Weak Stock Bycatch Avoidance in the West Coast Ocean Salmon Fishery: A Bioeconomic Model Using Spatio-Temporal Data from Commercial Fishermen

The spatio-temporal overlap of morphologically undistinguishable weak and healthy fish stocks is a major concern for the Pacific Northwest Chinook salmon fishery. A recent two-year closure led to a loss of 1800 jobs and 118 million dollar in the salmon fishing sector.  Based on a unique genetic dataset, collected by fishermen, fine-scale patterns of fishing effort and stock distributions were assessed. This new knowledge was then used to develop a simple bioeconomic model in order to evaluate costs and benefits of alternative management measures. The developed model is spatial-explicit and runs on a monthly basis. Fleet dynamics such as effort distribution are included in the model and are driven by profits. In turn, profits depend on fish prices, variable (e.g. fuel costs) and fixed (e.g. insurance costs) costs. A status-quo and alternative scenario of a 25% cut of weak stock catches were tested with the model. The alternative option led to lower profits and changes in the effort allocation, while effects differed considerably between fleets coming from different ports. The presented model is an innovative tool to use fine-scale, near real time, stock-specific data to assess the potential for minimizing economic impacts on coastal fishing communities while conserving weak stocks.