Sustainable Exploitation of Biological Populations

For a system of nonlinear difference equations that models the dynamics of exploited biological populations, a locally optimal periodic solutionis constructed. If this solution is unstable, a stabilizing feedback in the harvesting is introduced. The method is applied to an age-structured population model in fishery as well as to a host-parasitoid system for which the number of hosts and the number of introduced parasitoids shouldbe minimized.