Comparing alternative harvest strategies to address robustness to recruitment variability and uncertainty: Implications for Alaska Sablefish tested with management strategy evaluation

Developing robust fisheries management strategies for exploited fish stocks is imperative amid rapid ecosystem changes. In Alaska, sablefish (Anoplopoma fimbria) have recently experienced several large recruitment events, resulting in rapid population growth and a concomitant increase in catch of small, low value fish. Current management may not ensure long-term economic stability nor maintain the age structure diversity necessary for population resilience. Using a management strategy evaluation (MSE) framework, we assessed alternative management strategies under random, regime-like, and recruitment-failure scenarios. Data includes raw simulation output from 200, 75-year long, MSE simulations for all combinations of 10 harvest control rules and 4 recruitment scenarios. Strategies that substantially reduced fishing mortality improved stock size and age diversity. Catch stability constraint strategies provided minimal long-term benefits and increased risk during recruitment collapses, although they slightly accelerated population recovery times. Harvest caps maintained higher population sizes, promoted moderate, consistent catches, and modestly expanded population age structure. However, no strategy prevented population declines under prolonged recruitment failure. Results underscore the importance of refining harvest control rules to better balance catch and population stability.