Assessment of the impact of climate change on the Arctic nearshore ecosystems requires knowledge of the “reference points”, that is, the state of things before the effects of the warming become pronounced. For parasites, which play an essential role in the nearshore ecosystems, this knowledge is scarce and fragmentary. This study, based on the materials collected at Franz Josef Land (FJL) in 1990–1993, partly fills this gap. We present the first data on the diet of the common eider Somateria mollissima at FJL, the transmission of helminths in its population and the infection of nearshore invertebrates with helminth larvae. We found that gastrointestinal helminth communities were impoverished (only ten species) and dominated by cestodes and acanthocephalans. This is associated with the prevalence of nearshore crustaceans, the intermediate hosts of these helminths, in the diet of the eiders. The absence of the vulnerable free-living larvae also facilitates transmission of helminths parasitizing eiders at FJL. Infection with helminths and the diet were different in ducklings and in adult birds as well as in eiders from different parts of the archipelago. The infection distribution of molluscs and crustaceans with helminth larvae was patchy and higher in the vicinity of the eider colonies. A high-infection intensity of FJL eiders with cestodes and acanthocephalans recorded in our study seems to have a certain negative effect on the bird population. Its significance is likely to grow considering that the transmission of helminths is promoted by the climate warming in the Arctic.

评估气候变化对北极近岸生态系统的影响需要了解“参考点”，即在变暖的影响明显之前的状态。对于在近岸生态系统中发挥重要作用的寄生虫，这种知识是稀缺的和零碎的。这项研究基于1990-1993年在弗朗兹·约瑟夫土地（FJL）收集的材料，部分填补了这一空白。我们提出了关于常见绒毛S猴的饮食的第一个数据在FJL，蠕虫在其种群中的传播以及蠕虫幼虫对近岸无脊椎动物的感染。我们发现，胃肠蠕虫群落处于贫困状态（仅十种），并以and虫和棘头动物为主。这与绒毛虫饮食中这些蠕虫的中间宿主近岸甲壳类动物的流行有关。脆弱的自由生活幼虫的缺席也促进了寄生虫在寄生虫繁殖场的寄生虫的传播。小鸭，成年鸟类以及群岛不同地区的绒毛对蠕虫的感染和饮食的影响均不同。软体动物和甲壳类动物与蠕虫幼虫的感染分布在绒毛菌落附近呈片状且较高。在我们的研究中记录到的FJL绒毛高强度感染有节和棘头动物，似乎对禽类种群有一定的负面影响。考虑到北极地区气候变暖促进了蠕虫的传播，其重要性可能会增加。