Effects of Habitat Rehabilitation Activities on Fish Assemblages and Populations in the Kootenai River, Idaho

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 been subject to a variety of anthropogenic disturbances 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 fish populations.  However, additional information is needed to further guide the design of habitat rehabilitation efforts.  Our objectives were to describe microhabitat use by fishes, describe patterns in fish assemblage structure, and develop and test predictive models of resource use.  Prepositioned areal electrofishing devices (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 area centered on the electrofishing anode.  Across two field seasons and 542 sites, 1,522 fishes were collected representing four families and eight species.  Logistic regression was used to determine habitat associations among fish populations.  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.