Rovellini Alberto, Punt André E, Dorn Martin W, Kaplan Isaac C, Bryan Meaghan D, Adams Grant, Aydin Kerim, Baker Matthew R, Barnes Cheryl L, Ferriss Bridget E, Fulton Elizabeth A, Haltuch Melissa A, Hermann Albert J, Holsman Kirstin K, McGilliard Carey R, McHuron Elizabeth A, Morzaria-Luna Hem Nalini, Surma Szymon
School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA.
Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration, Seattle, Washington, USA.
Ecol Appl. 2025 Apr;35(3):e70036. doi: 10.1002/eap.70036.
Ecosystem-based fisheries management strives to account for species interactions and ecosystem processes in natural resource management and conservation. In this context, ecosystem-wide caps on total fishery catches have been proposed as one tool to manage multispecies fisheries with an ecosystem approach. However, determining effective ecosystem caps is complicated because fish stock production is influenced by environmental conditions, species interactions, and fishing. Consequently, the implementation of ecosystem caps in fisheries management frameworks remains uncommon. We investigated whether ecosystem caps should account for climate variability and for predator-prey dynamics to achieve management objectives in complex marine ecosystems. We considered the example of the Gulf of Alaska (United States), a North Pacific large marine ecosystem where annual groundfish catches are managed using an "optimum yield" ecosystem cap of 800,000 t. We simulated multispecies yield of the 12 most abundant and commercially valuable groundfish stocks under selected climate and fishing scenarios using an end-to-end marine ecosystem model (Atlantis), which accounts for predator-prey and ecosystem dynamics. We found that total groundfish yield was never projected to exceed the 800,000 mt optimum yield cap across scenarios and fishing mortalities. Projected climate change led to decreased groundfish yield, and predation from the underexploited groundfish predator arrowtooth flounder (Atheresthes stomias) led to foregone catches. Groundfish removals had negative indirect effects on groundfish predators, despite total yield never exceeding the optimum yield cap, highlighting that an ineffective cap may not protect non-target species. These results suggest that the optimum yield cap currently used in the Gulf of Alaska may be too high to constrain groundfish catches under future climate change and low exploitation rates of predators. We propose that ecosystem caps should be reviewed when environmental conditions, stock productivity, or species interactions change.
基于生态系统的渔业管理致力于在自然资源管理和保护中考虑物种相互作用和生态系统过程。在此背景下，已提出对总渔业捕捞量设置全生态系统上限，作为以生态系统方法管理多物种渔业的一种工具。然而，确定有效的生态系统上限很复杂，因为鱼类种群产量受环境条件、物种相互作用和捕捞影响。因此，在渔业管理框架中实施生态系统上限仍不常见。我们研究了生态系统上限是否应考虑气候变异性和捕食者 - 猎物动态，以在复杂的海洋生态系统中实现管理目标。我们以美国阿拉斯加湾为例，它是北太平洋的一个大型海洋生态系统，那里每年底栖鱼类捕捞量使用80万吨的“最佳产量”生态系统上限进行管理。我们使用一个考虑了捕食者 - 猎物和生态系统动态的端到端海洋生态系统模型（Atlantis），在选定的气候和捕捞情景下模拟了12种最丰富且具有商业价值的底栖鱼类种群的多物种产量。我们发现，在各种情景和捕捞死亡率下，底栖鱼类总产量预计从未超过80万吨的最佳产量上限。预计的气候变化导致底栖鱼类产量下降，未充分开发的底栖鱼类捕食者——太平洋庸鲽（Atheresthes stomias）的捕食导致了捕捞量的损失。尽管总产量从未超过最佳产量上限，但底栖鱼类的捕捞对底栖鱼类捕食者有负面间接影响，这突出表明无效的上限可能无法保护非目标物种。这些结果表明，阿拉斯加湾目前使用的最佳产量上限可能过高，无法在未来气候变化和捕食者低开发率的情况下限制底栖鱼类捕捞量。我们建议，当环境条件、种群生产力或物种相互作用发生变化时，应对生态系统上限进行审查。
