Swedish West Coast Research Articles

Swedish Plectida (Nematoda). Part 8. The genus Onchium Cobb, 1920.

Four known and one new species of Onchium are described from bottom sediments collected in Skagerrak off the west coast of Sweden. The following known species are redescribed: Onchium ocellatum Cobb, 1920, O. metocellatum Wieser, 1956, O. parocellatum (Allgén, 1940) and O. robustum Gerlach, 1965. Onchium longispiculum sp. n. is characterised by the 1.34-1.77 mm long body, anterior body end without cephalic capsule, anteriormost somatic sensilla located posterior to onchiostyle base, ocelli absent, excretory pore located at basis of lips, onchiostyle uniformly cylindrical, alveolar supplements indistinct, tubular supplements absent, spicules arcuate and 44-65 µm long. The new species has a unique set of characters (absence of developed ocelli and very long somewhat asymmetrical spicules) separating it from all other known species of the genus Onchium. The following nomenclatorial changes are proposed: O. conicaudatum (Allgén, 1935) is considered a junior synonym of O. metocellatum; O. conicaudatum apud Wieser, 1951 is considered a synonym of O. minutum Kito, 1981. The diagnosis of the genus Onchium is emended and a tabular compendium and dichotomous identification key to species of the genus Onchium are provided.

Effects of live and post-mortem shell structures of invasive Pacific oysters and native blue mussels on macrofauna and fish

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 518:123-138 (2015) - DOI: https://doi.org/10.3354/meps11044 Effects of live and post-mortem shell structures of invasive Pacific oysters and native blue mussels on macrofauna and fish P. Norling1,3,*, M. Lindegarth2, S. Lindegarth2, Å. Strand2 1Norwegian Institute for Water Research, Gaustadalléen 21, 0349 Oslo, Norway 2Department of Biology and Environmental Sciences - Tjärnö, University of Gothenburg, 452 96 Strömstad, Sweden 3Present address: Swedish Agency for Marine and Water Management, Box 11 930, 404 39 Gothenburg, Sweden *Corresponding author: pia.c.norling@gmail.com ABSTRACT: Blue mussels Mytilus edulis and the invasive Pacific oyster Crassostrea gigas are both ecosystem engineering species which modify the environment, thus having large effects on associated species. With the introduction of the Pacific oyster, a new biogenic structure has been added to subtidal sediment habitats in Scandinavia. By conducting a field experiment, the effects of live and post-mortem shell structures of C. gigas and M. edulis on associated infauna, epibenthic fauna and fish on the Swedish west coast were evaluated. Plots with 5 different treatments (live Pacific oysters, oyster shells, live blue mussels, mussel shells and sand control) were constructed on bare sandy sediment at 2 subtidal localities. Epibenthic macrofauna and fish were sampled with a drop trap, and sediment and infauna samples were collected with sediment cores. Live bivalve treatments had significant effects on organic content of the sediment; however, no treatment effects on infauna were found. In contrast, abundance and biomass of epibenthic fauna increased 4 to 8 times and species richness increased in the presence of the bivalves or their shells, compared to the sand control. Epibenthic fauna abundance and biomass was higher in the oyster shell treatment compared to the live bivalve treatments, which in turn had higher abundance and biomass than the mussel shell treatment. In general, the mussel shell treatment favoured small crustaceans, while the oyster shell and live bivalve treatments favoured fish and larger invertebrate species. Based on these results, we conclude that further establishment of the Pacific oyster in Swedish waters will cause large changes to community structure of benthic macrofauna and fish. KEY WORDS: Non-indigenous species · Ecosystem engineering · Habitat modification · Macroinvertebrates · Infauna · Epibenthic fauna · Sediment community · Crassostrea gigas · Mytilus edulis Full text in pdf format Supplementary material PreviousNextCite this article as: Norling P, Lindegarth M, Lindegarth S, Strand Å (2015) Effects of live and post-mortem shell structures of invasive Pacific oysters and native blue mussels on macrofauna and fish. Mar Ecol Prog Ser 518:123-138. https://doi.org/10.3354/meps11044 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 518. Online publication date: January 07, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Chronological aspects of the Hensbacka – a group of hunter-gatherers/fishers on the west coast of Sweden during the Pleistocene/Holocene transition: an example of early coastal colonization

