Replication Data for: Timing and magnitude of climate driven range shifts in transboundary fish stocks challenge their management

Climate change is shifting the distribution of shared fish stocks between neighboring countries’ Exclusive Economic Zones (EEZs) and the high seas. The timescale of these transboundary shifts determines how climate change will affect international fisheries governance. Here, we explore this timescale by coupling a large ensemble simulation of an Earth system model under a high emission climate change scenario to a dynamic population model. We show that by 2030, 23% of transboundary stocks will have shifted and 78% of the world’s EEZs will have experienced at least one shifting stock. By the end of this century, projections show a total of 45% of stocks shifting globally and 81% of EEZs waters with at least one shifting stock. The magnitude of such shifts is reflected in changes in catch-proportion between EEZs sharing a transboundary stock. By 2030, global EEZs are projected to experience an average change of 59% in catch proportion of transboundary stocks. Many countries that are highly dependent on fisheries for livelihood and food security emerge as hotspots for transboundary shifts. These hotspots are characterized by early shifts in the distribution of an important number of transboundary stocks. Existing international fisheries agreements need to be assessed for their capacity to address the social-ecological implications of climate change driven transboundary shifts and strengthened where necessary to limit potential conflict between the parties of interest. Meanwhile, new agreements will need to be anticipatory and consider these concerns and their associated uncertainties to be resilient to global change.

气候变化正在改变共享鱼类种群在邻国专属经济区（Exclusive Economic Zones，EEZs）与公海之间的分布格局。这类跨界鱼类种群（transboundary stocks）分布变动的时间尺度，决定了气候变化将如何影响国际渔业治理体系。本研究通过将高排放气候变化情景下地球系统模型的大集合模拟结果与动态种群模型相结合，探究了该时间尺度问题。研究结果显示，到2030年，全球将有23%的跨界鱼类种群发生分布变动，全球78%的专属经济区将至少遭遇一种发生分布变动的跨界种群。到本世纪末，预测结果显示全球将有总计45%的鱼类种群发生分布变动，81%的专属经济区海域将至少存在一种发生分布变动的种群。这类分布变动的强度，可通过共享跨界鱼类种群的各专属经济区之间捕捞占比的变化得以体现。到2030年，全球各专属经济区的跨界鱼类种群捕捞占比预计将平均变化59%。众多高度依赖渔业维持民生与粮食安全的国家，成为跨界鱼类种群分布变动的热点区域。这些热点区域的特征是，大量跨界鱼类种群较早发生了分布变动。现有国际渔业协定需针对其应对气候变化驱动的跨界种群变动所带来的社会生态影响的能力开展评估，并在必要时予以强化，以限制相关缔约方之间潜在的冲突。与此同时，新协定需具备前瞻性，充分考量上述问题及其相关不确定性，以提升对全球变化的适应韧性。