Understanding the sources, transport, and persistence of pollutants in estuarine systems is essential for assessing ecological risk and supporting effective management. Whilst cadmium (Cd), a persistent trace-metal in coastal waters, presents a challenge due to its toxicity and high capacity for bioaccumulation in benthic organisms, its cycling is well-understood compared to other heavy metals. In this study, we combine available Cd observations with numerical modeling to develop a first three-dimensional, system-scale model of dissolved Cd dispersal and bioaccumulation in blue mussels (Mytilus edulis) in Roskilde Fjord, a Danish temperate estuary. The coupled hydrodynamic-biological modeling framework resolves spatial and temporal variability in Cd concentrations and explicitly links water residence time to patterns of Cd retention and bioaccumulation in mussels. Model results show that the inner fjord, characterized by long residence times, exhibits enhanced Cd accumulation in biota, despite relatively low contemporary inputs, suggesting a key role of hydrodynamic retention in shaping exposure. Simulated mussel Cd concentrations reproduce observed spatial gradients and fall within the range of available monitoring data. The study identifies limitations related to data availability. Model performance depends strongly on observations of Cd inputs from streams and industrial sources, which are often monitored at the municipal level and not systematically accessible through national databases. Additionally, inconsistencies between water-column and biota Environmental Quality Standards (EQS) complicate interpretation of both observations and model results. Together, these findings demonstrate how data gaps constrain both modeling and regulatory assessment, while the modeling framework itself is readily transferable to other data-limited coastal systems.

Retinoids (vitamin A) and tocopherols (vitamin E) are essential for key biological functions in vertebrates, including cell growth, cell death and differentiation, embryonic development, reproduction and vision. In fish, however, much less is known about the retinoid functions, although retinoic acid has been shown to be involved in embryonic development. In this study, we quantified the levels of different retinoids, carotenoids and vitamin E in various tissues of both adult and embryos of the viviparous fish eelpout (Zoarces viviparus). Our results demonstrate clear seasonal differences in the levels of these vitamins in the liver of the female fish as well as in its ovarian tissues, eggs and/or embryos. Overall, this study is a baseline assessment and describes the annual variations in the vitamin status by comparing the tissue distribution of retinoids, carotenoids and vitamin E. This baseline study investigates the natural background levels of these compounds and relates their seasonal fluctuations to the reproductive cycle in the viviparous eelpout. The results of this study strengthen the current evidence base necessary to understand retinoid pathways during fish development. This understanding is crucial for utilizing retinoid composition in fish as a biological response to exposure to environmental pollution with hazardous substances in the marine environment.

Beach litter analysis is a cost-effective tool to identify litter sources and subsequent management actions. However, standard beach litter protocols are not generally developed to identify litter's origins and age. Data from Svalbard (North Atlantic/ Arctic Ocean) were therefore used to explore reliable methods to fill this knowledge gap. Written text and country specific brands, as well as printed production or expiry dates proved the most efficient and reliable identifiers. The use of product design and logos considerably increased the proportion of items that could be sourced (by 19%) and dated (by 22%). The successful use of these is defined by the expertise of the analysing team and may introduce bias. The bias can be reduced by developing picture guides and involving stakeholders. The analyses showed that littering is on-going and that the area's major fishing nations, Norway and Russia, dominated the identified litter (38% and 14%, respectively).

The aim of the present study was to investigate effects of defined mixtures of polycyclic aromatic hydrocarbons (PAHs) and perfluoroalkyl substances (PFASs), at low, environmentally relevant (1× = L), or high (20× = H) doses, on biological responses in Atlantic cod (Gadus morhua). To this end, farmed juvenile cod were exposed at day 0 and day 7 via intraperitoneal (i.p.) injections, in a two-week in vivo experiment. In total, there were 10 groups of fish (n = 21-22): two control groups, four separate exposure groups of PAH and PFAS mixtures (L, H), and four groups combining PAH and PFAS mixtures (L/L, H/L, L/H, H/H). Body burden analyses confirmed a dose-dependent accumulation of PFASs in cod liver and PAH metabolites in bile. The hepatosomatic index (HSI) was significantly reduced for three of the combined PAH/PFAS exposure groups (L-PAH/H-PFAS, H-PAH/L-PFAS, H-PAH/H-PFAS). Analysis of the hepatic proteome identified that pathways related to lipid degradation were significantly affected by PFAS exposure, including upregulation of enzymes in fatty acid degradation pathways, such as fatty acid β-oxidation. The increased abundances of enzymes in lipid catabolic pathways paralleled with decreasing levels of triacylglycerols (TGs) in the H-PFAS exposure group, suggest that PFAS increase lipid catabolism in Atlantic cod. Markers of oxidative stress, including catalase and glutathione S-transferase activities were also induced by PFAS exposure. Only minor and non-significant differences between exposure groups and control were found for cyp1a and acox1 gene expressions, vitellogenin concentrations in plasma, Cyp1a protein synthesis and DNA fragmentation. In summary, our combined proteomics and lipidomics analyses indicate that PFAS may disrupt lipid homeostasis in Atlantic cod.

