Atlantic menhaden (Brevoortia tyrannus) are an important forage fish for many predators, and they also support the largest commercial fishery by weight on the U.S. East Coast. Menhaden management has been working toward ecological reference points (ERPs) that account for menhaden’s role in the ecosystem. The goal of this work was to develop menhaden ERPs using ecosystem models. An existing Ecopath with Ecosim model of the Northwest Atlantic Continental Shelf (NWACS) was reduced in complexity from 61 to 17 species/functional groups. The new NWACS model of intermediate complexity for ecosystems (NWACS-MICE) serves to link the dynamics of menhaden with key managed predators. Striped bass (Morone saxatilis) were determined to be most sensitive to menhaden harvest and therefore served as an indicator of ecosystem impacts. ERPs were based on the tradeoff relationship between the equilibrium biomass of striped bass and menhaden fishing mortality (F). The ERPs were defined as the menhaden F rates that maintain striped bass at their biomass target and threshold when striped bass are fished at their Ftarget, and all other modeled species were fished at status quo levels. These correspond to an ERP Ftarget of 0.19 and an ERP Fthreshold of 0.57, which are lower than the single species reference points by 30–40%, but higher than current (2017) menhaden F. The ERPs were then fed back into the age-structured stock assessment model projections to provide information on total allowable catch. The ERPs developed in this study were adopted by the Atlantic menhaden Management Board, marking a shift toward ecosystem-based fishery management for this economically and ecologically important species.

中文翻译：

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使用中等复杂度的生态系统模型建立大西洋鲱鱼的生态参考点

大西洋鲱鱼（Brevoortia tyrannus）是许多捕食者的重要饲料鱼，它们还支持美国东海岸按重量计算最大的商业渔业。鲱鱼管理一直致力于生态参考点 (ERP)，以解释鲱鱼在生态系统中的作用。这项工作的目标是使用生态系统模型开发鲱鱼 ERP。西北大西洋大陆架 (NWACS) 的现有生态路径与 Ecosim 模型的复杂性从 61 种/功能组减少到 17 种。生态系统中等复杂性的新 NWACS 模型 (NWACS-MICE) 用于将鲱鱼的动态与主要受管理的捕食者联系起来。条纹鲈鱼 (Morone saxatilis) 被确定为对鲱鱼收获最敏感，因此可作为生态系统影响的指标。ERP 基于条纹鲈鱼的平衡生物量与鲱鱼捕捞死亡率 (F) 之间的权衡关系。ERPs 被定义为当条纹鲈鱼在其 Ftarget 下捕捞时，将条纹鲈鱼保持在其生物量目标和阈值的鲱鱼 F 率，而所有其他建模物种在现状水平下捕捞。这些对应于 0.19 的 ERP Ftarget 和 0.57 的 ERP Fthreshold，它们比单一物种参考点低 30-40%，但高于当前（2017 年）鲱鱼 F。然后将 ERP 反馈到年龄-结构化种群评估模型预测，以提供关于总可捕量的信息。本研究中开发的 ERP 被大西洋鲱鱼管理委员会采用，