Anders Ruus

• Jourdain, Eve Marie; McKinney, Melissa A.; Remili, Anaïs; Andvik, Clare Margaret; Fagerlund, Carl Johan Ludwig & Karoliussen, Richard [Show all 8 contributors for this article] (2026). Advancing Amino Acid Isotope‐Inferred Trophic Ecology in an Apex Predator: Insights From a Data‐Rich Killer Whale Population. Ecology and Evolution. 16(8), p. 1–16. doi: 10.1002/ece3.74121. Full text in Research Archive Show summary

  Amino acid‐specific nitrogen isotope analysis (δ 15 N‐AA) is increasingly used to infer trophic ecology, yet remains poorly validated in marine predators. We analyzed bulk tissue δ 15 N ( 15 N/ 14 N) and δ 13 C ( 13 C/ 12 C), and δ 15 N‐AA in 105 skin samples collected from individually identified Norwegian killer whales between 2017 and 2023. Forty‐two individuals with best documented diets in 2010–2023, based on field observations and corroborated by mercury concentrations and bulk tissue δ 15 N values in skin, provided reference diet groups against which δ 15 N‐AA‐derived hypotheses were tested: Fish‐only (100% fish prey; n  = 15), Intermediate mixed diet (~10% mammalian prey in addition to fish; n  = 14), and Top mixed diet (~50% mammals, 50% fish prey; n  = 13). Univariate and multivariate approaches identified diet as the primary driver of δ 15 N variation across individual amino acids and multivariate isotopic space, whereas sex and life stage had little effect. However, substantial inter‐individual variation remained unexplained and appeared to reflect metabolic processes. Metrics δ 15 N ΣTrophic—ΣSource (δ 15 N difference between the sum of trophic amino acids and the sum of source amino acids) and isotopic difference between glutamic acid/glutamine (Glu) and phenylalanine (Phe) (δ 15 N Glu–Phe ) successfully identified Top mixed diet whales but lacked the sensitivity to identify Intermediate mixed diet individuals, whilst δ 15 N values of Threonine showed no relationship with trophic position. Proline (Pro) and Phe used as trophic‐source pair provided the first plausible δ 15 N‐AA‐derived trophic position estimates for killer whales and performed better than bulk isotope‐derived trophic position when a priori knowledge was not available. Multivariate clustering of δ 15 N‐AA data complemented trophic position estimates by resolving finer‐scale dietary variation occurring within trophic levels.

• Andvik, Clare Margaret; Fagerlund, Carl Johan Ludwig; Jourdain, Eve Marie; Yuan, Bo; Haddad-Weiser, Gabrielle & Lyche, Jan Ludvig [Show all 9 contributors for this article] (2026). Comparing polychlorinated n-alkane occurrence and biomagnification with legacy contaminants in a killer whale food web. Environmental Research. ISSN 0013-9351. 306. doi: 10.1016/j.envres.2026.125367. Full text in Research Archive Show summary

  Polychlorinated n-alkanes (PCAs), the largest component of the commercial product chlorinated paraffins, have been used globally in increasing amounts since the regulations of legacy contaminants, such as polychlorinated biphenyls (PCBs). The bioaccumulative potential of PCAs compared to legacy contaminants is inconclusive, with limited data available for PCAs with carbon chain length ≤9 and ≥18, particularly in food webs which include mammalian top predators. Here, we analysed and compared PCAs of different carbon chain length (very-short: PCAs-C6-9 [vSCCPs], short: PCAs-C10-13 [SCCPs], medium: PCAs-C14-17 [MCCPs], and long: PCAs-C18-24 [LCCPs]), 57 legacy contaminants, and total mercury (Hg) in killer whales (Orcinus orca) from northern Norway (n = 59) and a range of fish and marine mammals. We found that legacy organic contaminants dominated in concentration and pattern in marine mammals (54–87%), whereas PCAs and Hg dominated in fishes (58–98%). A species' physiology (poikilotherm or homeotherm) influenced the food web magnification of several contaminants, with estimated trophic magnification factors (TMFs) underestimated in PCAs, and overestimated in PCB-153, p.p’-DDE and Hg, if unaccounted for. PCAs-C6-9 and PCAs-C10-13 had similar and low TMFs for poikilotherms and homeotherms, and similar to PCB-28 (TMF range: 1.9–2.4 [95% confidence interval 0.9–5.7]). PCAs-C14-17 and PCAs-C18-24, had high TMFs in poikilotherms (4.8 [1.3–18] and 4.6 [1.2–18], respectively), and no significant trophic magnification in homeotherms (1.0 [0.5–2.3] and 1.0 [0.4–2.8], respectively), with the opposite pattern for PCB-153 and p.p’-DDE. Our results indicate higher PCA concentrations and biomagnification potential in poikilotherms than homeotherms, which is likely due to lower biotransformation and elimination ability.

