The Impact of human Activity on Antarctic Coastal Areas: A Case Study of Hydrocarbon Contamination at Potter Cove, South Shetlands

MAC CORMACK WALTER PATRICIO; RUBERTO LUCAS ADOLFO MAURO; VODOPIVEZ CHISTIAN LEOPOLDO; CURTOSI ANTONIO; PELETIER EMILIEN

Ocean Yearbook, Vol 25

Martinus Nijhoff Publishers

Lugar: Halifax; Año: 2011; p. 141 - 170

The area of Potter Cove and Peninsula was selected as a suitable location or the evaluation of hydrocarbon concentration, distribution and dynamics, as well as for study of composition and hydrocarbon degradation potential of the bacterial communities present in the area based on their relevant biodiversity. Analysis of the levels of polycyclic aromatic hydrocarbons (PAHs) revealed low values in surface soils, but also showed a signifi  cant increase with depth, reach-ng the highest values in the permafrost table and decreasing sharply into the permafrost. Evidence also suggests that the thaw of glaciers and snow as well as heavy rains would be responsible for a washout phenomenon transporting the mallest soil particles, and the PAHs adsorbed to them, from coastal soils to the marine basin. There, a combination of bottom topography, predominant winds and water circulation would cause a differential accumulation of PAHs on the urface sediments in some sites, where PAHs showed levels ten-fold higher than n the rest of sampling sites. None of the studied marine organisms (Nacella oncinna, Laternula elliptica and Notothenia coriiceps) showed levels of PAHs that evi-denced some kind of accumulation mechanisms.The analysis of the natural bacterial communities from soils and coastal marine environments at the Potter Cove area revealed a high biodiversity, with predominance of Proteobacteria, which is dramatically reduced in the presence of hydrocarbons. Microbiological and genetic approaches revealed that natural bacterial communities from chronically contaminated Antarctic soils are closely adapted to the presence of hydrocarbons. Given this situation, fi  eld bioremedia-ion assays showed that biostimulation of hydrocarbon contaminated soils are effi  cient enough to remove a signifi  cant fraction of the contaminants, yielding he expensive bioaugmentation strategy unnecessary. Contrary to that, when a previously pristine soil is suddenly affected by a fuel spill, its non-adapted bacte-ial community is deeply affected, and the usefulness of inoculating with hydro-carbon degrading bacteria remains an open question.