West Virginia Imperiled Aquatic Species

This indicator counts the number of aquatic species within each 12-digit HUC subwatershed in West Virginia that are listed as G1 (globally critically imperiled), G2 (globally imperiled), or threatened/endangered under the U.S. Endangered Species Act. It originates from the Environmental Protection Agency’s EnviroAtlas data.

Reason for Selection

This indicator identifies areas with abundant rare and endemic aquatic species that would benefit from conservation action. It captures patterns of rare and endemic species diversity not well-represented by other freshwater indicators. It complements the other imperiled aquatic species indicator, which uses aquatic Species of Greatest Conservation Need, but does not yet cover West Virginia.

Input Data

• Total number of at-risk aquatic animal species observed by HUC12 from EnviroAtlas.

  The data come from a NatureServe analysis that includes all non-plant (i.e., animal) aquatic species ranked as Imperiled (G1/G2) by NatureServe or listed as threatened or endangered under the U.S. Endangered Species Act. More detail on these data are in the associated EnviroAtlas factsheet.

• Estimated Floodplain Map of the Conterminous U.S. from the EPA EnviroAtlas (see this factsheet for more information; download the data)

  The EPA Estimated Floodplain Map of the Conterminous U.S. displays “…areas estimated to be inundated by a 100-year flood, also known as the 1% annual chance flood. These data are based on the Federal Emergency Management Agency (FEMA) 100-year flood inundation maps with the goal of creating a seamless floodplain map at 30-m resolution for the conterminous United States. This map identifies a given pixel’s membership in the 100-year floodplain and completes areas that FEMA has not yet mapped.”

• Base Blueprint 2022 extent
• National Hydrography Dataset Plus Version 2 (NHDPlus Version 2): HUC12 Watershed Boundary Dataset
• Esri USA States Generalized

Mapping Steps

• Download the HUC12 watershed boundary dataset and the national metric tables in Esri FileGeodatabse format from the EPA EnviroAtlas and join the tabular and spatial data.
• Use the field with the total number of G1/G2 or threatened/endangered aquatic species to convert the vector HUC12 layer to a raster with 30 m cell size using the ArcGIS Polygon to Raster tool with a cell assignment type of maximum combined area.
• Mask the resulting raster to the EPA estimated floodplain.
• Reclassify the values depicting the total number of G1/G2 or threatened/endangered aquatic animal species observed in each HUC12 to the indicator values seen below.
• Mask to the spatial extent of Base Blueprint 2022 only within West Virginia, using the USA states layer to provide the West Virginia state boundary.

Note: For more details on the mapping steps, code used to create this layer is available in the Southeast Blueprint 2022 Data Download under BlueprintInputs > BaseBlueprint2022 > 6_Code.

Final Indicator Values

Indicator values are assigned as follows:

• 5 = 5 aquatic imperiled (G1/G2) or threatened/endangered species observed
• 3 = 3 aquatic imperiled (G1/G2) or threatened/endangered species observed
• 2 = 2 aquatic imperiled (G1/G2) or threatened/endangered species observed
• 1 = 1 aquatic imperiled (G1/G2) or threatened/endangered species observed
• 0 = No aquatic imperiled (G1/G2) or threatened/endangered species observed

There was no value of “4” present in the source data, so that class is not included in the indicator.

Known Issues

• This indicator uses a different definition of “imperiled” compared to the full imperiled aquatic species indicator that covers the rest of the Southeast. The West Virginia indicator defines imperiled as G1 (globally critically imperiled), G2 (globally imperiled), or threatened/endangered under the U.S. Endangered Species Act, while the full imperiled aquatic species indicator defines “imperiled” as a Species of Greatest Conservation Need (SGCN). We are investigating ways to add aquatic SGCN data for WV to improve the consistency of the underlying data and eliminate the need for this separate indicator.
• For the HUC12 watersheds that intersect with the Kentucky and Virginia state lines, this indicator took precedence over the full imperiled aquatic species indicator because this indicator was more accurate at those state boundaries.
• As this indicator is based on occurrence records, poorly surveyed areas may be scored too low. Therefore, this data does not imply absence of species.
• The data in this indicator was last updated in 2011. Subwatersheds with new imperiled species discovered after 2011 would be scored too low. Compared to the more recent data from the Southeast Aquatic Resources Partnership on aquatic Species of Greatest Conservation Need, which is used across the rest of the Southeast in the full imperiled aquatic species indicator, this WV-specific indicator likely underestimates imperiled aquatic species values.
• While this indicator generally includes the open water area of reservoirs, some open water portions of reservoirs are missing from the estimated floodplain dataset.

Disclaimer: Comparing with Older Indicator Versions

There are numerous problems with using Southeast Blueprint indicators for change analysis. Please consult Blueprint staff if you would like to do this (email hilary_morris@fws.gov).

Literature Cited

EPA EnviroAtlas. 2018. Estimated Floodplain Map of the Conterminous U.S. [https://enviroatlas.epa.gov/enviroatlas/DataFactSheets/pdf/Supplemental/EstimatedFloodplains.pdf].

Esri. U.S. States (Generalized). Published 2017-12-21. Data and Maps for ArcGIS®. 2017 - World, Europe, and United States. Redlands, California, USA [https://www.arcgis.com/home/item.html?id=99fd67933e754a1181cc755146be21ca].

U.S. Environmental Protection Agency (USEPA) Office of Research & Development (ORD) - National Exposure Research Laboratory (NERL) and NatureServe. 2013. EnviroAtlas - NatureServe Analysis of Imperiled or Federally Listed Species by HUC-12 for the Conterminous United States. [https://edg.epa.gov/data/Public/ORD/EnviroAtlas/National].

U.S. Environmental Protection Agency (USEPA) and the U.S. Geological Survey (USGS). 2012. National Hydrography Dataset Plus. 2.10. [http://www.horizon-systems.com/nhdplus/].