The Role of Complexity in Habitat Use and Selection by Stream Fishes in a Snake River Basin Tributary

Abstract

AbstractImpacts from grazing, agriculture, and other anthropogenic land uses can decrease stream habitat complexity that is important to stream biota and often is the goal of stream habitat restoration. We evaluated how microhabitat complexity structured a fish assemblage and influenced habitat selection by the Northern Leatherside Chub Lepidomeda copei, a recent candidate for listing under the U.S. Endangered Species Act, in Trapper Creek, a tributary to the Snake River in Idaho. Fishes were sampled using prepositioned areal electrofishing (about 1 m2), and microhabitat conditions were measured within a 1-m-diameter circle centered on the electrofishing anode. Constrained correspondence analysis showed complexity in water depths and velocity to structure the fish assemblage and partition habitat use by Northern Leatherside Chub, Rainbow Trout Oncorhynchus mykiss, and Redside Shiner Richardsonius balteatus. Habitat selection models showed that the chub used areas of heterogeneous depths and flows in addit...