Anders Ruus

Organochlorine contaminants in a local marine food chain from Jarfjord, Northern Norway

Abstract Polychlorinated biphenyls (PCBs; 17 congeners), ΣDDT (p,p′-DDT, p,p′-DDD, p,p′-DDE and o,p′-DDD), chlordanes (oxychlordane and trans-nonachlor), hexachlorocyclohexanes (HCHs; α-, β- and γ-isomers) and hexachlorobenzene (HCB) have been determined in a local marine food chain including the lesser sandeel (Ammodytes marinus), cod (Gadus morhua), harbour seal (Phoca vitulina) and grey seal (Halichoerus grypus), caught in Jarfjord, Northern Norway. The concentrations of the pollutants generally increased with trophic level. The highest biomagnification factor (36.9) was found for ΣDDT from sandeel to harbour seal. The compositional patterns of accumulated organochlorines also differed between the species. The proportions of highly chlorinated biphenyls, p,p′-DDE and oxychlordane increased with higher trophic level, while the proportions of mono-ortho substituted and meta–para unsubstituted PCB congeners, together with DDD decreased from fish to seal. The data suggest that the bioaccumulation mechanisms at lower trophic levels (fish) depend primarily on physicochemical factors, such as the water solubility and lipophilicity of the pollutants. At higher trophic levels (seals), the bioaccumulation mechanisms are primarily affected by biochemical factors, such as the metabolic capacity of the organisms. Prey preference may also influence the patterns of accumulated pollutants in the different species.

Bioaccumulation of native polycyclic aromatic hydrocarbons from sediment by a polychaete and a gastropod: freely dissolved concentrations and activated carbon amendment.

The present paper describes a study on the bioaccumulation of native polycyclic aromatic hydrocarbons (PAHs) from three harbors in Norway using the polychaete Nereis diversicolor and the gastropod Hinia reticulata. First, biota-sediment accumulation factors (BSAFs) were measured in laboratory bioassays using the original sediments. Median BSAFs were 0.004 to 0.01 kg organic carbon/kg lipid (10 PAHs and 6 organism-sediment combinations), which was a factor of 89 to 240 below the theoretical BSAF based on total sediment contents (which is approximately one). However, if BSAFs were calculated on the basis of measured freely dissolved PAH concentrations in the pore water (measured with polyoxymethylene passive samplers), it appeared that these BSAFfree values agreed well with the measured BSAFs, within a factor of 1.7 to 4.3 (median values for 10 PAHs and six organism-sediment combinations). This means that for bioaccumulation, freely dissolved pore-water concentrations appear to be a much better measure than total sediment contents. Second, we tested the effect of 2% (of sediment dry wt) activated carbon (AC) amendments on BSAE The BSAFs were significantly reduced by a factor of six to seven for N. diversicolor in two sediments (i.e., two of six organism-sediment combinations), whereas no significant reduction was observed for H. reticulata. This implies that either site-specific evaluations of AC amendment are necessary, using several site-relevant benthic organisms, or that the physiology of H. reticulata caused artifactually high BSAF values in the presence of AC.

Seasonality in contaminant accumulation in Arctic marine pelagic food webs using trophic magnification factor as a measure of bioaccumulation

Seasonality in biomagnification of persistent organic pollutants (POPs; polychlorinated biphenyls, chlorinated pesticides, and brominated flame retardants) in Arctic marine pelagic food webs was investigated in Kongsfjorden, Svalbard, Norway. Trophic magnification factors (TMFs; average factor change in concentration between two trophic levels) were used to measure food web biomagnification in biota in May, July, and October 2007. Pelagic zooplankton (seven species), fish (five species), and seabirds (two species) were included in the study. For most POP compounds, highest TMFs were found in July and lowest were in May. Seasonally changing TMFs were a result of seasonally changing POP concentrations and the δ¹⁵N-derived trophic positions of the species included in the food web. These seasonal differences in TMFs were independent of inclusion/exclusion of organisms based on physiology (i.e., warm- versus cold-blooded organisms) in the food web. The higher TMFs in July, when the food web consisted of a higher degree of boreal species, suggest that future warming of the Arctic and increased invasion by boreal species can result in increased food web magnification. Knowledge of the seasonal variation in POP biomagnification is a prerequisite for understanding changes in POP biomagnification caused by climate change.

Environmental risk assessment of combined effects in aquatic ecotoxicology: a discussion paper.

