Groupe d’études et de recherche en analyse des décisions

Viability of transboundary fisheries and international quota sharing: The case of the Bay of Biscay Anchovy

Vincent Martinet Institut national de la recherche agronomique (INRA)

This paper examines the viability of the management of a transboundary fishery. In a deterministic dynamic framework, we consider a fish stock with two age groups, juveniles and adults, exploited by two fisheries having different impact on the age groups. A regulatory agency defines the annual fishing quotas and their allocation between the two countries. We consider allocations satisfying a set of constraints representing viability conditions. The constraints include a minimal quota and minimal profit for each country. We compare the resulting intertemporal viable trajectory with the trajectory resulting from a cooperation game in which the two countries agree on the maximization of the fisheries' total profit. While the cooperative solution consists in allocating the whole fishing effort to the most efficient country, the viable solution is more equitable, and maintain a larger fish stock. The results are illustrated for the Bay of Biscay anchovy (Engraulis encrasicolus L.), exploited by Spain and France, with two different types of gear, the purse seiner for Spain and the pelagic trawler for France.