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  • Total Organic Carbon A 2 g homogenised wet sediment sub-sample from each core was weighed into a pre-combusted crucible and dried at 105 degrees C. The dried sample was reweighed before being analysed for total carbon by mass loss on ignition at 550 degrees C, the sample was placed in the muffle furnace for 4 hours. Samples 56698, 57062, 56837, 57058, and 580792 were analysed in triplicate to assess the reproducibility of the analytical procedure. (Total number of analyses was 117). - TOC - For the 107 samples: - Mean and SD: 3 plus or minus 4 % DMB, range: 0.16-15 %, n=107 - Considering the mean values for the 27 site locations: - Range: 0.33-14 % DMB, mean and SD: 3.3 plus or minus 3.7 % DMB, n=27 - Analytical uncertainty - Analytical precision: 5 samples analysed in triplicate: - RSD = 6 plus or minus 5% range 1-11%, n=5 - Site heterogeneity: reproducibility (RSD) of mean data from site replicate samples was 26% (mean, SD 15%, range 10-57%, n=27) - From the limited data on reproducibility summarised above, it can be concluded that site heterogeneity contributes most to the uncertainty of the TOC data for the site locations. - DMF - For the 107 samples: - Mean and SD: 0.57 plus or minus 0.23 %, range: 0.09-0.85, n=107 - Considering the mean values for the 27 site locations: - Range:0.17-0.83, mean and SD: 0.57 plus or minus 0.22, n=27 - Analytical uncertainty - Analytical precision: 5 samples analysed in triplicate: - RSD = 2 plus or minus 2% range 0.8-5%, n=5 - Site heterogeneity: reproducibility (RSD) of mean data from site replicate samples (mostly quadruplicates) was 10% (mean, SD 10%, range 1-37%, n=27) - From the limited data on reproducibility summarised above, it can be concluded that site heterogeneity contributes most to the uncertainty of the DMF data for the site locations. Collection of sediment cores Sediment for grain size and various chemical analysis were sampled using a core of PVC tubing (15cm long x 5cm diameter) pushed 10cm into the sediment. These cores were kept upright at all times to ensure the stratigraphy remained intact and frozen in the core tube at -20 degrees C. Grain size analysis The outer 5 mm edge of the core was removed with a scalpel blade and placed in a clean, dried preweighed beaker. The sample was weighed and placed in an oven at 45 degrees C to dry. Once dry the sample was reweighed and then sieved through a 2 mm sieve, any residual sediment in the beaker was weighed and the weight recorded. The less than 2 mm fraction and the greater than 2 mm fraction were separately collected and weighed. A 5 g sample of the less than 2 mm fraction was taken for grain size analysis which was carried out using the Mastersizer 2000 Particle Size Analyser by Associate Professor Damian Gore at the Department of Physical Geography, Macquarie University, Sydney.

  • Peter Sedwick collected water column samples (6 depths, less than 350m) and measured dissolved iron in these samples, using specialised trace-metal clean techniques, at 9 stations along the SR3 transect between 47 deg S and 66 deg S. These are the first such data for this oceanographic sector during spring. The dissolved iron levels were generally very low (less than 0.2 nM nM) in the upper water column, particularly south of the Subantarctic Front, and surprisingly there was no evidence of significant iron inputs from melting sea ice in our study region. Ongoing work quantified various size fractions of dissolved iron as well as total acid soluble iron. In addition, Jack DiTullio collected water samples for measurements of five biogenic sulfur pools at most shallow water CTD casts. The sulfur pools measured include: dimethylsulfide (DMS), particulate and dissolved dimethylsulfoniopropionate (DMSP) and particulate and dissolved pools of dimethylsulfoxide (DMSO). Taken from the referenced paper: A shipboard-deployable, flow-injection (FI) based instrument for monitoring iron(II) in surface marine waters is described. It incorporates a miniature, low-power photoncounting head for measuring the light emitted from the iron-(II)-catalyzed chemiluminescence (CL) luminol reaction. System control, signal acquisition, and data processing are performed in a graphical programming environment. The limit of detection for iron(II) is in the range 8-12 pmol L-1(based on 3s of the blank), and the precision over the range 8-1000 pmol L-1 varies between 0.9 and 7.6% (n )4). Results from a day-night deployment during a north to-south transect of the Atlantic Ocean and a daytime transect in the Sub-Antarctic Front are presented together with ancillary temperature, salinity, and irradiance data. The generic nature of the components used to assemble the instrument make the technology readily transferable to other laboratories and the modular construction makes it easy to adapt the system for use with other CL chemistries.