Plastic pollution is a great threat to the marine environment. Owing to its low density, a substantial fraction of plastic debris is transported across ocean surfaces by currents. Consequently, plastic debris has been concentrated in oceanic gyres such as the North Atlantic subtropical Gyre (NASG). This study presents data that describes plastic abundances and the concentrations of adhered PCBs (polychlorinated biphenyls) from 15 surface trawls conducted within and outside the NASG. Abundance of plastic pieces was significantly higher inside the gyre than outside supporting earlier findings about the importance of the gyres as accumulation zones for plastic debris. Concentrations of PCBs were comparable among different sizes fractions when measured per plastic piece but significantly higher on smaller pieces when measured per weight unit. Polyethylene pieces furthermore had higher concentrations of PCB than polypropylene pieces. These findings highlight the importance of accounting for particle size and polymer type when assessing sorbed contaminants to environmental plastic pollution.

Due to a northward shift in off-shore activities, including increased shipping traffic and oil and gas exploration there is a growing focus on the potential effects of oil pollution on Arctic marine ecosystems. Capelin (Mallotus villosus) is a small fish and a member of the smelt family, and is a key species in the marine food chain. Capelin are seasonally abundant in the Northern Atlantic and in coastal Arctic waters, e.g. in western Greenland and in the Barents Sea, where it undertakes aggregated spawning in the intertidal and subtidal zone. To study the possible effects of oil pollution on the physiology and development of early life stages in capelin, freshly fertilised capelin eggs were exposed to a water accommodated fraction of physically (WAF) and chemically (CEWAF) dispersed heavy fuel oil (IFO30) for 72 h. Subsequent mortality, hatching success, larvae malformations, growth and CYP1A/EROD activity was measured over a 4-week period. The nominal exposure concentrations of WAF and CEWAF were between 0.02 and 14.5 mg total hydrocarbon content (THC) L-1 and 0.5-304 mg THC L-1, respectively. Egg mortality correlated significantly with WAF exposure concentration. The proportions of hatched eggs decreased with increasing CEWAF exposure concentration. Further, the percentage of malformed larvae with craniofacial abnormalities, body axis defects, generally under developed larvae, reduced total body length (dwarfs), correlated significantly with exposure concentrations in both CEWAF and WAF treatments. The four types of the predominant malformations were distributed differently in two parallel experiments. At the biochemical level, we observed a significant relationship between CEWAF exposure concentration and CYP1A/EROD activity in newly hatched larvae and this effect persisted for 3 weeks after the 72 h exposure. We conclude that even short-term exposure to both heavy fuel oil WAF and CEWAF, at environmentally relevant THC concentrations following an oil spill, may induce adverse developmental effects on the vulnerable early life stages of capelin. The mechanisms responsible for the observed effects on mortality, growth and embryo development in capelin eggs and embryos following WAF and CEWAF exposure require further studies.

