A U-Turn for Mercury Concentrations over 20 Years: How Do Environmental Conditions Affect Exposure in Arctic Seabirds?

• Published in: Environmental Science & Technology
• Main Authors: Tartu, Sabrina, Blévin, Pierre, Bustamante, Paco, Angelier, Frédéric, Bech, Claus, Bustnes, Jan Ove, Chierici, Melissa, Fransson, Agneta, Gabrielsen, Geir, Goutte, Aurélie, Moe, Børge, Sauser, Christophe, Sire, Julien, Barbraud, Christophe, Chastel, Olivier
• Other Authors: 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), 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.), Norwegian University of Science and Technology (NTNU), Fram Centre, Norwegian Institute for Nature Research (NINA) Norway, Norwegian Institute for Nature Research (NINA), FRAM Centre, Norwegian Polar Institute, Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols (METIS), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE34-0005,ILETOP,Impact des polluants historiques et émergents sur les prédateurs supérieurs marins de l'Arctique(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: global change; trace elements; temporal trends; Rissa tridactyla; chlorophyll a; sea-ice extent; feeding ecology; [SDE]Environmental Sciences; Arctic; Norway; Svalbard; rissa tridactyla; Sea ice
• Online Access: https://hal.science/hal-03572425; https://doi.org/10.1021/acs.est.1c07633

International audience Mercury (Hg) is highly toxic in its methylated form (MeHg), and global change is likely to modify its bioavailability in the environment. However, it is unclear how top predators will be impacted. We studied blood Hg concentrations of chick-rearing black-legged kittiwakes Rissa tridactyla (2000-2019) in Svalbard (Norway). From 2000 to 2019, Hg concentrations followed a U-shaped trend. The trophic level, inferred from nitrogen stable isotopes, and chlorophyll a (Chl a) concentrations better predicted Hg concentrations, with positive and U-shaped associations, respectively. As strong indicators of primary productivity, Chl a concentrations can influence production of upper trophic levels and, thus, fish community assemblage. In the early 2000s, the high Hg concentrations were likely related to a higher proportion of Arctic prey in kittiwake's diet. The gradual input of Atlantic prey in kittiwake diet could have resulted in a decrease in Hg concentrations until 2013. Then, a new shift in the prey community, added to the shrinking sea ice-associated release of MeHg in the ocean, could explain the increasing trend of Hg observed since 2014. The present monitoring provides critical insights about the exposure of a toxic contaminant in Arctic wildlife, and the reported increase since 2014 raises concern for Arctic seabirds.