Data and code: Assessing fish-fishery dynamics from a spatially explicit metapopulation perspective reveals winners and losers in fisheries management

Sustainable management of living resources must reconcile biodiversity conservation and socioeconomic viability of human activities. In the case of fisheries, sustainable management design is made challenging by the complex spatiotemporal interactions between fish and fisheries.
We develop a comprehensive metapopulation framework integrating data on species life-history traits, connectivity and habitat distribution to identify priority areas for fishing regulation and assess how management impacts are spatially distributed. We trial this approach on European hake fisheries in the north-western Mediterranean, where we assess area-based management scenarios in terms of stock status and fishery productivity to prioritize areas for protection.
Model simulations show that local fishery closures have the potential to enhance both spawning stock biomass and landings on a regional scale compared to a status quo scenario, but that improving protection is easier than increasing productivity. Moreover, the interaction between metapopulation dynamics and the redistribution of fishing effort following local closures implies that benefits and drawbacks are heterogeneously distributed in space, the former being concentrated in the proximity of the protected site.
A network analysis shows that priority areas for protection are those with the highest connectivity (as expressed by network metrics) if the objective is to improve the spawning stock, while no significant relationship emerges between connectivity and potential for increased landings.

Synthesis and applications – Our framework provides a tool for 1) assessing area-based management measures aimed at improving fisheries outcomes in terms of both conservation and socioeconomic viability and 2) describing the spatial distribution of costs and benefits, which can help guide effective management and gain stakeholder support. Adult dispersal remains the main source of uncertainty that needs to be investigated to effectively apply our model to fisheries regulation.

生物资源的可持续管理必须兼顾生物多样性保护与人类活动的社会经济可行性。就渔业而言，鱼类种群与渔业活动间复杂的时空相互作用，使得可持续管理方案的设计极具挑战性。
我们构建了一套综合集合种群（metapopulation）框架，整合物种生活史特征、连通性与栖息地分布等多源数据，以识别渔业管制的优先区域，并量化评估管理措施的空间影响分布特征。本研究以地中海西北部的欧洲无须鳕渔业为研究对象，从种群现状与渔业生产力两个维度评估基于区域的管理情景，以此确定保护优先区域。
模型模拟结果显示，相较于现状基准情景（status quo），局部渔业禁捕举措有望在区域尺度上同时提升产卵群体生物量与渔获总量，但提升保护力度相较于提高渔业生产力更为可行。此外，集合种群动态与局部禁捕后捕捞努力量（fishing effort）的重新分配，意味着管理措施的收益与成本在空间上呈异质性分布，其中收益集中于保护区域的周边范围。
网络分析结果表明，若以提升产卵群体生物量为目标，保护优先区域应为连通性最高的区域（以网络度量指标衡量）；而连通性与渔获量提升潜力之间并未显现显著的相关性。
综合与应用——本研究框架可为两类工作提供工具：1）评估旨在兼顾生物多样性保护与社会经济可行性、优化渔业治理成效的基于区域的管理措施；2）刻画管理成本与收益的空间分布格局，这有助于指导高效渔业管理并获取利益相关者的支持。成体扩散仍是将本模型有效应用于渔业管制前，需进一步探究的核心不确定性来源。