  • This data describe a set of sea-ice and seawater physical and biochemical parameters obtained from seawater samples and ice cores drilled from land fast sea ice in the vicinity of Davis Station, East Antarctica at six different dates (stations 1-6) during late Spring 2016. Stations 1: 16 Nov. 2016 Stations 2: 21 Nov. 2016 Stations 3: 23 Nov. 2016 Stations 4: 26 Nov. 2016 Stations 5: 29 Nov. 2016 Stations 6: 02 Dec. 2016 Parameters measured: - Temperature, salinity; - Iron: Dissolved (less than 0.2um), soluble (less than 0.02um) colloidal (between 0.02 and 0.2um) and Particulate fractions (greater than 0.2um); - Macronutrients: Nitrate (NO3), nitrite (NO2), silicate (Si), phosfate (PO4) and ammonium (NH4); - Chlorophyll-a (Chla); - Particulate Organic Matter: Particulate Organic Carbon (POC) and Particulate Organic Nitrogen (PON) SW0: seawater collected at the surface SW3: seawater collected at 3m depth SW10: seawater collected at 10m depth

  • This data set was collected from a ocean acidification minicosm experiment performed at Davis Station, Antarctica during the 2014/15 summer season. It includes: - description of methods for all data collection and analyses. - marine microbial community data; Chlorophyll a concentration, particulate organic matter concentration (carbon and nitrogen), bacterial cell abundance. - phytoplankton primary productivity data; 14C-sodium bicarbonate incorporation raw data (decays per minute: DPM) and modelled productivity from photosynthesis versus irradiance (PE) curves, O2-evolution derived net community productivity, respiration, and gross primary productivity. - phytoplankton photophysiology data; community photosynthetic efficiency from PAM measurements (maximum quantum yield of PSII: Fv/Fm), PAM steady state light curve data and derived non-photochemical quenching of Chl a fluorescence (NPQ), relative electron transport rates (rETR), and effective quantum yield of PSII (delta F/Fm'). - phytoplankton carbon concentrating mechanism (CCM) data; maximum quantum yield of PSII (Fv/Fm) and effective quantum yield of PSII (∆F/Fm') from PAM measurements on size-fractionated phytoplankton samples (less than 10 microns and greater than 10 microns cells) exposed to; ethoxzolamide (EZA) which inhibits both intracellular carbonic anhydrase (iCA) and extracellular carbonic anhydrase (eCA), acetazolamide (AZA), which blocks eCA only, and a control (no inhibitor) sample. - bacterial productivity data; 14C-Leucine incorporation raw data (decays per minute: DPM) and calculated productivity.

  • 3 litres of seawater were collected every 2nd CTD (conductivity, temperature and depth) cast on every CTD transect of the BROKE-West voyage. 7 CTD transects were completed on the BROKE-West voyage, all on southwards legs. Samples were collected at 6 depths in the top 200 m of the water column using niskin bottles. 2 litres were filtered through polycarbonate filters and 1 litre was filtered through a fibreglass filter. Chemical digestion of the polycarbonate filter enabled us to determine the particulate silicon concentration for each sample (using the nutrient autoanalyser onboard the Aurora Australis, see hydrochemistry section), fibreglass filters have been dried and stored for CHN analysis back on shore. This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).

