Multidisciplinary field campaigns were carried out in the Fram Strait region during late summer 2019 (JR18007, 04/08/2019 to 28/08/2019) aboard RRS James Clark Ross. A motion-compensated Bongo net fitted with 200 um mesh was deployed at all locations to a maximum depth of 200 m or to within 10 m of the seabed.In the Arctic and sub-Arctic sectors adjacent to the Atlantic, three species of Calanus co-occur. However, their respective core distributions align with different water masses, with Calanus hyperboreus being a high-Arctic oceanic species, C. glacialis being associated with Arctic shelf waters, and C. finmarchicus dominating inflowing Atlantic Water.The proportions of these three species in each deployment was established through molecular analysis of the paired ethanol preserved sample. Subsamples of the ethanol sample were analysed using a 16S ribosomal RNA gene barcode (16SAR, 16SB2R primers) following an adapted protocol. Amplified DNA was sequenced using llumina high-throughput sequencing (HTS) platform. Resultant sequences processed through the Qiime pipeline, clustered into Operational Taxonomic Units at 97% homology and taxonomy was assigned using BLASTn (NCBI). Funded by UKRI Natural Environment Research Council (NERC; NE/P006213/1, NE/P006353/1, NE/P006302/1, NE/ P005985/1 amongst others).

During the expedition PS136 LTER HAUSGARTEN in 2023 105 samples of macrobenthic marine invertebrates and 3 samples of calanoid copepods were collected by epibenthic sledge and 28 samples of calanoid copepods were collected by Bongo and Multinet and subsequently frozen at -80 degrees Celsius for lipid and bulk stable isotope analyses. Katrin Linse, Saskia Brix, Jannifer Freer and Lydia Anastasia Schmidt collected, photographed and fixed the specimens on board. The macrobenthic invertebrates and calanoid copepods were collected to study elements of the biological lipid pump in the Arctic Ocean. The preparation and lab analyses of the lipid biomarker and stable isotope data were carried out by Rachel Jeffreys and Sabena Jane Blackbird at the University of Liverpool using Gas chromatography-mass spectrometry and an ECS8020 elemental analyser (NC Technologies) coupled to a Delta V isotope ratio mass spectrometer. Statistical analyses and interpretation of lipid biomarker and stable isotope data were carried out by Dewi Ford, Dan Mayor and Anna K. Wadsworth at the University of Exeter. The raw data files include lipid biomarker and stable isotope data for all analysed macrobenthic invertebrates and calanoid copepods, while the processed data files include all calanoid copepod data but selected macrobenthic taxa only, being Amphipoda, Decapoda, Isopoda, Mysidacea, Holothuroidea, Ophiuroidea, and Chaetognatha. The contributions of KL, JF and DJM were supported by the BIOPOLE National Capability Multicentre Round 2 funding from the Natural Environment Research Council (grant no. NE/W004933/1). DJM also received funding from OceanICU (EU Grant agreement ID: 101083922; UKRI grant reference: 10063673). SB received support via the Leibniz foundation and the ALONGate project (A Long-term Observatory of the North Atlantic Gateway to the Arctic Ocean) via grant number PS150/2023 in the program for women professors. The field work for PS136 was supported by grant no. AWI_PS136_01.