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The biliary trematode Pseudamphistomum truncatum parasitizes a wide range of fish-eating mammals, including humans. Here we report the emergence of this parasite in grey seals (Halichoerus grypus) in the Baltic Sea. One hundred eighty-three of 1 554 grey seals (11.9%) examined from 2002–2013 had detectable hepatobiliary trematode infection. Parasite identification was confirmed as P. truncatum by sequencing the ITS2 region of a pool of five to 10 trematodes from each of ten seals collected off the coast of seven different Swedish counties. The proportion of seals parasitized by P. truncatum increased significantly over time and with increasing age of seals. Males were 3.1 times more likely to be parasitized than females and animals killed in fishery interactions were less likely to be parasitized than animals found dead or hunted. There was no significant difference in parasitism of seals examined from the Gulf of Bothnia versus those examined from the Baltic Proper. Although the majority of infections were mild, P. truncatum can cause severe hepatobiliary disease and resulted in liver failure in at least one seal. Because cyprinid fish are the second intermediate host for opisthorchiid trematodes, diets of grey seals from the Baltic Sea were analysed regarding presence of cyprinids. The proportion of gastrointestinal tracts containing cyprinid remains was ten times higher in seals examined from 2008 to 2013 (12.2%) than those examined from 2002 to 2007 (1.2%) and coincided with a general increase of trematode parasitism in the host population. The emergence and relatively common occurrence of P. truncatum in grey seals signals the presence of this parasite in the Baltic Sea ecosystem and demonstrates how aquatic mammals can serve as excellent sentinels of marine ecosystem change. Investigation of drivers behind P. truncatum emergence and infection risk for other mammals, including humans, is highly warranted. [ABSTRACT FROM AUTHOR]

The present study examined the presence of perfluoroalkyl acids (PFAAs) and selected precursors in the Baltic Sea abiotic environment and guillemot food web, and investigated the relative importance of precursors in food web accumulation of PFAAs. Sediment, water, zooplankton, herring, sprat, and guillemot eggs were analyzed for perfluoroalkane sulfonic acids (PFSAs; C4,6,8,10) and perfluoroalkyl carboxylic acids (PFCAs; C6-15) along with six perfluoro-octane sulfonic acid (PFOS) precursors and 11 polyfluoroalkyl phosphoric acid diesters (diPAPs). FOSA, FOSAA and its methyl and ethyl derivatives (Me- and EtFOSAA), and 6:2/6:2 diPAP were detected in sediment and water. While FOSA and the three FOSAAs were detected in all biota, a total of nine diPAPs were only detected in zooplankton. Concentrations of PFOS precursors and diPAPs exceeded PFOS and PFCA concentrations, respectively, in zooplankton, but not in fish and guillemot eggs. Although PFOS precursors were present at all trophic levels, they appear to play a minor role in food web accumulation of PFOS based on PFOS precursor/PFOS ratios and PFOS and FOSA isomer patterns. The PFCA pattern in fish could not be explained by the intake pattern based on PFCAs and analyzed precursors, that is, diPAPs. Exposure to additional precursors might therefore be a dominant exposure pathway compared to direct PFCA exposure for fish. [ABSTRACT FROM AUTHOR]

In the eutrophicated Baltic Sea, several naturally produced hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been found in marine biota. OH-PBDEs are toxic to adult and developing zebrafish and shown to be potent disruptors of oxidative phosphorylation (OXPHOS). Disturbed OXPHOS can result in altered energy metabolism and weight loss. In herring, the concentration of OH-PBDEs (i.e. 2′-OH-BDE68 and 6-OH-BDE47) has increased during the period 1980–2010 in the Baltic Proper. Over the same time period, the condition and fat content in Baltic herring have decreased. Given the toxicity and increasing trends of OH-PBDEs in Baltic herring it is important to further assess the exposure to OH-PBDEs in Baltic herring. In this study, the concentrations of OH-PBDEs and related brominated substances i.e. polybrominated phenols (PBPs), polybrominated anisoles (PBAs), methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and polybrominated diphenyl ethers (PBDEs) were measured in herring sampled in the northern Baltic Proper (Askö, n = 12) and the southern Bothnian Sea (Ängskärsklubb, n = 12). The geometric mean (GM) concentrations (ng/g l.w.) at Askö and Ängskärsklubb were; Σ 2 PBPs: 4.3 and 9.6, Σ 2 PBAs: 34 and 20, Σ 6 OH-PBDEs: 9.4 and 10, Σ 7 MeO-PBDEs: 42 and 150, Σ 6 PBDEs: 54 and 27, respectively. 6-OH-BDE47 dominated the OH-PBDE profile and comprised 87% (Askö) and 91% (Ängskärsklubb) of the ΣOH-PBDEs. At Ängskärsklubb the mean concentration of ΣMeO-PBDEs (150 ng/g l.w.) was 15 times higher than ΣOH-PBDEs. As other fish species are known to metabolically transform MeO-PBDEs to OH-PBDEs, high levels of MeO-PBDEs can be of concern as a precursor for more toxic OH-PBDEs in herring and their roe. [ABSTRACT FROM AUTHOR]

