Microhabitat Use and Species Associations of Native Fishes in Rehabilitated Reaches of the Kootenai River

The Kootenai River is one of Idaho’s most unique and important resources.  Like many other large rivers of North America, the Kootenai River and its catchment have undergone extensive water and land use alterations that have had deleterious effects on ecosystem function.  The Kootenai Tribe of Idaho has implemented a multi-year habitat rehabilitation program to restore self-sustaining, native wildlife populations.  However, additional information is needed to further guide the design of habitat rehabilitation efforts in the Kootenai River.  Our objective was to describe the microhabitat and species associations of native fishes among the habitat-rehabilitated and untreated areas of the Kootenai River.  Prepositioned areal electrofishing devices (A=0.80 m²) were used to sample fishes.  Current was applied for 20 seconds following a 30 minute set time.  Microhabitat conditions were measured within a 4 m² quadrat centered on the electrofishing anode.  Across 217 sites, 383 fishes were collected representing four families and seven species.  Logistic regression and cluster analyses were used to determine habitat associations among fish populations and overall assemblage structure.  Results from this study provide information relating to specific habitat conditions selected by fishes in an attempt to maximize the benefit of the habitat rehabilitation program.