Lipids, fatty acids, and δ13C values in fatty acids measured in Arctic zooplankton and ice amphipod species during polar day (June and July) and polar night (January) in 2017/2018

This dataset consists of lipid analysis, fatty acid analysis, and compound specific stable isotope analysis of δ13C values in fatty acids. These parameters were measured in three pelagic zooplankton (Calanus glacialis, Thysanoessa inermis, and Themisto libellula) and two sea-ice associated amphipods (Apherusa glacialis, Gammarus wilkitzkii). Zooplankton and ice-associated amphipods were collected on the R/V Polarstern PS106/1 (23 May - 21 June 2017) and PS106/2 (23 June - 20 July 2017) campaigns and on two R/V Helmer Hanssen polar night campaigns (4 - 16 January 2017 and 5 - 18 January 2018). See document details for the different types of gear used, which included Multinets, pelagic trawls, Surface Underwater Ice Trawls, and ROV nets. Organisms were collected north of Svalbard, the Barents Sea, and within the Nansen Basin of the Arctic Ocean. Lipid class analysis was conducted using high performance liquid chromatography. Extracted lipids were converted into fatty acid methyl esters, and quantified (via an internal standard) using an Agilent 6890N gas chromatograph. Compound specific stable isotope ratios of fatty acid methyl esters (δ13C fa) were analyzed using a Trace Ultra gas chromatograph (GC), a GC Isolink system, and a Delta V Plus isotope ratios mass spectrometer, connected to a Conflo IV interface. The purpose of these measurements was to compare feeding activity between polar day (June/July) and polar night (January) in these five invertebrate species. Also, in light of recent research that there are higher levels of biological species activity during polar night than previously assumed, determine if these invertebrates were maintaining higher levels of activity on stored lipids, opportunistic feeding, or a combination of both.

本数据集涵盖脂肪酸中δ¹³C值的脂质分析、脂肪酸组成分析以及化合物特异性稳定同位素分析。实验测定样本为3种浮游桡足类：冰川哲水蚤（Calanus glacialis）、无刺莹虾（Thysanoessa inermis）与精致美肢钩虾（Themisto libellula），以及2种海冰附生端足类：冰川美钩虾（Apherusa glacialis）与威尔基茨钩虾（Gammarus wilkitzkii）。

样本采集于“极星号”（R/V Polarstern）科考船的PS106/1航次（2017年5月23日—6月21日）、PS106/2航次（2017年6月23日—7月20日），以及“赫尔默·汉森号”（R/V Helmer Hanssen）科考船的两次极夜航次：2017年1月4日—16日、2018年1月5日—18日。采样区域覆盖斯瓦尔巴群岛以北海域、巴伦支海以及北冰洋南森盆地。

相关采样设备的详细信息请参阅配套文档，所用设备包括多层浮游生物网（Multinets）、浮游拖网、冰下表面拖网（Surface Underwater Ice Trawls）以及遥控水下机器人网（ROV nets）。

脂质类别分析采用高效液相色谱（High Performance Liquid Chromatography）完成：提取得到的脂质被转化为脂肪酸甲酯，并通过内标法定量，定量过程依托安捷伦（Agilent）6890N气相色谱仪开展。针对脂肪酸甲酯的化合物特异性稳定同位素比值（δ¹³C_fa）分析，则通过Trace Ultra气相色谱仪、GC Isolink系统、Delta V Plus同位素比率质谱仪，并连接Conflo IV接口完成测定。

本测量的核心目的有二：其一，对比这5种无脊椎动物在极昼（6—7月）与极夜（1月）期间的摄食活动水平；其二，结合近期研究揭示的极夜期间生物活动水平远超此前假设的结论，探明这些无脊椎动物维持活动的能量供给模式——是依靠储存脂质、机会性摄食，还是二者兼具。