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 dataset contains Ffilter samples of known volume of sea water for - PIC (Particulate Inorganic Carbon) - POC (Particulate Organic Carbon) - BGSi (BioGenic Silicon) The dataset also contains transmissometer data. The transmissometer is an attempt at developing a correlation between the PIC filter samples and the transmissometer readings. This is development of methods. The data collection times are logged in the file and filter log sheets.

Five (out of a possible 7) ice stations were sampled for the Main Biology Site, collected from -63.88S 119.9E off East Antarctic in September to November 2012 during the Sea Ice Physics and Ecosystems eXperiment (SIPEX) II. Sampled pack ice floes were several 100 meters to several kilometres apart, and indicated variation in the degrees of physical deformation and biological characteristics. The sampled sites were selected on each floe due to low snow cover disturbances, were level, and free from surface deformations (limited rafting). For the production and carbon allocation dataset, the bottom 2 cm of 3 x 5 - 8 (dependant on level of biomass) cores were collected and combined within a 4 m grid using a 9 cm diameter SIPRE corer. Biology was isolated from the ice by gently mixing with 0.22 micron filtered sea water collected from the site with a Niskin bottle, and pass through a sieve. The liquid was then analysed for bacterial and algae productivity. The corresponding dataset (P:\Data\ Copy of SIPEX C14_Ugalde_Raw Data_St 8) describes data (expressed in disintegrations per minute) directly input into an excel file from the scintillation counter measured on board the Aurora Australis. The additional dataset (P:\Data\ SIPEX C14_Chloro_SIPEXII_Updated to Station 8) describes data directly input into an excel file of volume filtered for chlorophyll analysis (expressed in mls) of both the ice and liquid fraction. For the Main Biology dataset, 6 cores were taken from the same site: Core 1: temperature profile Core 2: nutrients, extracellular polymeric substances Core 3 and 4: chlorophyll, pigments (HPLC), bacteria and cell counts Core 5: particulate organic carbon/nitrogen, dissolved organic carbon Each core was sectioned from the ice-water interface at 0 - 2 cm, 2 - 10 cm, and then the remaining core was quartered. Core 1 was discarded after the temperature profile was taken. Core 3 and 4 were slow-melted in at 6 degrees cold room with 0.22 micron filtered sea water collected from the site as above (200 ml per cm ice). Cores 2 and 5 were slow-melted as above without the addition of filtered sea water. Additional measurements included 5 replicates of snow thickness and freeboard level. After melting, samples were taken/filtered for the parameters above within 12 hours of melting. The corresponding dataset (P:\Data\Data Updated to Station 8\ Main Bio Data Sheet_SIPEX II_Updated to Station 8) describes descriptive and quantitative parameters of the above cores, directly input into a spreadsheet.

