Defining viable recovery paths toward sustainable fisheries

Abstract

This paper develops a formal analysis of the recovery process for a fishery, from crisis situations to desired levels of sustainable exploitation, using the theoretical framework of viable control. We define sustainability as a combination of biological, economic and social constraints which need to be met for a viable fishery to exist. Biological constraints are based on the definition of a minimum resource stock to be preserved. Economic constraints relate to the existence of a guaranteed profit per vessel. Social constraints refer to the maintenance of a minimum size of the fleet, and to the maximum speed at which fleet adjustment can take place. Using fleet size adjustment and fishing effort per vessel as control variables, we first identify the states of this bioeconomic system for which sustainable exploitation is possible, i.e. for which all constraints can be dynamically met. Such favorable states are called viable states. We then examine possible transition phases, from non-viable to viable states. We characterize recovery paths with respect to the time of crisis of the trajectory, which is the number of periods during which the constraints are not respected. The approach is applied to the single stock of the bay of Biscay Nephrops fishery. The transition path identified through the viability approach is compared to the historical recovery process, and to both open-access and optimal harvesting scenarios.

Hare or Tortoise? Trade-offs in Recovering Sustainable Bioeconomic Systems

“…There will necessarily be trade-offs between the speed of recovery and the social and political acceptability of the adjustments required for fisheries to be restored. This problem is not addressed in Martinet et al [20].…”

“…In the present article, we extend the analysis of Martinet et al [20] to address the issue of the restoration of bioeconomic systems facing a crisis. More specifically, we examine the trade-offs between speed and acceptability of recovery programs.…”

“…Doyen and Saint-Pierre [11] extend the viability approach to deal with such issues and define the notion of minimum time of crisis. Martinet et al [20] use this notion to analyze recovery paths for bioeconomic marine resource systems facing crisis situations. They compare a recovery strategy based on the minimization of the time of crisis to other possible strategies (historical path, open access and maximum intertemporal economic yield).…”

Towards the implementation of an integrated approach to fisheries resources management in Ifremer, France

“…There is no shortage of prescriptions for "ill" fisheries but very little work still on viable recovery pathways [51] offering to managers a more complete panorama of the available options.…”

Interactive modelling for natural resource management

“…The simulation model then represents a mapping of points in input parameter space to an output data-space where projected outcomes of management decisions can be viewed and analysed. Seen from this perspective, a resource management problem appears similar to many engineering or applied mathematical problems, in which a numerical optimisation tool can be used to map a desired policy outcome (from the outcome space) back into the strategy space, thereby easily deducing a set of reasonable, if not optimal, strategies (Sainsbury et al, 2000;Doyen and Béné, 2003;Doyen et al, 2007;Martinet et al, 2007).…”