In this short article, we take a brief but concise look at chronological, and to a limited extent environmental and typological, aspects of the Hensbacka culture group in Bohuslän. Due to the extensive nature of the group in time and space, it is reasonable to refer to members of this group as colonizers – even if other groups may have visited western Sweden prior to the Hensbacka. Granted, the title is provocative but it should be made clear that we are addressing the Hensbacka group as we know it today, and not in the mid-1950s. In addition, and fairly obvious, it is only the Swedish west coast that is taken into consideration, since this particular area had an extensive seasonal population during the close of the Late Pleistocene and beginning of early Holocene; one that is difficult to find elsewhere in Scandinavia.

Evaluation of Self-Organized Approach for Predicting Compressor Faults in a City Bus Fleet

Managing the maintenance of a commercial vehicle fleet is an attractive application domain of ubiquitous knowledge discovery. Cost effective methods for predictive maintenance are progressively demanded in the automotive industry. The traditional diagnostic paradigm that requires human experts to define models is not scalable to today's vehicles with hundreds of computing units and thousands of control and sensor signals streaming through the on-board controller area network. A more autonomous approach must be developed. In this paper the authors evaluate the performance of the COSMO approach for automatic detection of air pressure related faults on a fleet of city buses. The method is both generic and robust. Histograms of a single pressure signal are collected and compared across the fleet and deviations are matched against workshop maintenance and repair records. It is shown that the method can detect several of the cases when compressors fail on the road, well before the failure. The work is based on data from a three year long field study involving 19 buses operating in and around a city on the west coast of Sweden.

EMC Europe 2014 in Gothenburg, Sweden - “A Memorable Symposium”

“Memorable Symposium” is of course not our words, but we take them to our hearts and would like to share them with the readers of the IEEE EMC Magazine. And yes, we will for sure also remember the symposium and perhaps in particular all the work behind it, although the memory of the latter already has started to fade. EMC Europe 2014 was arranged by the EMC department at the SP Technical Research Institute of Sweden in cooperation with the local event company Just Event. The symposium was held at the Swedish Exhibition & Congress Centre which is a very modern and practical venue in the center of Gothenburg on the Swedish west coast. During, and especially after the symposium, we received very positive feedback from the attendees; among one of the most surprising comments was that they were “even” very satisfied with the food provided by the venue restaurant, which in fact was of high quality. The word “even” indicates that delicious food is probably not what Sweden is most famous for! It was beyond our control, but we were also lucky with the weather with an unusually warm and sunny first week of September; the symposium was held over September 1 – 4.

Effects of More Stringent Sulphur Requirements for Sea Transports

In 2008 the International Maritime Organization (IMO) decided on more stringent requirements from 2015 for airborne emissions of sulphur dioxide from sea transports in the sulphur emission control areas (SECA). The European SECA comprises the Baltic Sea, the North Sea and the English Channel. The paper contains an overview of the European studies that have been carried out to investigate the impacts of IMO's more stringent sulphur requirements. All studies were carried out after IMO's decision in 2008 (which means that the decision was taken based on other reasons). The studies focus on different aspects but all of them estimate how IMO's stricter requirements will affect the sea transport costs. The Swedish impact studies are described in particular: in the 2009 study the national transport model Samgods was used and in 2013 both the Samgods model and the agent-based simulation model Tapas. Impacts on the choice of transport chains, routes and ports are calculated. The results indicate that shippers to some extent can reduce the increase in transport cost by transferring flows from the Swedish east coast to the Swedish south and west coast, the Norwegian coast and the land-based route via Denmark. Modal back shifts from sea to rail and road occur. These shifts are modest, especially if higher prices for diesel and higher rail track fees are assumed on top of more stringent sulphur requirements in the SECA. One important question is to what extent the increases in costs that are due to more stringent requirements can be compensated for by improved efficiency of the transports, such as the exploitation of economies of scale.

