Water column nutrient, particulate organic matter and isotopic data and porewater nutrient data for the west Antarctic Peninsula shelf from cruise JR15003.

The objective of cruise JR15003 in December 2015 was to examine organic matter and nutrient cycling and benthic-pelagic coupling in the West Antarctic Peninsula shelf region using biogeochemical and isotopic measurements of the water column, sediments and porewaters. Samples were collected at three stations at the beginning of the ice-free season, between 25th and 28th December 2015, as part of the Collaborative Gearing Scheme project CGS-109. Water column samples were collected from niskin bottles mounted on the CTD rosette of RRS James Clark Ross and analysed for nutrient and organic matter concentrations and their isotopic signatures, and the oxygen isotope composition of seawater. Temperature, pressure, salinity, and oxygen data from the CTD package are also provided to accompany water column biogeochemistry data. Upper sediment samples were collected by box-coring and subsequent sub-sampling. Interface waters were collected immediately, then sub-cores were taken from the box core for pore fluid extraction and core sectioning. Pore fluids were extracted every two centimetres using rhizon syringe filters with a filter membrane of <0.15 micrometres, and stored for analysis of macronutrient concentrations (ammonium, nitrate+nitrite, nitrite, phosphate, and silicate). Porewaters and water column samples were analysed for macronutrient concentrations at Plymouth Marine Laboratory and seawater oxygen isotopes were analysed at the British Geological Survey, Keyworth. Data were generated by Sian Henley at the School of Geosciences, University of Edinburgh, Katharine Hendry at the School of Earth Sciences, University of Bristol and Yvonne Firing at the National Oceanography Centre, Southampton. Data collection was funded by the NERC Independent Research Fellowship NE/K010034/1 entitled "Isotopic characterisation of nutrient dynamics and UCDW behaviour in the west Antarctic Peninsula sea ice environment". Additional funding was provided by British Antarctic Survey Collaborative Gearing Scheme project CGS-109, and NERC national capability funding for SR1b repeat transect (PI Firing). Major and minor element compositions of the upper sediments from X-ray fluorescence spectroscopy analysis, of samples from the same box-cores, are available in Henley and Odling (2020) doi:10.5285/b1282b1e-7852-5d16-e053-6c86abc04c61.