Legacy and emerging organohalogenated compounds in feathers of Eurasian eagle-owls (Bubo bubo) in Norway: Spatiotemporal variations and associations with dietary proxies (δ13C and δ15N)

The occurrence of organohalogenated compounds (OHCs) in wildlife has received considerable attention over the last decades. Among the matrices used for OHCs biomonitoring, feathers are particularly useful as they can be collected in a minimally or non-invasive manner. In this study, concentrations of various legacy OHCs –polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs)–, as well as emerging OHCs –per- and polyfluoroalkyl substances (PFAS) and organophosphate ester flame retardants (OPEs)– were determined in feathers of 72 Eurasian eagle-owls (Bubo bubo) from Norway, with the goal of studying spatiotemporal variation using a non-invasive approach. Molted feathers were collected at nest sites from northern, central and southern Norway across four summers (2013–2016). Additionally, two museum-archived feathers from 1979 to 1989 were included. Stable carbon (δ13C) and nitrogen isotopes (δ15N) were used as dietary proxies. In total, 11 PFAS (sum range 8.25–215.90 ng g− 1), 15 PCBs (4.19–430.01 ng g− 1), 6 OCPs (1.48–220.94 ng g− 1), 5 PBDEs (0.21–5.32 ng g− 1) and 3 OPEs (4.49–222.21 ng g− 1) were quantified. While we observed large variation in the values of both stable isotopes, suggesting a diverse diet of the eagle owls, only δ13C seemed to explain variation in PFAS concentrations. Geographic area and year were influential factors for δ15N and δ13C. Considerable spatial variation was observed in PFAS levels, with the southern area showing higher levels compared to northern and central Norway. For the rest of OHCs, we observed between-year variations; sum concentrations of PCBs, OCPs, PBDEs and OPEs reached a maximum in 2015 and 2016. Concentrations from 1979 to 1989 were within the ranges observed between 2013 and 2016. Overall, our data indicate high levels of legacy and emerging OHCs in a top predator in Norway, further highlighting the risk posed by OHCs to wildlife. Keywords: Bird of prey Feathers Isotopes OPE POP PFASpublishedVersio

Levels and Effects of Organohalogens on Corticosterone Hormones in glaucous gulls (Larus hyperboreus) from Kongsfjorden, Svalbard

Long-range atmospheric transport, ocean currents, sea ice and rivers are transporting environmental contaminants into the Arctic. Some of these contaminants can reach high concentrations in the upper trophic levels in the Arctic food web due to processes of bioaccumulation and biomagnification. The present study indicates a sex-specific pattern of levels and effects of selected organohalogenated contaminants (OHCs) in the avian top predator, glaucous gull (Larus hyperboreus), breeding in Kongsfjorden, Svalbard. The aim of this present study was to report levels of OHCs and investigate whether the high levels detected in glaucous gulls can induce stress and thereby influence the stress response (measured by corticosterone concentration). No statistical differences were recorded for stress-induced or baseline corticosterone concentrations for males and female glaucous gulls. In females, a significant negative association was reported for lipid weight in blood plasma and baseline corticosterone. In male glaucous gulls, positive associations were found between levels of twenty-two OHCs and elevated baseline levels of corticosterone; indicating for the first time a “cocktail” effect of specific OHCs in blood plasma associated with high baseline levels of corticosterone in male glaucous gulls. It is suggested that the high levels of OHCs may act as a chronic stressor. The OHCs may interfere with the Arctic seabirds’ ability to respond to environmental stressors, such as climate change and food availability, by disrupting the baseline levels of corticosterone and weakening the feedback mechanisms of the stress axis. Elevated baseline levels may lead to suppression of immune parameters and reduced survival rate. Due to a small sample size assessed in the present study, more research is needed to confirm a possible relationship between the disrupted stress axis and environmental contaminants in the Arctic seabirds.&#8195

Microplastic in sediments and fauna. Offshore and inshore

Samples of sediment and sediment-dwelling organisms were obtained from the Norwegian Continental Shelf and fjords in Southern Norway. These are referred to as offshore areas and inshore areas, respectively. The sediments samples in inshore areas had significantly higher concentrations of microplastics/kg dw. (mean ± SD: 6 132 ± 5 537) than the offshore sediments (mean ± SD: 1 298 ± 788). This is most likely due to closer proximity to anthropogenic influences and sources of plastic emissions, as well as the presence of accumulation areas of marine debris closer to the coastline. The inshore polychaeta samples trended towards higher concentrations of microplastic items/g w.w. (mean ± SD: 1 773 ± 2 598), than the offshore polychaeta (mean ± SD: 485 ± 607), though due to the large statistical variations in individual biota samples, this cannot be considered statistically significant The most frequently detected plastic polymers were polyolefins (PE, PP), chlorinated-polyethers (PVC, chlorinated PE), PS and rubber in both sediments and polychaeta samples, however there was also large variation in polymer composition between corresponding sediment and polychaeta samples. The environmental impact of microplastics on benthic ecosystems are unknown and in need pf further investigation. The anticipated concentrations of microplastics are expected to increase in the foreseeable future, potentially leading to threshold concentrations, so it is of relevance to repeat this monitoring exercise to account for this. In general the study in this survey were comparable with that of a previous survey also looking at microplastic and sediment concentrations in this region, though some of the polychaete concentrations were higher in this study, but nevertheless the biota-to-sediment enrichment factors (11 to 4 864 gd.w/ gw.w.) were on the low range of the previous study (100 to 11 000 11 to 4 864 gd.w/ gw.w.)