  • This data set contains chemical parameters determined for marine sediment samples collected in the 2014-15 summer field season as part of the Thala Valley Long term Monitoring (TV-LTM) project. The aim of this project is to examine changes in the marine benthic ecosystem in the vicinity of Casey station following clean-up of the abandoned Thala Valley waste disposal ('tip') site in 2003-04. The chemical parameters are: (1) 1 M hydrochloric acid-extractable elements (mainly metals) by ICP-AES (inductively coupled plasma - atomic emission spectrometry) (2) water-extractable nutrients by FIA (flow injection analysis) (3) petroleum hydrocarbon fractions (TPH: total petroleum hydrocarbons) and persistent organic pollutants (POPs) - polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) - by GC-FID, GC-ECD and GC-MS (gas chromatography - flame ionization detector / electron capture detector / mass spectrometry), respectively (4) Loss on Ignition at 550 degrees Celsius (LOI; as a proxy for Total Organic Matter) and Dry Matter Fraction (DMF) by gravimetric analysis. Data sets 1, 3 and 4 were obtained for composite samples prepared from the 0-5 cm section of 51 marine sediment cores collected by SCUBA divers from impacted (contaminated) and control (pristine) locations around Casey. Data set 2 was obtained for a subsample of the surface section (0-1 cm) of each of 74 marine sediment cores collected during the same sampling campaign. Sample locations: * Brown Bay (BB) - inner, mid and outer sites * Casey Wharf * McGrady Cove * O'Brien Bay (OB) - OB1, OB2, OB3 sites * Shannon Bay * Wilkes (adjacent to abandoned station) Analytical labs involved: * Wild Lab, AAD, Kingston, Tasmania (data sets 1 and 4; sample preparation for data set 2) * Analytical Services Tasmania (AST), New Town, Tasmania (data set 2) * Analytical Services Unit (ASU), Queen's University, Kingston, Ontario, Canada (data set 3) Information concerning analytical data quality (method reporting limits, accuracy and precision), are included with each data set. Complete analytical method details are available in a separate summary document.

  • Exopolysaccharide (EPS) is complex sugar made by many microbes in the Antarctic marine environment. This project seeks to understand the ecological role of microbial EPS in the Southern Ocean, where it is known to strongly influence primary production. We will investigate the chemical composition and structure of EPS obtained from Antarctic microbes, which will improve our knowledge of its ecological significance and biotechnological potential. Dataset includes the following: 1) Information on Exopolysaccharide-producing bacterial isolates, isolation sites, media used and growth conditions. 2) 16S rRNA gene sequence and fatty acid data of isolates for strain identification. 3) Exopolysaccharide chemistry data including EPS carbohydrate composition, organic acid composition, sulfate content, molecular weight. 4) Physiology of exopolysaccharide synthesis. Effects of temperature and other factors on EPS yield and glucose conversion efficiency. 5) Iron binding properties. The download file includes: 11 files File 1. Bacterial isolate 16S rRNA gene sequences obtained from Southern Ocean seawater or ice samples. The sequences are all deposited on the GenBank nucleotide (NCBI) database. Sequences are in FASTA format. File 2. Seawater and sea-ice sample information including sites samples, sample type. File 3. Data for exopolysaccharide (EPS)-producing bacteria isolated and subsequently selected for further studied. Information indicates special treatments used to obtain strains including plankton towing, filtration method, and enrichment. Identification to species level was determined by 16S rRNA gene sequence analysis. File 4. EPS-producing bacterial isolate fatty acid content determined using GC/MS procedures. File 5. Basic chemical data for EPS from Antarctic isolates including protein, sulfate, and sugar type relative content (determined by chemical procedures), molecular weight in kilodaltons and polydispersity (determined by gel-based molecular seiving). File 6 Monosaccharide unit composition determined by GC/MS of EPS from Antarctic isolates. File 7. Effect of temperature on culture viscosity and growth of EPS-producing bacterium Pseudoalteromonas sp. CAM025 as affected by temperature. File 8. Effect of temperature on EPS and cell yields and EPS synthesis efficiency (as indicated by glucose consumption) of EPS-producing bacterium Pseudoalteromonas sp. CAM025 as affected by temperature. File 9. Efficiency of copper and cadmium metal ion adsorption onto EPS from EPS-producing bacterium Pseudoalteromonas sp. CAM025. File 10. Phenotypic characteristics data for novel EPS-producing Antarctic strain CAM030. Represents type strain of Olleya marilimosa. File 11. Effect of temperature on chemical make up of EPS from EPS-producing bacterium Pseudoalteromonas sp. CAM025.