Distribution, delimitation and description of species of Archaphanostoma (Acoela)

Acoela is a small group of microscopic marine worms that live interstitially in sandy or muddy sediments. Although Acoela is an abundant group of the meiofauna, knowledge of their diversity is incomplete. The Swedish fauna with 66 nominal species is one of the best studied in the world. Despite this new species and species new to the area are still found in Swedish waters. In this study, we describe four new species belonging to the family Isodiametridae: Archaphanostoma fontaneti sp. n., Archaphanostoma occulta sp. n., Archaphanostoma sublittoralis sp. n. and Archaphanostoma ylvae sp. n. The new species were collected on the Swedish west coast and in northern Germany during 2011. Each description is accompanied by drawings and microphotographs. Nucleotide sequences for the ribosomal genes 18S rRNA and 28S rRNA as well as for the mitochondrial COI mtDNA gene have been determined for the new species and used in Bayesian and maximum‐likelihood analyses to further support their classification. Diagnostic molecular characters are presented for each species, and we use Bayesian methods and statistical parsimony to delimit the new species within Archaphanostoma. We also use species of Archaphanostoma to test patterns of acoel diversity.

Avian influenza A(H10N7) virus involvement in mass mortality of harbour seals (Phoca vitulina) in Sweden, March through October 2014.

We provide the first scientific report of influenza A virus involvement in a mass mortality event among harbour seals (Phoca vitulina) off the west coast of Sweden. Avian influenza A (H10N7) virus was detected in the lungs of two affected animals. This subtype has not been reported in seals to date, nor has influenza A-associated mortality been reported in seals in Europe. Circulation of avian influenza viruses in mammals may have implications for public health.

Conflict resolution in coastal resource management: Comparative analysis of case studies from four European countries

Coastal resource management requires the resolution of local resource use conflicts. The research on coastal conflict resolution is still scarce despite the progress made in fisheries and marine related conflict studies. Utilizing qualitative methodology this paper makes comparative analyses of strengths and deficits of coastal conflict resolution practices in three conflicts from the Swedish west coast and five conflicts from the United Kingdom, Italy and Belgium, all studied in the context of the European research project SECOA (Solutions to Environmental Contrasts in Coastal Areas). The analyses focus on power relations among the stakeholders and their practices of knowledge use, including knowledge integration and joint learning. The results show deficits of research and practical neglect of these aspects in coastal management. In the discussion the question of how approaches to conflict resolution can be improved and integrated into long-term strategies of sustainable resource management in coastal areas is addressed. It is concluded that complex conflicts over natural resource use require context specific combinations of formal and informal resolution methods. The interconnected components of transformation of power relations, knowledge integration and joint learning are seen as key components of conflict resolution.

Cancer Incidence among Oil Refinery Workers in Sweden

Cancer Incidence among Oil Refinery Workers in SwedenAbstract Number:2508 Ralph Nilsson, Gerd Sallsten, Magnus Akerstrom, Eva M Andersson, Lars Barregard*, and Bengt Järvholm Ralph Nilsson Occupational and Environmental Medicine, University of Gothenburg , Sweden, E-mail Address: [email protected] Search for more papers by this author , Gerd Sallsten Occupational and environmental medicine, University of Gothenburg, Sweden, E-mail Address: [email protected] Search for more papers by this author , Magnus Akerstrom Occupational and environmental medicine, University of Gothenburg, Sweden, E-mail Address: [email protected] Search for more papers by this author , Eva M Andersson Occupational and environmental medicine, University of Gothenburg, Sweden, E-mail Address: [email protected] Search for more papers by this author , Lars Barregard* Occupational and Environmental Medicine, University of Gothenburg, Sweden, E-mail Address: [email protected] Search for more papers by this author , and Bengt Järvholm Occupational and Environmental Medicine, University of Umeå, Sweden, E-mail Address: [email protected] Search for more papers by this author AbstractBackground: Refinery workers are exposed to hydrocarbons, including benzene, which could cause leukemia. They are also exposed to other carcinogenic substances, such as asbestos. The risk of leukemia at low exposure levels of benzene is unclear. In an earlier study, we found an excess incidence of leukemia in refinery operators when they were followed up until 1991. The objective of the present study was to extend the follow-up until 2008 to see if there were excess incidences of different forms of cancer.Methods: The employees at three oil refineries on the West coast of Sweden were followed up 1961 - 2008. The work force today consists of about 1300 persons, including about 500 employed after 1991. In total the cohort consisted of 2548 persons employed at least one year. The type of job and employment time was collected from personal files. Cases of cancer were found by a linkage with the Swedish Cancer Register. The incidence rates were compared to national incidence rates in stratified analyses and standardized incidence rates (SIR) and Poisson-based 95 % confidence intervals (95 % CI) were calculated.Results: There were 10 cases of leukemia. All of these had worked as refinery operators (SIR 2.4; 95 % CI 1.3 – 4.5). There was no significantly increased risk in the other occupational groups. There were four cases of mesothelioma (three in the pleura and one in the peritoneum), probably caused by previous asbestos exposure. We did not find any statistically increased risks for other types of cancer.Conclusion: Workers in the refineries had an excess incidence of leukemia and mesothelioma probably due to exposure to benzene and asbestos respectively.

