Résumé
Small pelagic fisheries produce more than 25% of the fish caught in the ocean. Their production is mainly dedicated to fish meal and fish oil production (more than 80%). In this system, there is a tension between a highly variable natural system and a more rigid economic system, with a high increase in demand. To make explicit the stakes of the management of this system, we propose a bioeconomic model, coupling the ecological and economic dynamics. The coupling is based on the computing of global equilibrium, on the network which interconnects the marine production systems (ecosystems, fisheries and manufacturing) and the fish product markets (fish oil and fish meal) all around the world. This model allows the consequences of several management hypotheses to be analysed (increase of carrying capacity of ecosystems through climate changes, politics of total allowable catches, etc.). To illustrate the model's behaviour we propose sensitivity analysis of the model results, with changes in specific values. We have derived from this work a dedicated role playing game in which players are not the stakeholders directly involved in the fishery business, but their delegates: South American, or European fisheries and industries, fish meal or fish oil buyers from Europe or China, scientific institutions studying the Atlantic or Pacific Oceans, international organisations from the Pacific or Europe. We present different plays of the game, leading to very different emergence of coordination or conflicts. This approach should help to anticipate negotiations about global management of small pelagic fisheries.