Optimal fishery policy: An equilibrium solution with irreversible investment (Q1057798)

The first author [ibid. 12, 265-293 (1981; Zbl 0469.92010)] showed by applying dynamic optimization techniques to several biologically realistic models (i.e. models that included size structure and either density or food dependent growth and recruitment rates) that the constant policy solution found for simpler, less realistic models was not possible. He concluded that optimal policy was a time-varying, possibly pulse-fishing policy. We show here that when the maximum allowed fishing mortality is low enough a different kind of constant policy is optimal for these realistic models. Interpretation of this condition requires explicit consideration of fixed capital costs in addition to operating costs. Practical considerations indicate that this constant policy would apply only to fisheries with high fixed capital costs.