Environmental regulatory edicts within the EU, such as the regulatory framework for chemicals REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), the Water Framework Directive (WFD), and the Marine Strategy Framework Directive (MSFD) focus mainly on toxicity assessment of individual chemicals although the effect of contaminant mixtures is a matter of increasing concern. This discussion paper provides an overview of the field of combined effects in aquatic ecotoxicology and addresses some of the major challenges related to assessment of combined effects in connection with environmental risk assessment (ERA) and regulation. Potentials and obstacles related to different experimental, modelling and predictive ERA approaches are described. On-going ERA guideline and manual developments in Europe aiming to incorporate combined effects of contaminants, the use of different experimental approaches for providing combined effect data, the involvement of biomarkers to characterize Mode of Action and toxicity pathways and efforts to identify relevant risk scenarios related to combined effects are discussed.

Brominated Flame Retardants in North-East Atlantic Marine Ecosystems

Background Concentrations of brominated flame retardants (BFRs) are reported to increase in marine ecosystems. Objectives Characterize exposure to BFRs in animals from different trophic levels in North-East Atlantic coastal marine ecosystems along a latitudinal gradient from southern Norway to Spitsbergen, Svalbard, in the Arctic. Calanoid species were collected from the Oslofjord (59°N), Froan (64°N), and Spitsbergen (> 78°N); Atlantic cod (Gadus morhua) from the Oslofjord and Froan; polar cod (Boreogadus saida) from Bear Island (74°N) and Spitsbergen; harbor seal (Phoca vitulina) from the Oslofjord, Froan, and Spitsbergen; and ringed seal (Phoca vitulina) from Spitsbergen. Eggs of common tern (Sterna hirundo) were collected from the Oslofjord, and eggs of arctic terns (Sterna paradisaea) from Froan and Spitsbergen. Results Levels of polybrominated diphenylethers (PBDEs) and hexabromocyclododecane (HBCD) generally decreased as a function of increasing latitude, reflecting distance from release sources. The clear latitudinal decrease in levels of BFRs was not pronounced in the two tern species, most likely because they are exposed during migration. The decabrominated compound BDE-209 was detected in animals from all three ecosystems, and the highest levels were found in arctic tern eggs from Spitsbergen. HBCD was found in animals from all trophic levels, except for in calanoids at Froan and Spitsbergen. Conclusions Even though the levels of PBDEs and HBCD are generally low in North-East Atlantic coastal marine ecosystems, there are concerns about the relatively high presence of BDE-209 and HBCD.

Explaining differences between bioaccumulation measurements in laboratory and field data through use of a probabilistic modeling approach.

In the regulatory context, bioaccumulation assessment is often hampered by substantial data uncertainty as well as by the poorly understood differences often observed between results from laboratory and field bioaccumulation studies. Bioaccumulation is a complex, multifaceted process, which calls for accurate error analysis. Yet, attempts to quantify and compare propagation of error in bioaccumulation metrics across species and chemicals are rare. Here, we quantitatively assessed the combined influence of physicochemical, physiological, ecological, and environmental parameters known to affect bioaccumulation for 4 species and 2 chemicals, to assess whether uncertainty in these factors can explain the observed differences among laboratory and field studies. The organisms evaluated in simulations including mayfly larvae, deposit-feeding polychaetes, yellow perch, and little owl represented a range of ecological conditions and biotransformation capacity. The chemicals, pyrene and the polychlorinated biphenyl congener PCB-153, represented medium and highly hydrophobic chemicals with different susceptibilities to biotransformation. An existing state of the art probabilistic bioaccumulation model was improved by accounting for bioavailability and absorption efficiency limitations, due to the presence of black carbon in sediment, and was used for probabilistic modeling of variability and propagation of error. Results showed that at lower trophic levels (mayfly and polychaete), variability in bioaccumulation was mainly driven by sediment exposure, sediment composition and chemical partitioning to sediment components, which was in turn dominated by the influence of black carbon. At higher trophic levels (yellow perch and the little owl), food web structure (i.e., diet composition and abundance) and chemical concentration in the diet became more important particularly for the most persistent compound, PCB-153. These results suggest that variation in bioaccumulation assessment is reduced most by improved identification of food sources as well as by accounting for the chemical bioavailability in food components. Improvements in the accuracy of aqueous exposure appear to be less relevant when applied to moderate to highly hydrophobic compounds, because this route contributes only marginally to total uptake. The determination of chemical bioavailability and the increase in understanding and qualifying the role of sediment components (black carbon, labile organic matter, and the like) on chemical absorption efficiencies has been identified as a key next steps.

