Seasonal use of tributaries by Missouri River fishes in the Garrison Reach, ND

Conservation and management of regulated rivers requires a riverscape approach (e.g. linking reservoirs, mainstem rivers, backwaters, and tributaries) because many native riverine species require access to diverse habitats on broad spatial scales. Several tributaries flow into the highly regulated Garrison Reach of the Missouri River near Bismarck, ND. Seasonal use of three tributaries by Missouri River larval, juvenile, and adult fishes was examined.  All three tributaries exhibited high catches of adult, juvenile, and larval walleye, suggesting that tributaries are important spawning and rearing areas for this species. Adult yellow perch and white bass were abundant in two of the three tributaries, but larvae of these species were not collected. Northern pike and channel catfish occasionally used tributaries, but were in low abundance. Additionally, tributaries provided spawning habitat for Catostomidae and Cyprinidae. Catches of larval Catostomidae were high in one of the study tributaries. Larval Cyprinidae were captured in all three study tributaries, but abundance of this family was always low. Our results suggest that tributaries provide important spawning and rearing habitat for many Missouri River fishes (e.g. walleye), whereas other species occasionally use the tributaries, but likely spawn elsewhere (e.g. main channel).