Endocrine disrupting bisphenol A, 4-tert-octylphenol and 4-nonylphenol in gonads of long-tailed ducks Clangula hyemalis wintering in the southern Baltic

This paper focuses on determining the concentrations of phenol derivatives in the gonads of seabirds and examining the potential factors (age, sex and region) affecting the degree of their bioaccumulation. The study involved assays of bisphenol A (BPA), 4-tert-octylphenol (4-t-OP) and 4-nonylphenol (4-NP) in the gonads of long-tailed ducks taken as bycatch from the Southern Baltic region in 2015-2016. Among phenol derivatives, 4-NP was found to reach the highest concentrations in the gonads of long-tailed ducks, and its concentrations were in the range of <0.1-717.5 ng g-1 dw. The concentrations of BPA and 4-t-OP were similar and amounted to <0.4-181.6 ng g-1 dw and <0.1-192.4 ng g-1 dw respectively. The concentration levels of phenol derivatives in the birds' gonads were similar to the levels which had been observed to have negative endocrine effects in other authors studies. This shows that the studied xenoestrogens can interfere with the reproduction and development of birds. Moreover, adult long-tailed ducks had higher concentrations of phenol derivatives compared to immature ones, possibly resulting from long-term bioaccumulation, as well as from diverse pollution in their respective habitats. Particularly in the case of 4-NP, the median concentrations in gonads of adult birds were 2-fold higher than in immature ones. In turn, among adult long-tailed ducks, phenol derivatives were characterized by higher concentrations in males than in females, with almost 3 times and approx. 3.5 times higher median concentrations of BPA and 4-t-OP, respectively. Lower concentrations of phenol derivatives in female gonads may result from the additional elimination of pollutants from their bodies through the transfer of pollutants from mother to egg. The results show the need for further research on phenol derivatives in the gonads of birds, focusing on their impact on the reproductive system and early development.

Elimination of endocrine disrupting phenolic compounds via feathers and claws in seabirds moulting in the Baltic and Russian Arctic

This paper investigates the effectiveness of phenol derivatives removal from bird organisms via claws and remiges, and performs a preliminary assessment of the usefulness of these epidermal products for environmental biomonitoring and estimating bird exposure levels. Concentrations of bisphenol A (BPA) and alkylphenols: 4-tert-octylphenol (4-t-OP) and 4-nonylphenol (4-NP) were determined in claws and remiges of long-tailed ducks Clangula hyemalis and razorbills Alca torda, obtained during a by-catch in the winter period (2014-2016) in the Southern Baltic region. For razorbills, the Baltic is a permanent habitat, while long-tailed ducks are migratory and stay in the Southern Baltic only during the non-breeding season. Their remiges are replaced in the Arctic seas of Siberia. The removal of phenol derivatives, depending on the compound and the epidermal product, ranges from 12 % to 34 %. Among these compounds, in both bird species, the highest degree of elimination was observed for 4-NP in remiges (<0.1-656.0 ng^.g^-1 dw) as well as claws (<0.1-338.6 ng^.g^-1 dw). On the other hand, the least removed compound in both the long-tailed duck and the razorbill was 4-t-OP. The removal of phenol derivatives from claws in both bird species was at the same level. However, 4-NP concentrations were found to be statistically significantly higher in razorbill remiges compared to those of the long-tailed duck (p < 0.05). Comparison of concentrations in the remiges of the long-tailed duck and the razorbill, moulted in two different environments with different levels of pollution and distances from sources, indicated that the Baltic Sea is approximately 3 times more polluted with 4-NP than the marine areas of the Russian Arctic. This demonstrates the potential for the use of 4-NP and remiges as indicators of environmental pollution with phenol derivatives.

Occurrence and tissue distribution of alkylphenols (APs) in selected waterbirds from the Southern Baltic

