There is a growing concern about the occurrence of bisphenols and benzophenone UV filters in natural ecosystems, while data are limited regarding their actual occurrence in wildlife species, especially in raptors. In this study, concentrations of bisphenol and benzophenone UV filter analogues were determined in liver tissue samples (n = 38) from white-tailed eagles (Haliaeetus albicilla) that were found dead in Smøla (2006–2018), which is a Norwegian municipality that holds one of the densest breeding populations of white-tailed eagles in Europe. Bisphenol AF (BPAF; a fluorinated analogue) was the most ubiquitous contaminant since it was detected in 32 liver samples at concentrations ranging from 1.08 to 6.68 ng/g wet weight (w.w.), followed by bisphenol A (BPA, mean 10.4 ng/g w.w.), benzophenone-1 (BzP-1, mean 3.24 ng/g w.w.), and 4-hydroxybenzophenone (4-OH-BzP, mean 0.62 ng/g w.w.). The concentrations found in livers suggested that white-tailed eagles potentially accumulate bisphenols and benzophenone UV filters, which raises concern, as these plastic and personal care product-related emerging contaminants can show endocrine-disrupting properties. The high detection frequency of the fluorinated BPAF warrants further attention as other fluorinated compounds have proven to be extremely persistent and potentially harmful to wildlife.
Exposure to pesticides is among the most far-reaching threats to raptors, but comprehensive analyses of the timing, spatial trends, species affected, and pesticides involved is lacking. Such knowledge is critical to target conservation action.We collated data on raptor poisoning across 22 European countries encompassing 3,196 incidents and affecting 4,437 poisoned raptors of 37 species between 1996 and 2016. The most commonly poisoned raptors were obligate or facultative scavengers. Together, buzzards, eagles, vultures, and kites accounted for 85% of victims. Common Buzzard (46% of 4,437 raptors), Eurasian Griffon (12%), White-tailed Eagle (9%), Red Kite (7%), and Marsh Harrier (5%) were the most frequent casualties. Nine species and 6% of all casualties have an imperiled global status; 17 are globally declining. Proportionally most obligate scavengers were poisoned in the Mediterranean, most facultative scavengers in North-west, Central and Eastern Europe. Fifty parent compound pesticides and 9 metabolic byproducts were detected. Carbofuran and aldicarb were reported in respectively 38% and 9.7% of poisoned raptors and over half of those after their bans. Of 1,584 raptors poisoned with carbofuran as a single substance, 88% were categorized as facultative scavengers. Poisoning peaked in March-April with 37% of 3,566 poisonings of known date. Most facultative scavengers were killed in those months, while poisoning of obligate scavengers, rodent feeders, and other raptors peaked in August, January and March-July, respectively. The victims of carbofuran and alphachloralose peaked in March-April, and those of aldicarb, parathion, and cholinesterase inhibitors in Jun-Aug.The results demonstrate the widespread extent of raptor exposure to pesticides in Europe, which suggests that there may be implications for reduction of ecosystem services in addition to the affected individuals and population status. A broader range of species than anticipated may be affected by poisoning, including non-scavenging species; monitoring of their poisoning may serve as early warning indicators.
Plastic ingestion in birds is a widespread phenomenon of increasing concern. However, little is known about how exposure to microplastics (MP) affects the health of birds. In other organisms, MP exposure alters lipid metabolism and composition. If also true in birds, this could affect their fitness, especially since birds heavily rely on lipids during migration and egg production. Therefore, the aim of this study was to determine if ingestion of MP (polypropylene and polyethylene collected in nature) in two size ranges, large (3 mm) and small (<125 μm), affects lipid metabolism in the Japanese quail (Coturnix japonica). We orally exposed 55 one-week-old quail during 5 weeks to a total of 600 mg of MP in sizes of either large, small, or a mixture of both. After the exposure period, females fed small MP had higher liver masses compared to control females (on average ± SD, 8.95 ± 2.3 g vs. 6.34 ± 1.0 g), while liver lipid content did not differ in either males or females. The levels of monounsaturated fatty acids were lower in females exposed to large MP and the mixture of both MP sizes compared to controls. Females exposed to MP also had different levels of oleic- (18:1) and palmitoleic (16:1) acid compared to controls dependent on MP size. Exposure to small MP increased levels of palmitic- (16:0) and palmitoleic (16:1) acid in both males and females suggesting a possible increase in de novo fatty acid synthesis. Taken together, our results point towards a sex-specific sensitivity to MP as well as size-dependent MP effects on lipid metabolism in birds. Disruption of fatty acid composition could affect important life stages in female birds, such as migration and egg-laying. We stress the importance of further research focused on determining the mechanisms of action of MP on lipid metabolism.
