Science Advisory Report  2011/054

Western Component (4Xopqrs5) Pollock Management Strategy Evaluation

Summary

• In July 2010, Fisheries Management initiated a Management Strategy Evaluation (MSE) process with Science and Industry for Western Component Pollock.
• Management Strategy Evaluation is a technique to explicitly consider the uncertainty in stock assessment assumptions and models, and to compare the likely consequences to Management Objectives (biological, economic, etc.) when a predetermined Management Procedure (MP) incorporating a Harvest Control Rule (HCR) is applied. Management Strategy Evaluation changes the focus from the traditional “best assessment” to identifying a “best procedure”, where “best” implies the procedure that most closely meets the desired Management Objectives.
• The medium-term Management Objectives for Western Component Pollock Management Strategy Evaluation were selected for resource sustainability and catch, and constraints were selected for annual catch variability.
• The 17 Operating Models (OMs) selected in this evaluation span the full range of plausible values for uncertainties. A subset of six Operating Models was chosen as the balanced Reference Set (RS). It is primarily against this Reference Set that the performance of Candidate Management Procedures (CMPs) was evaluated.
• A Pollock Management Procedure (and its constituent Harvest Control Rule) was selected that meets the defined Management Objectives under a core set of plausible scenarios that cover the most important uncertainties concerning the fishery. The choice was driven by the degree of desired conservatism, which traded off the level of catch in the medium-term against the extent of resource recovery.
• A three-year running geometric mean of the summer Research Vessel (RV) Survey Biomass Index provides the measure used in the Harvest Control Rule to establish future catch limits for Western Component Pollock. An annual review will determine if the RV Survey Biomass Index has moved outside projected ranges.
• Exceptional Circumstances provisions are defined and are intended to cover situations outside the range for which the Management Procedure was simulation tested.
• Unless an Exceptional Circumstance is triggered, the application of the Management Procedure will provide the catch limit for Western Component Pollock. The expected operating timeframe for this Management Strategy Evaluation is 5 years, after which there will be a thorough review.

This Science Advisory Report is from the Fisheries and Oceans Canada, Canadian Science Advisory Secretariat, regional advisory meeting of May 9-10, 2011 on 4X5 Pollock Management Strategy Evaluation. Additional publications from this process will be posted as they become available on the DFO Science Advisory Schedule.

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