BaselineBaseline concentrations of faecal sterols and assessment of sewage input into different inlets of Admiralty Bay, King George Island, Antarctica

•Faecal sterol concentrations in sediments of the Antarctic environment are presented.•Biogenic and human contributions of faecal sterols are discussed.•Sewage contamination was not detected in Admiralty Bay.•The baseline levels may be useful for Antarctic sewage monitoring programs.

The Antarctic region is one of the best preserved environments in the world. However, human activities such as the input of sewage result in the alteration of this pristine site. We report baseline values of faecal sterols in Admiralty Bay, Antarctica. Four sediment cores were collected during the 2006/2007 austral summer at the Ezcurra (THP and BAR), Mackelar (REF) and Martel (BTP) inlets. Concentrations of faecal sterols (coprostanol + epicoprostanol) were <0.16 μg g−1, suggesting no sewage contamination and probable “biogenic” contributions for these compounds. Baseline values, calculated using the mean concentration of faecal sterols in core layers for THP, BAR, REF and BTP, were 0.04 ± 0.02, 0.03 ± 0.01, 0.07 ± 0.01 and 0.04 ± 0.02 μg g−1, respectively. These results established as natural contributions of faecal sterols, suggesting that these markers can be useful indicators of human-derived faecal input and contributing to monitoring programs to prevent anthropogenic impacts.