Seabird colonies as relevant sources of pollutants in Antarctic ecosystems: Part 2 - Persistent Organic Pollutants

International audienceDespite typically not being taken into account (usually in favour of the "Global Distillation" process), the input of Persistent Organic Pollutants (POPs) via biological activity can be indeed relevant at the local scale in terrestrial Polar environments when seabird colonies are considered. The fact that seabirds bioaccumulate and biomagnify those POPs, gather in large numbers and excrete on land during their reproductive season can act locally as relevant secondary source of the same contaminants. The first part of this study indicated that these colonies act as so for several essential and non-essential trace elements and this second part tests the same hypothesis concerning POPs using the very same samples. Lichens (n=55), mosses (n=58) and soil (n=37) were collected in 13 locations within the South Shetlands Archipelago during the austral summers of 2013-14 and 2014-15. They were divided in colony (within the colony itself for soil and bordering it for vegetation) and control (at least 150m away from any colony interference), analysed for POPs: organochlorine pesticides, polychlorinated byphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs); and stable isotopes (C and N). Results showed that colonies act clearly as a secondary source for PCBs and likely for HCB. As in the first part, probable local sources other than the colonies themselves are hypothesised due to high concentrations found in control sites. Again, soil seemed the most adequate matrix for the intended purposes especially because of some particularities in the absorption of animal derived organic matter by vegetation, pointed out by stable isotope analyses