• Dulgheriu, Daniela; Andvik, Clare Margaret; Jourdain, Eve Marie; Borgå, Katrine; Ruus, Anders & Haug, Tore [Show all 9 contributors for this article] (2026). A sensitive liquid chromatography–tandem mass spectrometry analytical method of steroid hormones in small blubber samples from four whale species. Conservation Physiology. 14(1). doi: 10.1093/conphys/coag023. Full text in Research Archive Show summary

  Steroid hormones can give an indication of stress, physiological health and reproductive status in whales; however, analysis is often limited by sample mass. We developed a sensitive analytical method using solid phase extraction–liquid chromatography–electrospray ionization–tandem mass spectrometry (LC–ESI–MS/MS) for the identification and quantification of eight steroid hormones (cortisol, cortisone, testosterone, androstenedione, progesterone, 11-deoxycortisol, 11-deoxycorticosterone and 17-hydroxyprogesterone) in small amounts of whale blubber (≤50 mg). Blubber biopsies were collected from stranded killer whales (Orcinus orca; n = 7), harbour porpoises (Phocoena phocoena; n = 3) and sperm whales (Physeter macrocephalus; n = 4), harvested common minke whales (n = 10; Balaenoptera acutorostrata) and free-living killer whales (n = 2) in Norway and the Barents Sea. Steroid hormones were separated using pentafluorophenyl propyl stationary phase and an optimized gradient programme with a total 20-min run. All samples (n = 26) were analysed at 50-mg sample mass, and a subset (n = 11) at 25 mg or lower. Low limit of detection and limit of quantification values resulted in high detection rates of hormones, and we found similar hormone concentrations between parallel samples and at the lowest tested sample mass (14 mg). Cortisol concentrations in sperm whales (4.3 ± 1.6 ng/g) were four times higher than stranded killer whales (1.1 ± 0.96 ng/g), which in turn were up to four times higher than free-living killer whales (0.23 ± 0.12 ng/g), harbour porpoise (0.64 ± 0.38 ng/g) and harvested minke whales (0.22 ± 0.13), possibly due to fatality type and duration of stress prior to death. We provide the first quantification of blubber steroid hormones in killer whale, minke whale, sperm whale and harbour porpoise, and in less than 50-mg sample mass. By minimizing sample mass without compromising precision or sensitivity, our method allows for steroid hormone analysis even on samples with limited availability, strengthening our ability to monitor and conserve marine mammal populations.

