Summary
Terrestrial fuel spills in Antarctica commonly occur on ice-free land around research stations as the result of human activities. Successful clean-up of spills not only requires appropriate remediation strategies and technologies that are effective in cold climates, but also remediation targets that enable sites to be “signed off” as “clean” following remediation efforts. These targets are based on knowledge of the impacts of contaminants on the soil ecosystem and the response of native biota to contamination. This thesis examines the response of microbial functional genes to fuel contamination and assesses their utility as indicators of soil health in the presence of weathered and fresh fuels. Quantitative PCR was used to measure the abundances of five microbial functional genes; rpoB, alkB, cat23, nosZ and nifH in soils containing Special Antarctic Blend (SAB) diesel. Uncontaminated and contaminated soils were collected from the site of bioremediation treatment of an aged diesel spill at Casey Station, East Antarctica in December 2012. Uncontaminated soil was spiked with fresh SAB diesel to mimic the effects of a fresh spill, and partly remediated soil containing weathered SAB diesel was diluted with uncontaminated soils to simulate a range of concentrations of weathered fuel. Differences were observed between the functional genes in control soils and soils containing weathered and fresh fuels. Typical dose-response curves were generated for genes in response to the presence of fresh fuel. The response of functional genes to the range of concentrations of weathered fuel tested however appeared to be due to dilution, rather than to the actual toxicity of the fuel to the microbial community.
Related projects
