Evaluation of Alternative Management Strategies for a Spatially Structured Walleye Population and Fishery

Applications of structured decision making to resource management have become more commonplace and are often implemented within an adaptive management framework to incorporate uncertainty into the decision making process.  We used an iterative closed-loop simulation of Lake Erie walleye management procedures (i.e., management strategy evaluation) to contrast alternative management strategies for the spatially structured population and fishery with the goal of developing a robust harvest policy.  Management procedures included data collection, spatially structured stock assessment, short-term forecasts, and harvest control rules.  Biological, economic, social, and cultural based performance measures were evaluated against operational objectives after accounting for key system uncertainties (e.g., stock size, recruitment).  Operational objectives were defined in collaboration with international management agencies and stakeholders following several scoping workshops.  We present results showing tradeoffs among competing objectives and how these differences affect best policy choice.