Akvaplan-niva AS, Fram Centre, 9007, Tromsø, Norway.
Murmansk Marine Biological Institute, Vladimirskaya St. 17, 183010, Murmansk, Russian Federation.
Mar Environ Res. 2021 Apr;166:105262. doi: 10.1016/j.marenvres.2021.105262. Epub 2021 Jan 13.
The polar cod (Boreogadus saida) has a circumpolar distribution and is the most abundant planktivorous fish in the Arctic. Declining sea-ice coverage impacts polar cod directly and also facilitates expansion of human activities in the region leading to increasing anthropogenic pressures on biota. Here we summarize current data and knowledge on polar cod from the Russian sector of the Barents Sea and discuss knowledge needs for the management of polar cod under changing environmental conditions and anthropogenic impacts. We review 36 Russian historical (1935 - 2020) sources of data and knowledge largely unknown to western researchers, in addition to sources already published in the English language. This effort allowed for digitalization and visualization of 69 separate datasets on polar cod ecology, including maturation, fertility, feeding intensity, diet, lipid content, length-weight relationships and seasonal variation in larval size. Our review suggests that polar cod abundances are particularly large in the eastern Barents Sea and adjacent waters. Here, we identify and discuss key knowledge gaps. The review of polar cod in the eastern Barents Sea revealed 1) major variation in the timing and area of polar cod spawning, 2) uncertainty as to what degree the polar cod is dependent on sea ice, 3) deficient knowledge of juvenile (e.g., 0-group) distributions, particularly in the north-eastern Barents Sea, 4) deficient knowledge of the species' genetic structure and spatio-temporal distributions, and 5) insufficient understanding as to whether ongoing environmental change may induce phenological changes affecting the availability of potential food items for polar cod larvae and their match in space and time. Filling these knowledge gaps would provide an important step towards the reliable knowledge base needed in order to perform well-founded management and impact assessment under environmental changes and increasing anthropogenic impacts.
北极鳕鱼（Boreogadus saida）分布范围广泛，是北极地区最丰富的浮游动物食性鱼类。海冰覆盖范围的减少直接影响北极鳕鱼，同时也为人类活动在该地区的扩张提供了便利，导致生物区系承受的人为压力不断增加。本文总结了俄罗斯巴伦支海海域北极鳕鱼的现有数据和知识，并讨论了在环境变化和人为影响下，管理北极鳕鱼所需的知识需求。我们回顾了 36 个俄罗斯历史（1935-2020 年）数据和知识来源，这些资料对西方研究人员来说大部分是未知的，此外还有已经用英文发表的来源。这一努力使得对北极鳕鱼生态学、包括成熟度、繁殖力、摄食强度、饮食、脂肪含量、体长-体重关系和幼体大小季节性变化的 69 个独立数据集进行了数字化和可视化。我们的综述表明，在巴伦支海东部和邻近水域，北极鳕鱼的丰度特别大。在这里，我们确定并讨论了关键的知识差距。对巴伦支海东部北极鳕鱼的综述显示出：1）北极鳕鱼产卵的时间和区域存在重大变化；2）不确定北极鳕鱼在多大程度上依赖海冰；3）对幼鱼（例如 0 龄组）分布的了解不足，特别是在巴伦支海东北部；4）对该物种的遗传结构和时空分布的了解不足；5）对环境变化是否可能导致影响北极鳕鱼幼虫潜在食物供应的物候变化及其在空间和时间上的匹配的理解不够充分。填补这些知识空白将是朝着可靠知识库迈出的重要一步，以便在环境变化和人为影响增加的情况下进行有充分依据的管理和影响评估。