In the 1960s, the Baltic Sea was severely polluted by organic contaminants such as PCBs, HCHs, HCB, and DDTs. Elevated concentrations caused severe adverse effects in Baltic biota. Since then, these substances have been monitored temporally and spatially in Baltic biota, primarily in herring ( Clupea harengus) and in guillemot ( Uria aalge) egg, but also in cod ( Gadus morhua), perch ( Perca fluviatilis), eelpout ( Zoarces viviparous), and blue mussel ( Mytilus edulis). These chemicals were banned in Sweden in the late 1970s/early 1980s. Since the start of monitoring, overall significant decreases of about 70-90 % have been observed. However, concentrations are still higher in the Baltic Sea than in, for example, the North Sea. CB-118 and DDE exceed the suggested target concentrations (24 µg kg lipid weight and 5 µg kg wet weight, respectively) at certain sites in some of the monitored species, showing that concentrations may still be too high to protect the most sensitive organisms. [ABSTRACT FROM AUTHOR]

Abstract: Laboratory studies suggest that the cyclic volatile methylsiloxanes (cVMS) octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) will persist in the aquatic environment and bioaccumulate in fish. Here these cVMS were measured in herring collected in the Swedish waters of the Baltic Sea and the North Sea and in grey seals from the Baltic Proper. D4, D5, and D6 were present in herring muscle at concentrations around 10, 200, and 40ngg−1 lipid weight, respectively. The ratio of these concentrations was similar to the relative magnitude of estimated emissions to water, suggesting that the efficiency of overall transfer through the environment and food web was similar (within a factor 2–3) for the three chemicals. The concentrations of D5 and D6 were similar in herring caught in the highly populated Baltic Proper and in the less populated Bothnian Sea and Bothnian Bay. The D4 concentrations were lower at the most remote northern station, suggesting that D4 is less persistent than D5 and D6. Herring from the North Sea had lower levels of all three chemicals. The concentrations of D4, D5 and D6 in grey seal blubber were lower than the lipid normalized concentrations in herring, indicating that they do not biomagnify in grey seals. [Copyright &y& Elsevier]

Naturally occurring hydroxylated polybrominated diphenyl ethers (OH-PBDEs), their methoxylated counterparts (MeO-PBDEs), and polybrominated dibenzo- p-dioxins (PBDDs), together with their potential precursors polybrominated phenols (PBPs) and polybrominated anisoles (PBAs), were analyzed in blue mussels (Mytilus edulis) gathered along the east coast (bordering the Baltic Sea) and west coast of Sweden (bordering the North Sea). Brown algae (Dictyosiphon foenicolaceus) and cyanobacteria (Nodularia spumigena) from the Baltic Sea, considered to be among the primary producers of these compounds, were also analyzed for comparison. The samples were liquid–liquid extracted, separated into a phenolic and a neutral fraction, and subsequently analyzed by gas chromatography–mass spectrometry (GS-MS). The levels of OH-PBDEs, MeO-PBDEs and PBDDs were significantly higher in Baltic Sea mussels than in those from the west coast, whereas the levels of PBPs and PBAs displayed the opposite pattern. The blue mussels from the Baltic Sea contained high levels of all analyzed substances, much higher than the levels of, e.g., polybrominated diphenyl ethers. In addition, the GC-MS chromatogram of the phenolic fraction of the west coast samples was dominated by four unknown peak clusters, three of which were tentatively identified as dihydroxy-PBDEs and the other as a hydroxylated-methyl-tetraBDE. Clearly, all of the compounds analyzed are natural products, both in the Baltic and the North Sea. However, the geographical differences in composition may indicate different origin, e.g., due to differences in the occurrence and/or abundance of various algae species along these two coasts or possibly a more extensive dilution on the west coast. [ABSTRACT FROM AUTHOR]