The aim of the present study was to determine the concentrations of nonylphenols (NPs) and 4-t-octylphenol (4tOP) in the muscles, liver, and kidneys of selected waterbird species. Three species with different feeding habits were selected, i.e., greater scaup (Aythya marila), great crested grebe (Podiceps cristatus), and great cormorant (Phalacrocorax carbo) to investigate the potential effects of diet on the level of contaminants tested. The determination and quantification of analytes were performed using gas chromatography with mass spectrometric detection (GC-MS). The highest NP concentrations were noted in the kidneys of greater scaups and great crested grebes (208.3 and 160.8 μg kg^-1 ww, resp.), which were six to fourteen-fold higher than those in the muscles (15.0 and 25.6 μg kg^-1 ww, resp.) and livers (22.9 and 13.8 μg kg^-1 ww, resp.) of these species. In greater scaups, the mean concentration of NPs in the livers was lower than in the muscles, while in great crested grebes, it was the opposite and higher concentrations were noted in the muscles. The mean concentrations of NPs in the muscles and livers of great cormorants were at similarly low levels (12.5 and 9.7 μg kg^-1 ww, resp.). The concentrations of 4tOP in all samples were low, ranging from <LOQ to 0.29 μg kg^-1 ww. The results of our study indicated that sex and diet did not affect the NP tissue concentrations in different waterbird species, but the phenological period (migration vs breeding) might influence the contamination levels in the kidneys.

Distribution paths of endocrine disrupting phenolic compounds in waterbirds (Mergus merganser, Alca torda, Clangula hyemalis) from the Southern Baltic

This study determined the distribution of phenol derivatives in the organisms of waterbirds and the factors influencing their bioaccumulation and affinity to specific tissues. Concentrations of bisphenol A (BPA), 4-tert-octylphenol (4-t-OP) and 4-nonylphenol (4-NP) were determined in the brains, subcutaneous fat, kidneys, livers and pectoral muscles of goosanders Mergus merganser (GO), long-tailed ducks Clangula hyemalis (LO) and razorbills Alca torda (RA). The birds came from the winter by-catch (2014-2016) in the Southern Baltic. Different distribution routes of individual phenol derivatives in the birds were established, most likely due to their ability to bind to proteins and/or dissolve in lipids. BPA and 4-NP accumulated most in the muscles (BPA <2.0-223.0 ng^.g^-1 dw, 4-NP 26.0-476.4 ng^.g^-1 dw), livers (BPA <2.0-318.2 ng^.g^-1 dw, 4-NP 60.7-525.8 ng^.g^-1 dw), and kidneys (BPA <2.0-836.1 ng^.g^-1 dw, 4-NP 29.3-469.2 ng^.g^-1 dw), while 4-t-OP was stored mainly in the brains (2.6-341.1 ng^.g^-1 dw), subcutaneous fat (0.7-173.7 ng^.g^-1 dw) and livers (<0.5-698.8 ng^.g^-1 dw). The liver was the only organ where all compounds showed a positive correlation with each other and alkylphenols were also positively correlated with each other in tissues with high fat content (brains and subcutaneous fat), and negatively in muscles. Despite the different trophic levels of birds, the concentrations of phenol derivatives in the tissues between individual species in most cases did not differ significantly. However, between the species on a similar trophic level, the higher biomagnification coefficient was calculated for LO feeding on benthos, and the lower for RA feeding on pelagic fish (p < 0.05). The good condition of birds, resulting in large intestinal fat stores, promoted on the one hand the penetration of phenol derivatives from the intestine to the liver, and on the other hand their accumulation in subcutaneous fat, thereby protecting the brain.

Sex and age-specific differences in wing pointedness and wing length in blackcaps Sylvia atricapilla migrating through the southern Baltic coast

The blackcap Sylvia atricapilla shows a complex migratory pattern and is a suitable species for the studies of morphological migratory syndrome, including adaptations of wing shape to different migratory performance. Obligate migrants of this species that breed in northern, central, and Eastern Europe differ by migration distance and some cover shorter distance to the wintering grounds in the southern part of Europe/North Africa or the British Isles, although others migrate to sub-Saharan Africa. Based on ˃40 years of ringing data on blackcaps captured during autumn migration in the Southern Baltic region, we studied age- and sex-related correlations in wing pointedness and wing length of obligate blackcap migrants to understand the differences in migratory behavior of this species. Even though the recoveries of blackcaps were scarce, we reported some evidence that individuals which differ in migration distance differed also in wing length. We found that wing pointedness significantly increased with an increasing wing length of migrating birds, and adults had longer and more pointed wings than juvenile birds. This indicates stronger antipredator adaptation in juvenile blackcaps than selection on flight efficiency, which is particularly important during migration. Moreover, we documented more pronounced differences in wing length between adult and juvenile males and females. Such differences in wing length may enhance a faster speed of adult male blackcaps along the spring migration route and may be adaptive when taking into account climatic effects, which favor earlier arrival from migration to the breeding grounds.

