Dealing with dynamics and uncertainty of small pelagic fisheries: bioeconomic analysis of manager’s responses to alternative management strategies

摘要

Small pelagic fisheries have been characterized by large fluctuations in abundance due to environmental factors, harvest regimes, and reproduction patterns, among others. Given this complexity, the development of management schemes for sardine fisheries requires an evaluation of the impact of different management strategies. The evaluation of any management scheme would need to account for the uncertainty associated with the biological behavior of resources and economic performance of the fisheries to predict changes in resource abundance through simulation of alternative scenarios. In this study, an age-structured dynamic bioeconomic model of the Pacific sardine (Sardinops sagax) fishery off the Baja California peninsula in Mexico was used. The model assessed the effect of changes in recruitment over several state variables (biomass, net present value and catch). An analysis of risk and uncertainty allowed the identification of sensitive parameters (natural mortality, price and catchability) and a precautionary approach was used to evaluate the response of decision-makers with different attitudes toward risk (adverse, neutral and prone) given different management scenarios, from open access to restrictions in fishing effort. Incorporation of uncertainty and risk analyses into the assessment of the sardine fishery showed that management strategies that involve restrictions on fishing effort resulted in a lower probability (0-7, expressed in percentage) of exceeding limit reference points (LRPs) than those strategies that permit conditions of open access, or that aim for catch at maximum sustainable yield (MSY) and catch quotas (13-60%). The analysis highlights the advantages of using an approach that incorporates risk and uncertainty for generating management strategies for pelagic fisheries with high exposure to uncertain conditions.