• Chandrasekaran, Muthukumar; Panneerselvam, Karthikeyan; Bæk, Kine; Ranneklev, Sissel Brit; Grung, Merete & Ruus, Anders [Show all 11 contributors for this article] (2025). Assessment of selected organic pollutants in sediments from a highly urbanized environment along the southeast coast of India. Marine Pollution Bulletin. ISSN 0025-326X. 220. doi: 10.1016/j.marpolbul.2025.118456. Full text in Research Archive Show summary

  As part of the Marine Spatial Planning (MSP) for the Puducherry coast—a highly urbanized coastal area along India's southeast coast—an extensive assessment of organic pollutants was conducted in the sediments of the Thengaithittu Estuary, one of the major urban confluences in the region. Surface sediment samples were collected during both the dry season (June) and the wet season (September) in 2023 from six stations to measure polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs), including DDTs. The results indicated that high molecular weight (HMW) PAHs predominated in both seasons, primarily from pyrogenic sources with concentrations ranging from 0.26 to 369.16 ng g−1 dw. Carcinogenic PAHs (C-PAHs) accounted for 51–98 % of the total PAHs, although the overall PAH levels remained below the Effect Range Low (ERL) threshold, reflecting a low ecological risk. PCBs were detected only at the fishing harbour region at the estuary's mouth, with concentrations varying from 17.16 to 130.04 ng g−1 dw, where 5Cl and 6Cl biphenyls comprised 80 % of the total composition. DDT levels, ranging from below detection limit (BDL) to 2.30 ng g−1 dw, suggested minimal recent inputs. The mean sediment quality guideline quotient (mSQGq) indicated low overall biological adverse effects across all stations. These findings offer essential baseline data regarding organic pollutant levels and ecological risks, emphasizing the need for enhanced management strategies to mitigate contaminant inputs and protect both the estuarine ecosystem and public health.

• Alexander, Jan; Kvalem, Helen Engelstad; Mariussen, Espen; Ruus, Anders; Schlabach, Martin & Steffensen, Inger-Lise [Show all 12 contributors for this article] (2025). Kunnskapsgrunnlag for Mattilsynets arbeid med å beskytte drikkevann mot kjemisk og fysisk forurensning fra vindkraftverk på land. VKM Report. 2025(08), p. 1–67. doi: https:/vkm.no/risikovurderinger/allevurderinger/vindkraftogdrikkevannvkmgirfagligstottetilvindkraftutredninger.4.4be7365b1953687c4b4448a1.html. Full text in Research Archive Show summary

  Etablering av vindkraftverk på land kan medføre en risiko for drikkevann når installasjonene ligger i eller nær vanntilsigsområder til drikkevannskilder. Denne rapporten, utarbeidet av VKM på oppdrag fra Mattilsynet, gir Mattilsynet et kunnskapsbasert grunnlag for å stille krav til konsekvensutredninger og detaljplan for å beskytte drikkevannet. Rapporten identifiserer potensielle farer for kjemisk og fysisk forurensning av drikkevann gjennom hele livsløpet til et vindkraftverk – fra planlegging og anleggsfase, til drift og avvikling. Den beskriver relevante lover og forskrifter, sentrale aktører og deres roller, og legger vekt på når og hvordan Mattilsynet kan involveres og komme med innspill i den kommunale planprosessen etter plan- og bygningsloven og i konsesjonsprosessen etter energiloven som forvaltes av NVE. Det er av stor betydning at Mattilsynet varsles og involveres tidlig i prosessen. Tiltakshaver må sørge for at risiko for forurensning av drikkevann og vanntilsigsområde utredes på en etterprøvbar måte, slik at Mattilsynet kan gi tydelige innspill til utredningen for å sikre at drikkevannshensyn er ivaretatt.

• Baumgartner, Chérine D.; Jourdain, Eve Marie; Bonhoeffer, Sebastian; Borgå, Katrine; Heide-Jørgensen, Mads P. & Karoliussen, Richard [Show all 13 contributors for this article] (2025). Kinship clustering within an ecologically diverse killer whale metapopulation. Heredity. ISSN 0018-067X. 134, p. 109–119. doi: 10.1038/s41437-024-00740-y. Full text in Research Archive Show summary

