Managing interacting species in unassessed fisheries

This paper addresses the management of multispecies sheries, and suggests the use of restricted shing policies as an interesting option for unassessed sheries (as is the case within developing countries). Specically, we consider a predator-prey system where agents compete to harvest from two interacting sh species. Two management policies are considered: an unrestricted regime where agents can harvest from both species, and a second one where only the predators can be harvested. The performance of both policies is compared from an ecological and an economic point of view. For a suciently large number of agents (or for strong biological interaction parameters) the restricted shing policy is shown to yield both higher long run stock levels and prots. Thus, this contribution suggests that such a policy would require very little monitoring while meeting environmental and economic objectives.