Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, British Columbia, Canada.
Center for Limnology, University of Wisconsin, Madison, Wisconsin, USA.
Glob Chang Biol. 2022 Apr;28(7):2312-2326. doi: 10.1111/gcb.16058. Epub 2022 Jan 18.
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. Some of these agreements will need to be adjusted 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.
气候变化正在改变相邻国家专属经济区（EEZ）和公海之间共享鱼类种群的分布。这些跨界转移的时间尺度决定了气候变化将如何影响国际渔业管理。在这里，我们通过将高排放气候变化情景下的地球系统模型的大型集合模拟与动态种群模型耦合来探索这个时间尺度。我们表明，到 2030 年，23%的跨界种群将发生转移，全球 78%的 EEZ 将至少经历一次转移的种群。到本世纪末，预计全球将有 45%的种群转移，全球 81%的 EEZ 水域将至少有一个转移的种群。这种转移的幅度反映在共享跨界种群的 EEZ 之间的捕获比例变化上。到 2030 年，预计全球 EEZ 将经历跨界种群捕获比例平均变化 59%。许多高度依赖渔业维持生计和粮食安全的国家成为跨界转移的热点。这些热点的特点是，大量跨界种群的分布很早就发生了变化。需要评估现有的国际渔业协定，以确定它们应对气候变化驱动的跨界转移的社会-生态影响的能力。这些协定中的一些将需要进行调整，以限制有关各方之间潜在的冲突。同时，新的协定需要具有前瞻性，并考虑到这些问题及其相关的不确定性，以适应全球变化。
