Recent historic lows in sea ice and cold pool extent in the Bering Sea have been linked to large-scale biogeographic shifts in many demersal taxa. Snow crab (Chionoecetes opilio) are associated with the cold pool and thus may be especially prone to northward range contraction with continued warming. Data from the 1988–2019 National Marine Fisheries Service eastern Bering Sea (EBS) bottom trawl surveys were used to examine the effect of climate warming on snow crab thermal habitat use and spatial distributions. The northern Bering Sea (NBS) was also surveyed in 2010 and 2017–2019, allowing us to examine NBS snow crab demographic structure relative to potential climate-driven range contraction into the NBS. Across the time series, trends in temperatures occupied by snow crab were tightly coupled with average bottom temperatures in the EBS despite extreme temperatures in 2018–2019 that exceeded cold-water thermal preferences of juvenile snow crab. Furthermore, we found that increased temperatures and a reduced, more northerly cold pool extent resulted in a smaller area occupied by snow crab across different ontogenetic stages, although there was no evidence for a northward shift in centers of distribution within the EBS. These findings suggest that the spatial extent and average temperature of snow crab distribution are likely constrained by the availability of cold water habitat in the EBS, and dramatic declines in juvenile snow crab abundance observed in 2019 may be attributed to potential direct or indirect temperature effects on survival of highly stenothermic early benthic stages of snow crab. Despite limited support for a directional range shift, survey abundance estimates indicated a ~600% increase in abundance of larger size classes of male snow crab (≥61 mm carapace width) in the NBS between 2018 and 2019. Substantial shifts in juvenile abundances and NBS snow crab size structure in 2019 may have important management implications for the stock. While the increase in NBS mature male biomass may suggest the potential for a commercial fishery in more northern latitudes, concurrent declines in juvenile abundance suggest caution concerning the sustainability of the stock with continued warming.

白令海海冰和冷池范围最近的历史低点与许多深海生物分类的大规模生物地理变化有关。雪蟹（Chionoecetes opilio）与冷池有关，因此随着持续变暖，北向收缩尤其容易发生。1988-2019年国家海洋渔业局东部白令海（EBS）底拖网调查的数据用于检验气候变暖对雪蟹热栖息地使用和空间分布的影响。还于2010年和2017-2019年对北部白令海（NBS）进行了调查，这使我们可以检查NBS雪蟹的人口结构，与潜在的气候驱动范围收缩到NBS的情况有关。在整个时间序列中，尽管2018-2019年的极端温度超过了少年雪蟹的冷水热偏好，但雪蟹所占据的温度趋势与EBS中的平均最低温度紧密相关。此外，我们发现温度升高而温度降低，尽管没有证据表明EBS内分布中心向北移动，但北向冷池范围更大时，跨不同发育阶段的雪蟹所占面积较小。这些发现表明，雪蟹分布的空间范围和平均温度很可能受到EBS中冷水栖息地可用性的限制，2019年观察到的幼年雪蟹丰度急剧下降可能归因于对温度的直接或间接温度影响。积雪的高度恒温底栖动物早期阶段的生存。尽管对方向性范围变化的支持有限，但调查的丰度估计表明，2018年至2019年之间，国家统计局的大型雄性雪蟹（≥61毫米甲壳宽度）的丰度增加了〜600％。2019年幼鱼数量和NBS雪蟹尺寸结构的重大变化可能会对种群造成重要的管理影响。虽然NBS成熟雄性生物量的增加可能表明在更北部的纬度有商业化捕捞的潜力，但同时发生的幼鱼数量下降表明，在种群持续升温的情况下要保持谨慎。