Oceanographic measurements conducted on voyage 6 of the Aurora Australis of the 2000-2001 season. These data comprise CTD (Conductivity, Temperature and Depth) and ADCP (Acoustic Doppler Current Profiler) data. These data were collected by Mark Rosenberg. This metadata record was completed by AADC staff when the data were discovered bundled with acoustics data during a data cleaning exercise. Basic information about voyage 6: The voyage will complete a range of Marine Science activities off the Mawson Coast, and off the Amery Ice Shelf before calling at Davis to retrieve summer personnel and helicopters prior to returning to Hobart. Science equipment calibration will be undertaken at Mawson. (Marine Science activities were interrupted when the Aurora Australis was required to provide assistance in the Polar Bird's attempt to reach Casey, complete the station resupply and return to open water.) Leader: Dr Graham Hosie Deputy Leader: Mr Andrew McEldowney See the readme files in the downloads for more information.

Oceanographic measurements conducted on voyage 1 of the Aurora Australis of the 1999-2000 season. These data comprise CTD (Conductivity, Temperature and Depth) and ADCP (Acoustic Doppler Current Profiler) data. These data were collected by Mark Rosenberg. This metadata record was completed by AADC staff when the data were discovered bundled with acoustics data during a data cleaning exercise. Basic information about voyage 1: Polynya study off Mertz Glacier at about 145 deg E. The vessel departed from Port Arthur for the polynya study site without returning to Hobart. The voyage also deployed moorings and delivered biologists (for seal and penguin programs) and a small quantity of essential supplies and mail to Macquarie Island. Leader: Dr Ian Allison Deputy Leader: Dr Tony Worby Cargo Supervisor: Dr Vicky Lytle See the readme files in the downloads for more information.

Australian fishing vessels involved in exploratory fishing for Antarctic toothfish in East Antarctica under the auspices of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) collected data required under their exploratory fishing permit. Conductivity, temperature and depth (CTD) loggers were attached to bottom longlines sets to collect data while fishing for Antarctic toothfish in Antarctic waters. The data relates to Objective 2 of the research work required: Collect and utilise environmental data to inform spatial management approaches for the conservation of toothfish, bycatch species and representative areas of benthic biodiversity (CCAMLR 2016). Data were collected on two fishing vessels during the austral summers (December to February) of 2015/16, 2016/17 and 2017/18 in CCAMLR Divisions 58.4.1 and 58.4.2. The data were collected with DST CTD (Conductivity, Temperature and Depth Recorder) from Star-Oddi (Conductivity: 13-50 mS/cm, maximum depth: 2400 m). Files were then downloaded with SeaStar and are available in the original data format. Recordings were made at 5 or 10 second intervals for the duration of up to around 24h, recording data throughout the water column while setting the longline and then while stationary on the sea floor. Each deployment has data on time, temperature (degrees C), salinity (psu), conductivity (mS/cm) and depth (m), and is linked to geographical coordinates. Number of deployments: 2015/16: 34 2016/17: 31 2017/18: 75 CCAMLR (2016) Joint research proposal for the Dissostichus spp. exploratory fishery in East Antarctica (Divisions 58.4.1 and 58.4.2) by Australia, France, Japan, Republic of Korea and Spain. Delegations of Australia, France, Japan, Republic of Korea and Spain. Report to Fish Stock Assessment Working Group, WG-FSA-16/29, CCAMLR, Hobart, Australia. Dates and times in the data files are recorded in UTC. Further information is provided in a pdf document in the download file.

Australian vessels fishing in the Commonwealth managed fishery for Patagonian Toothfish and mackerel icefish in the Heard Island and MacDonald Island area deployed conductivity, temperature and depth (CTD) loggers attached to their fishing gear. In most cases CTDs were deployed on demersal longlines but in some cases they were attached to trawl nets and traps. Data were collected on five fishing vessels during the fishing seasons of 2019/20 and 2020/21 The data were collected with a CTD (Conductivity, Temperature and Depth Recorder) from the Sea Mammal Research Unit (SMRU) at St Andrew’s University Scotland. Files were downloaded with their TagConfig software in text (.txt) format. Recordings were made at (typically) 1 second intervals for the duration of the fishing event, recording data throughout the water column while setting the gear, then while fishing on the sea floor and again through the water column when the gear was retrieved. Each data file has data on date/time, pressure referenced to surface pressure (dbar), absolute pressure (dbar), temperature (°C), conductivity *mS/cm) and salinity (psu). The data are currently not linked to geographical coordinates which are confidential, but these may be able to be released on contact with the data owner and subject to appropriate confidentiality arrangements. Number of deployments: 2019/20: 25 2020/21: 27

