Because fish reflect the quality of the habitat where they live, habitat conditions were evaluated by estimating how strongly various human habitat disturbances affect stream fish in all parts of the country. The national datasets used for this assessment included 26 variables that accounted for different human disturbances to aquatic habitats. These included: the quantity of urban, agriculture, and pasture lands in watersheds; major point-sources of water pollution; frequency of dams and road crossings throughout river networks; and intensity of mining activities in watersheds. Five natural landscape variables were also used to account for their potential influences on stream fishes. Because of broad differences in distributions [...]
