Institute of Marine Research, Nordnes, B.O. Box 1870, 5817, Bergen, Norway.
Institute of Marine Research, Framsenteret, Stakkevollan, Postboks 6606, 9296, Tromsö, Norway.
Sci Rep. 2023 Jan 18;13(1):1000. doi: 10.1038/s41598-023-27957-x.
The rapid ongoing changes in the Central Arctic Ocean call for baseline information on the pelagic fauna. However, sampling for motile organisms which easily escape vertically towed nets is challenging. Here, we report the species composition and catch weight of pelagic fishes and larger zooplankton from 12 trawl hauls conducted in ice covered waters in the Central Arctic Ocean beyond the continental slopes in late summer. Combined trawl catches with acoustics data revealed low amounts of fish and zooplankton from the advective influenced slope region in the Nansen Basin in the south to the ice-covered deep Amundsen Basin in the north. Both arctic and subarctic-boreal species, including the ones considered as Atlantic expatriate species were found all the way to 87.5N. We found three fish species (Boreogadus saida, Benthosema glaciale and Reinhardtius hippoglossoides), but the catch was limited to only seven individuals. Euphausiids, amphipods and gelatinous zooplankton dominated the catch weight in the Nansen Basin in the mesopelagic communities. Euphausiids were almost absent in the Amundsen Basin with copepods, amphipods, chaetognaths and gelatinous zooplankton dominating. We postulate asymmetric conditions in the pelagic ecosystems of the western and eastern Eurasian Basin caused by ice and ocean circulation regimes.
快速变化的北极中央海呼吁对浮游动物进行基线信息调查。然而，对容易通过垂直拖网逃脱的活动生物进行采样是具有挑战性的。本研究报告了在北极中央海冰覆盖水域中进行的 12 次拖网调查中采集的浮游鱼类和大型浮游动物的物种组成和捕捞量。结合声学数据的拖网捕捞结果显示，在南至纳森盆地的大陆坡上的平流影响区和北至冰覆盖的深阿蒙森盆地的鱼类和浮游动物数量较少。在北纬 87.5 度，甚至在更北的地方，都发现了北极和亚北极-北方物种，包括被认为是大西洋外来物种的物种。我们发现了三种鱼类（白海鲂、冰海拟磷虾和北极红点鲑），但捕捞量仅局限于七个个体。在中层带的纳森盆地，磷虾、端足类和凝胶状浮游动物在渔获物重量中占主导地位。在阿蒙森盆地，磷虾几乎不存在，桡足类、端足类、毛颚类和凝胶状浮游动物占主导地位。我们假设，由于冰和海洋环流模式，在欧亚大陆西部和东部的浮游生态系统中存在不对称的条件。
