Mercury biomagnification in an Antarctic food web of Antarctic Peninsula

• Published in: Environmental Pollution
• Main Authors: Matias, Ricardo, Guímaro, Hugo, Bustamante, Paco, Seco, José, Chipev, Nesho, Fragão, Joana, Tavares, Sílvia, Ceia, Filipe, Pereira, Maria, Barbosa, Andrés, Xavier, José
• Other Authors: Marine and Environmental Sciences Centre (MARE UC), Universidade de Coimbra Coimbra, LIttoral ENvironnement et Sociétés - UMR 7266 (LIENSs), Institut national des sciences de l'Univers (INSU - CNRS)-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.), Centre for Environmental and Marine Studies Aveiro (CESAM), Universidade de Aveiro, School of Biology University of St Andrews, University of St Andrews Scotland, Central Laboratory of General Ecology, Bulgarian Academy of Sciences (BAS), Centre for Functional ecology, University of Coimbra Portugal (UC), Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales Madrid (MNCN), Consejo Superior de Investigaciones Científicas Madrid (CSIC)-Consejo Superior de Investigaciones Científicas Madrid (CSIC), British Antarctic Survey (BAS), Natural Environment Research Council (NERC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: Trophodynamics; Trace metals; Stable Isotopes; Livingston Island; Trophic Magnification; [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Antarctic; Southern Ocean; The Antarctic; Antarctic Peninsula; Giganteus; Antarc*; Antarctic Krill; antarcticus; Elephant Seals; Euphausia superba; Giant Petrels; Macronectes giganteus; Mirounga leonina; Pygoscelis papua; Southern Elephant Seals; Stercorarius antarcticus
• Online Access: https://hal.science/hal-03768790; https://hal.science/hal-03768790/document; https://hal.science/hal-03768790/file/Matias%20et%20al.%202022%20ENPO.pdf; https://doi.org/10.1016/j.envpol.2022.119199

International audience Under the climate change context, warming Southern Ocean waters may allow mercury (Hg) to become more bioavailable to the Antarctic marine food web (i.e., ice-stored Hg release and higher methylation rates by microorganisms), whose biomagnification processes are poorly documented. Biomagnification of Hg in the food web of the Antarctic Peninsula, one of world's fastest warming regions, was examined using carbon (δ 13 C) and nitrogen (δ 15 N) stable isotope ratios for estimating feeding habitat and trophic levels, respectively. The stable isotope signatures and total Hg (T-Hg) concentrations were measured in Antarctic krill Euphausia superba and several Antarctic predator species, including seabirds (gentoo penguins Pygoscelis papua, chinstrap penguins Pygoscelis antarcticus, brown skuas Stercorarius antarcticus, kelp gulls Larus dominicanus, southern giant petrels Macronectes giganteus) and marine mammals (southern elephant seals Mirounga leonina). Significant differences in δ 13 C values among species were noted with a great overlap between seabird species and M. leonina. As expected, significant differences in δ 15 N values among species were found due to interspecific variations in diet related to their trophic position within the marine food web. The lowest Hg concentrations were registered in E. superba (0.007 ± 0.008 μg•g-1) and the highest values in M. giganteus (12.090 ± 14.177 μg•g-1). Additionally, a significant positive relationship was found between Hg concentrations and trophic levels (reflected by logarithm-transformed T-Hg values), biomagnifying nearly 2 times its concentrations each level. Our results support that trophic interactions are the major pathways for Hg biomagnification in Southern Ocean ecosystems and warn about an increase in the effects of Hg on long-lived (and high trophic level) Antarctic predators under climate change in the future.