Evaluating linkages in the social-ecological system of U.S. West Coast fisheries from ecological and spatial perspectives

Unintended, detrimental effects of fishing have pushed fisheries science and management to innovate beyond the traditional single-species focus, towards a broader perception of a fishery. Increasingly, spatially-explicit fisheries science and management is being used to strategize for sustainable resource use. In this dissertation, the focus is the social-ecological system U.S. West Coast fisheries, an amalgam of target species and their ecosystem, fishing fleets, port communities, and management agencies. The overall goal of this dissertation is to use quantitative models to evaluate linkages between components of the U.S. West Coast fishery at different spatial scales (local and regional) and with varied levels of ecosystem complexity. A quantitative justification for the importance of incorporating space in the modeling was conducted by evaluating recent trends in components of the fishery to highlight spatially synchronous behavior. Two quantitative models were then used to evaluate linkages between components of the fishery at local and regional spatial scales and with varied levels of ecosystem complexity. In the first model, an economic component was layered onto a trophodynamic model to evaluate coarse scale linkages, including quantification of ecological-economic tradeoffs and exploration of system resilience properties. Outputs were then scaled to highlight proportional differences to port groups. In the second model, a dynamic, integrated simulation model of biology and fleet dynamics was built to evaluate how port groups and two groundfish species were affected by status quo and individual transferable quota management of the limited-entry groundfish trawl fleet given different underlying assumptions about the spatial structure of the biological populations. Through this research, novel approaches were established for using quantitative models to evaluate linkages in social-ecological systems. The spatially and temporally variable landings and revenues, direct and indirect links between ecology and economy, and spatial shifts simulated in response to a new management style all support a recommendation that U.S. West Coast marine resource management strive to be more flexible and adaptive to unforeseen change.