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As humans are present in Antarctica only for scientific and tourism-related purposes, it is often described as a pristine region. However, studies have identified measurable levels of Persistent Organic Pollutants (POPs), such as organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), in the Antarctic region. These are highly toxic anthropogenic compounds with tendency to travel long distances and reach remote environments, where they can bioaccumulate in the biota. Penguins are exposed to POPs mainly through their diet, which they partially eliminate via feathers. Species of the genus Pygoscelis occur around Antarctic continent and its surrounding regions, and can act as indicators of contaminants that reach the continent. Here, we report OCP and PCB levels in feathers of male and female penguins of P. adeliae, P. antarcticus and P. papua from King George Island, South Shetland Islands, Antarctica. Interspecific, sex- and body-size-related differences were investigated in the contamination profiles of PCBs and OCPs. Feather samples were collected from adult penguins (n = 41). Quantification of compounds was performed by gas chromatography-tandem mass spectrometry. The three Pygo s celis species presented similar contamination profiles, with higher concentrations of dichlorodiphenyltrichloroethane (∑DDT; 1.56–3.82 ng g−1 dw), lighter PCB congeners (∑PCB: 11.81–18.65 ng g−1 dw) and HCB (hexachlorobenzene: 1.65–4.06 ng g−1 dw). Amongst the three penguin species, P. antarcticus had lower and P. papua higher concentrations of most of the compounds identified. We found interspecific differences in POPs accumulation as well as sex differences in POP concentrations. Our data indicate a small but significant positive correlation between body size and the concentrations of some compounds. Despite the overall low concentrations found, this study increases knowledge of the occurrence of POPs in Antarctic penguins, thereby reinforcing concerns that Antarctica, although remote and perceived to be protected, is not free from the impact of anthropogenic pollutants. Image 1 • First study to report on PCB levels in Pygoscelis feathers. • DDTs, PCBs and HCB are the predominant compounds in Pygoscelis feathers. • Pygoscelis papua has the highest OC concentrations compared to other Pygoscelis. • Sex-related differences are detected in P. adeliae and P. papua. • Body size is found to influence POP concentrations. This is the first report of PCB levels in Pygoscelis penguin feathers and presents original data on the accumulation of POPs in Antarctic penguins. [ABSTRACT FROM AUTHOR]

Penguins in Antarctica occupy high trophic levels, thus accumulating high amounts of mercury (Hg) through bioaccumulation and biomagnification. Blood reflects the current levels of contaminants circulating in the body, while feathers are known as the main route of Hg elimination in birds. Studies sampling chicks and adults can provide a comprehensive picture of bioaccumulation and local contamination. Three pygoscelid species (Pygoscelis adeliae, Pygoscelis antarcticus and Pygoscelis papua) have circumpolar distributions being the ideal sentinels of Antarctic environmental pollution. This study aimed to assess Hg contamination of the pristine Antarctic region using non-destructive penguin samples. Fieldwork was carried out during the austral summer of 2013/2014 in the South Shetland Islands, off the north-west Antarctic Peninsula. Concentrations of total Hg (ng.g−1 dw) in blood ranged from 39 to 182 in chicks and 45 to 581 in adults, while concentrations in feathers ranged from 73 to 598 in chicks and 156 to 1648 in adults. Most Hg in feathers (about 70%) is accumulated in the form of methylmercury. Differences were demonstrated in mercury bioaccumulation were related to species and age, but not to sex. To our knowledge this is the first study to report MeHg levels in both juvenile and adult pygoscelid penguins. Image 1 • THg and MeHg were measured in blood and feathers of Pygoscelis penguins. • Pygoscelis antarcticus had the highest Hg levels. • Hg concentrations were different according to age group and species. • Most of the Hg in penguins' feathers is in methylmercury form. • Hg was higher in feathers, reflecting the long-term bioaccumulation of matrix. [ABSTRACT FROM AUTHOR]