Salmon Migration

High velocities and complex flow structures are one of the primary factors that contribute to salmon passage failure. Understanding the connection between flow conditions and upstream salmon migration success and faiure has been limited by a lack of detailed hydraulic information such as encounter velocities that force anaerobic swimming and flow dynamics near key hydraulic barriers (e.g., surface velocities, flow fields). Hydraulic observations from Hydraulics and Flow Dynamics, fine-scale monitoring of radio-tagged fish, and assessments of high energy anaerobic swimming via radio-accelerometer tags will be used to tease apart hydraulic and biologic controls of upstream salmon migration.

Current work

In 2021, we remotely tracked over 1700 Chinook, Sockeye, Pink, and Coho salmon via radio-tags and recovered six acceleration tags from Sockeye salmon, providing a complete archive of swimming activity every six seconds from the time of tagging through the entire migration to spawning grounds. Using these archives of salmon migration, we assessed how river discharge affected different species' ability to migrate past the Big Bar Landslide. For the 2022 salmon migration, we have installed a series of radio-telemetry stations throughout the Fraser Canyon (Chapman's Rapid, Black Canyon, Hell's Gate, the Big Bar Landslide site) to monitor behavior and migration strategies of radio-tagged fish in 2022 (e.g., migration rates, number of passage attempts at barriers). We are currently developing models to explore fine-scale migration pathways at key hydraulic barriers.

Sockeye at Yale, B.C. 

Video Credit: Dan Murphy