Mercury Levels in Feathers of Penguins from the Antarctic Peninsula Area: Geographical and Inter-Specific Differences.

Miguel Motas,Marta Esteban,José Javier Cuervo,Silvia Jerez,Francisco Valera,Andrés Barbosa

doi:10.3390/ijerph18189918

Abstract

Polar regions, symbols of wilderness, have been identified as potential sinks of mercury coming from natural and anthropogenic sources at lower latitudes. Changes in ice coverage currently occurring in some areas such as the Antarctic Peninsula could enhance these phenomena and their impacts on local biota. As long-lived species at the top of food chains, seabirds are particularly sensitive to this highly toxic metal with the capacity to be biomagnified. Specifically, their feathers can be useful for Hg monitoring since they mainly accumulate its most toxic and persistent form, methyl-Hg. To that end, feathers of gentoo (Pygoscelis papua), chinstrap (P. antarcticus), and Adélie penguins (P. adeliae) (n = 108) were collected by passive sampling in seven different locations throughout the Antarctic Peninsula area and analyzed by ICP-MS after microwave-digestion. More than 93% of the samples showed detectable Hg levels (range: 6.3–12,529.8 ng g−1 dry weight), and the highest ones were found in the feathers of chinstrap penguins from King George Island. Hg bioconcentration and biomagnification seem to be occurring in the Antarctic food web, giving rise to high but non-toxic Hg levels in penguins, similar to those previously found in Arctic seabirds.

Highlights

Mercury levels naturally present in the environment have increased during the last decades as a consequence of direct emissions from human activities and the mobilization of previously deposited mercury [1,2].This heavy metal has physicochemical properties that confer it special characteristics from the environmental point of view
Concentrations of Hg in the feathers of gentoo (P. papua), chinstrap (P. antarcticus), and Adélie penguins (P. adeliae) and the study of geographical differences are shown in Figures 1–3, respectively
Comparing our results with those described in the feathers of other seabirds from different regions, we found that some chinstrap penguins from King George Island showed high Hg levels, similar to those found in Arctic seabirds

Summary

Introduction

Mercury levels naturally present in the environment have increased during the last decades as a consequence of direct emissions from human activities (industry, combustion of fossil fuels, and solid wastes) and the mobilization of previously deposited mercury [1,2]. This heavy metal has physicochemical properties that confer it special characteristics from the environmental point of view. Methylmercury is taken up by higher organisms and accumulated and concentrated in the food chain. Mercury is deposited near its emission sources but can suffer long-range atmospheric transport resulting in significant contamination of terrestrial and aquatic environments and organisms, which constitutes an environmental problem in remote regions in which

Methods

Results

Conclusion