The epi- and mesopelagic ecosystems of four sub-polar ocean basins, the Labrador, Irminger, Iceland and Norwegian seas, were surveyed during two legs from Bergen, Norway, to Nuuk, Greenland, and back to Bergen. The survey was conducted from 1 May to 14 June, and major results were published in five papers (Drinkwater et al., Naustvoll et al., Strand et al., Melle et al., this issue, and Klevjer et al., this issue a, this issue b). In the present paper, the structures of the ecosystem are reviewed, and aspects of the functioning of the ecosystems examined, focusing on a comparison of trophic relationships in the four basins. In many ways, the ecosystems are similar, which is not surprising since they are located at similar latitudes and share many hydrographic characteristics, like input of both warm and saline Atlantic water, as well as cold and less saline Arctic water. Literature review suggests that total annual primary production is intermediate in the eastern basins and peaks in the Labrador Sea, while the Irminger Sea is the most oligotrophic sea. This was not reflected in the measurements of different trophic levels taken during the cruise. The potential new production was estimated to be higher in the Irminger Sea than in the eastern basins, and while the biomass of mesozooplankton was similar across basins, the biomass of mesopelagic micronekton was about one order of magnitude higher in the western basins, and peaked in the Irminger Sea, where literature suggests annual primary production is at its lowest. The eastern basins hold huge stocks of pelagic planktivore fish stocks like herring, mackerel and blue whiting, none of which are abundant in the western seas. As both epipelagic nekton and mesopelagic micronekton primarily feed on the mesozooplankton, there is likely competitive interactions between the epipelagic and mesopelagic, but we're currently unable to explain the estimated ~1 order of magnitude difference in micronekton standing stock. The results obtained during the survey highlight that even if some aspects of pelagic ecosystems are well understood, we currently do not understand overall pelagic energy flow in the North Atlantic.

在从挪威卑尔根到努克，格陵兰再到卑尔根的两条腿上，对四个亚极海盆地拉布拉多，艾明格，冰岛和挪威海的上，中古生态系统进行了调查。该调查于5月1日至6月14日进行，主要结果发表在5篇论文中（Drinkwater等人，Naustvoll等人，Strand等人，Melle等人，本期杂志，以及Klevjer等人，本期问题a，问题b）。在本文中，对生态系统的结构进行了审查，并考察了生态系统的功能方面，重点是比较四个流域的营养关系。在许多方面，生态系统都是相似的，这并不奇怪，因为它们位于相似的纬度，并具有许多水文特征，例如温暖的和咸的大西洋水的输入，以及冷水和少盐的北极水。文献综述表明，东部盆地的年总初级产量处于中间水平，而拉布拉多海的峰值处于高峰，而艾明格海则是最贫营养的海。在巡航期间对不同营养水平的测量中未反映出这一点。据估计，艾明格海潜在的新产量要比东部盆地的高，而各盆地的中层浮游生物的生物量相似，而西部盆地的中生微浮游生物的生物量大约高一个数量级，并在埃尔明格海（Irminger Sea）的文献表明，每年的初级生产量处于最低水平。东部盆地拥有大量的浮游浮游鱼类，例如鲱鱼，鲭鱼和蓝鳕鱼，在西方海域中没有一个是丰富的。由于表皮上的神经元和中上微生的微神经元都主要以中生浮游动物为食，因此上表皮和中生微神经元之间可能存在竞争性相互作用，但是我们目前无法解释估计的微中生常备存量数量级差异约1个数量级。在调查过程中获得的结果表明，即使人们对中上层生态系统的某些方面了如指掌，但我们目前尚不了解北大西洋中上层的总体能流。