Risk and Sustainability: Assessing Fishery Management Strategies

We develop a theoretical framework to assess the sustainability of fishery management strategies, when the bioeconomic dynamics are marked by uncertainty and several conflicting objectives have to be accounted for. Stochastic viability ranks management strategies according to their probability to sustain economic and ecological outcomes over time. The approach is extended to build stochastic sustainable production possibility frontiers representing the trade-offs between sustainability objectives at any risk level, given the current state of the fishery. This framework is applied to a Chilean fishery faced with El Nio uncertainty. We study the viability of effort and quota strategies when catch and biomass levels have to be sustained. We show that (1) for these sustainability objectives, whatever the level of the outcomes to be sustained, quota-based management results in a better viability probability than effort-based management, and (2) the fishery's historical quota levels were not sustainable given the stock levels in the early 2000s.