Author(s): Matt Blank; Erin Ryan; David R. Dockery; Kevin M. Kappenman

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Keywords: Fish passage; Grayling; Open-channel; Survival analysis; Distance of ascent; Age 1+

Abstract: Abstract Installing effective fish passage structures that provide connectivity for Arctic grayling is a promising conservation strategy for imperiled populations. The swimming abilities and behaviour of age 1+ adfluvial grayling from Montana were examined in an open-channel flume to provide design information for passage structures. Swimming behaviours and distance of ascent (Dmax) in a 12.25 m section was measured at four velocities (0.49, 1.04, 1.43, 2.26 m/s) at an average temperature of 11.3 °C (SD = 0.7); effects of fish length and time of day were also examined. Median Dmax was equal to 12.25 m for all treatments except the 2.26 m/s treatment, where it dropped to 4.5 m. Average fish swimming velocities increased from 0.85 to 2.97 m/s from the lowest to the highest velocity treatments and the maximum velocity observed was 4.03 m/s. Survival model parameterization allowed prediction of the proportion passing relative to distance for covariate values within the range tested. There was strong evidence Dmax was related to water velocity (p

DOI: https://doi.org/10.1080/24705357.2019.1599306

Year: 2020