Conservation and Yield Performance of Harvest Control Rules for the Transboundary Pacific Hake Fishery in U.S. and Canadian Waters

Pacific Hake (Merluccius productus) are the most abundant groundfish off the west coast of the USA and Canada, and four large cohorts have supported nearly half of the cumulative coast-wide catch since 1981. These cohorts created wide fluctuations in abundance, yet the total catch of hake has remained mostly between 250,000 and 360,000 mt per year since 1991.  Managers have often set the Total Allowable Catch (TAC) less than what is suggested by the stock assessment, and it is unclear how this disconnect affects future risk to the hake stock and fishery.  In this study, we used closed-loop simulations as part of a larger Management Strategy Evaluation (MSE) to investigate the short- and long-term hake population responses and fishery outcomes to harvest control rules incorporating ceilings and floors on the TAC, similar to those observed in the past.  Introducing ceilings on the TAC slightly reduced risk to low stock levels while a floor increased risk.  Combinations of ceilings and floors showed higher average long-term TACs, and lower annual variability in the TAC. This study provides insight into possibly better alternatives to the current harvest rule and paves the way for continuing a MSE for Pacific Hake.