KAxis Zooplankton isotopes - data collected from the K-Axis voyage of the Aurora Australis, 2016

Published: 2018-01-12

These data were collected on the K-Axis voyage of the Aurora Australis, in 2016. The voyage was so named because data were collected along the "Kerguelen Axis" of the undersea Kerguelen Plateau. Representative specimens of zooplankton will be analysed for elemental and stable isotope composition, and diet compositions will be determined using isotopic mixing models. The data files will contain elemental (carbon, hydrogen, nitrogen) and stable isotope (del15N and del13C) compositions for each of the analysed specimens, and an estimate of each species diet composition in terms of the different prey items. Krill, salps and pteropods were collected with an RMT8 net during the K-Axis cruise. Specimens were removed from the samples, measured and frozen at -20C until ready for analysis in Hobart. Individuals of known species were dried at -60C, ground to a fine powder, encapsulated into tin cups and analysed with an ICP-MS in the Central Science Laboratories, University of Tasmania. Samples were analysed for delta15N and delta13C. The salp was the common Southern Ocean species Salpa thompsoni and the krill were Euphausia superba, E. triacantha, E. frigida and Thysanoessa macrura. A small number (2) of the siphonphore Diphyes antarctica were also analysed. Pteropods analysed included both shelled (thecosomes) and naked (gymnosomes) pteropods. Columns E-O in the Pteropods worksheet in the spreadsheet are expressed as ratios.