Large-scale monitoring of the exposure to per- and polyfluoroalkyl substances and mercury in the white-tailed eagle (Haliaeetus albicilla):Clinical-chemical effects and the role of diet

Large-scale monitoring of the exposure to per- and polyfluoroalkyl substances and mercury in the white-tailed eagle (Haliaeetus albicilla): clinical-chemical effects and the role of diet I. Eulaers, Aarhus University AU Arctic Research Centre / Department of Bioscience; C. Sonne, Aarhus University AU Arctic Research Centre; P. Ambus, Copenhagen University / Department of Geosciences and Natural Resource management; R. Bossi, Aarhus University / Dept of Environmental Science; R. Dietz, Aarhus University AU Arctic Research Centre / Department of Bioscience, Arctic Research Centre; B. Helander, Swedish Museum of Natural History / Environmental Research & Monitoring; D. Herzke, Norwegian Institute for Air Research / FRAM Centre Tromso; V. Jaspers, Norwegian University of Science & Technology / Biology; V. Johansson, University of Helsinki / Department of Food and Environmental Sciences; T.V. Johnsen, Norwegian Institute for Nature Research NINA; A.K. Krogh, Copenhagen University / Department of Veterinary Clinical and Animal Sciences; O. Krone, Leibniz Institute for Zoo and Wildlife Research; T. Laaksonen, Natural Resources Institute Finland Luke; G. Lepoint, University of Liege; M.E. Løseth, The Norwegian University of Science and Technology / Biology; T. Nygård, Norwegian Institute for Nature Research NINA; C. Stjernegaard, Copenhagen University / Department of Veterinary Clinical and Animal Sciences; J. Sun, University of Antwerp / Department of Biology; J. Søndergaard, Aarhus University AU Arctic Research Centre; J.O. Bustnes, Norwegian Institute for Nature Research NINA; K. Skarphedinsson, Icelandic Institute of Natural History Although bird of prey nestlings are considered valuable sentinels of local environmental contamination, an effort to evaluate their extended suitability for large-scale monitoring was yet to be endeavoured. We have therefore sampled blood and body feathers from white-tailed eagle (Haliaeetus albicilla) nestlings along the Swedish, Finnish, Estonian, German, Danish, Norwegian and Icelandic coasts. This large-scale effort represents the anticipated exposure spectrum and has documented individual traits (age, crop content, foraging habitat and trophic level) that may confound contaminant exposure and effects. Body feathers and blood plasma were analysed for mercury (Hg) and per- and polyfluoroalkyl substances (PFASs), respectively, and a range of blood clinical-chemical parameters (BCCPs) was quantified as well. Finally, stable carbon (foraging habitat) and nitrogen (trophic level) isotopes were analysed in the same body feathers. Our first results confirm elevated exposure to Hg and PFASs in Baltic nestlings and lower exposure in Norway and Iceland. Notable Hg hotspots are located along the Swedish coast and in Finnish Lapland, while only the central Swedish and Finnish Baltic seem to be hotspots for PFASs. We did not observe a significant overall relationship between trophic level and contaminant exposure, which supports the notion of locally elevated environmental background levels. Multiple regression models investigating the simultaneous effects of individual contaminant exposure, age, short-term food ingestion, foraging habitat and trophic level indicate that the latter two stable isotope based dietary descriptors also show relationships with BCCPs indicative for liver, kidney and blood metabolism. Moreover, short-term diet ingestion (recorded crop content) as well as an individual’s age influences these same BCCPs as well as a range of elements. Finally, the models show the potential effect of Hg and PFAS exposure on clinical health as significant relationships where found between the contaminant levels and BCCPs indicative of liver and kidney functioning. We will present a more thorough data analysis of this expanding dataset in order to show the feasibility and importance of large-scale monitoring, which allows evaluating the efficiency of dedicated contaminant Conventions as well as the impact of increasing environmental change.