This project was designed to quantify and qualify the termina survival of adult Chinook Salmon, staging in Cowichan Bay before entering the Cowichan River. The primary objective was to try and identify where and when mortality occurred during this staging period and what anthropogenic (i.e., log booms, river flows, underwater sound) and environmental (i.e., river flows, river temperatures, size, age) mechanisms had a greater influence on survival to spawn.

The study used Passive integrated transponder (PIT) and acoustic telemetry to track individual fish through the bay, estuary and lower river corridor. Survival was estimated across discrete river reaches using a network of detection antennas and receivers, allowing survival to be evaluated at a relatively fine spatial and temporal scale. Study design and analysis were developed to produce defensible estimates that could be directly compared across years and management scenarios.

Results provide survival estimates and have identified patterns relevant to recovery planning, habitat restoration, and flow and water-use discussions. The project generated evidence that supports more informed decision-making around freshwater constraints on Cowichan River Chinook and the effectiveness of future management actions.

Outputs: Technical reports, reach-specific survival estimates, and analytical products supporting recovery planning and adaptive management.