Plasma protein fractions in free-living white-tailed eagle (Haliaeetus albicilla) nestlings from Norway

Background Capillary electrophoresis of plasma proteins has shown great potential as a complementary diagnostic tool for avian species. However, reference intervals for plasma proteins are sparse or lacking for several free-living avian species. The current study reports electrophoretic patterns and concentrations of plasma proteins determined for 70 free-living white-tailed eagle (Haliaeetus albicilla) nestlings from two locations in Norway (Steigen and Smøla) in order to establish reference values for this subpopulation using capillary electrophoresis. The nestlings were between 44 and 87 days of age, and the plasma protein concentrations were investigated for age, sex, year (2015 and 2016) and location differences. To our knowledge, this is the first report of reference intervals of plasma proteins analysed by capillary electrophoresis in free-living white-tailed eagle nestlings. Results The plasma protein concentrations (% of total protein, mean ± SE) were determined for prealbumin (13.7%, 4.34 ± 0.15 g/L), albumin (46.7%, 14.81 ± 0.24 g/L), α1-globulin (2.4%, 0.74 ± 0.03 g/L), α2-globulin (11.7%, 3.72 ± 0.06 g/L), β-globulin (15.9%, 5.06 ± 0.08 g/L) and γ-globulin (9.6%, 3.05 ± 0.09 g/L). Significant differences were found between the two locations for prealbumin, α2- and γ-globulins. No significant differences were found between the two sampling years or sexes, and no effect of age was found for any of the plasma proteins. However, prealbumin levels were several folds higher than previously reported from adults of closely related birds of prey species. There were no other studies on capillary electrophoresis of nestling plasma available for comparison. Conclusion Significant differences were found between sampling locations for prealbumin, α2- and γ-globulins, which may indicate differences in inflammatory or infectious status between nestlings at the two locations. Sampling year, sex or age had no significant effect on the plasma protein concentrations. These results provide novel data on plasma protein concentrations by capillary electrophoresis and may be useful for evaluation of health status in free-living white-tailed eagle nestlings.publishedVersio

Microplastic in sediments and fauna. Offshore and inshore

Samples of sediment and sediment-dwelling organisms were obtained from the Norwegian Continental Shelf and fjords in Southern Norway. These are referred to as offshore areas and inshore areas, respectively. The sediments samples in inshore areas had significantly higher concentrations of microplastics/kg dw. (mean ± SD: 6 132 ± 5 537) than the offshore sediments (mean ± SD: 1 298 ± 788). This is most likely due to closer proximity to anthropogenic influences and sources of plastic emissions, as well as the presence of accumulation areas of marine debris closer to the coastline. The inshore polychaeta samples trended towards higher concentrations of microplastic items/g w.w. (mean ± SD: 1 773 ± 2 598), than the offshore polychaeta (mean ± SD: 485 ± 607), though due to the large statistical variations in individual biota samples, this cannot be considered statistically significant The most frequently detected plastic polymers were polyolefins (PE, PP), chlorinated-polyethers (PVC, chlorinated PE), PS and rubber in both sediments and polychaeta samples, however there was also large variation in polymer composition between corresponding sediment and polychaeta samples. The environmental impact of microplastics on benthic ecosystems are unknown and in need pf further investigation. The anticipated concentrations of microplastics are expected to increase in the foreseeable future, potentially leading to threshold concentrations, so it is of relevance to repeat this monitoring exercise to account for this. In general the study in this survey were comparable with that of a previous survey also looking at microplastic and sediment concentrations in this region, though some of the polychaete concentrations were higher in this study, but nevertheless the biota-to-sediment enrichment factors (11 to 4 864 gd.w/ gw.w.) were on the low range of the previous study (100 to 11 000 11 to 4 864 gd.w/ gw.w.)

Plasma protein fractions in free-living white-tailed eagle (Haliaeetus albicilla) nestlings from Norway

