Digital Distribution of Native U.S. Fishes by Watershed

Version 3.0Data, Maps & Tools


Numerous studies have demonstrated that the freshwater fauna of the United States is both remarkably rich and grimly imperiled. Although freshwater fish diversity peaks in the tropics, the U.S. nonetheless hosts the seventh most diverse fauna of any country in the world. Unfortunately, many species face an array of threats, including the destruction and degradation of freshwater habitats, invasive alien species, and climate change.

To promote the conservation of this fauna, NatureServe has dedicated over a decade to developing and refining a database of the current and historical distribution of freshwater fishes by small watershed (8-digit cataloging unit of the USGS). NatureServe zoologists combed the published literature, interviewed regional ichthyologists, and solicited data from state natural heritage programs to develop the database. Subsequent review by ichthyologists, particularly those at the USGS, has improved the accuracy and completeness of the database. The result of this effort is a digital map library of the distributions of the freshwater fishes of the 48 conterminous U.S. states, now covering 865 species.


These data are useful for aquatic research and analyses and for conservation planning. 

Features & Benefits

The maps are coded to indicate the historical and current distribution of each species in each watershed unit. The data also note whether the species is native or introduced in a particular watershed. The non-native distribution is primarily derived from expert review of published records thought (falsely) to represent native occurrences and do not aim to be comprehensive. For complete information about non-native fish distributions, please see the USGS Nonindigenous Aquatic Species Program.

The maps are presented as a free resource for conservationists, researchers, and citizens alike. To view the map for a particular species, visit NatureServe Explorer, search for the species of interest, and click on "Distribution." To view the map in GIS format, see below.

Financial support for this project was generously provided by the Regina Bauer Frankenberg Foundation for Animal Welfare, The Nature Conservancy, the Central Administrative Office of the USDA Forest Service (Fort Collins, CO), and the U.S. Geological Survey. We also thank Howard Jelks and Jennifer Staiger of the USGS for verifying distribution data in Tennessee, Alabama, Georgia, and Florida.

Citation and Attribution

Citation of this data compilation is as follows:

NatureServe. 2010. Digital Distribution Maps of the Freshwater Fishes in the Conterminous United States. Version 3.0. Arlington, VA. U.S.A.

All products that make use of these data (produced in any media, including but not limited to publications, databases, theses, websites, and oral presentations) should acknowledge the data contributors in the following manner:

"Data provided by NatureServe."

Copyright Notice

Compilation ©2010 NatureServe. All Rights Reserved.

NatureServe grants to the public a nonexclusive, irrevocable, royalty-free license to reproduce, translate, publish and use these data for noncommercial purposes.