Bounds on the Optimal Age-at-First-Capture for Stochastic, Age-Structured Fisheries

Abstract

This paper addresses the problem of optimally exploiting an age-structured fishery with stochastic, density-dependent recruitment; stochastic dynamics; and cohort-dependent prices, costs, catchabilities, and survival rates. Sufficient conditions are derived for an age-at-first-capture to be a necessary component of the optimal management regime, and a lower bound on this critical age is calculated. The method consists of replacing the stochastic, density-dependent model with more traditional (stochastic, density-independent and deterministic, density-independent) models which yield lower bounds on the optimal escapement. A numerical example demonstrates the practical applicability of the results.