Swimming endurance tests for fish passage design for emerald shiners (Notropis atherinoides) in the upper Niagara River (NY, USA)

Laboratory experiments were conducted to test the swimming capabilities of emerald shiner (ES, Notropis atherinoides ), a minnow that serves as an important keystone species in many parts of the United States. The study was designed to provide a recommended target velocity for design of a fish passage structure along a seawall in the upper Niagara River (UNR) near Buffalo, NY, that would allow ES to swim upstream, thus reconnecting ES populations in the UNR and Lake Erie. Flow velocities along the wall can exceed 100 cm/s, much higher than previously reported capabilities of ES that are around 40–60 cm/s. The goal of the study was to determine the typical swimming speed these fish could maintain for a sufficient period to allow them to traverse the seawall. This information was then used to guide the design of amendments to the seawall that could produce the required reduction in water speed. The experiments were based on fatigue tests in a laboratory flume and results were confirmed using survival analysis. Nearly 200 fish were tested, and averaging over a variety of conditions (including fish length, weight, and age, water temperature, and time and location of fish collection), it was determined that at least 50 % of the fish population in the UNR could maintain a sustained swimming speed of at least 40 cm/s. This study expands our knowledge of ES swimming capability and provides a sound basis for design of the fish passage structure.