Under a particular representation of the impact path way of natural resource management (NRM) research, economic surplus techniques can also be used for ex ante impact assessment. The method is applied to the case of the WorldFish Center, an international organization specializing in research on aquatic resources in developing countries. A survey of expert opinion is used to estimate productivity improvements and adoption rates for NRM research and its application. A supply-demand model for aquatic commodities is constructed to calculate the resulting change in economic surplus. Results indicate that ex ante economic impact is highest for NRM on coral reefs and inland aquatic systems.