Seabed sediment data (upper 6 cm) on water content, total nitrogen, total carbon, total organic carbon, total inorganic carbon, carbon and nitrogen isotopic composition from the Nansen Legacy seasonal cruise 2021703 (Q1).

This dataset includes contents of water content, total nitrogen (TN), total carbon (TC), total organic carbon (TOC), total inorganic carbon (TIC), and carbon and nitrogen isotopic composition (d13C, d15N) in marine sediments. Samples were collected during the Nansen Legacy cruises in March as part of cruise 2021703 (Q1) in the northern Barents Sea. Sediment material was subsampled from three replicate deployments of a giant box corer at four stations (P1 to P6). At P7, only two deployments were completed. The samples were immediately sliced into 1 cm layers (0 - 6 cm) and placed into plastic jars, and frozen on board. Two replicates at P1 were sliced down to 3 cm. All samples were freeze-dried under vacuum in the laboratory and homogenized. Elemental analysis of carbon and nitrogen concentrations was undertaken with an Elemental Analyser - Isotope Ratio Mass Spectrometry (EA-IRMS; Iso - Analytical Ltd., UK). Before d13C analysis, samples were acidified with 1M HCl and left overnight to allow the inorganic carbon to be liberated as CO2. The samples were then neutralized by repetitively washing with distilled water and oven drying at 60 degrees Celsius. The standards d13CV-PDB (Vienna PeeDee Belemnite) and d15NAIR (atmospheric N2) were used as references for the carbon and nitrogen isotope values, respectively. The measured TOC content was corrected for weight loss upon acid washing, TIC content was calculated by subtracting TOC from TC.