Background Capillary electrophoresis of plasma proteins has shown great potential as a complementary diagnostic tool for avian species. However, reference intervals for plasma proteins are sparse or lacking for several free-living avian species. The current study reports electrophoretic patterns and concentrations of plasma proteins determined for 70 free-living white-tailed eagle (Haliaeetus albicilla) nestlings from two locations in Norway (Steigen and Smøla) in order to establish reference values for this subpopulation using capillary electrophoresis. The nestlings were between 44 and 87 days of age, and the plasma protein concentrations were investigated for age, sex, year (2015 and 2016) and location differences. To our knowledge, this is the first report of reference intervals of plasma proteins analysed by capillary electrophoresis in free-living white-tailed eagle nestlings. Results The plasma protein concentrations (% of total protein, mean ± SE) were determined for prealbumin (13.7%, 4.34 ± 0.15 g/L), albumin (46.7%, 14.81 ± 0.24 g/L), α1-globulin (2.4%, 0.74 ± 0.03 g/L), α2-globulin (11.7%, 3.72 ± 0.06 g/L), β-globulin (15.9%, 5.06 ± 0.08 g/L) and γ-globulin (9.6%, 3.05 ± 0.09 g/L). Significant differences were found between the two locations for prealbumin, α2- and γ-globulins. No significant differences were found between the two sampling years or sexes, and no effect of age was found for any of the plasma proteins. However, prealbumin levels were several folds higher than previously reported from adults of closely related birds of prey species. There were no other studies on capillary electrophoresis of nestling plasma available for comparison. Conclusion Significant differences were found between sampling locations for prealbumin, α2- and γ-globulins, which may indicate differences in inflammatory or infectious status between nestlings at the two locations. Sampling year, sex or age had no significant effect on the plasma protein concentrations. These results provide novel data on plasma protein concentrations by capillary electrophoresis and may be useful for evaluation of health status in free-living white-tailed eagle nestlings

No evidence of avian influenza antibodies in two species of raptor nestlings inhabiting Norway

Background: Since 2016, incursions of highly pathogenic avian influenza virus (HPAIV) H5N8 clade 2.3.4.4b have caused unprecedented clinical signs and mortality in white-tailed eagles (WTE; Haliaeetus albicilla) across Europe and have been found to be infecting other raptor species, such as the northern goshawk (NG; Accipiter gentilis). Before this study, no screening of Norwegian raptors had been undertaken. Results: Plasma samples from 43 white-tailed eagle and 29 northern goshawk nestlings, from several locations across Norway were screened for antibodies to avian influenza viruses. No antibodies, and thus, no evidence of AIV exposure, were found in these Norwegian raptors. No clinical signs of AIV were observed in 43 white tailed eagles and 29 northern goshawks. Conclusions: There are currently no indications that white-tailed eagles and northern goshawks inhabiting Norway are threatened by the recent HPAIV outbreaks in other areas of Europe. Ongoing monitoring should, however, be maintained to detect potential future outbreaks

No evidence of avian influenza antibodies in two species of raptor nestlings inhabiting Norway

Background: Since 2016, incursions of highly pathogenic avian influenza virus (HPAIV) H5N8 clade 2.3.4.4b have caused unprecedented clinical signs and mortality in white-tailed eagles (WTE; Haliaeetus albicilla) across Europe and have been found to be infecting other raptor species, such as the northern goshawk (NG; Accipiter gentilis). Before this study, no screening of Norwegian raptors had been undertaken. Results: Plasma samples from 43 white-tailed eagle and 29 northern goshawk nestlings, from several locations across Norway were screened for antibodies to avian influenza viruses. No antibodies, and thus, no evidence of AIV exposure, were found in these Norwegian raptors. No clinical signs of AIV were observed in 43 white tailed eagles and 29 northern goshawks. Conclusions: There are currently no indications that white-tailed eagles and northern goshawks inhabiting Norway are threatened by the recent HPAIV outbreaks in other areas of Europe. Ongoing monitoring should, however, be maintained to detect potential future outbreaks

The influence of natural variation and organohalogenated contaminants on physiological parameters in white-tailed eagle (Haliaeetus albicilla) nestlings from Norway

Environmental exposure to organohalogenated contaminants (OHCs), even at low concentrations, may cause detrimental effects on the development and health of wild birds. The present study investigated if environmental exposure to OHCs may influence the variation of multiple physiological parameters in Norwegian white-tailed eagle (Haliaeetus albicilla) nestlings. Plasma and feather samples were obtained from 70 nestlings at two archipelagos in Norway in 2015 and 2016. The selected physiological parameters were plasma concentrations of thyroid hormones (thyroxine, T4 and triiodothyronine, T3), plasma proteins (prealbumin, albumin, α1-, α2-, β- and γ-globulins) and selected blood clinical chemical parameters (BCCPs) associated with liver and kidney functioning. Feather concentrations of corticosterone (CORTf) were also included to investigate the overall stress level of the nestlings. Concentrations of all studied physiological parameters were within the ranges of those found in other species of free-living birds of prey nestlings and indicated that the white-tailed eagle nestlings were in good health. Our statistical models indicated that perfluoroalkyl substances (PFASs) and legacy OHCs, such as polychlorinated biphenyls, organochlorinated pesticides and polybrominated diphenyl ethers, influenced only a minor fraction of the variation of plasma thyroid hormones, prealbumin and CORTf (5–15%), and partly explained the selected BCCPs (<26%). Most of the variation in each studied physiological parameter was explained by variation between nests, which is most likely due to natural physiological variation of nestlings in these nests. This indicates the importance of accounting for between nest variation in future studies. In the present nestlings, OHC concentrations were relatively low and seem to have played a secondary role compared to natural variation concerning the variation of physiological parameters. However, our study also indicates a potential for OHC-induced effects on thyroid hormones, CORTf, prealbumin and BCCPs, which could be of concern in birds exposed to higher OHC concentrations than the present white-tailed eagle nestlings