  • This work was completed as part of the SIPEX - Sea Ice Physics and Ecosystem eXperiment - voyage. Adapted from the SIPEX website: During SIPEX we investigated the biogeochemistry of iron (Fe), including a comprehensive examination of its distribution, speciation (i.e. the different forms of Fe), cycling and its role in fuelling sea ice-based and pelagic algal communities. A major part of this research concentrated on the influence of organic exopolysaccharides (EPS) on Fe solubility and its bio-availability. The distribution of other bioactive trace elements was also examined as a means of fingerprinting the source(s) of Fe, as well as indicating their biological requirements. ######### Data on the small- to medium scale (0.1-1000 m) spatial and temporal distribution of Fe and EPS in sea ice cores, surface snow, brine and underlying seawater were determined in each sampled medium by the interdisciplinary team working on the SIPEX project (AAS 3026) in the East Antarctic sector in September/October 2007. Data include Chlorophyll a, salinity, temperature, sea-ice thickness, ice texture analysis, macro-nutrients (nitrate, phosphate, silicate), oxygen stable isotopes, POC and DOC, EPS, iron. This work was completed as part of AAS (ASAC) project 3026. See the parent metadata record (ASAC_3026) for more information.

  • Metadata record for data from AAS (ASAC) project 3026. Public This project will assess the importance of the trace micro-nutrient element iron to Antarctic sea-ice algal communities during the International Polar Year (2007-2009). We will investigate the biogeochemistry of iron, including a comprehensive examination of its distribution, speciation, cycling and role in fuelling ice-edge phytoplankton blooms. A significant part of this research will concentrate on the the influence of organic exopolysaccharides on iron solubility, complexation and bioavailability, both within the ice and in surrounding snow and surface seawater. This innovative research will improve our understanding of key processes that control the productivity of the climatically-important Antarctic sea-ice zone. Project objectives: This project will assess the importance of the trace element iron (Fe) as a micro-nutrient to seasonal sea-ice algal communities in the Australian sector of Antarctica during the International Polar Year (2007-09). We will investigate the biogeochemistry of Fe, including a comprehensive examination of its distribution, speciation, cycling and role in fuelling ice-edge phytoplankton blooms. A significant part of this research will concentrate on the influence of organic exopolysaccharides (EPS) on Fe solubility and complexation (and hence bioavailability), both within the ice and in surrounding surface waters. This innovative research will improve our understanding of key processes that control the productivity of the climatically-important Antarctic sea-ice zone. Specifically, in this project: - The biogeochemical behaviour of Fe in sea-ice with regards to EPS complexation, and key physicochemical and biological data will be evaluated. - The bioavailability of Fe for phytoplankton growth during sea-ice melt will be investigated through laboratory-based experiments designed to mimic spring conditions. - The distribution of other bioactive trace elements in the Antarctic sea-ice environment will be examined as a means of fingerprinting the source(s) of Fe, as well as indicating their biological requirement. Taken from the 2008-2009 Progress Report: Progress against objectives: In the last twelve months we achieved all the objectives planned for the shore-based sample processing and analysis from the SIPEX voyage (fieldwork September-October 2007). An extensive and unique seasonal and spatial data set was put together including parameters such as ice texture, salinity, temperature, Chlorophyll a, particulate organic carbon (POC), dissolved organic carbon (DOC), macro-nutrients (silicate, phosphate and nitrate), and exoplysaccharides (EPS, using both alcian blue and PSA methods). Dissolved iron (dFe) and total