Cooperative Fish and Wildlife Research Units Program: Idaho
Education, Research and Technical Assistance for Managing Our Natural Resources

Smith, C. D., M. C. Quist, and R. S. Hardy. 2015. Detection probabilities of electrofishing, hoop nets, and benthic trawls for fishes in two western North American rivers. Journal of Fish and Wildlife Management 6:371-391.


Research comparing different sampling techniques helps improve the efficiency and efficacy of sampling efforts. We compared the effectiveness of three sampling techniques (small-mesh hoop nets, benthic trawls, boat-mounted electrofishing) for 30 species in the Green (WY, USA) and Kootenai (ID, USA) rivers by estimating detection probabilities (probability of detecting a species given its presence at a site). Electrofishing had the highest detection probabilities for most species, but hoop nets also had high detectability for several species (e.g., adult Burbot Lota lota, juvenile Northern Pikeminnow Ptychocheilus oregonensis). Benthic trawls had low detection probabilities for most fishes. Gear-specific effects were present for most species indicating large differences in gear efficacy among techniques. In addition to gear effects, habitat characteristics also influenced detectability of fishes. Most species-specific habitat relationships were idiosyncratic and reflected differences in the ecology of the species. Overall, this study provides important information on the effectiveness of various techniques targeting fish assemblages and will help improve future sampling efforts in coldwater river systems.