Fisheries management: what uncertainties matter?

Uncertainty is pervasive in fisheries management. Bioeconimists have undertaken long-standing effort to derive economically optimal management rules under uncertainty and provide explicitly optimal feedback solutions. Based on this body of work, we determine the importance of different kinds of uncertainty in the definition of harvest control rules. The performances of harvest policies which dictate how harvest is determined as a function of the state of the resource are sensitive to uncertainty. We discuss six sources of uncertainties and illustrate how these have affected the management process. We then describe how those classes of uncertainty affect optimal harvest control rules. We summarize the conclusions of economists based on structural assumptions affecting objective functions under different classes of uncertainties. We identify common classes of harvest control rules and the resulting precaution of the harvest strategy. Finally, we discuss the opportunities to develop fully adaptive management to decide upon structural assumptions through the extension of Markov decision process and feedback solutions to complex models.