| Summary: | Abstract: The release of a large number of persistent contaminants by human activities remains of paramount environmental concern. Long-term and large-scale spatiotemporal trend monitoring is crucial for the adequate assessment of the effectiveness of legal regulations, as well as for identifying hotspots of continued or emerging contamination. The present thesis aimed to reconstruct spatiotemporal trends of three major groups of persistent contaminants: mercury (Hg), legacy organochlorines (OCs), and perfluoroalkyl substances (PFAS). We sampled archived body feathers of an established sentinel species – the white-tailed eagle (Haliaeetus albicilla) from the West Greenland coast (n = 124; 1884 - 2013), the Norwegian coast (n = 102; 1866 - 2015), and the central Swedish Baltic coast (n = 152; 1967-2011). We observed generally highest concentrations of Hg, OCs, and PFASs in Swedish feathers, except for chlordanes, hexachlorobenzene and perfluorooctanesulfonamide (FOSA), which were elevated in Greenland feathers. These results likely indicate the relative difference between local contaminant influx in Sweden versus the long-range transport to Greenland. Overall decreasing temporal trends of Hg and OCs were observed across all three studied subpopulations, except for Hg and PCBs in Greenland. Such declining trends suggest that the measures taken to reduce Hg and OC emissions have been generally effective. Comparably, decreasing trends of perfluorooctane sulfonate (PFOS) and FOSA in both Greenland and Norwegian feathers aligned well with the phase-out of their precursor compound. However, PFOS levels in the Swedish feathers remained elevated and are not decreasing, suggesting prolonged contamination in the Baltic Sea region. Perfluoroalkyl carboxylates (PFCAs) by contrast are still being used, and were consequently observed to continuously increase in all three subpopulations. In addition, feather corticosterone remained constant over time in the Swedish feathers and therefore, may not be a suitable physiological ...
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