Metadata record for data from ASAC Project 2751 See the link below for public details on this project. Public Viruses are tiny particles that cannot reproduce by themselves. To reproduce they have to parasitise a bacterial cell, or another organism. In the sea viruses infect bacteria and phytoplankton cells and can cause those cells to die and break open, thereby liberating more virus particles into the environment to re-infect more host cells. They effectively short-circuit the carbon cycle - recycling carbon to the pool of dissolved and particulate organic carbon before it can be eaten by organisms higher in the food chain. Our research will elucidate the role of viruses in the water column and sea-ice over a year. Taken from the 2008-2009 Progress Report: Project objectives: BACKGROUND Since the microbial loop was first described, a wealth of data has appeared on the species composition and interactions among bacterioplankton and Protozoa, both heterotrophic and mixotrophic, and their role in biogeochemical cycling in marine and lacustrine environments. An additional dimension to the microbial loop was discovered when high concentrations of viruses (bacteriophage) were first described from marine samples. The supposition was that infected bacteria might be lysed, and their carbon returned to the pool before it could be grazed by Protozoa, short-circuiting the microbial loop. Both heterotrophic bacteria and cyanobacteria were found to be infected by viruses and later work revealed that viruses may also attack algae and protists, but the database on the viruses of these groups is far less detailed than for bacteriophages. Viruses are now the focus of considerable attention in aquatic environments. The role of viruses is more complex than simply causing the mortality of bacteria and phytoplankters. Viruses also play a role in maintaining the clonal diversity of host communities through gene transmission (transduction), and indirectly by causing the mortality of dominant host species. Moreover, viruses can act as a potential source of food for heterotrophic and mixotrophic flagellates. Based on decay rates an ingestion of 3.3 viruses per flagellate h-1 was calculated, and experiments with fluorescently labelled microspheres demonstrated that nanoflagellates may gain significant carbon through ingesting viruses. Early studies suggested that the majority of viruses in marine waters were lytic. More recently lysogeny has been found in both marine and freshwater systems ranging up to 71% in both marine and freshwaters. Thus aquatic viruses may exist in a lysogenic condition within their hosts where they replicate and are passed on in the host's progeny during division. This condition may continue until a factor, or a combination of factors, initiates the lytic cycle. Clearly it is disadvantageous to embark on a lytic cycle when the concentration of potential hosts is low. Long term seasonal studies of viruses and their potential hosts are relatively few, and have focussed on a specific aspects, for example the abundance of lysogenic bacteria in an estuary and Lake Superior and viral control of bacterial production in the River Danube. A recent study of annual patterns of viral abundance and seasonal microbial plankton dynamics in two lakes in the French Massif Central, suggested that a weakened correlation between viruses and bacteria in the more productive of the two lakes was indicative of an increase in non-bacterial hosts as trophic status increased. We have conducted a year long study of virus dynamics in three of the saline lakes in the Vestfold Hills, our hypothesis being that they may be regarded as a proxy for the marine environment, but with the difference that top-down control is lacking in food webs that are microbially dominated. Our results revealed that virus numbers showed no clear seasonal pattern and were high in winter and summer (range 0.89 x 107 plus or minus 0.038 mL-1 to 12.017 x 107 plus or minus 1.28 mL-1). However, the lysogenic cycle was predominant in winter (up to 73% of the bacteriophage were lysogenic), while in summer the lytic cycle dominated. There was a strong negative correlation between virus numbers and photosynthetically active radiation. Viruses are subject to destruction or decay when subjected to full sunlight, even when UV- B radiation is excluded. During summer in Antarctica there is 24 hour daylight as well as significant UV-B radiation in spring and early summer when one might expect high levels of viral decay. UV-B radiation penetrates lake ice and the water column, though attenuation is rapid. PAR and UV-B penetration to the water column increases as the ice thins. It is likely that low decay rates in winter allowed the survival and build up of VLP numbers, while in summer when the lytic cycle predominated, decay rates were high. Seasonal variation in decay rates may in part account for the poor correlation between bacterial numbers and VLP in our study. High virus to bacteria ratios in the saline lakes (reaching 115 in Pendant Lake) and viral production rates comparable to those seen in temperate lakes suggest that viruses may play an important role in these microbially dominated extreme environments. Data from Antarctic marine waters are limited. Bacteria to virus ratios ranged between 15 - 40 in the sea-ice region, but were lower (3-15) in the open ocean. Higher ratios under ice may indicate that ice and its impact on light climate, reduces viral decay rates and enhances the ratios between bacteria and viruses. The sea-ice itself provides another habitat for bacteria and their viral parasites with abundances of viruses reaching 109 mL-1. OVERALL AIM We wish to undertake a year long study in the inshore marine environment in Prydz Bay focussing on viral dynamics in relation to microbial loop functioning. We will investigate the water column and the communities within the sea-ice. Within the context of the International Polar Year it is important that we further knowledge of microbial processes in the Southern Ocean. Changes in the length and thickness of ice-cover in response to climate warming and the impact on the sea-ice community, may have knock on impacts on water column microbial community and carbon cycling. SPECIFIC OBJECTIVES: 1. The quantify viral dynamics (numbers, production and levels of lysogeny) within the context of the microbial loop processes in the water column and sea-ice of Prydz Bay over an annual cycle. 2. To link viral/bacterial dynamics to physical and chemical parameters such as temperature, UV radiation, Photosynthetically Active Radiation, dissolved organic carbon (DOC) and total organic carbon (TOC) and inorganic nutrients. (N and P). 3. To ascertain linkages between microbial processes iin the sea-ice and water column, particularly during the melt phase. 4. To ascertain the effects of UV-B on viral decay rates below ice and in the open water phase. Progress against objectives: Detailed time series sampling of the sea ice in Prydz Bay has been completed. Bacterial production and viral production, along with the level of lysogeny were conducted. Abundances of viruses, bacterial and nanoflagellates have been completed. Chlorophyll, DOC and TOC, inorganic nutrients also completed. Ciliate samples are still to analysed as are frozen preparations from viral production and lysogeny experiments.

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.

These POC export flux maps (units of g C. m-2 day-1) were compiled from Lutz et al. (2007) algorithm, following Woolley et al. (2016) procedure. They were produced after calculation of the Seasonal Variation Index of Net Primary Production layers (NPP, g C. m-2 day-1, see Lutz et al. 2007 for the methodology) available on a monthly basis at http://www.science.oregonstate.edu/ocean.productivity/custom.php (accessed on April 05, 2017). NPP layers are derivates of the Carbon-based Productivity Model that integrates several compounds such as satellite data color measurements, photosynthetically active radiation values or mix layer and nitrocline depth estimations (Westberry et al. 2008). Bathymetric layers used for the calculation were derived from Fabry-Ruiz et al. (submitted paper).

Sediment Recruitment Experiment 4 (SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks, 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125? hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison.