Nitrogen fixation in shallow‐water sediments: Spatial distribution and controlling factors

Nitrogenase activity (NA) in shallow‐water (< 1 m) sediments was investigated at 60 randomly selected sites along a 150 km stretch on the brackish‐water Swedish west coast, without targeting any specific type of sediments, such as microbial mats. Benthic nitrogen (N) fixation and diazotrophs (nifH genes) were found at all sites, regardless of the presence of cyanobacterial or microbial mats. The majority of sites showed N fixation rates between 0.03 and 1 mmol N m−2 d−1. These rates were similar to those of benthic denitrification previously measured in the area. Maximum rates up to 3.4 mmol N m−2 d−1 were measured. A structural equation model was used to investigate direct and indirect effects of biogeochemical and physical factors on NA. Number of nifH genes had the largest direct positive influence on NA, whereas increasing wave exposure had an indirect negative effect on NA through its influence on the diazotrophic abundance. Increased salinity, previously been shown to suppress NA in coastal waters, was found to directly stimulate benthic N fixation, likely by generating favorable conditions for diazotrophic sulfate‐reducing bacteria. Our field data confirmed previously observed negative effects of dissolved inorganic nitrogen on NA, which have so far mainly been experimentally studied. Both NA rates and the number of nifH genes correlated positively with pore‐water dissolved inorganic phosphorus concentrations. These findings show that the potential for N fixation in illuminated sediments can be considerable, stretching beyond cyanobacterial mats, being controlled by complex interactions between biotic and abiotic factors.

An Arctic seal in temperate waters: History of the ringed seal (Pusa hispida) in the Baltic Sea and its adaptation to the changing environment

The ringed seal ( Pusa hispida) is an early immigrant in the Baltic Basin and has since its arrival experienced substantial changes in the climate, salinity and productivity of the Basin. In this paper, we discuss the dispersal and distribution of the ringed seal during different stages of the Baltic Sea in relation to past and ongoing environmental changes. Subfossil ringed seal remains around the Baltic Sea and the Danish Straits were radiocarbon dated in order to map the distribution of the species in different time periods. The δ13C data were used in evaluating the changes in the marine character of the Baltic Basin. The sequence of the dates indicates a continuous presence of the species in the Baltic Basin. The earliest ringed seal finds come from the Skagerrak/Kattegat area (Denmark, Swedish west coast) and date to the full glacial period and Baltic Ice Lake. In the Baltic Basin, the species appears in the subfossil record during the Ancylus period, but the main part of the remains date to the Littorina stage. During the Littorina stage, the distribution of the species was at least periodically wider than today, covering also southern parts of the Baltic. The presence of breeding populations in southern parts of the Baltic during the Holocene Thermal Maximum (HTM) indicates that the winters were at least periodically cold enough for winter ice. The changes in the marine influence in the Baltic Basin can be seen in the seal collagen δ13C values, which serve as a proxy for qualitative changes in water mass salinity.