Persistent organic pollutants (POPs) are readily detected in biological samples at remote sites in the Arctic and sub-Arctic due to long-range transport from source areas. The aim of this study was to investigate the presence of POPs, polybrominated contaminants and their metabolites in guillemot (Uria aalge) eggs from Iceland, the Faroe Islands, Norway and Sweden to assess spatial trends of these compounds in the Arctic and sub-Arctic areas of Europe. Egg samples were extracted, and cleaned for chemical analysis. Concentrations of PCBs, 4,4′-DDE and β-HCH were an order of magnitude higher in eggs from the Baltic Proper compared to eggs from the North Atlantic. Concentrations of HCB were of the same magnitude at all sites, ranging from 160 to 520 ng/g fat. Concentration of BCPS was 100 times higher in eggs from the Baltic compared to eggs from the North Atlantic and seems therefore to be special regional problem. Concentrations of PBDEs were lower in eggs from the North Atlantic compared to eggs from the Baltic Proper but the difference was not as large as for PCBs and 4,4′-DDE. HBCDD showed the same spatial trend as PCBs, where the concentrations in eggs from the Baltic Proper were an order of magnitude higher than in eggs from the North Atlantic. OH-PCB and MeSO2-PCB metabolites of PCBs, showed the same trend as the parent compounds while spatial trends of MeSO2-DDE and OH-PBDEs, metabolites of 4,4′-DDE and PBDEs, respectively, differed from the trend of the parent compounds. This may be due to two factors; firstly, the limited ability of birds to metabolise DDT, and secondly, to natural production of OH-PBDE, respectively. Guillemot is suggested as a monitoring species for circumpolar monitoring. [Copyright &y& Elsevier]

The article presents a research study of levels and homologue profiles of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in sediments along the Swedish coast of the Baltic Sea. It provides the background, aim, and scope, materials and methods, results and discussion, conclusions, and recommendations and perspectives of the study. It notes that there are variations in profiles indicating that local emissions are the major causes of pollution.

Guillemot eggs from the Baltic Sea, sampled between 1969 and 2001, were analyzed for tetra- and pentabromo-diphenyl ethers (2,2',4,4'tetraBDE (BDE-47), 2,2',4,4',5-pentaBDE (BDE-99), and 2,2',4,4',6-pentaBDE (BDE-100)), and hexabromocyclododecane (HBCD). This temporal trend study indicates that the concentrations of the polybrominated diphenyl ether compounds increased from the 1970s to the 1980s, peaking around the mid- to the late-1980s. These peaks are then followed by a rapid decrease in concentrations during the rest of the study period, with the concentrations of the malor BDE congener below 100 ng/g lipid weight at the end of the period. This corresponds to less than 10% of its peak values. The concentrations of HBCD show a different pattern over time. After a peak in the middle of the 1970s followed by a decrease, the concentrations increased during the latter part of the 1980s. During the recent 10-yr period no significant change has occurred, and the annual mean concentrations are more or less stable at a higher level as compared to the beginning of the study period. [ABSTRACT FROM AUTHOR]

Presents a description of the pathology of the kidney in Baltic grey seals and ringed seals at the light microscopic and, in part, electron microscopic level. Factors attributed to a severe reduction in the population size of seals in the Baltic; Influence of autolytic changes on microscopy in animals; Differences between grey and ringed seals with regards to renal lesions.

Comparative temporal trend studies of SIGMA DDT and PCB on the Baltic pollution, using matrices from Baltic biota and dated lamina from sediment cores in anoxic sediment areas of the Baltic (no bioturbation) have been carried out. Chemical analyses of consecutive laminas of the cores representing individual years were compared to long-term temporal trend monitoring of Baltic biota based on annual sampling and analyses. Earlier studies of sediment cores from the Baltic have often indicated increasing concentrations of halogenated organic compounds in recent time whereas monitoring of Baltic biota showed decreasingconcentrations from the 1970s and onwards. In the present study two sediment cores from the northwestern Baltic proper indicate a concentration (dry weight basis) peak in the same time period as for biota, but the decrease during recent decades is slower than for biota. In lamina representing the period 1940-1950 remarkably high concentrations of both PCB and SIGMA DDT were found. Interestingly also a high proportion of nonmetabolized DDT was found in these old lamina, whereas lamina representing 1960-1970 showed a low portion of nonmetabolized DDT and high portions of the metabolites DDE and DDD during the period 1970-1998. The results are discussed in relation to resuspension ofsediments, diffusion and interstitial transport of halogenated organic compounds in the sediment cores. The results indicate the importance of resuspension of sediment and that carbon normalized data are inappropriate for interpretation of temporal trends. The results also show that we have no appropriate model to interpret the pollution of the Baltic by halogenated organic compounds, retrospectively, by usinglamina from anoxic sediment cores, but that we urgently need more knowledge on the important retention mechanisms in sediment. [ABSTRACT FROM AUTHOR]

