Mercury and selenium levels in feathers of Southern Giant Petrels (Macronectes giganteus) from South Shetland Islands, Antarctica

Concentrations of Hg and Se were assessed in dorsal feathers of Southern Giant Petrels (SGP) from three Antarctic islands. Feather sampling was conducted during four breeding seasons (2011 to 2014) at Elephant and King George Islands, and during two breeding seasons (2012 and 2013) at Livingston Island. Hg concentrations found in SGP feathers ranged from 1.99 to 68.38 μg g−1, while Se concentrations varied from 1.18 to 12.0 μg g−1. Inter-annual and inter-colony differences were observed, which could be associated to ecological factors such as diet, foraging patterns and migration. Sex does not significantly influence the concentration of metals. The highest concentrations of Hg were found on Elephant Island, which is the northernmost island of the three, where the SGP feathers had the maximum mercury value ever recorded since the 1950s in the Southern Ocean and Antarctic Islands. The present data contributes to monitoring efforts of Hg exposure in Antarctic seabirds and can be used to obtain relevant information about the SGP, such as differences in food preferences at different breeding sites and foraging patterns.