dissolvable iron (TDFe) were analysed by flow injection - chemiluminescence (FIA-CL) analysis in Hobart. Polycarbonate (PC) filters (Nuclepore 0.2 micron pore size) retaining particulate metals were digested in a mixture of strong, ultrapure acids (750 micro litre 12N HCl, 250 micro litre 40% HF, 250 micro litre 14N HNO3) on a hotplate at 125 degrees C for 8 h. The procedure was successfully applied to plankton, estuarine and river sediment reference materials to verify the recovery of the digestion treatment. The concentrations of particulate iron (PFe) were determined by high resolution ICP-MS at the Central Science Laboratory at UTAS. This data has been quality-controlled, analysed, interpreted and published (see below). Due to the fact that logistical support was not possible for 2008/09 (insufficient berths at Casey Station) despite approval of our project, the field component of the project was delayed. Taken from the 2009-2010 Progress Report: Progress against objectives: Monthly Milestones of PhD student Pier van der Merwe: Successful Antarctic research expedition occurred in Oct-Dec 2009 at Casey Station Antarctica with logistical support from AAS project #3026 (flight on FA02 and berths at Casey station as well as field support of personnel). OCT-DEC 2009 - Antarctic time series data collection and processing successful. Data analysis scheduled for Jan - Mar. Write up of last paper(s) scheduled for Mar-June. Final completion of thesis due in August. DEC - Chlorophyll a data analysed JAN - FIA and CLECSV analyses start simultaneously FEB - Finish FIA analyses and attend Ocean science meeting in Portland Oregon. MAR - Finish CLECSV analyses and run POC and PFe digestions and analyses. Scheduled with Thomas Rodemann and Ashley Townsend at the CSL, UTAS. APR - MAY Data analysis and write up of 3rd paper, and possibly 4th based on field work at Casey station Oct-Dec 2009. See the child metadata records for more information about the data.

  • The BROKE-West survey was conducted on voyage 3 of the Aurora Australis during the 2005-3006 season. It was intended to be a comprehensive biological and oceanographic survey of the region between 30 degrees and 80 degrees east. A number of metadata records providing more detail about aspects of the voyage are linked off this metadata record. Copies of the public summaries from the underlying ASAC projects of the voyage are below: A planned acoustic biomass survey for krill in CCAMLR Division 58.4.2 (South West Indian Ocean) in January-March 2006 will produce the data for a revised catch limit on the krill fishery. The survey will utilise a standardised design as adopted in previous biomass surveys in the CCAMLR Area and will consist of 11 parallel transects between 30 degrees and 80 degrees east. A full suite of ecological measurements will be conducted: physical and chemical oceanography, primary productivity, microbial diversity, zooplankton distribution and abundance, krill distribution, abundance and demographics, fish distribution, abundance and genetics, and seabird and cetacean distribution. The three-dimensional ocean circulation from the 30 to 80 degrees E and 200nm from Antarctica is being studied through the use of direct measurements of velocity, temperature, salinity, oxygen, nutrients , chloro-flourocarbons, dissolved inorganic carbon and bio-geochemical cycles. This multi-disciplinary experiment (see also project 2655) will determine the circulation of the region, its relation to bio-geochemical cycles, carbon cycle and ecosystems. The temperature and salinity data will also be used to test for long term trends that could be related to climate change. This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679). A pdf copy of the proposed voyage track is available for download from the provided URL. Two csv files detailing the locations (latitudes and longitudes), plus times and dates (UTC) of the trawl and ctd stations on the BROKE-West voyage are available for download from the provided URL. Additional comments (where applicable) about each station are also provided.