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.
Toxicity studies on freshwater organisms are commonly conducted by quantifying effects on asexual (clonal) reproductive rates in Daphnia, whereas studies of effects on sexual reproductive rates remain relatively rare. Sexual reproduction in Daphnia and the associated production of resting eggs allows them to survive unfavorable environmental conditions and is thus a crucial component of their long-term fitness. It also maintains genetic diversity within Daphnia populations and hence their potential for adaptation to new environmental conditions. This aspect of their biology may therefore be important to consider in toxicity studies. The aim of this study was to investigate for the first time how mercury (Hg) affects sexual versus asexual reproduction in Daphnia under varying environmental conditions. Specifically, we experimentally tested the interactive effects of Hg and temperature on the population dynamics of Daphnia magna. For this purpose, we exposed D. magna to environmentally relevant concentrations (0 μg/L, 0.5 μg/L and 2 μg/L) of Hg (in the form of mercury (II) chloride) found in stream water and measured biomass growth rate resulting from asexual reproduction, and resting egg production resulting from sexual reproduction. This was done at both 17 °C and 24 °C. Biomass growth rate did not vary across Hg treatments and depended mainly on temperature and population density. Density dependence of biomass growth rate was indeed more pronounced at 24 °C than at 17 °C, as resource limitation from intraspecific competition was further exacerbated by the rise in feeding rates with temperature. Density dependence of resting egg production was unaffected by Hg and temperature, but resting egg production was higher under Hg exposure at low temperature. These findings show that depending on environmental conditions, rates of sexual reproduction in D. magna may respond to metal exposure at lower concentrations than those impacting population growth during the asexual phase.
The chlorinated polyfluoroalkyl ether sulfonate F-53B is used as a mist suppressant in the Chinese electroplating industry. Because of the regulations on perfluorooctanesulfonate (PFOS), its use is expected to increase. Until now, F-53B toxicity data have been scarce and are, to our knowledge, lacking for birds. This study therefore investigated the effects of PFOS and F-53B, separately and as mixtures, on the development of the chicken ( Gallus gallus domesticus). Compounds were injected in ovo, before incubation, at 150 and 1500 ng/g egg. At embryonic day 20, a significantly lower heart rate was observed in all treated groups compared to the control group and hatchlings exposed to the high dose of F-53B had a significantly enlarged liver (8%). Embryonic survival was not affected and no significant effects on hatchling body mass or oxidative stress parameters were found. Our results suggest that these compounds likely have different toxicity thresholds for the investigated endpoints, and/or different modes of action. This study thereby underlines the potential developmental toxicity of PFOS and F-53B at environmentally relevant concentrations. Assessment of PFOS alternatives should therefore continue, preferably prior to their large scale use, as they should be ensured to be less harmful than PFOS itself.
Psychiatric drugs are considered among the emerging contaminants of concern in ecological risk assessment, due to their potential to disrupt homeostasis in aquatic organisms. Bupropion is an antidepressant that acts by selective reuptake inhibition of norepinephrine and dopamine. Little is known about this compound's effects on aquatic organisms, despite being detected in significant concentrations in both water and biota close to waste-water treatment plants and densely populated areas. Dynamic Energy Budget (DEB) models are flexible mechanistic tools that can be applied to understand toxic effects and extrapolate individual responses to higher biological levels and under untested environmental conditions. In this work, we used the stdDEB-TKTD (an application of the DEB theory to ecotoxicology) approach to investigate the possible physiological mode of action of Bupropion on the model organism Daphnia magna. Next, Dynamic Energy Budget Individual-Based Models (DEB-IBM) were used to extrapolate the results to the population level and to predict the combined effects of Bupropion exposure and food availability on the daphnids. Our results revealed an increasing negative effect of this antidepressant on the reproduction and survival of the animals with increasing concentration (0.004, 0.058, 0.58 and 58 μM). At the population level, we found that even the lowest used doses of Bupropion could reduce the population density and its reproductive output. The impacts are predicted to be stronger under limited food conditions.
