Persistent organic pollutants and stable isotopes in pinnipeds from King George Island, Antarctica

In the present work, fat, skin, liver and muscle samples from Leptonychotes weddellii (Weddell seal, n = 2 individuals), Lobodon carcinophagus (crabeater seal, n = 2), Arctocephalus gazella (Antarctic fur seal, n = 3) and Mirounga leonina (southern elephant seal, n = 1) were collected from King George Island, Antarctica, and analysed for POPs (PCBs, organochlorine pesticides and PBDEs) and stable isotopes (δ13C and δ15N in all tissues but fat). PBDEs could be found in only one sample (L. weddellii fat). Generally, PCBs (from 74 to 523 ng g−1 lw), DDTs (from 14 to 168 ng g−1 lw) and chlordanes (from 9 to 78 ng g−1 lw) were the prevailing compounds. Results showed a clear stratification in accordance with ecological data. Nonetheless, stable isotope analyses provide a deeper insight into fluctuations due to migrations and nutritional stress. Correlation between δ15N and pollutants suggests, to some degree, a considerable ability to metabolize and/or excrete the majority of them.

► PCBs, DDTs and Chlordanes are the prevailing organochlorines in Antarctic seals. ► Results showed a clear stratification in accordance to ecological data. ► Stable isotopes analysis provides a deeper insight on data fluctuations.