Arctic gadids in a rapidly changing environment
Arctic gadids in a rapidly changing environment
复制标题
快速变化的环境中的北极牛
作者：
F. Mueter;C. Bouchard;H. Hop;B. Laurel;B. Norcross
本期特刊源于2018年6月在阿拉斯加费尔班克斯召开的北极鳕鱼生物学和生态学国际研讨会，该研讨会是亚北极和北极海洋生态系统研究（ESSAS）年度科学会议的一部分。这是继2014年4月在丹麦哥本哈根举行的早期ESSAS北极gadids研讨会之后（Mueter et al. 2016）。这两个研讨会的目的是在快速变化的北极海洋环境的背景下，综合我们对环北极附近北极gadids的生物学、生态学和动力学的理解的最新进展。对人类产生直接影响的北极海洋生态系统结构变化在主要的北极流入大陆架上尤为明显（图1），包括北白令海和楚科奇海（Huntington et al. 2020）以及巴伦支海（SkernMauritzen et al. 2018; Haug et al. 2020），大部分贡献论文都集中在这些大陆架上。对北极日益增长的兴趣，加上这些通往北极的主要门户内以前被冰覆盖的地区的可达性增加，导致近几十年来对北极海洋的研究激增，包括对北极栅极的研究（图2）。这些论文对极地鳕鱼（Boreogadus saida）的强烈关注反映了该物种在北极海洋生态系统中的核心作用（Bradstreet et al. 1986; Hop and Gjøsæter 2013），以及它的环极分布（Mecklenburg et al. 2011）。极地鳕鱼作为海鸟和海洋哺乳动物猎物的重要性与楚科奇海非常高的自然死亡率的估计是一致的（Marsh et al. 2020）。除了对极地鳕鱼的一些区域研究外，贡献还包括极地鳕鱼的饮食环极研究（Bouchard and Fortier 2020）和遗传学研究（Nelson et al. 2020），以及将极地鳕鱼与其他亚北极和北极鳕鱼进行比较的实验室研究（Copeman et al. 2020; Leo et al. 2020; Spencer et al. 2020）。只有两项研究主要关注其他物种，即纳瓦加（Eleginus nawaga） （Maznikova和Orlov 2020）和藏红花鳕鱼（Eleginus gracilis） （sm<s:1> et al. 2020）。这些同系物分别局限于白海、巴伦支海和喀拉海的相对近岸水域，以及太平洋北极地区。在俄罗斯文献之外，关于纳瓦加的研究很少，Maznikova和Orlov（2020）对它们在白海的生物学和分布的综合研究使人们对这种真正的北极加德的了解更加广泛。本期特刊的第一个主题是极地鳕鱼和其他北极生物的种群结构。种群遗传结构在北极周围收集的极地鳕鱼中很明显，表明在阿拉斯加北极（白令海北部到波弗特海西部），加拿大西部水域（波弗特海和阿蒙森湾），加拿大东部水域（雷索特湾到圣劳伦斯湾）以及包括格陵兰岛，冰岛和拉普捷夫海在内的欧洲水域中至少存在四个主要群体（Nelson et al. 2020）。阿拉斯加和加拿大西部群体之间的差异与早期的一项区域研究一致，该研究发现这些群体之间的过渡区存在小规模的地理划分（Wilson et al. 2019）。然而，线粒体基因组表明，从白令海北部到加拿大波弗特海的极地鳕鱼几乎没有种群水平结构，但遗传多样性水平很高，这表明可能存在局部分化（Wilson et al. 2020）。太平洋北极地区的种群分化是由与楚科奇海相邻的波弗特海西部和阿拉斯加东部之间的幼鱼极地鳕鱼分布的明显差距所支持的* Franz Mueter fmueter@alaska.edu
This special issue originated from an international workshop on the Biology and Ecology of Arctic Cods convened in Fairbanks, Alaska, in June 2018 as part of the Ecosystem Studies of the Subarctic and Arctic Seas (ESSAS) Annual Science Meeting. This followed an earlier ESSAS workshop on Arctic gadids held in Copenhagen, Denmark, in April 2014 (Mueter et al. 2016). The aim of both workshops was to synthesize recent advances in our understanding of the biology, ecology, and dynamics of Arctic gadids around the circumpolar North in the context of a rapidly changing Arctic marine environment. Changes in the structure of Arctic marine ecosystems with direct effects on humans have been particularly pronounced on the major Arctic inflow shelves (Fig. 1), including the Northern Bering Sea and Chukchi Sea (Huntington et al. 2020) and the Barents Sea (SkernMauritzen et al. 2018; Haug et al. 2020), where the majority of the contributed papers are focused. The growing interest in the Arctic, combined with increased accessibility of formerly ice-covered regions within these major gateways to the Arctic, has led to a proliferation of research in Arctic seas over recent decades, including research on Arctic gadids (Fig. 2). The strong focus on the polar cod (Boreogadus saida) throughout these papers reflects the central role of this species in Arctic marine ecosystems (Bradstreet et al. 1986; Hop and Gjøsæter 2013), as well as its circumpolar distribution (Mecklenburg et al. 2011). The importance of polar cod as prey for seabirds and marine mammals is consistent with estimates of very high natural mortality rates in the Chukchi Sea (Marsh et al. 2020). In addition to a number of regional studies of polar cod, contributions include circumpolar studies on diets (Bouchard and Fortier 2020) and genetics (Nelson et al. 2020) of polar cod and laboratory studies comparing aspects of polar cod with other Subarctic and Arctic gadids (Copeman et al. 2020; Leo et al. 2020; Spencer et al. 2020). Only two studies primarily focus on other species, namely the navaga (Eleginus nawaga) (Maznikova and Orlov 2020) and the saffron cod (Eleginus gracilis) (Smé et al. 2020). These congeners are limited to relatively nearshore waters in the White, Barents, and Kara seas, and in the Pacific Arctic, respectively. Few studies on navaga are available outside the Russian literature, and the synthesis of their biology and distribution in the White Sea by Maznikova and Orlov (2020) makes much of what is known about this true Arctic gadid more widely available. The first main theme in this special issue is the population structure of polar cod and other Arctic gadids. Population genetic structure is evident in polar cod collections from around the Arctic, suggesting the existence of at least four major groups in the Alaskan Arctic (northern Bering Sea to western Beaufort Sea), western Canadian waters (Beaufort Sea and Amundsen Gulf), eastern Canadian waters (Resolute Bay to Gulf of St. Lawrence), and European waters including the Greenland, Iceland and the Laptev Sea (Nelson et al. 2020). The differentiation between the Alaskan and western Canadian groups is consistent with an earlier regional study that found small-scale geographic partitioning in the transition zone between these groups (Wilson et al. 2019). However, the mitochondrial genome suggests little populationlevel structure but high levels of genetic diversity in polar cod from the northern Bering Sea to the Canadian Beaufort Sea, suggesting the potential for local differentiation (Wilson et al. 2020). Population differentiation in the Pacific Arctic is supported by a distinct gap in the distribution of juvenile polar cod between the western Beaufort Sea, which is contiguous with the Chukchi Sea, and the eastern Alaskan * Franz Mueter fmueter@alaska.edu