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.

For the ROV net data, Date/Time refers to the start of the ice station. The start and end of the ROV net sampling can be found in the columns "Date/Time start" and "Date/Time end".