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  • Very little information is available on the geomorphology of areas surrounding Australian Antarctic stations. This type of information is generally collected during geological surveys. This metadata record gathers a range of descriptive geomorphological information of various nature: -Habitat surveys were conducted in the season 2002-2003 in the Windmill Islands in parallel with bird nest mapping (reported in metadata record BIRDSCASEY0203) in order to study selection of nest sites by a range of species. Habitat was described in the survey sites searched for bird nests following various methods (described in BIRDSCASEY0203). Information is stored as GIS files (Arcview 3.2) -polygon shapefile gathering all the geomorphological units. -line shapefile describing habitat along transects used for searching bird nests -polygon shapefile describing habitat in small 25*25m quadrats used for searching bird nests -A collection of 1309 digital photos showing the sites searched for bird nests indexed by grid site number. Plus another set of 194 photos showing region of the Windmill Islands or bird nests more in detail -A set of Digital Elevation Models (DEM) covering the entire Windmill Islands area generated separately for 18 regions. -200m*200m grid created from the coverage of ice-free areas (Aerial photography 93-94) providing site numbers for the photographic database -A series of Black and White aerial Photos (500 m, Zeiss, 1994) scanned at high resolution for the purpose of substrate study. See the word document in the file download for more information. This work has been completed as part of ASAC project 1219 (ASAC_1219). The fields in this dataset are: Date Boulderbig Bouldsmall Baresubst Morsed Scree Snowcover Permice Slope Aspect Photonumber Sitedotid Comments

  • Very little information is known about the distribution and abundance of snow petrels at the regional scale. This dataset contains locations of bird nests, mostly snow petrels, mapped in the Windmill Islands during the 2002-2003 season. Location of nests were recorded with handheld GPS receivers connected to a pocket PC and stored as a shapefile using Arcpad (ESRI software). Descriptive information relating to each bird nest was recorded and a detailed description of data fields is provided in the detailed description of the shapefiles. Two observers conducted the surveys using distinct methodologies, Frederique Olivier (FO) and Drew Lee (DL). Three separate nest location files (ArcView point shapefiles) were produced and correspond to each of the survey methodologies used. Methodology 1 was the use of 200*200 m grid squares in which exhaustive searches were conducted (FO). Methodology 2 was the use of 2 transects within each the 200*200 m grid squares; methodology 3 was the use of 4 small quadrats (ca 25 m) located within the 200*200m grid squares (DL). Nests mapped in a non-systematic manner (not following a specific methodology) are clearly identified within each dataset. Datasets were kept separate due to the uncertainties caused by GPS errors (the same nest may have different locations due to GPS error). Three separate shapefiles describe survey methodologies: - one polygon shapefile locates the 200*200 grid sites searched systematically (FO) - one polygon shapefile locates the small quadrats (DL) - one line shapefile locates line transects (DL) Spatial characteristics, date of survey, search effort, number of nests found and other parameters are recorded for the grid sites, transect and quadrats. See the word document in the file download for more information. This work has been completed as part of ASAC project 1219 (ASAC_1219). The fields in this dataset are: Species Activity Type Entrances Slope Remnants Latitude Longitude Date Snow Eggchick Cavitysize Cavitydepth Distnn Substrate Comments SitedotID Aspect Firstfred Systematic/Edge/Incidental RecordCode The full dataset, including a word document providing further information about the dataset, is publicly available for download from the provided URL. Also available for download from another URL is polygon data representing flying bird nesting areas. The polygon data was derived from the flying bird nest locations by the Australian Antarctic Data Centre for displaying on maps.

  • 1.The lakes and ponds in the Larsemann Hills and Bolingen Islands (East-Antarctica) are characterised by cyanobacteria-dominated, benthic microbial mat communities. A 56-lake dataset representing the limnological diversity among the more than 150 lakes and ponds in the region was developed to identify the nature and quantify the effects of the abiotic conditions structuring the cyanobacterial and diatom communities. 2.Limnological diversity in the lakes of the Larsemann Hills and Bolingen Islands is primarily determined by salinity and salinity related variables (concentrations of major ions, conductivity and alkalinity), and variation in lake morphometry (depth, catchment and lake area). Low pigment, phosphate and nitrogen concentrations, and DOC and TOC levels in the water column of most lakes underscore the ecological success of benthic microbial mats in this region. 3.Benthic communities consisted of prostrate, sometimes finely laminated mats, flake mats, epilithic and interstitial microbial mats. Mat physiognomy and chlorophyll/carotenoid ratios were strongly related to lake depth, but not to salinity. 4.Morphological-taxonomic analyses revealed the presence of 27 diatom morphospecies and 34 cyanobacterial morphotypes. Mats of shallow lakes (interstitial and flake mats) and those of deeper lakes (prostrate mats) were characterized by different dominant cyanobacterial morphotypes. No relationship was found between the distribution of these morphotypes and salinity. In contrast, variation in diatom species composition was strongly related to both lake depth and salinity. Shallow ponds are mainly characterised by aerial diatoms (e.g. Diadesmis cf. perpusilla and Hantzschia spp.). In deep lakes, communities are dominated by Psammothidium abundans and Stauroforma inermis. Lakes with conductivities higher than 1.5 mS/cm become susceptible to freezing out of salts and hence pronounced salinity fluctuations. In these lakes Psammothidium abundans and Stauroforma inermis are replaced by Amphora veneta. Stomatocysts were only important in shallow freshwater lakes. 5.Ice cover influences microbial mat structure and composition both directly by physical disturbance in shallow lakes and by influencing light availability in deeper lakes, as well as indirectly by generating salinity increases and promoting the development of seasonal anoxia. 6.The relationship between diatom species composition and salinity and depth is statistically significant. Transfer functions based on these data can therefore be used in paleolimnological reconstruction to infer changes in the precipitation-evaporation balance in continental Antarctic lakes. These data were also collected under the auspices of the Micromat Project, Biodiversity of Microbial mats in Antarctica (see the URL below). The fields in this dataset are: Lake Lake number Location Latitude Longitude Altitude (m) Area (ha) Catchment (ha) Depth (m) Distance from Plateau Distance from Sea Geology Substrate Presence Absence pH Alkalinity Nitrate Nitrite Ammonium Silicate Phosphate Oxygen Salinity Turbidity Conductivity Sodium Potassium Calcium Magnesium Chlorine Sulphur Bicarbonate Hydrocarbonate Total Organic Carbon Dissolved Organic Carbon