During the 2005-2006 austral summer, an extensive field season was conducted at the MPH site. Soil from the contaminated site was sampled at regular intervals over the course of the summer and an array of soil toxicity assays were conducted on the soil to determine the sensitivity of each assay. The sensitivity of carbohydrate utilization, nitrifying and denitrifying activity to SAB ... contamination were assessed.
The contaminated site that I was working at was the Casey Main power house (MPH) Special Antarctic Blend (SAB) spill site. The existing spill occurred in the summer of 2000 when the tank that supplies SAB to the MPH was being refilled. An estimated 10,000L SAB fuel was spilled. 32 sites were chosen from the Casey MPH fuel spill and the sites will be referred to as ecotox sites. All sites were upsloped from the permeable reactive barrier (PRB) which was installed during the same field season (austral summer 2005-2006). The sites were chosen to represent a range of SAB contamination from 0 - 25,000 mg kg-1 SAB. The soil at the spill site consisted mostly of fill from the quarry, with lots of large rocks present. A sampling grid was established and surveyed using a total station. The location of each ecotox site is described by easting and northing from the baseline sight (0,0) which is marked on the north east corner of the bund surrounding the fuel tank on the north side of the MPH. Thermocouples and time-domain reflectometry (TDR) probes were installed at each ecotox site to measure soil temperature and soil liquid water content, respectively. A deep snow pack covered the site at the beginning of the summer (early November), and as the melt progressed a thick basal ice layer developed (mid-December). The snow on the site had melted by early January and the soil began to dry out. Pools of water that were present had algal growth. There was some moss present at a few of the sites. The soil was sampled nine times over the course of the summer, and the data are divided into folders titled ecotox 1, ecotox 2, ecotox 3, etc. to represent the nine sampling periods. For each sampling period soil from each site was subdivided into samples for five different soil toxicity assays including carbohydrate utilization, nitrification activity, denitrification activity (Nar/Nir/Nor), denitrification activity (N2OR), and molecular analysis for biodiversity and abundance of nitrifying and denitrifying bacteria. The activity assays (CHO utilization, nitrification, and denitrification) were performed at Casey station, while the sub-sample taken for molecular analysis was stored at -80C and shipped to the University of Saskatchewan. The soil temperature and soil liquid water content was measured for each ecotox site at the time of sampling. The data for the activity assays are located in their own folder for each sampling period.
This work was completed as part of ASAC project 1163 (ASAC_1163).