The aim of this study was to assess whether fish in Kollevåg, a sheltered bay on the western coast of Norway, previously utilized as a waste disposal site, could be affected by environmental contaminants leaking from the waste. Farmed, juvenile Atlantic cod (Gadus morhua) were caged for six weeks at three different locations in Kollevåg bay and at one reference location. Sediments and cod samples (bile and liver) were analyzed for polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), brominated flame retardants (BFRs), per-and polyfluoroalkyl substances (PFASs) and polycyclic aromatic hydrocarbon (PAH) metabolites, revealing a contamination gradient at the four stations. Furthermore, hepatosomatic index (HSI) and Fulton's condition factor (CF) were significantly lower in cod caged closest to the disposal site. Levels and activities of biomarker proteins, such as vitellogenin (Vtg), metallothionein (Mt), and biotransformation and oxidative stress enzymes, including cytochrome P450 1a and 3a (Cyp1a, Cyp3a), glutathione s-transferase (Gst) and catalase (Cat), were quantified in blood plasma and liver tissue. Hepatic Cat and Gst activities were significantly reduced in cod caged at the innermost stations in Kollevåg, indicating modulation of oxidative stress responses. However, these results contrasted with reduced hepatic lipid peroxidation. Significant increases in transcript levels were observed for genes involved in lipid metabolism (fasn and acly) in cod liver, while transcript levels of ovarian steroidogenic enzyme genes such as p450scc, cyp19, 3β-hsd and 20β-hsd showed significant station-dependent increases. Cyp1a and Vtg protein levels were however not significantly altered in cod caged in Kollevåg. Plasma levels of estradiol (E2) and testosterone (T) were determined by enzyme immunoassay (EIA) and showed elevated E2 levels, but only at the innermost station. We conclude that the bay of Kollevåg did not fullfill adequate environmental condition based on environmental quality standards (EQSs) for chemicals in coastal waters. Following a six weeks caging period, environmental contaminants accumulated in cod tissues and effects were observed on biomarker responses, especially those involved in reproductive processes in cod ovary.

Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous class of toxic organic compounds in coastal waters. The aim of this study was to assess the potential of goby fish (Periophthalmus sobrinus) and rabbit fish (Siganus sutor) as bioindicators for PAH pollution in Zanzibar coastal waters. The fish samples were collected from four sites along the coasts of Zanzibar between February to July, 2016. The analysis of PAH metabolites from bile was conducted using Synchronous Fluorescence Scanning (SFS) spectroscopy. The parent PAH compounds (naphthalene; fluorene; phenanthrene; pyrene; fluoranthene; anthracene; benzo (a) pyrene) in the fish muscle tissues were analyzed using Gas Chromatography with Mass Spectrometric detection (GC/MS). The levels of PAH metabolites in bile of goby fish (P. sobrinus) ranged from 100 ng mL(-1) to 690 ng mL(-1). The PAH contents in goby tissues fish ranged from 0.028 +/- 0.008 ng g(-1) ww to 0.037 +/- 0.005 ng g(-1) ww with the average of 0.032 +/- 0.005 ng g(-1) ww. PAH metabolites were not detected in the bile samples from rabbit fish (S. sutor) in any sampled areas. The results suggest that the goby fish (P. sobrinus) could be promising PAH biondicator in coastal waters of tropical regions including Zanzibar islands. This is the first study applying biliary PAH metabolites in bioindicator fish species to trace PAH pollution conducted in West Indian Ocean region that can serve as a baseline information of biliary PAH metabolites as biomarkers of fish PAH pollution in the regional waters. (C) 2017 Elsevier B.V. All rights reserved.

The aim of this study was to investigate the spatial distribution, levels of dioxin-like compounds (DLC), and biological responses in two fish species. The viviparous eelpout (Zoarces viviparus) was collected from various locations in the Baltic Sea and in fjords of Kattegat and Skagerrak, while shorthorn sculpin (Myoxocephalus scorpius) was obtained at the polychlorinated biphenyl (PCB) polluted site in North West Greenland. Significant differences were detected both in contaminant levels and relative contributions from either polychlorinated dibenzodioxins (PCDD) or polychlorinated dibenzofurans (PCDF or furans) and mono-ortho- and non-ortho (coplanar) polychlorinated biphenyls (dl-PCB). Fish from the eastern Baltic Sea generally displayed higher contributions from PCDD/F compared to dl-PCB, whereas dl-PCB were generally predominated in fish from Danish, Swedish, and German sites. Levels of dl-PCB in muscle tissues were above OSPAR environmental assessment criteria (EAC) for PCB118, indicating a potential risk of adverse biological effects in the ecosystem, whereas levels of the total WHO-TEQs were below threshold for sea food suggesting limited risks for humans. No significant relationships between levels of DLC (expressed as WHO-TEQ), and biological responses such as the induction of CYP1A enzymatic activity and fry reproductive disorders were observed in eelpout. No marked relationship between WHO-TEQ and combined biological aryl hydrocarbon receptor-mediated transactivity (expressed as AhR-TEQ) was noted. However, there was a positive correlation between polycyclic aromatic hydrocarbon (PAH) metabolites and induction of CYP1A activity, suggesting that PAH exhibited greater potential than DLC to produce biological effects in eelpout from the Baltic Sea.

