Assessment of the Attractiveness and Passage Efficiency of Different Fish Passage Solutions at a Hydropower Plant by Combining Fine Scale 2D-Telemetry and Hydraulic Numerical Modelling

Mitigation measures for downstream-migrating Atlantic salmon smolts (Salmo salar L.) are commonly insufficiently attractive to enable safe entrance and passage with no delay. Combining 2D telemetry hydrodynamic modelling has been shown be a good tool better understand the influence of factors on migration route choice fishes. In this study, we investigated smolt downstream at hydropower plant in Belgium that offers five routes, including two Archimedes screws one nature-like fishway. At plant, were most used due higher discharges more important water depths their entrance. The weir canal intake less by smolts. fishway turned out used, 23% Its associated crossing time was significantly longer, probably shallow high flow velocities. had potential become after improvements increase attractiveness efficiency. Moreover, not detrimental did cause any significant delays time.