  Metapopulation dynamics can be shaped by foraging ecology, and thus be sensitive to shifts in prey availability. Genotyping 204 North Atlantic killer whales at 1346 loci, we investigated whether spatio-temporal population structuring is linked to prey type and distribution. Using population-based methods (reflecting evolutionary means), we report a widespread metapopulation connected across ecological groups based upon nuclear genome SNPs, yet spatial structuring based upon mitogenome haplotypes. These contrasting patterns of markers with maternal and biparental inheritance are consistent with matrilineal site fidelity and philopatry, and male-mediated gene flow among demes. Connectivity between fish-eating and ‘mixed-diet’ (eating both fish and mammal prey) killer whales, marks a deviation within a species renowned for its marked structure associated with ecology. However, relatedness estimates suggest distinct spatial clusters, and heterogeneity in recent gene flow between them. The contrasting patterns between inference of structure and inference of relatedness suggest that gene flow has been partially restricted over the past two to three generations (50–70 years). This coincides with the collapse of North Atlantic herring stocks in the late 1960s and the subsequent cessation of their seasonal connectivity. Statistically significant association between diet types and assignment of Icelandic killer whales to relatedness-based clusters indicated limited gene flow was maintained through Icelandic ‘mixed-diet’ whales when herring-mediated connectivity was diminished. Thus, conservation of dietary variation within this metapopulation is critical to ensure genetic health. Our study highlights the role of resource dynamics and foraging ecology in shaping population structure and emphasises the need for transnational management of this widespread migratory species and its prey.

• Jourdain, Eve Marie; Karoliussen, Richard; Martin, Sarah Louise; Langangen, Øystein Ole Gahr; Robeck, Todd & Borgå, Katrine [Show all 8 contributors for this article] (2024). Social and genetic connectivity despite ecological variation in a killer whale network. Proceedings of the Royal Society of London. Biological Sciences. ISSN 0962-8452. 291(2021). doi: 10.1098/rspb.2024.0524. Full text in Research Archive Show summary

  Philopatric kin-based societies encourage a narrow breadth of conservative behaviours owing to individuals primarily learning from close kin, promoting behavioural homogeneity. However, weaker social ties beyond kin, and across a behaviourally diverse social landscape, could be sufficient to induce variation and a greater ecological niche breadth. We investigated a network of 457 photo-identified killer whales from Norway (548 encounters in 2008–2021) with diet data available (46 mixed-diet individuals feeding on both fish and mammals, and 411 exclusive fish-eaters) to quantify patterns of association within and between diet groups, and to identify underlying correlates. We genotyped a subset of 106 whales to assess patterns of genetic differentiation. Our results suggested kinship as main driver of social bonds within and among cohesive social units, while diet was most likely a consequence reflective of cultural diffusion, rather than a driver. Flexible associations within and between ecologically diverse social units led to a highly connected network, reducing social and genetic differentiation between diet groups. Our study points to a role of social connectivity, in combination with individual behavioural variation, in influencing population ecology in killer whales.

• Schultze, Sabrina; Langva, Hilde Kleppe; Wei, Jing; Chatzigeorgiou, Marios; Rundberget, Thomas & Hessen, Dag Olav [Show all 9 contributors for this article] (2024). Do DOM quality and origin affect the uptake and accumulation of a lipid-soluble contaminant in a filter feeding ascidian species (Ciona) that can target small particle size classes? Aquatic Toxicology. ISSN 0166-445X. 273. doi: 10.1016/j.aquatox.2024.107026. Full text in Research Archive Show summary

