The distribution of Atlantic cod ( Gadus morhua ) in northern Norwegian waters is expanding eastward and northward in the Barents Sea and along western Svalbard. In the Arctic fjords of Svalbard, cod has become abundant, but little is known about the biology, origin, or residence patterns of these populations. To address this issue, we used laser ablation inductively coupled plasma mass spectrometry to quantify the trace elemental composition of cod otoliths at age-0, age-3 and the year of spawning at five distinct locations in northern Norway and western Svalbard. Chemical composition data was used to identify natal sources of cod, their broad-scale migration patterns, and to determine if cod are currently resident in Arctic fjords. Our results suggest that cod collected at Kongsfjord, Isfjord, outside Svalbard, Lofoten, and Porsangerfjord were recruited mainly from the Barents Sea, conforming to the Northeast Arctic cod ecotype. The degree of chemical overlap between Porsangerfjord and Isfjord cod, however, varied with fish age, suggesting individual movements consistent with the Norwegian coastal cod ecotype. Finally, the chemical composition of mature fish at Isfjord, and to a lesser extent Kongsfjord, suggests that cod from the Barents Sea might have recently established residency in these two Arctic fjords.

中文翻译：

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耳石微化学揭示北极峡湾和巴伦支海鳕鱼的个体发育运动

大西洋鳕鱼 (Gadus morhua) 在挪威北部水域的分布正在巴伦支海和斯瓦尔巴群岛西部向东和向北扩展。在斯瓦尔巴群岛的北极峡湾，鳕鱼已经变得丰富，但对这些种群的生物学、起源或居住模式知之甚少。为了解决这个问题，我们使用激光烧蚀电感耦合等离子体质谱法来量化在挪威北部和斯瓦尔巴群岛西部的五个不同地点在 0 岁、3 岁和产卵年份的鳕鱼耳石的微量元素组成。化学成分数据用于确定鳕鱼的出生来源、它们的广泛迁移模式，并确定鳕鱼目前是否栖息在北极峡湾中。我们的结果表明，鳕鱼在康斯峡湾、伊斯峡湾、斯瓦尔巴群岛外、罗弗敦群岛、和 Porsangerfjord 主要来自巴伦支海，符合东北北极鳕鱼生态型。然而，Porsangerfjord 和 Isfjord 鳕鱼之间的化学重叠程度因鱼龄而异，这表明个体运动与挪威沿海鳕鱼生态型一致。最后，Isfjord 以及在较小程度上 Kongsfjord 成熟鱼类的化学成分表明，来自巴伦支海的鳕鱼最近可能已经在这两个北极峡湾中定居。