Deglaciation, sea-level change and the Holocene colonization of Norway

Abstract The Norwegian coast facing the Atlantic Ocean was ice free as early as the Allerød oscillation in the late Pleistocene. The landscape was probably habitable for humans. It has, therefore, been assumed by several scholars that this coastline was visited or inhabited from the Late Glacial period onwards. In part, this argumentation is based on the presumed proximity of the Norwegian mainland and Doggerland, which existed between present-day Denmark and Great Britain because of a much lower global sea level. The aim of this paper is to examine the 14 C dates available from the oldest Norwegian settlement sites, and to compare them to the Quaternary processes of deglaciation and sea-level change. The hypothesis is advanced that humans did not settle in present-day Norway before a sheltering passage of islands and peninsulas had developed between the Swedish west coast (Bohuslän) and the Oslo area. This happened in the second half of the Preboreal period, at approximately 9.3 cal ka BC, or in the final centuries of the tenth millenniun BC. Supplementary material: 14 C dates used in Figures 2, 4 and 9 are available at http://www.geolsoc.org.uk/SUP18779 .

Toxicity of ciprofloxacin and sulfamethoxazole to marine periphytic algae and bacteria

Ciprofloxacin and sulfamethoxazole are two antibiotics commonly detected in the aquatic environment, but information on their toxicity towards natural microbial communities is largely absent. In particular no data are available for marine microorganisms. The aim of the current study was therefore to evaluate the chronic toxicity of ciprofloxacin and sulfamethoxazole to natural marine biofilms (periphyton), a complex ecological community comprising a variety of bacterial and algal species. The biofilms were sampled along the Swedish west coast and subsequently exposed over 4 days in a semi-static system to a concentration series of each antibiotic.Effects on the bacterial part of the periphyton community were assessed using Biolog Ecoplates, reflecting total respiration and functional diversity of the bacterial community. Exposure to either antibiotic resulted in a clear concentration–response relationship with EC10 and EC50 values for the inhibition of total carbon source utilization of 46.1nmol/L and 490.7nmol/L for ciprofloxacin, and 56nmol/L and 1073nmol/L for sulfamethoxazole. The NOEC for ciprofloxacin was 26nmol/L, with a minimum significant difference of 19.24%, for sulfamethoxazole it was 140nmol/L with a minimum significant difference of 14%. Multivariate data exploration of the whole carbon source utilization pattern confirmed these results. The data indicate that sulfamethoxazole leads to a general decrease in carbon source utilization, while ciprofloxacin exposure leads to a re-arrangement of the carbon-utilization pattern in the region of 20– 50% effect. This corresponds with the higher specificity of ciprofloxacin for certain bacterial species.Effects on the algal part of the communities were evaluated by analyzing the amount and composition of photosynthetic pigments, and neither ciprofloxacin nor sulfamethoxazole caused any inhibitory effects up to the maximum tested concentration of 9000nmol/L. However, sulfamethoxazole exposure did lead to a significant stimulation (75% above control level) of the total pigment content of the biofilm already at the lowest tested concentration of 5nmol/L. The stimulation then decreased with increasing concentrations to finally return to control level at 3000nmol/L. No shifts in the relative pigment composition were observed, indicating a generally increased algal biomass without major shifts in community composition.

Swedish Plectida (Nematoda). Part 7. Setostephanolaimus tchesunovi sp. n. from the west coast of Sweden.

A new species of Setostephanolaimus, S. tchesunovi sp. n., is described from bottom sediments collected in the Skagerrak and Gullmarn Fjord off the west coast of Sweden. It is characterised by 1.0-1.3 mm long body, outer labial setae 6.5-8.5 µm long, cephalic setae 9-11 µm long, subcephalic setae 4-6 µm long, transversely-oval amphid, female with monodelphic opisthodelphic reproductive system, male with 6-9 tubular and without alveolar supplements, spicules arcuate and 54-64 µm long, gubernaculum with dorsal apophysis. A tabular compendium and dichotomous identification key to species of the genus Setostephanolaimus are provided.

