Common and thick–billed murres are among the most numerous and widespread seabirds in the northern hemisphere though they appear to be especially susceptible to mass die–off events. During the spring and summer of 2018, the Bering Sea experienced warmer than average sea temperatures following a winter of unprecedented, near complete lack of sea ice. To determine if breeding murres were negatively affected by these warm sea temperatures, surveys at most of the major murre breeding colonies in the eastern Bering and eastern Chukchi seas were conducted during the 2018 breeding season. Nearly all colonies surveyed experienced near-complete reproductive failure. Concurrently, above average levels of murre mortality were observed, primarily at St. Lawrence Island and in the Bering Strait region. The timing of this mortality is somewhat unusual and concerning as it occurred during the breeding season. Based on surveys at sea, overall murre abundance offshore was generally lower in 2018 compared to recent years (2012–2017), particularly in the northern Bering Sea, yet mean density for thick–billed murres increased in the Chukchi Sea. Reproductive failure is rare at monitored murre colonies within the study area and the widespread reproductive failures observed in 2018 were unprecedented over four decades of monitoring, but consistent with the reproductive failure of murres documented in the Gulf of Alaska and southeastern Bering Sea following a large murre die–off in 2015–2016. The combination of large–scale reproductive failure, evidence of elevated levels of mortality, and low abundance of birds offshore suggest that murres experienced severe distress in the Bering and Chukchi sea region during the summer of 2018.

尽管北半球的海鸟似乎特别容易发生大规模死亡事件，但它们却是北半球数量最多，分布最广的海鸟之一。在一个空前的，几乎完全没有海冰的冬天之后，白令海在2018年的春季和夏季经历了比平均海温更高的温度。为了确定繁殖海藻是否受到这些温暖的海水温度的负面影响，在2018年繁殖季节期间对白令东部和楚科奇东部海域的大多数主要海藻繁殖种群进行了调查。几乎所有接受调查的菌落都经历了几乎完全的生殖衰竭。同时，主要在圣劳伦斯岛和白令海峡地区观察到鼠疫死亡率高于平均水平。这种死亡的时机有些不同寻常，令人担忧，因为它发生在繁殖季节。根据海上调查，与最近几年（2012-2017年）相比，2018年近海的总体鱼糜丰度普遍较低，特别是在白令海北部，而楚科奇海的厚嘴鱼平均密度增加。在研究区域内受监测的黑粉菌菌落中，生殖功能衰竭很少见，2018年观察到的广泛生殖功能衰竭在过去四十年的监测中是史无前例的，但与阿拉斯加湾和白令海东南部记录的黑默氏菌的生殖功能衰竭一致在2015-2016年死亡。大规模生殖衰竭，死亡率升高的证据，