Mercury accumulation in gentoo penguins Pygoscelis papua: spatial, temporal and sexual intraspecific variations

Mercury emissions have increased over the past decades affecting even remote areas such as Antarctica. As gentoo penguins (Pygoscelis papua) breed on many of the islands surrounding Antarctica, foraging close to their colonies, their mercury load should reflect concentrations in the region. We therefore evaluated mercury concentrations in adult gentoo penguin feathers at Bird Island, South Georgia. We found no significant differences in mercury levels between 2009 and 2010 (mean ± SD 0.97 ± 0.67 mg kg−1, mean ± SD 1.13 ± 0.62 mg kg−1, respectively). Stable nitrogen isotope values in feathers indicated that feeding habits had a stronger influence on male mercury concentrations, whereas stable carbon isotope values indicated that foraging habitat had a stronger influence on females. Though no temporal variation in levels of mercury in gentoo penguin feathers was observed, spatial differences were evident when compared with previous studies. Our results could have implications for other animals higher in the food web that prey upon gentoo penguins, with potential consequential effects on their reproduction and development.