The success of marine reserves depends on establishing evidence that they are useful conservation tools in the long term. At the same time, few marine reserves have been designed and managed using rigorous scientific methods. We are developing approaches to identify reserve efficacy and optimal monitoring strategies. While most reserves have focused on nearshore and benthic fish and invertebrates, our work has advanced the idea that reserves may benefit wide-ranging species. In this work we have embraced the international policy implications of marine reserves in developing strategies at on an international scale (e.g., International Whaling Commission Sanctuaries). These approaches are being applied in the Gulf of California, where a network of marine reserves to conserve marine biodiversity and enhance fisheries is being developed. We are developing predictive capabilities for the management of marine reserve networks. Our team is developing novel ecological and socioeconomic models to determine the efficacy of marine reserves in the Gulf of California (GOC) and the policy changes needed to achieve these goals. Our approach consists of 1) identifying conservation goals, 2) forecasting changes in the ecosystem after reserve establishment, 3) monitoring the state of the ecosystem, 4) evaluating the efficacy of the reserves, and 5) evaluating different management alternatives to achieve conservation goals. The evaluation of different management alternatives is based on the costs and benefits of political decisions, from both ecological and economic points of view.