Abstract: Forty-four unhatched eggs from white-tailed sea eagle (Haliaeetus albicilla), collected in four regions in Sweden in 1992–2005, were analysed for contents of polybrominated diphenyl ethers (PBDEs), polybrominated biphenyl (PBB), hexabromocyclododecane (HBCD) and naturally occurring methoxylated polybrominated diphenyl ethers (MeO-PBDEs). Two freshwater areas—Lapland in the arctic zone (LAP) and inland lakes in central and southern Sweden (INL), and two brackish marine areas in the Baltic Sea—the south Bothnian Sea (SB) and the Baltic Proper (BP)—were chosen for comparison of the concentrations and congener distributions in white-tailed sea eagles with different diet and migratory patterns. The geometric mean (GM) concentrations (ng/g lipid weight (l.w.)) of ∑5PBDE (BDE-47, -99, -100, -153, and -154) were 720 (LAP), 1500 (INL), 4 100 (SB) and 4 300 (BP), whereas BDE-209 was not detectable in any of the samples. The GM concentrations for HBCD content in LAP, INL, SB and BP were 60, 90, 150 and 140ng/g l.w., respectively, whereas the corresponding values for BB-153 were 20, 30, 100 and 120ng/g l.w. In general, the eggs from all four regions demonstrated similar patterns of PBDE congeners, with concentrations in descending order of BDE-47, -100, -99, -153 and -154. The ∑3-MeO-BDEs (6-MeO-BDE47, 2′-MeO-BDE68, 5-Cl-6-MeO-BDE47) for these same regions (as above) were 80, 40, 340 and 240ng/g l.w., respectively. ∑3-MeO-BDEs for LAP and INL (freshwaters) were significantly different, whereas those for SB and BP were not. The presence of MeO-PBDEs in all of the inland samples indicates that there is an as-yet-unidentified source of these compounds in the freshwater ecosystem. Between the two more contaminated subpopulations from the Baltic Sea coast, SB showed significantly lower productivity than BP, but no correlation was found between productivity and PBDE, PBB and HBCD at the concentrations found in this study. [Copyright &y& Elsevier]

Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) have recently been identified as ubiquitous environmental contaminants. Although they have been produced for 50 years, little is known about when they first appeared in the environment and how their concentrations have changed over time, particularly in response to the phase-out of FF05, which began in 2000. In this study temporal trends in the concentrations of FF05 and PFOA in the Baltic Sea marine environmentwere measured using archived guillemot eggs. Samples collected from Stora Karlsö (Sweden) between 1968 and 2003 were received from an environmental specimen bank and concentrations of PFOS and PFOA were analyzed using HPLC coupled to ESI-MS/ MS. FFOA was not detected in any of the samples (LOD 3 ng/g), but there was an almost 30-fold increase in FF05 concentrations in the guillemot eggs during the time period, from 25 ng/g in 1968 to 614 ng/g in 2003 (wet weight). Regression analysis indicated a significant trend, increasing on average between 7 and 11% per year. A sharp peak in FFOS concentrations was observed in 1997 followed by decreasing levels up to 2002, but this cannot be linked to the FF05 phase-out, which occurred at the end of this period. [ABSTRACT FROM AUTHOR]

