The efficacy of fisheries closure in rebuilding depleted stocks: Lessons from size-spectrum modeling

Fishery closure has increasingly been used for rebuilding depleted fish stocks; however, trophic interactions have rarely been included in studying stock rebuilding in fisheries management. This study used a size-spectrum modeling approach to explicitly capture the effects of trophic interactions in the evaluation of simulated fishery closure. We generalize model parameters to evaluate the influence of community complexity, life-history characteristics and fishing regimes. A target fish stock of large body size showed the potential to recover after being depleted; however, the timescale for recovery ranged from 10 to more than 100 years. Increased number of species could smooth community dynamics and prolong the duration for recovery. The fish species characterized by large body sizes or preference of small-sized prey tended to recover slowly. Bycatch rate had substantial influence on community structure and stocks recovery rate. We showed that an external modification of community size-structure could largely promote stock rebuilding. We conclude that community complexity, life-history characteristics and fishing regimes should be explicitly taken into account in the implementation of fisheries closure.