We observed herring horizontal and vertical distribution during feeding migration along a 128 km transect across the Arctic front of the Norwegian and Iceland seas, in early June, in relation to its physical, chemical and biological environment, distribution of prey organisms and pelagic and mesopelagic competitors. The Norwegian Spring Spawning herring is one of the largest and economically most important stocks of pelagic fish in the world and understanding what controls its feeding migration is, and has been for centuries, a major research question that also has major implications for management. High resolution ecosystem data were obtained by hull mounted multi-frequency acoustics and a towed platform undulating between 10 and 400 m equipped with multi-frequency acoustics, temperature, salinity and fluorescence sensors, an Optical Plankton Counter and a Video Plankton Recorder. Additional sampling was done by MOCNESS, Macroplankton trawl, and CTD equipped with water bottles for temperature, salinity, nutrients and chlorophyll at discrete stations along the transect. Biological characteristics and stomach content of the herring were obtained from samples at discrete trawl stations. The Arctic front proved to be an important transitional zone in zooplankton biomass, abundance and diversity. Phenology of phyto- and zooplankton also changed across the front, being somewhat delayed on the cold side. The herring were distributed all along the transect showing a shallow distribution on the warm side and both deep and shallow on the cold side, not clearly related to light and time of the day. The herring stomach content was higher on the cold side. There was no significant pattern in average age, weight, or body length of the herring along the transect. The herring were present and fed in the area of the transect during the time when the overwintering generation of Calanus finmarchicus dominated, before the development of the new generation of the year. We suggest that the phenology of C. finmarchicus can be an important driver of the herring feeding migration. While prey-availability was higher on the Arctic side of the front, light conditions for visual feeding at depth were probably better on the Atlantic side. The herring did not show classical dial vertical migration, but its prey did, and the herring's prey were probably available within the upper 100 m during the course of a 24 h cycle. With a general westward direction of migration, the herring along the transect moved towards lower temperatures and temperature did not seem to be a probable driver for migration. We conclude that fine-scale studies of herring migration and feeding can increase our understanding of the migratory processes and add to our understanding of large-scale distributional patterns, changes therein, and herring trophodynamics and ecological role. The fine-resolution parameters can also be important as input to ecosystem models.

我们在6月初观察到了在沿挪威和冰岛海的北极前沿沿128 km样带进食迁移期间鲱鱼的水平和垂直分布，这涉及其物理，化学和生物环境，猎物生物的分布以及中上层和中层竞争者。挪威春季产卵鲱鱼是世界上最大的和经济上最重要的远洋鱼类种群之一，并了解什么控制着它的饲料迁移，并且已经有数百年的历史了，这是一个主要的研究问题，对管理也有重大影响。高分辨率的生态系统数据是通过安装在船体上的多频声波和在10至400 m之间起伏的拖曳平台获得的，该平台配备了多频声波，温度，盐度和荧光传感器，光学浮游生物计数器和视频浮游生物记录仪。通过MOCNESS，Macroplankton拖网和装有水瓶的CTD进行了额外采样，这些水用于在样带的离散位置进行温度，盐度，养分和叶绿素的测量。鲱鱼的生物学特性和胃含量是从离散的拖网站的样品中获得的。事实证明，北极锋是浮游动物生物量，丰富度和多样性的重要过渡带。浮游植物和浮游动物的物候特征也在整个前部发生了变化，在寒冷的一面有所延迟。鲱鱼沿整个样带分布，在温暖的一侧呈浅层分布，在寒冷的一侧呈深浅分布，与白天的光照和时间没有明显关系。鲱鱼胃的含量在冷侧较高。沿样带的鲱鱼的平均年龄，体重或体长没有明显的规律。在越冬产生时，鲱鱼存在并被喂入样带区域。在新一代的发展之前，Calaus finmarchicus占主导地位。我们建议C.finmarchicus的物候学可能是鲱鱼进食迁移的重要驱动力。虽然在北极的前侧猎物利用率较高，但在大西洋一侧，用于深度目视觅食的光照条件可能更好。鲱鱼没有表现出典型的表盘垂直迁移，但是它的猎物确实表现出来，并且在24小时周期内，鲱鱼的猎物可能在上部100 m以内。在总体上向西迁移的情况下，沿着样地的鲱鱼移向了较低的温度，而温度似乎并不是迁移的可能动力。我们得出的结论是，对鲱鱼迁徙和觅食的精细研究可以增进我们对迁移过程的理解，并增加我们对大规模分布模式，其中的变化以及鲱鱼营养动力学和生态作用的理解。