Fisheries benefits and optimal design of marine reserves

We used fishery population models to assess the potential for marine fisher y reserves, areas permanently closed to fishing, to enhance long-term fishe ry yields. Our models included detailed life history data. They also includ ed the key assumptions that adults did not cross reserve boundaries and tha t larvae mixed thoroughly across the boundary but were retained sufficientl y to produce a stock-recruitment relationship for the management area. We a nalyzed the results of these models to determine how reserve size, fishing mortality, and life history traits, particularly population growth potentia l, affected the fisheries benefits from reserves. We predict that reserves will enhance catches from any overfished population that meets our assumpti ons, particularly heavily overfished populations with low population growth potential. We further predict that reserves can enhance catches when they make up 40% or more of fisheries management areas, significantly higher pro portions than are ty reserve systems. Finally, we predict that reserves in systems that meet our assumptions will reduce annual catch variation in sur rounding fishing grounds. The fisheries benefits and optimal design of mari ne reserves in any situation depended on the life history of the species of interest as well as its rate of fishing mortality. However, the generality of our results across a range of species suggest that marine reserves are a viable fisheries management alternative.