The study aimed to supplement the Arctic Oil and Gas Assessment 2007 report by AMAP that recommended research to be conducted to give a better understanding of shortand long-term effects of oil pollution on the Arctic marine ecosystem, evaluate Arctic species sensitivity to oil pollution compared to counterpart temperate species and assure integration of environmental monitoring and toxicological studies.

Due to high lipid content and a slow metabolism, there is a higher risk of bioaccumulation of oil compounds in Arctic than in temperate copepods. There is also a concern that the bioavailability of oil compounds is higher when oil is dispersed with dispersants. The purpose of this project was to increase the knowledge on how the use of dispersants on an oil spill may affect the passive uptake of PAHs in resting high arctic copepods using Calanus hyperboreus as a model organism. To evaluate this, resting high arctic C. hyperboreus were caught in Disko Bay at > 250 meters depth, November 2013, and subsequent experimental work was initiated immediately after, at nearby Arctic Station at Disko Island Western Greenland. C hyperboreus females were incubated in phenanthrene (111, 50 and 10 nM), pyrene (57, 28 and 6 nM) and benzo(a) pyrene (10,5 and 1 nM) for three days in treatments with and without oil (corn oil) and dispersant (AGMA DR372). After exposure, the highest measured concentrations of respectively phenanthrene, pyrene and benzo(a) pyrene in the copepods were 129,30 and 6 nmol PAH g female(-1). Results showed that with addition of oil and dispersant to the water, the accumulation of PAH was significantly reduced, due to the deposition of the PAHs in the oil phase, decreasing the available PAHs for copepod uptake. While PAH metabolites and a depuration of the PAHs were observed, the copepods still contained PAHs after 77 days of incubation in clean seawater. Differences of treatments with and without oil and dispersant on the egg production were not statistically conclusive, although it is the most likely an effect of the highly variable day-to-day egg production between individual copepods. Equally, although there was an indication that the addition of dispersant and oil increased the mortality rate, there was no statistical difference. (C) 2015 Elsevier B.V. All rights reserved.

Nordic co-operationNordic co-operation is one of the world's most extensive forms of regional collaboration, involving Denmark, Finland, Iceland, Norway, Sweden, and the Faroe Islands, Greenland, and Åland.Nordic co-operation has firm traditions in politics, the economy, and culture.It plays an important role in European and international collaboration, and aims at creating a strong Nordic community in a strong Europe.Nordic co-operation seeks to safeguard Nordic and regional interests and principles in the global community.Common Nordic values help the region solidify its position as one of the world's most innovative and competitive.

Elevated frequencies of abnormal embryos in female eelpout Zoarces viviparus have been demonstrated in Danish, Swedish and German monitoring programmes at certain geographic locations with high levels of anthropogenic input. Pollutants present in areas with high malformation frequencies were selected and tested in a controlled laboratory experiment for their potential to induce abnormalities among eelpout embryos upon injection into pregnant eelpout. Tributyltin, 2,3,7,8-tetrachlorodibenzo-p-dioxin, pyrene, nonylphenol, 2,2′,4,4′-tetrabromophenylether and heptadecafluorooctanesulfonic acid were tested, either individually or combined. Generally, the chemicals were transferred to eggs and/or embryos. Some of the exposures increased the proportion of broods with more than 10% abnormal or 5% malformed embryos, although the average percentages of abnormal development were not affected. Spinal, cranial and eye deformities were evident, similarly to what is seen in nature. Some of the exposures resulted in increased percentages of females with as well a low reproductive capacity as embryos with a low condition index.