  The widely reported increase of terrestrial dissolved organic matter (terrDOM) in northern latitude coastal areas (“coastal darkening”) can impact contaminant dynamics in affected systems. One potential impact is based on differences in chemical adsorption processes of the molecularly larger terrDOM compared to marine DOM (marDOM) that leads to increased emulsification of lipophilic contaminants with terrDOM. Filter feeders filter large amounts of water and DOM daily and thus are directly exposed to associated contaminants through both respiration and feeding activity. Thus, increased exposure to terrDOM could potentially lead to an increase in bioaccumulation of lipid soluble contaminants in filter feeders. To assess the effect of DOM on bioaccumulation in filter feeders, we exposed the mucous based filter feeding ascidian Ciona intestinalis (formerly known as Ciona intestinalis Type B), to the lipophilic veterinary drug teflubenzuron (log KOW: 5.39) in combination with four DOM treatments: TerrDOM, marDOM, a mix of the two called mixDOM, and seawater without DOM addition. The exposure lasted for 15 days, after which the individuals in all DOM treatments showed a trend towards higher bioaccumulation of Teflubenzuron than those in the seawater control. However, there was considerable overlap in posterior distributions. Against our expectations, marDOM resulted in the highest bioaccumulation factor (BAF), followed by mixDOM, with terrDOM resulting in the lowest BAF except for seawater (kinetic BAF L/kg median, 2.5 %–97.5 % percentile marDOM 94, 74–118; mixDOM 82, 63–104; terrDOM 79; 61-99; seawater 61, 44–79). All BAFs were below the level of concern according to the EU REACH regulation (BAF < 2000 L / kg) and, therefore, likely not environmentally problematic in the examined context. However, the results show that DOM can act as a dietary vector; thus, different combinations of contaminants, DOM, and filter feeding organisms should be tested further.

• Mariussen, Espen; Alexander, Jan; Bukhvalova, Barbara Alexandra; Dahl, Lisbeth Jane; Olsen, Ann-Karin Hardie & Kvalem, Helen Engelstad [Show all 12 contributors for this article] (2024). Risk assessment of grilled and barbecued food. VKM Report. 2024(2), p. 1–116. Full text in Research Archive Show summary

  When grilling, more harmful substances can be formed than when frying in a pan. For most people, there is a low risk associated with eating grilled food. Grilling food at a high temperature and/or on a campfire, often, and eating a lot of it may damage one's health. Distance to the heat source, how early food is placed onto the grill, and the type of fuel used can affect the formation of harmful substances. It is known that heat treatment such as grilling and frying can give rise to unwanted toxic compounds in the food, so-called process-induced contaminants. Grilling is a common way of preparing food in Norway, and the grilling season has become longer. The food selection has become ever wider and sales of different types of grills are increasing. Many factors may thus have changed since VKM's previous assessment of health risks from the consumption of grilled food, which was published in 2007. To be able to give current and relevant advice to consumers and others who sell or offer grilled food, the Norwegian Food Safety Authority has asked VKM for updated knowledge about the formation of process-induced contaminants in different food products by different grilling methods, and an assessment of what risk this may pose. Main findings: Harmful substances can be formed at high cooking temperatures. When grilling, the temperature is higher and less controllable than when frying in a pan. There is good evidence that two groups of genotoxic and carcinogenic substances, heterocyclic amines (HAA) and polycyclic aromatic hydrocarbons (PAH), are formed in higher concentrations in grilled food than in fried food. VKM has assessed PAH, for which there are good studies of occurrence in barbecued food. PAHs are formed when fat burns after dripping from the food onto the heat source. PAHs can also be released from coal, briquettes and wood. The smoke with PAH settles on the food. The occurrence of PAH in grilled food varies greatly and depends on how the food is grilled. The concentration of PAH is highest in very well-done meat with a high fat content, such as pork ribs and hamburgers. The highest concentration of PAH was found in sausage grilled on a campfire. This is caused by unburnt fat or soot/smoke from the fire that stick to the sausage. By avoiding fat dripping directly onto the heat source, preventing smoke from coming into contact with the food, and not overcooking the food, the amount of PAH in grilled food can be reduced. When using charcoal, the PAH emission is higher immediately after lighting, and the amount of PAH in the food can be reduced by waiting sufficiently long before start grilling. It is not the number of times you grill that is a critical factor, but how. A "worst-case" scenario shows that the annual consumption of more than 15-25 meals that have been grilled in a way that produces a high PAH incidence may provide too low margin of exposure* for the risk to be low. If, on the other hand, you prefer lean barbecue food that is not overcooked, then you can eat it more than 100 times a year according to our calculations and still have a high enough margin of exposure. * Margin of exposure is the ratio between the lowest dose (reference point) that causes increased cancer in experimental animals and the calculated intake. Exposure margin below 10,000 is considered a public health concern. Norsk: Ved grilling kan det dannes flere helseskadelige stoffer enn ved steking i panne. For de fleste er det lav risiko knyttet til å spise grillmat.