Overview of the project and objectives: To investigate whether nitrate uptake and processes other than nitrate uptake by phytoplankton are significant and show spatial variability possibly induced by varying availability of Fe and other parameters in the region, seawater was collected from CTD (Conductivity, Temperature and Depth) and TMR (Trace Metals Rosette) casts jointly with the nutrient sampling, as well as well as sea-ice collected from Bio ice-core types on Ice Station, for analysis of nitrate d15N, d18O isotopic composition. Results have been interpreted in the light of prevailing nitrate-nutrient concentrations (Belgian team) and N-uptake regimes for the Ice Stations (new vs. regenerated production and nitrification; see Silicon, Carbon and Nitrogen in-situ incubation Metadata file). Methodology and sampling strategy: Samples for isotopic composition of nitrate were collected from the CTD rosette, TMR and Bio ice-core jointly with the nutrient sampling. Sea-ice sampling: sampling strategy follows ice stations deployment via Bio ice-core type. Most of the time we worked close to / directly on the Trace Metal site following precautions concerning TM sampling (clean suits etc.). When we worked close to the TM site, precautions were not such important because we don't need the same drastic precautions for our own sampling. We work together because we want to propose a set of data which helps to characterize the system of functioning in close relation with TM availability (for that, sampling location have to be as close as possible). All samples were filtered on 0.2 microns acrodiscs and kept at -20 degrees C till analysis in the home-based laboratory. We applied the denitrifier method elaborated by Sigman et al. (2001) and Casciotti et al. (2002). This method is based on the isotopic analysis of delta 15N and delta 18O of nitrous oxide (N2O) generated from nitrate by denitrifying bacteria lacking N2O-reductase activity. As a prerequisite the nitrate concentrations need to be known (nutrients analysis in the home lab.) as this sets sample amount provided to the denitrifier community. Briefly, sample nitrate is reduced by a strain of denitrifying bacteria (Pseudomonas aureofaciens) which transform nitrate into N2O, but lack the enzyme to produce N2. N2O is then analysed for N, O isotopic composition by IRMS (Delta V, Thermo) after elimination of CO2, volatile organic carbon and further cryogenic focusing of N2O (Mangion, 2011). Casciotti K.L., D.M.Sigman, M.G. Hastings, J.K. Bohlke and A. Hilkert, 2002. Measurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method, Analytical Chemistry, 74 (19): 4905-4912. Mangion P., 2011. Biogeochemical consequences of sewage discharge on mangrove environments in East Africa, PhD Thesis, Vrije Universiteit Brussel, 208 pp. Sigman D.M., Casciotti K.L., Andreani M., Barford C., Galanter M. and J.K. Bohlke, 2001. A bacterial method for the nitrogen isotopic analysis of nitrate in seawater and freshwater, Analytical Chemistry, 73: 4145-4153.

Oceanographic measurements conducted on voyage 7 of the Aurora Australis of the 2001-2002 season. These data comprise CTD (Conductivity, Temperature and Depth) and ADCP (Acoustic Doppler Current Profiler) data. These data were collected by Mark Rosenberg. This metadata record was completed by AADC staff when the data were discovered bundled with acoustics data during a data cleaning exercise. Basic information about voyage 7: Subject to ice conditions, the voyage will undertake a range of Marine Science activities in the Prydz Bay area and will retrieve summer personnel, helicopters and limited RTA cargo from Davis station. Leader: Mr Rob Easther Deputy Leader: Ms Gerry Nash See the readme files in the downloads for more information.

The RSV Aurora Australis V2 – Casey Resupply and Marine Science Voyage took place from 5 December 2014 to 25 January 2015. The voyage code is v2_201415020. The principal objective of the voyage was to undertake the Casey Resupply and then conduct marine science in the Dalton Polynya and near the Mertz Glacier. A downwards looking video camera system was fitted to the CTD and operated during most casts. The system was remotely controlled and typically operated only while the CTD was near the bottom although some videos show the complete descent through the water column. The video footage for each deployment was labelled as follows: VOYAGE_DATE_TIME_SITE.MTS Where: VOYAGE = v2_201415020 DATE = YYYY-MM-DD TIME = HHMMUTC (in 24 hr time) SITE = the CTD site name (e.g. SiteA5) Details on each site, including geographic coordinates and depth, are available in the Marine Data Voyage Report. The underway data from the voyage is available here: https://data.aad.gov.au/metadata/records/201415020