Mitogenomes of Accipitriformes and Cathartiformes Were Subjected to Ancestral and Recent Duplications Followed by Gradual Degeneration

The rearrangement of 37 genes with one control region, firstly identified in Gallus gallus mitogenome, is believed to be ancestral for all Aves. However, mitogenomic sequences obtained in recent years revealed that many avian mitogenomes contain duplicated regions that were omitted in previous genomic versions. Their evolution and mechanism of duplication are still poorly understood. The order of Accipitriformes is especially interesting in this context because its representatives contain a duplicated control region in various stages of degeneration. Therefore, we applied an appropriate PCR strategy to look for duplications within the mitogenomes of the early diverged species Sagittarius serpentarius and Cathartiformes, which is a sister order to Accipitriformes. The analyses revealed the same duplicated gene order in all examined taxa and the common ancestor of these groups. The duplicated regions were subjected to gradual degeneration and homogenization during concerted evolution. The latter process occurred recently in the species of Cathartiformes as well as in the early diverged lineages of Accipitriformes, that is, Sagittarius serpentarius and Pandion haliaetus. However, in other lineages, that is, Pernis ptilorhynchus, as well as representatives of Aegypiinae, Aquilinae, and five related subfamilies of Accipitriformes (Accipitrinae, Circinae, Buteoninae, Haliaeetinae, and Milvinae), the duplications were evolving independently for at least 14–47 Myr. Different portions of control regions in Cathartiformes showed conflicting phylogenetic signals indicating that some sections of these regions were homogenized at a frequency higher than the rate of speciation, whereas others have still evolved separately.

Gastrointestinal and respiratory exposure of water birds to endocrine disrupting phenolic compounds

Aquatic birds found at the top of the trophic chain are exposed to xenobiotics present both in food and inhaled air. The aim of this study was to indicate and assess the routes and levels of exposure of aquatic birds to bisphenol A (BPA), 4-tert-octylphenol (4-t-OP) and 4-nonylphenol (4-NP). The birds constituting the study material (Clangula hyemalis, Alca torda, Mergus merganser) originated from by-catches (winter 2014-2016) in the Southern Baltic. The studies show that the exposure of birds to phenol derivatives is determined by the specifics of a compound, the habitat area, trophic level and food consumed. BPA was characterized by the highest intestinal concentrations in all birds (6.6-1176.2 ng^.g^-1 dw). Higher concentrations of 4-t-OP were determined in the lungs of birds from the eastern part of the Southern Baltic (9.1-135.7 ng^.g^-1 dw) and in the intestines of birds from the western part (<0.5-191.4 ng^.g^-1 dw). In the case of 4-NP, higher concentrations were found in the intestines of carnivorous species (64.9-524.5 ng^.g^-1 dw), and the lungs of benthos-eating species (39.4-399.7 ng^.g^-1 dw). The intestines that were most burdened with 4-NP were those of birds from the highest trophic level. Correlations between the concentrations of phenol derivatives in the blood and the intestines and lungs indicated that birds are exposed to the penetration of phenol derivatives through the digestive and respiratory tracts. BPA and 4-NP were characterized by the highest concentrations in the intestines and lungs, whereas 4-t-OP in blood (3.2-39.2 ng^.cm^-3), which may indicate the largest endocrine potential of this compound in birds. Significant differences in phenol derivatives concentrations in the intestines and lungs of birds from the western and eastern part of the Southern Baltic, shows that these tissues can be useful for assessing the contamination of the environment with EDCs.

Estimation of native and alkylated polycyclic aromatic hydrocarbons (PAHs) in seabirds from the south coast of the Baltic Sea

Native and alkylated polycyclic aromatic hydrocarbons (PAHs) were examined in the muscle, liver, kidneys, and lungs of greater scaup (Aythya marila) and great crested grebe (Podiceps cristatus). Both species showed differences in distribution and profiles among the tissues. The highest ƩPAH concentrations were in the scaup lungs and the grebe kidneys (20 and 19 ng g^-1 wet weight, respectively). Alkylated derivatives were in the range of 61 to 77% of ΣPAHs in both species. Differences in PAH profiles between birds, analyzed by PCA, were probably results of metabolic capability, not various diet. In comparison to available data from other regions of the world, PAH levels in investigated species are relatively low and do not pose a threat to birds themselves.