Swedish Plectida (Nematoda). Part 6. Neocamacolaimus parasiticus gen. n., sp. n.

A new genus Neocamacolaimus gen. n., with one new species N. parasiticus gen. n., sp. n. is described from the benthic polychaete Sphaerosyllis cf. hystrix collected in the Skagerrak off the west coast of Sweden. Neocamacolaimus gen. n. is placed in the family Camacolaimidae and is particularly characterised by having annulated cuticle with lateral alae; setiform cephalic sensilla located at level with amphids; amphidial fovea ventrally spiral; buccal cavity without armament; pharynx muscular; nerve ring located at base of pharynx; male reproductive system diorchic with outstretched testes; spicules weakly arcuate with straight manubrium; gubernaculum absent; alveolar supplements located in the pharyngeal region; tubular supplements absent; tail conoid; caudal glands and spinneret present. Juveniles of this genus are particularly characterised by their parasitic lifestyle and the following unique morphological features: lips form a dorso-ventrally elongated perioral disc with internal sclerotizations: one midventral and two dorsosublateral (right and left); cephalic sensilla setiform, subventral sensilla are noticeably longer than the subdorsal ones; intestine extends posterior to rectum and anal opening, forming a post-anal pouch.

Abundance and Size Distribution of the Sacoglossan Elysia viridis on Co-Occurring Algal Hosts on the Swedish West Coast

Sacoglossans are specialized marine herbivores that tend to have a close evolutionary relationship with their macroalgal hosts, but the widely distributed species Elysia viridis can associate with several algal species. However, most previous investigations on the field abundance and size distribution of E. viridis have focussed on Codium spp. in the British Isles, and algae from this genus are considered superior hosts for E. viridis. In the present study, we investigated the abundance and size distribution of E. viridis on 6 potential host algae with differing morphologies (the septate species Cladophora sericea, Cladophora rupestris, Chaetomorpha melagonium, and Ceramium virgatum, as well as the siphonaceous species Codium fragile and Bryopsis sp.) at 2 sites on the Swedish west coast over the course of a year. In spring, slugs were almost absent from all algal hosts. In summer and autumn, E. viridis consistently occurred on several of the algal species at both sites. The highest number of small E. viridis were found on C. sericea, intermediate numbers of significantly larger E. viridis were found on C. rupestris, while fewer, intermediate sized animals were found on C. fragile. Throughout the study period, only a few E. viridis individuals were found on C. melagonium, Bryopsis sp., and C. virgatum. Our results indicate that E. viridis is an annual species in Sweden, capable of exploiting co-occurring congeneric and intergeneric algal hosts with differing morphologies. These results corroborate previous findings that E. viridis can exploit several different algal species, but does not indicate that C. fragile is a superior host.

Swedish Plectida (Nematoda). Part 5. Rhadinema timmi (Vitiello, 1971) comb. n.

Leptolaimus timmi Vitiello, 1971 is redescribed from bottom sediments collected in the Skagerrak off the west coast of Sweden. New morphological data necessitate the transfer of this species to the genus Rhadinema Cobb, 1920. The main diagnostic characters of Rhadinema timmi (Vitiello, 1971) comb. n. include: 1.3-1.8 mm long body; rounded labial region weakly offset from body contour; cephalic setae 2-4 µm long; amphid located 12-19 µm from anterior end; first body pore located 22-30 µm from anterior end; lateral field absent; stoma tubular: cheilostom with six weakly cuticularised longitudinal rugae, gymnostom with sclerotized bar-shaped rhabdia, stegostom long, tubular; female without supplements, vagina without pars refringens, vulva midventral; male with 10-11 tubular and without alveolar supplements; spicules arcuate and 21-30 µm long.

