Glacial ice supports a distinct and undocumented polar bear subpopulation persisting in late 21st-century sea-ice conditions
Glacial ice supports a distinct and undocumented polar bear subpopulation persisting in late 21st-century sea-ice conditions
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DOI：
10.1126/science.abk2793
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发表时间：
2022-06-17
期刊：
影响因子：
56.9
通讯作者：
Shapiro, Beth
中科院分区：
文献类型：
--
作者：
Laidre, Kristin L.;Supple, Megan A.;Shapiro, Beth
北极熊很容易受到气候变暖的影响，因为它们依赖于海冰，而海冰正在迅速减少。我们提出了第一个证据，在格陵兰岛东南部的一个遗传上独特的和功能上孤立的北极熊群。这些熊占据的海冰条件类似于21世纪后期北极高纬度地区的预测，每年的无冰期比估计的禁食阈值长100天以上。北极大部分地区的北极熊依靠每年的海冰来捕捉海豹，而格陵兰东南部的北极熊则拥有一个以淡水冰川混合物形式存在的全年狩猎平台。这表明，海洋终止冰川，虽然有限的可用性，可能作为以前未被承认的气候避难所。格陵兰东南部的北极熊符合世界上第20个北极熊亚群的标准，保护它们对保护该物种的遗传多样性和进化潜力是必要的。
Polar bears are susceptible to climate warming because of their dependence on sea ice, which is declining rapidly. We present the first evidence for a genetically distinct and functionally isolated group of polar bears in Southeast Greenland. These bears occupy sea-ice conditions resembling those projected for the High Arctic in the late 21st century, with an annual ice-free period that is >100 days longer than the estimated fasting threshold for the species. Whereas polar bears in most of the Arctic depend on annual sea ice to catch seals, Southeast Greenland bears have a year-round hunting platform in the form of freshwater glacial melange. This suggests that marine-terminating glaciers, although of limited availability, may serve as previously unrecognized climate refugia. Conservation of Southeast Greenland polar bears, which meet criteria for recognition as the world's 20th polar bear subpopulation, is necessary to preserve the genetic diversity and evolutionary potential of the species.