Use of Natural and Added Cover Types by Game and Nongame Fishes in a Great Plains River

Abstract

AbstractThe rivers in the western Great Plains of the United States are characterized by low gradients, sandy substrates, and a relative scarcity of structural habitat. Habitat improvement projects in these systems often involve the addition of large wood and rock riprap to increase habitat for nonnative game fishes, such as piscivorous Brown Trout Salmo trutta. However, little is known about the use of added habitats by the small‐bodied nongame fishes that historically dominated the fish assemblages in these systems. We evaluated habitat availability and fish habitat use in the Laramie River (Wyoming, USA) at four sites that contained natural and added habitats. We calculated habitat selection for three natural cover types (natural wood, macrophytes, and undercut bank), two added cover types (added wood and rock riprap), and open water. Open‐water habitat dominated all sites (87–94% of the stream area), but all species except Johnny Darter Etheostoma nigrum showed negative selection for this cover type. Most species showed positive selection for both natural and added cover types but showed greater selectivity for natural wood compared to added wood. Native, small‐bodied fishes in the Laramie River used added cover types intended to benefit populations of Brown Trout. Thus, features that enhance habitat for Brown Trout also should benefit native species in Great Plains rivers that have limited natural structural habitat.