Water samples of 1 to 2L from Niskin bottles filled close to the surface, mid mixed layer depth and bottom of the mixed layer were drawn cleanly through a 210um mesh to exclude zooplankton. All samples were filtered as two size fractions, 1.2 to 20um (larger particles excluded by 20um Nitex mesh) and a separate 1.2 to 210um total sample. The filters were 1.2um silver membranes (Sterlitech) 13mm diameter. The samples were preserved by drying at 60C in a dedicated clean oven. Prior to encapsulation, a 5mm diameter subsample was taken for biogenic silica analysis, which is delayed until there has been evaluation of the particle data from the flow cam and UVP. Samples were encapsulated in silver (Sercon sc0037) after acidification and drying. The decarbonated encapsulated POC samples were analysed by elemental analyser at the CSL UTAS by Dr Thomas Rodemann (EA TCD 960C, single point standardisation every 12 samples).  EA detection limit 0.001umol POC. POC and PON are presented as molar units. Blanks were process blanks (seawater) and 7% of the average for the combined data n=177. 1sd=0.12uM. The ctd casts were all given the prefix K, so K001, K002 etc. Not all stations were sampled due to budget constraints. Niskin is the Niskin bottle number.

This data features stable carbon and nitrogen isotopes of co-occurring Southern Ocean pteropods in order to estimate and compare their Bayesian isotopic niches. Other data includes station number, latitude and longitude, species names and sample ID. Details for each column are as follows: A: "species" - Species analysed including, "clio" = Clio pyramidata f. sulcata; "clione" = Clione limacina antarctica; "spongio" = Spongiobranchaea australis; "Large-fraction POM" = large-fraction particulate organic matter; "Small-fraction POM" = small-fraction particulate organic matter B: "speciesID" - Sample ID = unique identifier from Central Science Laboratory, University of Tasmania C: "station" = CTD number (KAxis research voyage) D: "date" = Date of sample (RMT-8 net trawl, KAxis research voyage) E: "lat" = Latitude (degS) F: "long" = Longitude (degE) G: "%C" = percent carbon (no unit) H: "%N" = percent nitrogen (no unit) I: "C:N (bulk)" = uncorrected (raw) carbon-to-nitrogen ratio (no unit) J: "delta 13C (bulk)" = uncorrected (raw) stable carbon isotope values (‰) H: "delta 15N (bulk)" = uncorrected (raw) stable nitrogen isotope values (‰) L: "notes" = samples may be duplicated or triplicated M: "atomic C:N" = C:N (bulk) x 14/12 (no unit) N: "atomic L" = 93/(1+ (1/((0.246 x atomic C:N) - 0.775))) O: "L" = 93/(1+(1/((0.246 x C:N (bulk) - 0.775))) P: "delta 13C (Kiljunen)" = delta 13C (bulk) corrected using formula by Kiljunen et al. 2006 Q: "delta 13C (atomic Kiljunen)" = delta 13C (bulk) corrected using formula by Kiljunen et al. 2006 and atomic L value (column N) R: "delta 13C (Post)" = delta 13C (bulk) corrected using formula by Post et al. 2007 S: "delta 13C (Weldrick)" = delta 13C (bulk) corrected using formula by Weldrick et al. 2019 T: "delta 13C (atomic Smyntek)" = delta 13C (bulk) corrected using formula by Smyntek et al. 2007 and atomic L value (column N) U: "delta 13C (Smyntek)" = delta 13C (bulk) corrected using formula by Smyntek et al. 2007 V: "delta 13C (Logan)" = delta 13C (bulk) corrected using formula by Logan et al. 2008 W: "delta 13C (Syvaranta)" = delta 13C (bulk) corrected using formula by Syvaranta and Rautio 2010 The analysis is featured within a recently accepted paper titled "Trophodynamics of Southern Ocean pteropods on the southern Kerguelen Plateau" peer-reviewed for Ecology and Evolution (2019). It is based on samples collected during the KAxis research voyage, 2015/16.

