Do foraging ecology and contaminants interactively predict parenting hormone levels in common eider?

• Published in: General and Comparative Endocrinology
• Main Authors: Smith, Reyd A., Fort, Jérôme, Legagneux, Pierre, Chastel, Olivier, Mallory, Mark, Bustamante, Paco, Danielsen, Jóhannis, Hanssen, Sveinn, Einar Jónsson, Jón, Magnúsdóttir, Ellen, Moe, Børge, Parenteau, Charline, Parkinson, Kyle J.L., Parsons, Glen, Tertitski, Grigori, Love, Oliver
• Other Authors: University of Windsor Ca, LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Département de Biologie and Centre d’Études Nordiques, Université Laval Québec (ULaval), 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), Acadia University, 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 Institute for Nature Research (NINA), University of Iceland Reykjavik, Institute of Geography of RAS, Russian Academy of Sciences Moscow (RAS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: Stable isotopes; Carbon-13; Nitrogen-15; Mercury; Seabird; Arctic; [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology; Climate change; Common Eider; Phytoplankton; Sea ice; Somateria mollissima
• Online Access: https://hal.science/hal-04277214; https://hal.science/hal-04277214/document; https://hal.science/hal-04277214/file/Smith%20et%20al.%202023%20GCE.pdf; https://doi.org/10.1016/j.ygcen.2023.114261

International audience Global climate change is causing abiotic shifts such as higher air and ocean temperatures, and disappearing sea ice in Arctic ecosystems. These changes influence Arctic-breeding seabird foraging ecology by altering prey availability and selection, affecting individual body condition, reproductive success, and exposure to contaminants such as mercury (Hg). The cumulative effects of alterations to foraging ecology and Hg exposure may interactively alter the secretion of key reproductive hormones such as prolactin (PRL), important for parental attachment to eggs and offspring and overall reproductive success. However, more research is needed to investigate the relationships between these potential links. Using data collected from 106 incubating female common eiders (Somateria mollissima) at six Arctic and sub-Arctic colonies, we examined whether the relationship between individual foraging ecology (assessed using δ13C, δ15N) and total Hg (THg) exposure predicted PRL levels. We found a significant, complex interaction between δ13C, δ15N and THg on PRL, suggesting that individuals cumulatively foraging at lower trophic levels, in phytoplankton-dominant environments, and with the highest THg levels had the most constant significant relationship PRL levels. Cumulatively, these three interactive variables resulted in lowered PRL. Overall, results demonstrate the potential downstream and cumulative implications of environmentally induced changes in foraging ecology, in combination with THg exposure, on hormones known to influence reproductive success in seabirds. These findings are notable in the context of continuing environmental and food web changes in Arctic systems, which may make seabird populations more susceptible to ongoing stressors.