美国华盛顿大学Kristin L. Laidre课题组通过对冰川研究，发现了在21世纪后期海冰条件下持续存在的独特且未记录的北极熊亚种群。相关论文发表在2022年6月16日出版的《科学》杂志上。

研究人员提供了格陵兰东南部一种基因不同且功能孤立北极熊存在的第一个证据。这些熊栖息的海冰条件类似于21世纪后期北极高地的预测条件，每年的无冰期比该物种预计的禁食阈值长100天以上。北极大部分地区的北极熊依靠每年的海冰捕捉海豹，而东南格陵兰熊则以淡水冰川混合物的形式可在全年狩猎。

这表明海洋边缘的冰川虽然可用性有限，但可能是以前未被认可的气候避难所。东南格陵兰北极熊符合世界第20个北极熊亚群的保护标准，对于保护该物种的遗传多样性和进化是必要的。

据了解，北极熊很容易受到气候变暖的影响，因为它们依赖的海冰正在迅速减少。

附：英文原文

Title: Glacial ice supports a distinct and undocumented polar bear subpopulation persisting in late 21st-century sea-ice conditions

Author: Kristin L. Laidre, Megan A. Supple, Erik W. Born, Eric V. Regehr, ystein Wiig, Fernando Ugarte, Jon Aars, Rune Dietz, Christian Sonne, Peter Hegelund, Carl Isaksen, Geir B. Akse, Benjamin Cohen, Harry L. Stern, Twila Moon, Christopher Vollmers, Russ Corbett-Detig, David Paetkau, Beth Shapiro

Issue&Volume: 2022-06-17

Abstract: 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 mélange. 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.

DOI: abk2793

Source: https://www.science.org/doi/10.1126/science.abk2793