Summary
Australia’s Antarctic territory contains several hydrocarbon-contaminated sites of varying size and severity as a result of fifty years of human activities in the region. Contaminated site remediation in Antarctica is more challenging than in Australia. This presentation will explore some of the technical difficulties faced when working in Antarctica as well as some of the technologies that could potentially be used to remediate oil spills in the Antarctic. The Australian Antarctic Division has been investigating the effects of hydrocarbon contamination on polar ecosystems and the potential of biodegradation as part of a remediation strategy for several years. In a field trial using soil from a weathered diesel spill, we found that the addition of nutrients was the most important factor for increased hydrocarbon degradation. In the top five centimetres of the soil aerobic microbes containing alkane mono-oxygenases appear to be responsible for much of the alkane degradation. Interestingly, we also found that this nutrient addition preferentially stimulated denitrifying hydrocarbon-degrading bacteria in the oxygen-poor regions of the soil. Contrary to expectations, aerating this soil decreased hydrocarbon biodegradation. This work has been utilized in the development of a pilot-scale permeable reactive barrier to treat a recent spill of diesel fuel at Casey Station. Less is known of the effects of hydrocarbons on the Antarctic marine environment. A five-year study of the comparative effects of several classes of oils on the benthic ecosystem found that the oils have different effects on the microbial ecology of the marine ecosystem with some having immediate and significant effects. Again, alkane mono-oxygenases appear to have an important role in diesel biodegradation. An indication of the longevity of these effects will be obtained by analysis of the most recent samples collected in the 2006-2007 field season.