Mercury concentrations in feathers of albatrosses and large petrels at South Georgia: contemporary patterns and comparisons with past decades

• Published in: Archives of Environmental Contamination and Toxicology
• Main Authors: Mills, William, Bustamante, Paco, Ramírez, Francisco, Forero, Manuela, Phillips, Richard
• Other Authors: British Antarctic Survey (BAS), Natural Environment Research Council (NERC), LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Institute of Marine Sciences / Institut de Ciències del Mar Barcelona (ICM), Consejo Superior de Investigaciones Cientificas España = Spanish National Research Council Spain (CSIC), Estación Biológica de Doñana (EBD)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: Metals; Seabirds; Carbon-13; Nitrogen-15; Southern Ocean; Wandering Albatross; [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology; [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology; Diomedea exulans; Giant Petrels
• Online Access: https://hal.science/hal-04673914; https://hal.science/hal-04673914/document; https://hal.science/hal-04673914/file/Mills%20et%20al%202024%20AECT.pdf; https://doi.org/10.1007/s00244-024-01067-9

International audience Mercury (Hg) is an environmental contaminant that can negatively impact the health of humans and wildlife. Albatrosses and large petrels show some of the highest levels of Hg contamination among birds, with potential repercussions for reproduction and survival. Here, body feather total Hg (THg) concentrations were determined in breeding adults of five species of albatrosses and large petrels in the foraging guild at South Georgia during the mid-2010s. We tested the effects of species, sex and trophic ecology (inferred from stable isotopes) on THg concentrations and compared our results with published values from past decades. Feather THg concentrations differed significantly among species (range: 1.9–49.6 µg g$^{-1}$ dw), and were highest in wandering albatrosses Diomedea exulans , intermediate in black-browed albatrosses Thalassarche melanophris and northern giant petrels Macronectes halli , and lowest in southern giant petrels M. giganteus and white-chinned petrels Procellaria aequinoctialis . Females were more contaminated than males in all species, potentially due to differences in distributions and diet composition. Across species, THg concentrations were not correlated with feather δ$^{13}$C or δ$^{15}$N values, implying that species effects (e.g., breeding and moulting frequencies) may be more important than trophic effects in explaining feather THg concentrations in this foraging guild. Within species, the only significant correlation was between THg and δ$^{13}$C in wandering albatrosses, which could reflect higher Hg exposure in subtropical waters. Comparisons with THg concentrations from past studies, which reflect contamination from 10 to > 60 years ago, revealed considerable annual variation and some evidence for increases over time for wandering and black-browed albatrosses since before 1950 and from the late 1980s, respectively.