Metadata record for data from ASAC Project 867 See the link below for public details on this project. Dataset Sea-ice bacteria data are associated with ASAC_1012 and included there Data for bacteria from ornithogenic soil samples collected from the Vestfold Hills Region is included (associated with ref 9899): 1) Isolate designations, availability, media used and growth conditions. 2) Phenotypic data - morphology, nutritional and biochemical traits 3) Chemical data - fatty acids, wax esters 4) Genotypic data - DNA base composition, DNA:DNA hybridisation analysis 5) Phylogenetic data - 16S rRNA gene sequences The download file contains: Sample data obtained. Includes sea-ice sampling sites, location, information on ice cores including presence or absence of algal assemblage band communities and whether under-ice seawater was collected or not. Samples were melted and/or melted then filtered (0.2 micron size) for cultivation and DNA-related analyses carried out primarily in AAS project 1012.

Crustaceans are an important component of the Antarctic marine ecosystem. Large numbers live in or close to the sea-ice cover, using it as a refuge from predation and a source of food. However, the impact of these animals on algae that grows in the sea ice is unknown. This study is examining the diets and grazing rates of crustaceans in the Antarctic sea-ice ecosystem. These results will aid our understanding of the fate of algal production in sea-ice and will enable the construction of realistic carbon budgets for this ecosystem. This project was commenced in July 2002. A five-week voyage was undertaken on the RV Aurora Australis in October and November 2002, in the vicinity of the Mertz Glacier. Pack ice cores and sub-ice water samples were collected from 8 locations, with 3 to 5 samples of each type collected per site. The cores were sectioned in the field, melted and treated for further analysis. All samples were either preserved or frozen, depending on future requirements, and returned to Australia. Sea ice cores were processed for a range of analyses including microscopy, lipid class and fatty acid determination and stable isotope analysis. A physical description of the pack ice environment (ice type, ice thickness, snow cover, temperature profiles, salinity profiles) was also compiled. A second sampling of the pack ice occurred in Sept-Oct 2003. To date, the salinity and temperature profiles of the pack ice cores have been described and a database compiled of the physical description of the region. A large number of samples (10 sites; 5 ice/water/animal samples per site) was collected and analysis has begun of stable isotopic signatures, fatty acids, chlorophyll a and species identifications. Crustaceans have been sorted under the microscope and initial descriptions of gut contents begun. The third successful sampling trip was to the fast ice surrounding Davis Station during the 2003/04 summer. Two sites were sampled regularly, with a full suite of analyses undertaken. This will provide a temporal component to the project to complement the spatial approach used in the pack ice. Analysis of the fast ice samples is ongoing. Two more sampling trips were carried out during the 2004/05 season. The first in the pack ice offshore from Casey and the second in the fast ice at Casey. The same suite of analyses as listed above was carried out and analyses are ongoing. The download file contains five excel spreadsheets, as well as a word document which further explains data collection.

This metadata record covers ASAC projects 113, 191 and 625. (ASAC_113, ASAC_191, ASAC_625). The total lipid, fatty acid, sterol and pigment composition of water column particulates collected near the Australian Antarctic Base, Davis Station, were analysed over five summer seasons (1988-93) using capillary GC, GC-MS, TLC-FID and HPLC. Polar lipids were the dominant lipid class. Maximum lipid concentrations usually occurred in samples collected in December and January and corresponded with increased algal biomass. Both lipid profiles and microscopic observations showed significant variation in algal biomass and community structure in the water column during each season and on an interannual basis. During the period of diatom blooms (predominantly Nitzschia species) the dominant sterol and fatty acid were trans-22-dehydrocholesterol and 20:5w3, accompanied by a high 16:1w7 to 16:0 ratio. Very high polyunsaturated fatty acid and total lipid concentrations were associated with diatom blooms in the area. Bacterial markers increased late in all seasons after the summer algal blooms. Long chain C30 sterols also increased during the latter half of all seasons. Fjord samples collected in the area reflected greater biomass and diversity in algal and bacterial makers than coastal sites. Signature lipids for the alga Phaeocystis pouchetii, thought to be a major alga in Antarctic waters, were identified in field samples over the five summer seasons studied. Methods Study site Davis Base is situated on the Vestfold Hills, Antarctica and incorporates numerous lakes and fjords (Fig. 1). Samples of water column particulate matter were collected during five summer seasons (1988-93), 500 meters off-shore from Magnetic Island, situated 5 km NW of Davis. Three other sampling areas were situated in the fjords of the Vestfold hills and include two sites in Ellis Fjord, one midway along Ellis Fjord and one near Ellis Fjord mouth and one sample midway along Long Fjord (Fig. 1). These fjords are protected from the marine environment, but are both marine fjords. Davis Station and Magnetic Island were used for the weekly sample sites. The mouth of Long Fjord, the mouth of Ellis Fjord, midway down Long Fjord, the deep basin in Ellis Fjord, O'Gorman Rocks and Hawker island (ocean side) were used for monthly samples. Field collection There was an initial pilot season in 1988-89, which was followed by two more detailed studies in the summers of 1989-90 and 1990-91. Four samples was also analysed from the 1991-92 and five from the 1992-93 summer seasons. During the initial pilot study at Magnetic Island in the 1988-89 summer, three water column particle samples were taken for lipid analyses. The 1989-90 and 1990-91 summer field seasons incorporated weekly sampling of the water column particulates at Magnetic Island. The phytoplankton in the fjords were studied during the summers of 1989-90 and 1990-91. The three sites that were chosen were all sampled three times in each season. Samples were also collected during the 1989-90 and 1990-91 seasons from the Magnetic Island and Fjord site s for pigment analyses. Three and five samples were collected respectively in the 1991-92 and 1992-93 seasons. Samples were also taken for microscopic analyses. For lipid analyses 30-40 liter water column particulate samples were collected at a depth of 10 m. A Seastar or INFILTREX water sampler was used in situ to filter the water through a 14.2 cm Schleicher and Schuell glass fibre filter over a three to four hour period. All filters used during sampling were preheated in a muffle furnace at 500 degrees C overnight to minimise contamination. For pigment analyses 2 to 4 litres were filtered through glass fibre filters (4.7 cm GF/F, nominal pore size 0.7 micro meters). The samples were frozen at -20 degrees C until extraction.