Single-Pass Electrofishing Predicts Trout Abundance in Mountain Streams with Sparse Habitat

Abstract Fish abundances in mountain streams are typically estimated over a reach with multiple-pass-removal electrofishing techniques, but such estimates are time consuming and they potentially harm fish. Recent research has indicated that a single electrofishing pass can provide an index of trout abundance in some streams, but applicable circumstances were not clarified. We sampled 30 stream reaches in northwestern Wyoming to determine if the number of trout captured with a single electrofishing pass could be used to predict trout abundance as estimated by a multiple-pass-removal maximum-likelihood model. Stream width, depth, channel slope, instream cover, and substrate were also assessed to determine their possible influences on the relationship between the number of fish captured with a single pass and multiple-pass estimates. We found that trout samples from a single electrofishing pass accurately indexed the abundance of trout in small mountain streams with little instream cover and low fish densiti...