Water Column Monitoring of the Biological Effects of Produced Water from the Ekofisk Offshore Oil Installation from 2006 to 2009

The Norwegian water column monitoring program investigates the biological effects of offshore oil and gas activities in Norwegian waters. In three separate surveys in 2006, 2008, and 2009, bioaccumulation and biomarker responses were measured in mussels (Mytilus edulis) and Atlantic cod (Gadus morhua) held in cages at known distances from the produced water (PW) discharge at the Ekofisk oil field. Identical monitoring studies performed in all three years have allowed the biological effects and bioaccumulation data to be compared, and in addition, enabled the potential environmental benefits of a PW treatment system (CTour), implemented in 2008, to be evaluated. The results of the 2009 survey showed that caged animals were exposed to low levels of PW components, with highest tissue concentrations in mussels located closest to the PW discharge. Mussels located approximately 1–2 km away demonstrated only background concentrations of target compounds. Concentrations of polycyclic aromatic hydrocarbons (PAH) and alkyl phenol (AP) metabolites in the bile of caged cod were elevated at stations 200–250 m from the discharge. There was also a signal of exposure relative to discharge for the biomarkers CYP1A in fish and micronuclei in mussels. All other fish and mussel biomarkers showed no significant exposure effects in 2009. The mussel bioaccumulation data in 2009 indicated a lower exposure to the PW effluent than seen previously in 2008 and 2006, resulting in an associated general improvement in the health of the caged mussels. This was due to the reduction in overall discharge of PW components (measured as oil in water) into the area in 2009 compared to previous years as a result of the improved PW treatment system.

Simulating climate change‐induced alterations in bioaccumulation of organic contaminants in an Arctic marine food web

Climate change is expected to alter environmental distribution of contaminants and their bioaccumulation due to changes in transport, partitioning, carbon pathways, and bioaccumulation process rates. Magnitude and direction of these changes and resulting overall bioaccumulation in food webs is currently not known. The present study investigates and quantifies the effect of climate change in terms of increased temperature and primary production (i.e., concentrations of particulate organic carbon, C(POC)), on bioaccumulation of organic contaminants in biota at various trophic levels. The present study covers only parts of the contaminant behavior that is influenced by climate change, and it was assumed that there were no changes in food web structure and in total air and water concentrations of organic contaminants. Therefore, other climate change-induced effects on net bioaccumulation, such as altered contaminant transport and food web structure, should be addressed in future studies. To determine the effect of climate change, a bioaccumulation model was used on the pelagic marine food web of the Arctic, where climate change is expected to occur fastest and to the largest magnitude. The effect of climate change on model parameters and processes, and on net bioaccumulation, were quantified for three modeling substances (gamma-hexachlorocyclohexane [HCH], polychlorinated biphenyl [PCB]-52, and PCB-153) for two possible climate scenarios. In conclusion, increased temperature and C(POC) reduced the overall bioaccumulation of organic contaminants in the Arctic marine food web, with the largest change being for PCB-52 and PCB-153. Reduced bioavailability, due to increased C(POC), was the most influential parameter for the less water soluble compounds. Increase in temperature resulted in an overall reduction in net bioaccumulation.

Biomarker responses in Atlantic cod (Gadus morhua) exposed to produced water from a North Sea oil field: Laboratory and field assessments

Biological markers of produced water (PW) exposure were studied in Atlantic cod (Gadus morhua) in both laboratory and field experiments, using authentic PW from a North Sea oil field. In the laboratory study, the PW exposure yielded significantly elevated levels of metabolites of polycyclic aromatic hydrocarbons (PAHs) and alkylphenols (APs) in bile even at the lowest exposure dose (0.125% PW). Other biomarkers (hepatic CYP1A induction and DNA adduct formation) responded at 0.25% and 0.5% PW concentrations. In the field study, bile metabolite markers and hepatic CYP1A were clearly increased in fish caged close to the PW outfall. Induction of plasma vitellogenin was not found in laboratory or field exposures, suggesting that the levels of oestrogen agonists (such as APs) might not have been sufficient to elicit induction, under the present conditions. The applicability of the biomarkers for use in water column biomonitoring programs is discussed.

Differences between Arctic and Atlantic fjord systems on bioaccumulation of persistent organic pollutants in zooplankton from Svalbard

Differences in bioaccumulation of persistent organic pollutants (POPs) between fjords characterized by different water masses were investigated by comparing POP concentrations, patterns and bioaccumulation factors (BAFs) in seven species of zooplankton from Liefdefjorden (Arctic water mass) and Kongsfjorden (Atlantic water mass), Svalbard, Norway. No difference in concentrations and patterns of POPs was observed in seawater and POM; however higher concentrations and BAFs for certain POPs were found in species of zooplankton from Kongsfjorden. The same species were sampled in both fjords and the differences in concentrations of POPs and BAFs were most likely due to fjord specific characteristics, such as ice cover and timing of snow/glacier melt. These confounding factors make it difficult to conclude on water mass (Arctic vs. Atlantic) specific differences and further to extrapolate these results to possible climate change effects on accumulation of POPs in zooplankton. The present study suggests that zooplankton do biomagnify POPs, which is important for understanding contaminant uptake and flux in zooplankton, though consciousness regarding the method of evaluation is important.