Natural resource management is evolving toward holistic, ecosystem-based approaches to decision making. The ecosystem science underpinning these approaches needs to account for the complexity of multiple interacting components within and across coupled natural–human systems. In this research, we investigate the potential economic and ecological gains from adopting ecosystem-based approaches for the sardine and anchovy fisheries off of the coast of California, USA. Research has shown that while predators in this system are likely substituting one forage species for another, the assemblage of sardine and anchovy can be a significant driver of predator populations. Currently, the harvest control rules for sardine and anchovy fisheries align more with traditional single species framework. We ask what are the economic and ecological gains when jointly determining the harvest control rules for both forage fish stocks and their predators relative to the status quo? What are the implications of synchronous and anti-synchronous environmental recruitment variation between the anchovy and sardine stocks on optimal food-web management? To investigate these questions, we develop an economic-ecological model for sardine, anchovy, a harvested predator (halibut), and an endangered predator (Brown Pelican) that includes recruitment variability over time driven by changing environmental conditions. Utilizing large-scale numerical optimal control methods, we investigate how the multiple variants of integrated management of sardine, anchovy, and halibut impact the overall economic condition of the fisheries and Brown Pelican populations over time. We find significant gains in moving to integrated catch control rules both in terms of the economic gains of the fished stocks, and in terms of the impacts on the Brown Pelican populations. We also compare the relative performance of current stylized catch control rules to optimal single species and optimal ecosystem-based fisheries management (EBFM) across ecological and economic dimensions, where the former trade-off considerable economic value for ecological goals. More generally, we demonstrate how EBFM approaches introduce and integrate additional management levers for policymakers to achieve non-fishery objectives at lowest costs to the fishing sectors.

中文翻译：

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基于生态系统的渔业管理在饲料鱼类渔业中的直接和辅助效益

自然资源管理正在朝着基于生态系统的整体决策方法发展。支撑这些方法的生态系统科学需要考虑耦合的自然-人类系统内和跨耦合的多个交互组件的复杂性。在这项研究中，我们调查了美国加利福尼亚海岸外的沙丁鱼和鳀鱼渔业采用基于生态系统的方法所带来的潜在经济和生态收益。研究表明，虽然这个系统中的捕食者可能会用一种草料替代另一种，但沙丁鱼和凤尾鱼的组合可能是捕食者种群的重要驱动因素。目前，沙丁鱼和鳀鱼渔业的捕捞控制规则更符合传统的单一物种框架。我们问，相对于现状，共同确定饲料鱼类种群及其捕食者的捕捞控制规则时，经济和生态收益是什么？鳀鱼和沙丁鱼种群之间的同步和反同步环境补充变化对最佳食物网管理有何影响？为了调查这些问题，我们为沙丁鱼、鳀鱼、捕食者（大比目鱼）和濒临灭绝的捕食者（褐鹈鹕）开发了一个经济生态模型，其中包括随时间变化的环境条件变化导致的招募变化。利用大规模数值优化控制方法，我们研究沙丁鱼、鳀鱼和大比目鱼综合管理的多种变体如何随着时间的推移影响渔业和褐鹈鹕种群的整体经济状况。我们发现，在渔业资源的经济收益和对褐鹈鹕种群的影响方面，采用综合捕捞控制规则取得了重大进展。我们还将当前程式化的捕捞控制规则的相对性能与最佳单一物种和最佳基于生态系统的渔业管理 (EBFM) 在生态和经济方面进行了比较，其中前者权衡了生态目标的可观经济价值。更一般地，我们展示了 EBFM 方法如何为决策者引入和整合额外的管理杠杆，以以最低成本实现渔业部门的非​​渔业目标。我们还将当前程式化的捕捞控制规则的相对性能与最佳单一物种和最佳基于生态系统的渔业管理 (EBFM) 在生态和经济方面进行了比较，其中前者权衡了生态目标的可观经济价值。更一般地，我们展示了 EBFM 方法如何为决策者引入和整合额外的管理杠杆，以以最低成本实现渔业部门的非​​渔业目标。我们还将当前程式化的捕捞控制规则的相对性能与最佳单一物种和最佳基于生态系统的渔业管理 (EBFM) 在生态和经济方面进行了比较，其中前者权衡了生态目标的可观经济价值。更一般地，我们展示了 EBFM 方法如何为决策者引入和整合额外的管理杠杆，以以最低成本实现渔业部门的非​​渔业目标。