• Remili, Anaïs; Dietz, Rune; Sonne, Christian; Samarra, Filipa I. P.; Rikardsen, Audun H. & Kettemer, Lisa Elena [Show all 16 contributors for this article] (2023). Quantitative fatty acid signature analysis reveals a high level of dietary specialization in killer whales across the North Atlantic. Journal of Animal Ecology. ISSN 0021-8790. 92(6), p. 1216–1229. doi: 10.1111/1365-2656.13920. Full text in Research Archive Show summary

  Quantifying the diet composition of apex marine predators such as killer whales (Orcinus orca) is critical to assessing their food web impacts. Yet, with few exceptions, the feeding ecology of these apex predators remains poorly understood. Here, we use our newly validated quantitative fatty acid signature analysis (QFASA) approach on nearly 200 killer whales and over 900 potential prey to model their diets across the 5000 km span of the North Atlantic. Diet estimates show that killer whales mainly consume other whales in the western North Atlantic (Canadian Arctic, Eastern Canada), seals in the mid-North Atlantic (Greenland), and fish in the eastern North Atlantic (Iceland, Faroe Islands, Norway). Nonetheless, diet estimates also varied widely among individuals within most regions. This level of inter-individual feeding variation should be considered for future ecological studies focusing on killer whales in the North Atlantic and other oceans. These estimates reveal remarkable population- and individual-level variation in the trophic ecology of these killer whales, which can help to assess how their predation impacts community and ecosystem dynamics in changing North Atlantic marine ecosystems. This new approach provides researchers with an invaluable tool to study the feeding ecology of oceanic top predators.

• Schultze, Sabrina; Andersen, Tom; Knudtzon, Nina; Ruus, Anders; Rundberget, Jan T. & Brooks, Steven J. [Show all 9 contributors for this article] (2023). Do DOM quality and origin affect the uptake and accumulation of lipid-soluble contaminants in coastal filter feeders? An experimental simulation of teflubenzuron exposure to blue mussels. Aquatic Toxicology. ISSN 0166-445X. 263. doi: 10.1016/j.aquatox.2023.106696. Full text in Research Archive Show summary

  The increased export of terrestrial dissolved organic matter (terrDOM) to coastal marine ecosystems may affect local filter feeders and the local food web via the altered uptake of organic material and associated contaminants. To compare terrDOM to marine DOM (marDOM) as contaminant vectors to coastal biota, we exposed blue mussels (Mytilus sp.) to the different DOM types in combination with teflubenzuron, a widely applied lipophilic aquaculture medicine targeting salmon lice (Lepeophtheirus salmonis). A 16-day exposure of the blue mussels to DOM and teflubenzuron was followed by a depuration phase of 20 days without teflubenzuron. We calculated teflubenzuron adsorption rates and bioaccumulation factors (BAF) using a Bayesian model, expecting teflubenzuron uptake to be greater with terrDOM than marDOM due to the higher prevalence of large amphipathic humic acids in terrDOM. Humic acids have strong absorption properties and are able to envelope lipophilic molecules. Thus, humic acids can function as an efficient contaminant vector when taken up by filter feeders. Although there were varying degrees of overlap, the mussels tended to accumulate higher amounts of teflubenzuron in the DOM treatments than in the seawater control (bioaccumulation factor [BAF] in seawater: median 106 L/kg; 2.5 %–97.5 % percentile: 69–160 L/kg). Contrary to expectations, mussels exposed to marDOM showed a trend toward more bioaccumulation of teflubenzuron than those exposed to terrDOM (BAF marine 144 L/kg; 102–221 L/kg versus BAF terrestrial: 121 L/kg; 82–186 L/kg). The highest teflubenzuron accumulation was observed with the 50:50 mixture of marDOM and terrDOM (BAF mix: 165 L/kg; 117–244 L/kg). The slight difference in DOM-type accumulation rates observed in this experiment—especially the accumulation rate of terrDOM compared to that of the seawater-only treatment type—was not considered environmentally relevant. Further studies are necessary to see if the observed trends transfer to complex environmental systems.

