimens evaluated grossly and histologically for the presence of lesions and abnormalities. Data presented here was collected seasonally (spring through fall) in 2006 and from 2015 to 2017. Data for each specimen includes date and location of collection, morphometrics, gender (if known), and gross abnormalities, and histological lesions observed. This body of data is stored in spreadsheet format.

Data described herein was collected by USGS personnel and the project funded by USGS. Northern snakehead specimens were collected from the Potomac River and its tributaries by regional natural resource management agencies in the course of their field investigations working with this priority invasive aquatic species. Specimens were provided to USGS for the purpose of conducting health related assessments of northern snakehead in the region, with approximately 90 specimens evaluated grossly and histologically for the presence of lesions and abnormalities. Data presented here was collected seasonally (spring through fall) in 2006 and from 2015 to 2017. Data for each specimen includes date and location of collection, morphometrics, gender (if known), and gross abnormalities, and histological lesions observed. This body of data is stored in spreadsheet format.

Critical habitat includes the stream channels within the designated stream reaches, and includes a lateral extent as defined by the ordinary high-water line (33 CFR 319.11). In areas where ordinary high-water line has not been defined, the lateral extent is defined by the bankfull elevation. Bankfull elevation is the level at which water begins to leave the channel and move into the floodplain and is reached at a discharge which generally has a recurrence interval of 1 to 2 years on the annual flood series. Critical habitat in lake areas is defined by the perimeter of the water body as displayed on standard 1:24,000 scale topographic maps or the elevation of ordinary high water, whichever is greater.See the final rule (70 FR 52630) for descriptions of areas excluded from this critical habitat designation. Excluded Indian lands were not clipped out of the data.

Background: The Nonindigenous Aquatic Species (NAS) Database functions as a repository and clearinghouse for the occurrence of nonindigenous aquatic species information from across the United States. The Database contains locality information on more than 1,300 species introduced as early as 1800, including freshwater vertebrates and invertebrates, aquatic plants, and marine fishes. Taxa include both foreign species and North American native species that have been translocated outside of their natural range. Locality data are derived from many sources, including scientific literature; Federal, State, and local natural resource monitoring programs; museum collections; news agencies; and direct submission through online reporting forms. To effectively identify and record new introductions for North American native taxa, a robust estimate of their natural native ranges is required. Previously, the NAS Database has used native range information for fishes provided by NatureServe, which was collected from State natural heritage program inventory data and published State fish books. Although these range maps represent an essential first step in assembling native range data, the NatureServe data has varied for many species due to initial data assumptions (i.e., species presence = nativity). Additionally, NatureServe native ranges exhibit watershed gaps for many species. NAS program staff members have made thousands of corrections to these data internally and periodically communicate these changes back to NatureServe. Methods: Native ranges were developed from several data sources. Dr. Dana Infante, Michigan State University, provided the NAS program with occurrence (presence) data from 40-50 Federal, State, museum, and university data providers gathered during her work on the National Fish Habitat Partnership (NFHP). Although many data providers have offered datasets with no restrictions, some have restrictions on redistribution. In addition to the NFHP data, we utilized occurrence datasets for United States museum collections from Biodiversity Information Serving Our Nation (BISON), National Science Foundation's VertNet, FishNet 2 (fish collections in natural history museums, universities, and other institutions), Multistate Aquatic Resources Information System (MARIS) data and Global Biodiversity Information Facility (GBIF), along with a review of State fish books and other primary literature, to complete native range data maintained locally in the NAS Database. Occurrence datasets will be combined into larger, species-specific datasets for further processing at a hydrologic unit code (HUC). We will use GIS analyses to identify watershed occurrence at the eight-digit (HUC8) and twelve-digit (HUC12) level, using the 2015 version of the Watershed Boundary Dataset. HUCs containing known nonindigenous occurrences will be removed from the native range. Watershed gaps (i.e., a HUC that lies between two that are identified as part of the native range) will be investigated using historical literature to identify data gaps from actual range gaps. We will supply native range data by HUC8 (and HUC12 where possible) for 320 species listed below. These data will be provided as a comma-separated values (CSV) file and be made available on the NAS website via web services application programming interface (API).

This USGS data release documents presence and absences of 419 fish species in the conterminous United States for 35,918 stream reaches of the National Hydrography Dataset Plus Version 2.1 (NHDPlusV2.1). Sample dates for this dataset span 1990-2019. Fish samples were aligned to the Integrated Taxonomic Information System (ITIS), where each species record was assigned a Taxonomic Serial Number (TSN). The dataset is structured with records representing a stream reach (i.e. comid), sample description (i.e. source, date) and a series of 419 columns representing species where each species column is named as the TSN. Data can be visualized on the NHDPlusV2.1 after a tabular join using the field 'comid' or can be projected and visualized as point data using the latitude and longitude fields (using coordinate reference system NAD83) that represent the midpoint of the stream reach that they were associated with. Data are provided in comma separated value (CSV) format.

This USGS data release documents presence and absences of 419 fish species in the conterminous United States for 35,918 stream reaches of the National Hydrography Dataset Plus Version 2.1 (NHDPlusV2.1). Sample dates for this dataset span 1990-2019. Fish samples were aligned to the Integrated Taxonomic Information System (ITIS), where each species record was assigned a Taxonomic Serial Number (TSN). The dataset is structured with records representing a stream reach (i.e. comid), sample description (i.e. source, date) and a series of 419 columns representing species where each species column is named as the TSN. Data can be visualized on the NHDPlusV2.1 after a tabular join using the field 'comid' or can be projected and visualized as point data using the latitude and longitude fields (using coordinate reference system NAD83) that represent the midpoint of the stream reach that they were associated with. Data are provided in comma separated value (CSV) format.

This USGS data release documents presence and absences of 419 fish species in the conterminous United States for 35,918 stream reaches of the National Hydrography Dataset Plus Version 2.1 (NHDPlusV2.1). Sample dates for this dataset span 1990-2019. Fish samples were aligned to the Integrated Taxonomic Information System (ITIS), where each species record was assigned a Taxonomic Serial Number (TSN). The dataset is structured with records representing a stream reach (i.e. comid), sample description (i.e. source, date) and a series of 419 columns representing species where each species column is named as the TSN. Data can be visualized on the NHDPlusV2.1 after a tabular join using the field 'comid' or can be projected and visualized as point data using the latitude and longitude fields (using coordinate reference system NAD83) that represent the midpoint of the stream reach that they were associated with. Data are provided in comma separated value (CSV) format.

Environmental DNA detection results from samples collected using autonomous water sampling robots and manual approaches. Samples were collected in the Upper Yellowstone River (Montana) and Upper Snake River (Idaho/Wyoming) in 2018 and 2019. Samples were tested for the DNA of the following species: the waterborne protozoa Naegleria spp., the fish pathogen Tetracapsuloides bryosalmonae, Scomber japonicas (mackerel fish), kokanee salmon (Oncorhynchus nerka) and dreissenid mussel (Dreissena spp.).