Laboratory of Biodiversity and Evolutionary Genomics, KU Leuven, Leuven, Belgium.
Alfred-Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany.
J Fish Biol. 2021 Jul;99(1):49-60. doi: 10.1111/jfb.14697. Epub 2021 Mar 1.
The current and projected environmental change of the Arctic Ocean contrasts sharply with the limited knowledge of its genetic biodiversity. Polar cod Boreogadus saida (Lepechin, 1774) is an abundant circumpolar marine fish and ecological key species. The central role of polar cod in the Arctic marine food web warrants a better understanding of its population structure and connectivity. In this study, the genetic population structure of 171 juveniles, collected from several fjords off West-Svalbard (Billefjorden, Hornsund and Kongsfjorden), the northern Sophia Basin and the Eurasian Basin of the Arctic Ocean, was analysed using nine DNA microsatellite loci. Genetic analyses indicated moderate to high genetic diversity, but absence of spatial population structure and isolation-by-distance, suggesting ongoing gene flow between the studied sampling regions. High levels of connectivity may be key for polar cod to maintain populations across wide spatial scales. The adaptive capacity of the species will be increasingly important to face challenges such as habitat fragmentation, ocean warming and changes in prey composition. In view of a limited understanding of the population dynamics and evolution of polar cod, a valuable next step to predict future developments should be an integrated biological evaluation, including population genomics, a life-history approach, and habitat and biophysical dispersal modelling.
当前和预计的北极海洋环境变化与对其遗传生物多样性的有限了解形成鲜明对比。北极鳕鱼(Boreogadus saida (Lepechin, 1774))是一种丰富的环极海洋鱼类和生态关键物种。北极鳕鱼在北极海洋食物网中的核心作用需要更好地了解其种群结构和连通性。在这项研究中，使用九个 DNA 微卫星基因座分析了来自西斯瓦尔巴群岛（Billefjorden、Hornsund 和 Kongsfjorden）、北部索菲亚盆地和北极洋欧亚盆地的 171 条幼鱼的遗传种群结构。遗传分析表明存在中等至高遗传多样性，但不存在空间种群结构和距离隔离，表明研究采样区域之间存在持续的基因流动。高水平的连通性可能是北极鳕鱼在广泛的空间尺度上维持种群的关键。在面对栖息地破碎化、海洋变暖以及猎物组成变化等挑战时，物种的适应能力将变得越来越重要。鉴于对北极鳕鱼种群动态和进化的了解有限，预测未来发展的下一步宝贵措施应该是进行综合的生物评估，包括种群基因组学、生活史方法以及栖息地和生物物理扩散建模。
