Bioeconomic analysis of stock rebuilding strategies for the green abalone fishery in Mexico under climate uncertainty

Abstract

Globally, overexploitation of fishery stocks is a complex problem aggravated by climate change's effects. The green abalone in Mexico is an overexploited fishery, resulting in stakeholders committing to its recovery. Part of a comprehensive co-management strategy was to implement a fishing closure in some fishing areas. Now they are exploring reopening the fishery and gradually increasing fishing efforts. This research evaluates compatible management strategies with stock rebuilding under climate uncertainty. An age-structured bioeconomic model for the green abalone fishery was parameterized, which considered the impact of SST anomalies on population dynamics (i.e., recruitment, mortality, and growth). Three management strategies were evaluated under future climate scenarios (RCP 4.5, RCP 8.5, and a scenario without climate change). Results indicate that an effort level that aims to generate Maximum Sustainable Yield (MSY) based on historical fishery data may lead to overexploitation under warming scenarios. Instead, applying the minimum acceptable effort for the fishing community can support biomass recovery and is a strategy more resilient to climate change. This finding highlights the risk of overexploitation by assuming stock productivity stability under favorable climatic conditions when designing rebuilding plans. A stock rebuilding strategy will be more likely to succeed if it is cautious, recognizes uncertainties, and is flexible in considering stock productivity changes.