• Lyche, Jan Ludvig; Boahene, Nana Yaa; Eklo, Ole Martin; Holth, Tor Fredrik; Dirven, Hubert & Engeset, Dagrun [Show all 8 contributors for this article] (2022). Risikovurdering av kombinasjonseffekter av plantevernmiddelrester i stikkprøver fra importerte rosiner, druer, pærer og norske jordbær. Vitenskapelig uttalelse fra faggruppen for plantevernmidler i Vitenskapskomiteen for mat og miljø. VKM Report. Full text in Research Archive
• Keilen, Ellen Kristine; Borgå, Katrine; Thorstensen, Helene Skjeie; Hylland, Ketil; Helberg, Morten & Warner, Nicholas Alexander [Show all 9 contributors for this article] (2022). Differences in Trophic Level, Contaminant Load, and DNA Damage in an Urban and a Remote Herring Gull (Larus argentatus) Breeding Colony in Coastal Norway. Environmental Toxicology and Chemistry. ISSN 0730-7268. 41(10), p. 2466–2478. doi: 10.1002/etc.5441. Full text in Research Archive Show summary

  Herring gulls (Larus argentatus) are opportunistic feeders, resulting in contaminant exposure depending on area and habitat. We compared contaminant concentrations and dietary markers between two herring gull breeding colonies with different distances to extensive human activity and presumed contaminant exposure from the local marine diet. Furthermore, we investigated the integrity of DNA in white blood cells and sensitivity to oxidative stress. We analyzed blood from 15 herring gulls from each colony—the urban Oslofjord near the Norwegian capital Oslo in the temperate region and the remote Hornøya island in northern Norway, on the Barents Sea coast. Based on d13C and d34S, the dietary sources of urban gulls differed, with some individuals having a marine and others a more terrestrial dietary signal. All remote gulls had a marine dietary signal and higher relative trophic level than the urban marine feeding gulls. Concentrations (mean ± standard deviation [SD]) of most persistent organic pollutants, such as polychlorinated biphenyl ethers (PCBs) and perfluorooctane sulfonic acid (PFOS), were higher in urban marine (PCB153 17 ± 17 ng/g wet weight, PFOS 25 ± 21 ng/g wet wt) than urban terrestrial feeders (PCB153 3.7 ± 2.4 ng/g wet wt, PFOS 6.7 ± 10 ng/g wet wt). Despite feeding at a higher trophic level (d15N), the remote gulls (PCB153 17 ± 1221 ng/g wet wt, PFOS 19 ± 1421 ng/g wet wt) were similar to the urban marine feeders. Cyclic volatile methyl siloxanes were detected in only a few gulls, except for decamethylcyclopentasiloxane in the urban colony, which was found in 12 of 13 gulls. Only hexachlorobenzene was present in higher concentrations in the remote (2.6 ± 0.42 ng/g wet wt) compared with the urban colony (0.34 ± 0.33 ng/g wet wt). Baseline and induced DNA damage (doublestreak breaks) was higher in urban than in remote gulls for both terrestrial and marine feeders.