The determination of PAH metabolites in fish bile is performed to assess the PAH contamination in fish for environmental monitoring. A growing number of laboratories in Europe use this parameter for national monitoring. However, an international intercomparison between laboratories has not taken place in the last years. Therefore the determination of the PAH metabolite 1-hydroxypyrene was tested in a collaborative trial performed by 10 laboratories from eight countries. Five samples of naturally contaminated fish bile covering different concentration levels were distributed among the participants. The present study was open for different methods: GS/MS, HPLC-fluorescence (HPLC-F), fixed wavelength fluorescence (FWF), and synchronous fluorescence spectrometry (SFS), respectively. The results suggest that all four methods under investigation are suitable for screening purposes, but only three methods have produced comparable results which could be used for a common monitoring database: GC/MS, HPLC-F, and SFS (with conversion factor). Most z-scores were within the acceptance criteria of ±2. The comparability of GC/MS, HPLC-F, and SFS results should be further improved because SFS is a widely used method with a great potential for monitoring. The present study contributes to the quality assurance of results for European marine monitoring.

Eelpouts (Zoarces viviparus) sampled at surveillance stations during the fall of 2007 and spring 2008 in different Danish coastal areas, were studied for biomarkers of polycyclic aromatic hydrocarbons (PAHs) exposure and effects. Two analytical techniques, synchronous fluorescence spectrometry (SFS) and high-performance liquid chromatography with fluorescence detection (HPLC/F), were applied for detecting PAH metabolites in bile and urine. CYP1A activity, in this study regarded as potential biomarker of effect, was measured as 7-ethoxyresorufin-O-deethylase (EROD) activity in liver of eelpouts from different stations. Biliary PAH metabolite measurements were used for monitoring the environmental PAH load at the surveillance stations. There was found significant difference in biliary PAH metabolite content between sexes with male fish containing higher concentrations of PAH metabolites than females. The urinary PAH metabolite content did not show the same spatial trends as biliary PAH metabolites. However, fish from Aarhus Bight and Vejle Fjord had significantly higher levels of PAH metabolites in both urine and bile compared to the reference station Agersø. Normalisation methods applied for bile and urine matrices did not have any effect or only slightly reduced the coefficients of variation in data sets. The CYP1A activity in eelpout liver did not show the same spatial distribution trends between sampling sites as did biliary or urinary PAH metabolite contents. Male eelpouts showed significantly higher CYP1A activity than females in fall sampling period but there were no differences found in the spring period. General comparison between both seasons showed that eelpouts sampled in the fall had significantly higher CYP1A activity than fish sampled during spring season. Overall, the results of this study describe selected biomarker responses in eelpouts to environmental PAH load at the different areas along Danish coasts.

An almost ubiquitous occurrence of imposex and butyltins in the molluscs from US Virgin Islands gives evidence to a widespread contamination with the antifouling agent tributyltin (TBT), which most likely is related to a relatively intense ship traffic. Three different muricid neogastropod species Thais deltoidea, Thais rustica and Purpura patula all seem to have potential as suitable and sensitive bioindicators for assessing levels and effects of TBT pollution in coastal areas including coral reefs in the Caribbean Sea. However, considerable interspecies differences in especially accumulation potential of butyltins were seen in this study. Furthermore, a high accumulation potential of TBT in the edible gastropod West Indian topshell (Cittarium pica) was found, despite that no signs of imposex were observed in this archaeogastropod species.

The possibility of using the pyrene metabolite 1-hydroxypyrene as a biomarker of polycyclic aromatic hydrocarbons (PAHs) exposure was investigated by exposure of the marine polychaete Nereis diversicolor to several PAHs in the laboratory. Animals were exposed to pyrene alone and to five different PAHs – phenanthrene, anthracene, pyrene, benzo[a]pyrene and benzo[k]flouranthene. After five days of exposure the concentrations of parent PAHs and 1-hydroxypyrene were identified using three different analytical methods, high-performance liquid chromatography with fluorescence detection (HPLC/F), synchronous fluorescence spectroscopy (SFS) and gas chromatography with mass spectrometric detection (GC/MS). The SFS measurements of 1-hydroxypyrene were validated by the more sensitive method HPLC/F. The positive correlation between total PAHs and 1-hydroxypyrene concentrations in the polychaete tissues observed in experiments, suggests the feasibility of 1-hydroxypyrene as a suitable biomarker for total PAH exposure assessment. Furthermore, the possibility of employment of the simple and rapid SFS method instead of HPLC/F for biomarker analysis has been confirmed by the positive and significant correlation between results achieved by these two analytical methods.