Climate change threatens global biodiversity. Many species vulnerable to climate change are important to humans for nutritional, cultural, and economic reasons. Polar bears Ursus maritimus are threatened by sea-ice loss and represent a subsistence resource for Indigenous people. We applied a novel population modeling-management framework that is based on species life history and accounts for habitat loss to evaluate subsistence harvest for the Chukchi Sea (CS) polar bear subpopulation. Harvest strategies followed a state-dependent approach under which new data were used to update the harvest on a predetermined management interval. We found that a harvest strategy with a starting total harvest rate of 2.7% (˜85 bears/yr at current abundance), a 2:1 male-to-female ratio, and a 10-yr management interval would likely maintain subpopulation abundance above maximum net productivity level for the next 35 yr (approximately three polar bear generations), our primary criterion for sustainability. Plausible bounds on starting total harvest rate were 1.7–3.9%, where the range reflects uncertainty due to sampling variation, environmental variation, model selection, and differing levels of risk tolerance. The risk of undesired demographic outcomes (e.g., overharvest) was positively related to harvest rate, management interval, and projected declines in environmental carrying capacity; and negatively related to precision in population data. Results reflect several lines of evidence that the CS subpopulation has been productive in recent years, although it is uncertain how long this will last as sea-ice loss continues. Our methods provide a template for balancing trade-offs among protection, use, research investment, and other factors. Demographic risk assessment and state-dependent management will become increasingly important for harvested species, like polar bears, that exhibit spatiotemporal variation in their response to climate change.

中文翻译：

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受气候变化威胁的捕捞物种的人口风险评估：楚科奇海的北极熊

气候变化威胁着全球生物多样性。由于营养、文化和经济原因，许多易受气候变化影响的物种对人类很重要。北极熊Ursus maritimus受到海冰流失的威胁，是土著人民的生存资源。我们应用了一种基于物种生活史并考虑栖息地丧失的新型种群建模管理框架来评估楚科奇海 (CS) 北极熊亚群的生存收获。收获策略遵循依赖状态的方法，根据该方法，新数据用于在预定的管理间隔内更新收获。我们发现，起始总收获率为 2.7%（在当前丰度下约为 85 头熊/年）、2:1 的男女比例和 10 年管理间隔的收获策略可能会保持亚种群丰度高于未来 35 年（大约三代北极熊）的最高净生产力水平，这是我们衡量可持续性的主要标准。起始总收获率的合理界限为 1.7-3.9%，其中该范围反映了由于采样变化、环境变化、模型选择和不同风险承受水平造成的不确定性。不良人口结果（如过度采伐）的风险与采伐率、管理间隔和预计的环境承载能力下降呈正相关；与人口数据的精确度负相关。结果反映了几条证据表明近年来 CS 亚群一直富有成效，尽管随着海冰流失的继续，这种情况会持续多久还不确定。我们的方法为平衡保护、使用、研究投资和其他因素之间的权衡提供了一个模板。