P>To explore the drivers of change in the complex system relating small pelagic fisheries and fishmeal/fish oil markets, to identify the interactions between these drivers and their overall impacts, we propose a bio-economic model, coupling the ecological and the economic dynamics of these global commodities. The model enables an analysis of the consequences of both global and local changes in the environment of production systems. Through sensitivity analysis of specific input parameters, we evaluate the robustness of the overall system to such changes and show that local responses of production systems and markets cannot be considered in isolation from the set of interactions at global level.