Management strategies for reducing variation in annual yield: when can they work?

Abstract

Abstract Skagen, D. W. 2007. Management strategies for reducing variation in annual yield: when can they work? – ICES Journal of Marine Science, 64: 698–701. Management with permanently fixed quota, an extreme form of a catch-stabilizing strategy, poses the risk of severely depleting a stock. Simulation studies of artificial populations are conducted to show that the maximum fixed total allowable catch (TAC) consistent with a low risk of depletion is related to biological properties of the stock and to the fishing mortality (F) at the time the regime is introduced. If the stock can be assumed to be fully exploited, a safe fixed TAC can be derived as a percentage of the mean catch obtained previously under a constant-F regime. This percentage will be in the order of 50–100%, and is largely independent of the previous F-value. The lower end of the range is associated with large variations in recruitment and short lifespans, but is insensitive to the growth rate of a species. The relationship between previous catch and a safe fixed TAC can be used as a guideline in setting a precautionary TAC in data-poor situations.