Classification of species attributes for Pacific Northwest freshwater fishes

Fish assemblages integrate physical and chemical habitat conditions and are used to evaluate the condition of water resources in the Pacific Northwest. To facilitate such evaluations, we classified each of the 132 freshwater fish species known to occur in the Pacific Northwest (Idaho, Oregon, Washington) by its origin, overall pollution tolerance, adult habitat, adult feeding, and water temperature preference. Recommendations from regional fishery experts, published literature, and the aggregate experience of the authors were used to classify species. The attribute classifications were responsive to human disturbance of aquatic habitats when applied to fish assemblages sampled from throughout the region. Our attribute classification of fish species promotes use of fish assemblages to evaluate water resource conditions regionally and fosters greater acceptance of biological measures of water resource quality.