Gross Primary Production Six depths were sampled per CTD station ranging from near-surface to 125 m. Sample depths were based on downward fluorescence profiles and two of six samples always included both near-surface (approximately 5-10 m) and the depth of the chlorophyll maximum where applicable. Photosynthetic rates were determined using radioactive NaH14CO3. Incubations were conducted according to the method of Westwood et al. (2011). Cells were incubated for 1 hour at 21 light intensities ranging from 0 to 1200 µmol m-2 s-1 (CT Blue filter centred on 435 nm). Carbon uptake rates were corrected for in situ chlorophyll a (chl a) concentrations (µg L-1) measured using high performance liquid chromatography (HPLC, Wright et al. 2010), and for total dissolved inorganic carbon availability, analysed according to Dickson et al. (2007). Photosynthesis-irradiance (P-I) relationships were then plotted in R and the equation of Platt et al. (1980) used to fit curves to data using robust least squares non-linear regression. Photosynthetic parameters determined included light-saturated photosynthetic rate [Pmax, mg C (mg chl a)-1 h-1], initial slope of the light-limited section of the P-I curve [α, mg C (mg chl a)-1 h-1 (µmol m-2 s-1)-1], light intensity at which carbon-uptake became maximal (calculated as Pmax/ α = Ek, µmol m-2 s-1), intercept of the P-I curve with the carbon uptake axis [c, mg C (mg chl a)-1 h-1] , and the rate of photoinhibition where applicable [β, mg C (mg chl a)-1 h-1 (µmol m-2 s-1)-1]. Gross primary production rates were modelled using R. Depth interval profiles (1 m) of chl a from the surface to 200 m were constructed through the conversion of up-cast fluorometry data measured at each CTD station. For conversions, pooled fluorometry burst data from all sites and depths was linearly regressed against in situ chl a determined using HPLC. Gross daily depth-integrated water-column production was then calculated using chl a depth profiles, photosynthetic parameters (Pmax, α , β, see above), incoming climatological PAR, vertical light attenuation (Kd), and mixed layer depth. Climatological PAR was based on spatially averaged (49 pixels, approx. 2 degrees) 8 day composite Aqua MODIS data (level 3, 2004-2017) obtained for Julian day 34. Summed incoming light intensities throughout the day equated to mean total PAR provided by Aqua MODIS. Kd for each station was calculated through robust linear regression of natural logarithm-transformed PAR data with depth. In cases where CTD stations were conducted at night, Kd was calculated from a linear relationship established between pooled chlorophyll a concentrations and Kd’s determined at CTD stations conducted during the day (Kd = -0.0421 chl a * -0.0476). Mixed layer depths were calculated as the depth where density (sigma) changed by 0.05 from a 10 m reference point. Gross primary production was calculated at 0.1 time steps throughout the day (10 points per hour) and summed.

The data set consists of the FlowCAM vignette images and associated files of particles (e.g. protists, zooplankton, inorganic particles) sampled during the K-AXIS (Kerguelen Axis) cruise (Aurora Australis Voyage 3, 2016) from the CTD rosette and underway seawater line. All images selected as non-identified or unwanted particles have been removed from this clean dataset. Calibration and particle library (identified objects) are also included. The "KAXIS_FlowCAM_logsheet.xlsx" file describes all sampling information.

Locations of sampling sites for ASAC project 40/1343 on voyage 3 of the Aurora Australis in the 2001/2002 season. The dataset also contains information on chlorophyll, carotenoids, coccolithophorids and species indentification and counts. The data can be accessed via the Biodiversity Database at the provided URL. From the abstract of the referenced publication: Variations of phytoplankton assemblages were studied in November-December 2001, in surface waters of the Southern Ocean along a transect between the Sub-Antarctic Zone (SAZ) and the Seasonal Ice Zone (SIZ; 46.9-64.9 degrees S; 142-143 degrees E; CLIVAR-SR3 cruise). Two regions had characteristic but different phytoplankton assemblages. Nanoflagellates (less than 20 microns) and pico-plankton (~2 microns) occurred in similar concentrations along the transect, but were dominant in the SAZ, Sub-Antarctic Front (SAF), Polar Front Zone (PFZ) and the Inter-Polar Front Zone (IPFZ), (46.9-56.9 degrees S). Along the entire transect their average cell numbers in the upper 70 m of water column, varied from 300,000 to 1,100,000 cells per litre. Larger cells (greater than 20 microns), diatoms and dinoflagellates, were more abundant in the Antarctic Zone-South (AZ-S) and the SIZ (60.9-64.9 degrees S). In AZ-S and SIZ diatoms ranged between 270,000 and 1,200,000 cells per litre, dinoflagellates from 31,000 to 102,000 cells per litre. A diatom bloom was in progress in the AZ-S showing a peak of 1,800,000 cells per litre. Diatoms were dominated by Pseudo-nitzschia spp., Fragilariopsis spp., and Chaetoceros spp. Pseudo-nitzschia spp. outnumbered other diatoms in the AZ-S. Fragilariopsis spp. were most numerous in the SIZ. Dinoflagellates contained autotrophs (eg Prorocentrum) and heterotrophs (Gyrodinium/Gymnodinium, Protoperidinium). Diatoms and dinoflagellates contributed most to the cellular carbon: 11-25 and 17-124 micrograms of carbon per litre, respectively. Small cells dominated in the northern region characterised by the lowest N-uptake and new production of the transect. Larger diatom cells were prevalent in the southern area with higher values of N-uptake and new production. Diatom and nanoflagellate cellular carbon contents were highly correlated with one another, with primary production, and productivity related parameters. They contributed up to 75% to the total autotrophic C biomass. Diatom carbon content was significantly correlated to nitrate uptake and particle export, but not to ammonium uptake, while flagellate carbon was well correlated to ammonium uptake, but not to export. Diatoms have contributed highly to particle export along the latitudinal transect, while flagellates played a minor role in the export. This work was completed as part of ASAC projects 40 and 1343. See also the related metadata record, "Spring Phytoplankton Assemblages in the Southern Ocean Between Australia and Antarctica".