Preference for Landings' Smoothing and Risk of Collapse in Optimal Fishery Policies: The Ibero-Atlantic Sardine Fishery

摘要

Several world fish stocks are being explored at unsustainable levels and require management plans to rebuild stock abundance. Defining a management plan is, however, a complex task that entails multidisciplinary work. In fact, while it requires solid scientific knowledge of fish stocks, the inclusion of economic and social objectives is crucial to a successful management implementation. In this paper we develop an age-structured bioeconomic model where the objective function is modified to accommodate preferences from different stakeholders. In particular, we consider important characteristics that a management plan should take into account: profit maximization, fishermen's preference for reducing landings' fluctuations and risk of fishery collapse. Modeling preferences for reducing landings' fluctuations is accomplished by defining a utility function with aversion to intertemporal income fluctuations. Building upon biology literature, we model precautionary concerns by incorporating a probability of collapse that depends on current spawning biomass. We illustrate how this framework is able to assist in the analysis and design of harvest control rules applying it to the Ibero-Atlantic sardine stock.