Sediment Recruitment Experiment 4 (SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks, 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125? hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison.

The actual piece of equipment used was an International Light IL 1700Radiometer equipped with broad band detectors to measure PAR, UV-A and erythemal UV-B. The effects of UV-B radiation on the fatty acid, total lipid and sterol composition and content of three Antarctic marine phytoplankton were examined in a preliminary culture experiment. Exponential growth phase cultures of the diatoms Odontella weissflogii and Chaetoceros simplex and the Haptophyte Phaeocystis antarctica were grown at 2 (plus or minus 1)degrees C and exposed to 16.3 (plus or minus 0.7) W.m-2 photosynthetically active radiation (PAR). UV-irradiated treatments were exposed to constant UV-A (4.39 (plus or minus 0.20) W.m-2) and low (0.37 W.m-2) or high UV-B (1.59 W.m-2). UV-B treatments induced species specific changes in lipid content and composition. The sterol, fatty acid and total lipid content and profiles for O. weissflogii changed little under low UV-B when compared with control conditions (PAR alone), but showed a decrease in the lipid content per cell under high UV-B treatment. In contrast, when P. antarctica was exposed to low UV-B irradiance, storage lipids were reduced and structural lipids increased indicating that low UV-B enhanced cell growth and metabolism. P. antarctica also contained a higher proportion of polyunsaturated fatty acids under low UV-B in comparison with PAR irradiated control cultures. The flagellate life stage of P. antarctica died under high UV-B irradiation. However, exposure of P. antarctica to high UV-B irradiance increased total lipid, triglyceride and free fat. The effect of UV-B irradiances on the lipid content of Antarctic marine phytoplankton is species specific. Changes in ambient UV-B may alter the nutritional quality of food available to higher trophic levels. EXPERIMENTAL All measurements of irradiance were made with an International Light IL 1700 Radiometer equipped with broad band detectors to measure PAR, UV-A and erythemal UV-B [14]. A National Institute of Standards and Technology intercomparison package (NIST Test #534/240436-88) was used to calibrate each light sensor. Unialgal cultures of the diatoms Odontella weissflogii and Chaetoceros simplex were isolated from sea ice collected in Prydz Bay, Antarctica during the 1990/91 austral summer. Phaeocystis antarctica was isolated from Prydz Bay in 1982/83 summer. Cultures of diatoms and Phaeocystis antarctica were maintained in 2 l glass flasks using f/2 growth medium [32] and GP5 medium [33] respectively at a temperature of 2 plus or minus 1 degrees C. Cool white fluorescent lights provided photosynthetically active radiation (PAR) intensity of 17.08 J.m-2.s-1 (84.7 micro E.m-2.s-1), with no UV-B enhancement, on a 12 h light : 12 h dark cycle. Immediately before experimental irradiation, three replicate subsamples of approximately 15 ml were obtained from each parental culture and fixed with Lugols iodine, a known sample volume sedimented, and cells counted over 15 replicate fields using a Labovert inverted microscope. Mean cell concentration and standard deviation were then computed. Each exponential growth phase parental culture was thoroughly mixed and 3 replicate 300 ml Costar polystyrene culture flasks (which completely absorbed wavelengths below 295 nm) established for each light treatment (control, low and high UV exposures). Cultures were irradiated for 24 hours in a 48 hour experimental period (6 h light : 12 h dark : 12 h light : 12 h dark : 6 h light) [14, 23]. Exposures were conducted in a Thermoline controlled environment cabinet at 2 plus or minus 1 degrees C with cool white fluorescent tubes to provide PAR and UV-A (320-400 nm), with UV-B provided by FS20T 12 UV-B Westinghouse sunlamps. PAR and UV-A irradiances were 16.3 plus or minus 0.7 W.m-2 (81.3 plus or minus 3.4 micro E.m-2.s-1) and 4.39 plus or minus 0.20 W.m-2 respectively. The spectral distribution and UV-B irradiance were varied by attenuation with glass filters [5] to provide low (0.37 W.m-2) or high UV-B (1.59 W.m-2). Sensors were each covered by an attenuating glass screen and a single layer of Costar culture flask to measure the experimental irradiances to which the algae were exposed. UV-B irradiances were chosen to reflect less than (74%) and greater than (318%) peak UV-B exposure as measured at an Antarctic coastal site (Casey station, 66 degrees S, [34]). Following irradiation each culture was well mixed and approximately 15 ml was fixed with Lugols Iodine for subsequent estimation of cell concentration (as above). Chlorotic and greatly vesicularised cells were considered to be dead [23]. The remainder of each experimental culture was filtered through Whatman GF/F filters. On completion of filtration, the filters were stored at -20C overnight before extraction of lipids the following day.

Sediment Recruitment Experiment 4 (SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks, 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125 hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison.