HEURES A BIOECONOMIC MODEL FOR MEDITERRANEAN FISHERIES, TOWARDS AN APPROACH FOR THE EVALUATION OF MANAGEMENT STRATEGIES

The bio-economic model ''Heures'' is a first attempt to develop a simu lation procedure to understand the Northwestern Mediterranean fisherie s, to evaluate management strategies and to analyze the feasibility of implementing an adaptative management. The model is built on the inte raction among three boxes simulating the dynamics of each of the basic actors of a fishery: the stock, the market and the fishermen. A fourt h actor, the manager, imposes or modifies the rules, or. in terms of t he model, modifies some particular parameters. Thus, the model allows us to simulate and evaluate the mid-term biologic and economic effects of particular management measures. The bio-economic nature of the mod el is given by the interaction among the three boxes, by the market si mulation and, particularly, by the fishermen behaviour. This last elem ent confers to the model its Mediterranean ''selfregulated'' character . The fishermen allocate their investments to maximize fishing mortali ty but, having a legal effort limit, they invest in maintenance and te chnology in order to increase the catchability, which, as a consequenc e, will be function of the invested capital.