Mercury compound distribution and stable isotope composition in the different compartments of seabird eggs: The case of three species breeding in East Greenland.

Autor: Charrier J; Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS - La Rochelle Université, 2 rue Olympe de Gouges, 17000, La Rochelle, France. Electronic address: julie.charrier@univ-lr.fr., Fort J; Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS - La Rochelle Université, 2 rue Olympe de Gouges, 17000, La Rochelle, France., Tessier E; Université de Pau et des Pays de l'Adour, E2S UPPA - CNRS, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et la Matériaux (IPREM), 2 avenue P. Angot, 64053, Pau, France., Asensio O; Université de Pau et des Pays de l'Adour, E2S UPPA - CNRS, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et la Matériaux (IPREM), 2 avenue P. Angot, 64053, Pau, France., Guillou G; Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS - La Rochelle Université, 2 rue Olympe de Gouges, 17000, La Rochelle, France., Grémillet D; Centre d'Ecologie Fonctionnelle & Evolutive (CEFE), UMR 5175 CNRS - Université de Montpellier, 1919 route de Mende, 34293, Montpellier 5, France; FitzPatrick Institute of African Ornithology, Department of Biological Sciences, University of Cape Town, University Ave N, Rondebosch, 7701, Cap Town, South Africa., Marsaudon V; Centre d'Ecologie Fonctionnelle & Evolutive (CEFE), UMR 5175 CNRS - Université de Montpellier, 1919 route de Mende, 34293, Montpellier 5, France., Gentès S; Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS - La Rochelle Université, 2 rue Olympe de Gouges, 17000, La Rochelle, France., Amouroux D; Université de Pau et des Pays de l'Adour, E2S UPPA - CNRS, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et la Matériaux (IPREM), 2 avenue P. Angot, 64053, Pau, France.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2024 Sep; Vol. 363, pp. 142857. Date of Electronic Publication: 2024 Jul 18.
DOI: 10.1016/j.chemosphere.2024.142857
Abstrakt: Mercury (Hg) is a toxic contaminant of global concern and the impact on Arctic ecosystems, particularly in seabirds, is critical due to large-scale Hg transport towards polar regions and its biomagnification in marine trophic systems. While the adverse effects of Hg on reproductive processes in seabirds are established, the understanding of Hg maternal transfer pathways and their control on Hg reproductive toxicity is limited. The combination of Hg compounds speciation (inorganic mercury and monomethylmercury MMHg) and Hg stable isotope composition in the different egg compartments (yolk, albumen, membrane, and shell) before embryo development was investigated to provide information on (i) Hg maternal transfer mechanisms, (ii) influence of egg biochemical composition on Hg organotropism and (iii) proxies of inputs of Hg contamination. Eggs of three seabird species (the common eider, the black-legged kittiwake and the little auk) collected within the same breeding period (summer 2020) in East Greenland were investigated. For all seabirds, albumen and membrane, the most protein-rich compartments, were the most contaminated (from 1.2 to 2.7 μg g -1 for albumen and from 0.3 to 0.7 μg g -1 for membrane). In these two compartments, more than 82% of the total Hg amount was in the form of MMHg. Additionally, mass-dependent fractionation values (δ 202 Hg) were higher in albumen and membrane in the three species. This result was mainly due the organotropism of MMHg as influenced by the biochemical properties and chemical binding affinity of these proteinous compartments. Among the different egg compartments, individuals and species, mass-independent fractionation values were comparable (mean ± sd were 0.99 ± 0.11‰, 0.78 ± 0.11‰, 0.03 ± 0.05‰, 0.04 ± 0.10‰ for Δ 199 Hg, Δ 201 Hg, Δ 200 Hg and Δ 204 Hg, respectively). We conclude that initial MMHg accumulated in the three species originated from Arctic environmental reservoirs exhibiting similar and low photodemethylation extent. This result suggests a unique major source of MMHg in those ecosystems, potentially influenced by sea ice cover.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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