Evaluating escapement goals and harvest control rules for salmon stocks of the Arctic-Yukon-Kuskokwim region of Alaska

Salmon fisheries in the Arctic-Yukon-Kuskokwim region of Alaska are managed in the face of large uncertainties in stock size and productivity.  These uncertainties are exacerbated by limited data available for the vast and sparsely populated region, but are typical of most salmon fisheries, and include observation errors, policy implementation errors, poor recruitment forecasts, and uncertainty in recruitment mechanisms.  Fishery objectives in the AYK region are multi-faceted and often in conflict as subsistence needs limit opportunities for commercial harvests.  Further complicating the situation, managers must implement fair allocation rules in mixed stock and sequential fisheries where decisions on downstream harvests are made before the run size has been determined.  In this context, we evaluated the relative performance of alternative harvest policies while explicitly accounting for key uncertainties.  We used a closed-loop simulation analysis called management strategy evaluation (MSE) that was applied to the Chinook salmon fishery of the Kuskokwim River.  Preliminary analyses suggest that fixed escapement (S) policies set below S_MSY may result in annual harvests close to MSY without substantially increasing the risk of poor returns, but only if harvest rates are moderate (~50%).  The MSE approach provided a useful framework for evaluating harvest policies, particularly in this data-poor region.