Novel Octabrominated Phenolic Diphenyl Ether Identified in Blue Mussels from the Swedish West Coast

Hydroxylated (OH-) and methoxylated (MeO-) polybrominated diphenyl ethers (PBDEs) are compounds present in the marine environment and OH-PBDEs are of toxicological concern and are therefore of interest to monitor in the environment. A phenolic octaBDE was tentatively identified in the phenolic fraction of previously analyzed mussel samples after methylation of the halogenated phenolic compounds (HPCs). The aim of the present study was to confirm the identity of this compound in blue mussels and investigate whether the analyte is diOH- and/or OH-MeO-octaBDE. Two reference standards, 6,6'-dimethoxy-2,2',3,3',4,4',5,5'-octabromodiphenyl ether (6,6'-diMeO-BDE194) and 6-ethoxy-6'-methoxy-2,2',3,3',4,4',5,5'-octabromodiphenyl ether (6-EtO-6'-MeO-BDE194) were prepared via O-arylation of 2,3,4,5-tetrabromo-6-methoxyphenol and 2,3,4,5-tetrabromo-6-ethoxyphenol, respectively, with a novel unsymmetrical diaryliodonium salt, 2,3,4,5-tetrabromo-6-methoxydiphenyliodonium triflate. The GC retention time and GC/MS spectrum of the synthesized 6,6'-diMeO-BDE194 correspond well with the analyte in the methylated phenolic fraction of a mussel extract from a previous study. Structural analysis performed in this study indicate that the synthesized 6,6'-diMeO-BDE194 and 6-EtO-6'-MeO-BDE194 correspond well with 6-hydroxy-6'-methoxy-2,2',3,3',4,4',5,5'-octabromodiphenyl ether (6-OH-6'-MeO-BDE194) after methylation and ethylation, respectively, of the HPCs in the mussel extracts. The compound 6-OH-6'-MeO-BDE194 was identified and quantified in new mussels, sampled in 2012 from two locations on the Swedish west coast, with geometric mean concentrations of 3700 and 410 ng/g fat, respectively.

Temporal trends of perfluoroalkane sulfonic acids and their sulfonamide-based precursors in herring from the Swedish west coast 1991–2011 including isomer-specific considerations

A method was developed for simultaneous analysis of perfluoroalkane sulfonic acids (PFSAs) and their sulfonamide-based precursors (perfluoroalkane sulfonamidoacetic acids (FASAAs), sulfonamides (FASAs), and sulfonamidoethanols (FASEs)) in fish muscle. Extraction was performed with acetonitrile followed by a clean-up and fractionation step and instrumental analysis by UPLC/MS/MS and GC/MS. Time trends of PFSAs and their precursors in herring muscle samples originating from the Kattegat at the west coast of Sweden were investigated covering the years 1991–2011. The following analytes were detected, all with decreasing or unchanged trends between 1991 and 2011: Perfluorobutane sulfonic acid (PFBS, below the method detection limit (<MDL)-10pg/g), perfluorohexane sulfonic acid (PFHxS, 9–38pg/g), perfluorooctane sulfonic acid (PFOS, 240–930pg/g), perfluorodecane sulfonic acid (PFDS, <MDL-4pg/g), N-methyl and N-ethyl perfluorooctane sulfonamidoacetic acid (MeFOSAA and EtFOSAA, 2–39 and 2–31pg/g, respectively) and perfluorooctane sulfonamide (FOSA, 78–920pg/g). The highest concentrations were found for PFOS and FOSA around the turn of the century. Shorter disappearance half-lives were observed for precursors compared to PFSAs. Assuming that these trend differences are representative for fish consumed by the general Swedish population, this observation suggests that the relative contribution of precursors to total human exposure to PFOS via fish intake has decreased in Sweden over the study period. PFOS precursors in fish may have constituted a significant indirect exposure pathway for PFOS in the 1990s. Isomer-specific analysis of PFOS and FOSA revealed <10% relative contributions of branched isomers to total PFOS and total FOSA. Furthermore, the percentage branched isomers decreased over time for both compounds. These findings are contrary to patterns and temporal trends of PFOS isomers commonly found in human serum. In combination with literature data on isomer patterns in other edible fish species and on isomer-specific human toxicokinetics, our results suggest that fish consumption alone cannot account for the PFOS isomer patterns and trends observed in humans.