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

• Published in: Chemosphere
• Main Authors: Charrier, Julie, Fort, Jérôme, Tessier, Emmanuel, Asensio, Océane, Guillou, Gaël, Grémillet, David, Marsaudon, Valère, Gentès, Sophie, Amouroux, David
• Other Authors: LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry - Montpellier 3 (UPVM)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud )-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Montpellier (UM), ANR-20-CE34-0006,ARCTIC-STRESSORS,Effets combinés des stresseurs environnementaux multiples sur les oiseaux marins Arctiques(2020)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: Arctic; Egg development; Maternal transfer; Mercury sources; Monomethylmercury; Stable isotopes; [CHIM.MATE]Chemical Sciences/Material chemistry; [CHIM.ANAL]Chemical Sciences/Analytical chemistry; [CHIM.POLY]Chemical Sciences/Polymers; [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry; Black-legged Kittiwake; Common Eider; East Greenland; Greenland; little auk
• Online Access: https://univ-pau.hal.science/hal-04672797; https://univ-pau.hal.science/hal-04672797/document; https://univ-pau.hal.science/hal-04672797/file/1-s2.0-S004565352401751X-main.pdf; https://doi.org/10.1016/j.chemosphere.2024.142857

International audience 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 (δ202Hg) 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 Δ199Hg, Δ201Hg, Δ200Hg and Δ204Hg, 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 ...