Abstract: Concentrations of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and dioxin-like non-ortho-PCBs were measured in white-tailed sea eagle (WTSE) eagle eggs collected along the Swedish coast of the Baltic Sea during the period 1992–2004. The eggs represent two different subpopulations with significantly different nestling brood sizes; the Baltic Proper (BP) with an approximately normal nestling brood size (1.62), and the south Bothnian Sea (sBS) with reduced nestling brood size (1.22) combined with a significantly higher rate of dead eggs. The aim was to investigate if this difference in reproductive outcome was linked to differences in exposure to dioxin-like compounds. Three eggs collected in Greenland in 2000 were included in the study to provide a reference sea eagle population outside of the Baltic Sea region. The concentrations of ∑PCDD, ∑PCDF and ∑non-ortho-PCB in the two subpopulations from the Baltic Sea (BS) region ranged from 0.41–4.1, 1.2–5.3 and 180–970ng/g lipids, respectively, while in the Greenland population the ranges were 0.11–0.16, 0.22–0.33 and 57–83ng/g lipid, respectively. 2,3,4,7,8-PCDF was the predominant congener in all areas and accounted for on average 31–49% of the total ∑PCDD/F concentrations. The total toxic equivalents (TEQ) in sBS WTSEs were higher (approximately 39ng TEQ/g lipid) than reported in eggs for many other birds, and the major contributors to the TEQ in the Baltic Sea were the non-ortho-PCBs. A principal component analysis (PCA) showed a difference in congener pattern between the two Baltic regions that was statistically significant (Hotelling''s T2 test). We found no significant differences in the total TEQ between the two populations (sBS–BP) and thus no evidence was found linking the reproductive impairment in WTSE in sBS to the concentrations of PCDD/Fs or non-ortho-PCBs in the eggs. [Copyright &y& Elsevier]

The concentrations of polybrominated dibenzo-p-dioxins (PBDDs) and polybrominated methoxylated diphenyl ethers (MeO-PBDEs) were investigated in perch (Perca fluviatilis) collected from a Baltic Sea background contaminated area between 1990 and 2005. No temporal trend was found, but large variations were observed — up to 5-fold and 160-fold differences in MeO-PBDE and PBDD concentrations, respectively — between consecutive years, suggesting that retention of these compounds, particularly the PBDDs, is limited. Examination of the congener profiles using principal component analysis (PCA) and correlation analysis indicated that MeO-PBDEs without adjacent substituents (6-MeO-BDE47) or with two adjacent substituents (2'-MeO-BDE68 and 6-MeO-BDE90) are retained more than MeO-PBDEs with three adjacent substituents (6-MeO-BDE85 and 6-MeO-BDE99) and that 1,3,6,8-tetraBDD and 1,3,7,9-tetraBDD are retained more than the other PBDDs which have vicinal hydrogen. Debromination could explain the limited retention of 6-MeO-PBDE85 and 6-MeO-BDE99 and the absence of 2-MeO-BDE123 and 6-MeO-BDE137, and cytochrome P-450 mediated oxidation could explain the limited retention of PBDDs containing vicinal hydrogen. The levels of organobromines, especially MeO-PBDEs, were found to covary with water conditions related to primary production, for example temperature, depth visibility, and inorganic nutrient concentrations, which also favor fish productivity. The results suggest natural production of MeO-PBDEs and PBDDs and imply that they fluctuate considerably over time, as do common marine toxins in fish. Thus, assessments of human and environmental risk should consider both the average and peak concentrations of these contaminants in marine biota. [ABSTRACT FROM AUTHOR]

Abstract: Annual investigations of the health status of female perch (Perca fluviatilis) were performed during 8–13 years in order to detect long-term, large-scale changes in the Baltic Sea. These background data are also meant to be used as baselines in recipient investigations at various point sources in the Baltic Sea. Fish were sampled at three coastal sites in Sweden: two in the Baltic Proper (since 1988) and one in the Bothnian Bay (since 1993). In all, 19 biochemical, physiological and histopathological variables were measured. By reflecting central functions of life, such as red blood cell functions, immune defence, liver function, biotransformation processes, intermediary metabolism, ion balance, and reproduction, the selected variables give a good picture of the health status of the fish. The most important observations were strong trends towards decreased gonadosomatic index (relative gonad size) and increased hepatic EROD activity in female perch in the Baltic Proper. Most of the other variables varied little between the years. The reduced gonad size and the EROD induction indicate that factors in the environment, e.g. the occurrence of pollutants, affect important physiological functions, such as reproduction and biotransformation processes, in fish even in a reference area in the Baltic Proper. It is urgent to make further studies in order to identify which pollutant(s) or other possible cause(s) are responsible for the observed biological effects. [Copyright &y& Elsevier]