| Summary: | "A recent article by Lauck et al. (1998) questions our ability to manage marine fisheries in the face of "persistent and irreducible scientific uncertainty." This paper examines the role that a safe minimum biomass level (SMBL) might play when stochastic recruitment is compounded by unbiased (honest) observation error. Specifically, a bioeconomic optimum is combined with a 5MBL to formulate a linear, total allowable catch (TAC) policy. In a deterministic world such a policy may asymptotically guide an overfished stock to the optimum. In a stochastiC model, the TAC policy will result in a distribution of stock and harvest about the bioeconomic optimum. The approach is applied to the Norwegian spring-spawning herring, a once abundant and highly migratory species in the northeast Atlantic. The effectiveness of the proposed 5MBL for spring-spawning herring is examined with stochastic recruitment, and observation error. Observation error greatly increases the coefficient of variation for harvest, and may allow the stock to (unknowingly) fall below the 5MBL."
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