Mercury exposure in an endangered seabird: long-term changes and relationships with trophic ecology and breeding success

• Published in: Proceedings of the Royal Society B: Biological Sciences
• Main Authors: Mills, William, Bustamante, Paco, Mcgill, Rona, Anderson, Orea, Bearhop, Stuart, Cherel, Yves, Votier, Stephen, Phillips, Richard
• Other Authors: British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Centre for Ecology and Conservation, University of Exeter, LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Institut universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), NERC Life Sciences Mass Spectrometry Facility Glasgow, Scottish Universities Environmental Research Centre (SUERC), University of Glasgow-University of Edinburgh (Edin.)-University of Glasgow-University of Edinburgh (Edin.)-Natural Environment Research Council (NERC), Joint Nature Conservation Committee (UK), Inverdee House, Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Heriot-Watt University Edinburgh (HWU)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: pollution; seabirds; Thalassarche chrysostoma; heavy metals; Southern Ocean; [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Antarctic; Antarc*
• Online Access: https://hal.science/hal-03108889; https://hal.science/hal-03108889/document; https://hal.science/hal-03108889/file/Mills%20et%20al%202020%20PROC%20B.pdf; https://doi.org/10.1098/rspb.2020.2683

International audience Mercury (Hg) is an environmental contaminant which, at high concentrations, can negatively influence avian physiology and demography. Albatrosses (Diomedeidae) have higher Hg burdens than all other avian families. Here, we measure total Hg (THg) concentrations of body feathers from adult grey-headed albatrosses (Thalassarche chrysostoma) at South Georgia. Specifically, we (i) analyse temporal trends at South Georgia (1989–2013) and make comparisons with other breeding populations; (ii) identify factors driving variation in THg concentrations and (iii) examine relationships with breeding success. Mean ± s.d. feather THg concentrations were 13.0 ± 8.0 µg g−1 dw, which represents a threefold increase over the past 25 years at South Georgia and is the highest recorded in the Thalassarche genus. Foraging habitat, inferred from stable isotope ratios of carbon (δ13C), significantly influenced THg concentrations—feathers moulted in Antarctic waters had far lower THg concentrations than those moulted in subantarctic or subtropical waters. THg concentrations also increased with trophic level (δ15N), reflecting the biomagnification process. There was limited support for the influence of sex, age and previous breeding outcome on feather THg concentrations. However, in males, Hg exposure was correlated with breeding outcome—failed birds had significantly higher feather THg concentrations than successful birds. These results provide key insights into the drivers and consequences of Hg exposure in this globally important albatross population.