Sediment cores were collected from the East Antarctic margin, aboard the Australian Marine National Facility R/V Investigator from January 14th to March 5th 2017 (IN2017_V01; (Armand et al., 2018). This marine geoscience expedition, named the “Sabrina Sea Floor Survey”, focused notably on studying the interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles. The cores were collected using a multi-corer (MC) and a Kasten corer (KC). The MC were sliced every centimetre, wrapped up in plastic bags, and stored in the fridge. The KC was sub-sampled using a u-channel; and sliced every centimetre once back the home laboratory (IMAS, UTAS, Hobart, Australia). This dataset presents stable isotopes measured in total and fumigated (i.e. organic) sediment samples collected during the IN2017_V01 voyage. The data include the sampling date (day/month/year), the latitude and longitude (in decimal degrees), the seafloor depth (in meter), the sediment core ID, the sediment depth (in cm), the elemental concentration (in %) and the stable isotope (13C, 15N and 34S) compositions reported as delta values (in ‰). This dataset presents stable isotopes measured in fumigated (i.e. organic) sediment samples collected during the IN2017_V01 voyage. The data include the sampling date (day/month/year), the latitude and longitude (in decimal degrees), the seafloor depth (in meter), the sediment core ID, the sediment depth (in cm), the elemental concentration (in %) and the stable isotope (13C and 15N) compositions reported as delta values (in ‰). Sediment samples were dried in an oven at 40°C and ground using a pestle and a mortar. Thirty mg of sediment was weighed into a tin cup for elemental and stable isotope analysis at the Central Science Laboratory (CSL), University of Tasmania. Total carbon (C), nitrogen (N) and sulfur (S) content was analysed by elemental analyser using flash combustion (Elementar, vario PyroCube, Germany). The stable isotopes 13C, 15N and 34S were analysed by isotope Ratio Mass Spectrometry (IRMS, Isoprime100). A duplicate sample of 35 mg was weighed into a silver cup for organic C measurement. Fifty µL of MQW was added into this cup and the samples were fumigated with concentrated HCl within a desiccator for 24h (Komada et al., 2008) to remove inorganic C. Samples were finally dried in an oven at 60°C and analysed. Isotopic results are reported as delta values (δX; where X = 13C,15N or 34S): δX =(R_sample / R_standard -1)×1000 ‰ where R is the ratio 13C/12C, 15N/14N or 34S/32S respectively. The δ13C value is reported respective to the PDB (Pee Dee Belemnite) standard; the δ15N is reported with reference to air; and δ34S is reported respective to the CTD (Canyon Diablo troilite) standard. References - Armand, L. K., O’Brien, P. E., Armbrecht, L., Baker, H., Caburlotto, A., Connell, T., … Young, A. (2018). Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles (IN2017-V01): Post-survey report. ANU Research Publications. - Komada, T., Anderson, M. R., and Dorfmeier, C. L. (2008). Carbonate removal from coastal sediments for the determination of organic carbon and its isotopic signatures, δ 13 C and Δ 14 C: comparison of fumigation and direct acidification by hydrochloric acid . Limnology and Oceanography: Methods, 6(6), 254–262.

Midwater fish nitrogen isotope data from the Kerguelen Axis ecosystem study (AAS_4344): These data are based on samples collected as part of the Kerguelen Axis marine ecosystem study (AAS_4344), chief scientist Andrew Constable. This research was supported by the Australian government under the (i) Cooperative Research Centre Program through the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), (ii) Australian Antarctic Science Program (Projects 4343, 4344, 4347 and 4366), and (iii) Australian Research Council’s Special Research Initiative for Antarctic Gateway Partnership (Project ID SR140300001). The preferred citation is: Walters et al. Food sources and trophic structure of deep sea midwater (fish) food webs in the Southern Ocean as inferred from nitrogen isotopic compositions. Midwater fish samples were collected on board the R.S.V. Aurora Australis during the austral summer of 2016 (22 January-17 February) as part of the Kerguelen Axis marine ecosystem study (AAS_4344). Samples were collected from 9 sampling stations along one transect from the Antarctic continental shelf to the BANZARE Bank over the Kerguelen Plateau. Midwater fish were sampled from the surface to 1000 m depth using an IYGPT (International Young Gadoid Pelagic Trawl) net equipped with a MIDOC (Mid-water Open Close) multiple cod-end device. Analyses focused on mesopelagic and bathypelagic fish taxa. The nitrogen isotopic composition of individual amino acids was measured in muscle tissue from each fish. As of 2022-09-30, these data were still being worked up for publication.

Carbon and nitrogen stable isotope data for a range of benthic invertebrates, macroalgae, phytoplankton, sea ice algae and fish from shallow marine coastal region around Davis Station. Part of the TRENZ program (The TRophic Ecology of the antarctic Nearshore Zone: local and global constraints on patterns and processes), and AAS project 2948.

Project Objectives 1) To describe trophic relationships in near shore marine benthic ecosystems of East Antarctica and determine the importance of environmental forces (such as sea ice and primary production) to the structure of food webs and biological interactions in benthic assemblages. 2) To determine how marine benthic food webs in East Antarctica respond to local scale disturbances (such as sewage outfalls and abandoned waste disposal sites) and develop predictive models of the influence of local human activities on trophic relationships. Collections of organisms from coastal ecosystems around Casey and Davis stations were made between 2006/07 and 2010/11.