• Schultze, Sabrina; Andersen, Tom; Hessen, Dag Olav; Ruus, Anders; Borgå, Katrine & Poste, Amanda (2022). Land-cover, climate and fjord morphology drive differences in organic matter and nutrient dynamics in two contrasting northern river-fjord systems. Estuarine, Coastal and Shelf Science. ISSN 0272-7714. 270. doi: 10.1016/j.ecss.2022.107831. Full text in Research Archive Show summary

  Climate and land-use changes are leading to impacts on individual ecosystems as well as shifts in transfer dynamics between interconnected systems. At the land-ocean interface, changes in riverine inputs of organic matter (OM) and nutrients have the potential to lead to shifts in coastal carbon and nutrient cycling with consequences for ecosystem structure and function. In this study, we assess OM and nutrient dynamics for two contrasting Norwegian river-to-fjord systems: a boreal system with a forested catchment draining into a narrow fjord (‘narrow boreal system’), and a subarctic system where lowland forests and mountainous regions drain into a broad fjord (‘broad subarctic system’). We characterized seasonal organic carbon and nutrient concentrations and DOM absorption properties for samples collected along transects from river to outer fjord during 2015/2016. While differences in catchment properties drove contrasts in river chemistry between the two study rivers, fjord morphology and hydrodynamics as well as dissolved organic carbon (DOC) and nutrient concentrations in marine receiving waters predicted water-chemistry patterns along the transect. The narrow boreal system, with high riverine DOC and nutrient concentrations, was structured mainly by a horizontal salinity gradient from river to outer fjord, with limited impact of seasonality. In contrast, the broad subarctic system tended to be dominated by vertical salinity stratification, with strong between-date differences in surface water salinity linked to seasonality in river discharge. These dynamics were also reflected in the strong horizontal gradients in DOC, nutrients and DOM properties in the narrow boreal system, in contrast to the broad subarctic system, where strong seasonality paired with a lack of strong contrast between riverine and marine concentrations of DOC and most nutrients led to an uncoupling between salinity and other water chemistry variables. In the narrow boreal system, terrestrial OM dominated both the particulate and dissolved OM pools, while OM in the broad subarctic system was derived primarily from marine phytoplankton. Non-linear declines in NO3 + NO2 were observed consistently in the boreal system and during the productive spring season in the subarctic system, suggesting biological uptake and a potentially important role of these rivers as sources of bioavailable N to coastal ecosystems. The results from these two case studies highlight the complex and interacting effects of catchment land-cover, river water chemistry and discharge, fjord morphometry and hydrodynamics in structuring the transport, fate and potential impacts of terrestrially-derived nutrients and organic matter in northern coastal environments.

• Allan, Ian; Vrana, Branislav & Ruus, Anders (2022). Passive Sampling Helps the Appraisal of Contaminant Bioaccumulation in Norwegian Fish Used for Regulatory Chemical Monitoring. Environmental Science and Technology. ISSN 0013-936X. 56(12), p. 7945–7953. doi: 10.1021/acs.est.2c00714. Full text in Research Archive Show summary

  Hexachlorobenzene (HCB), listed on the Stockholm Convention on persistent organic pollutants and regulated as a hazardous priority pollutant by the Water Framework Directive (WFD), is ubiquitously distributed in the environment and assumed to mildly biomagnify in aquatic foodwebs. The proposal to include trophic magnification factors (TMFs) in the procedure for comparing contaminant levels in biota at different trophic levels (TLs) with WFD environmental quality standards requires adequate selection of TMFs. In the first step of our study, we compared two independently obtained datasets of pentachlorobenzene (PeCB) and HCB concentration ratios from passive sampling (PS) in water and in fish through routine monitoring programs in Norway to evaluate possible biomagnification. In this procedure, PeCB is used for benchmarking the bioconcentration in fish, and the observed HCB/PeCB ratios in fish are compared with ratios expected in the case of (i) HCB bioconcentration or (ii) biomagnification using published TMF values. Results demonstrate that it is not possible to confirm that HCB biomagnifies in fish species that would be used for WFD monitoring in Norway and challenges the proposed monitoring procedures for such compounds in Norwegian or European waters. In the second step, fish-water chemical activity ratios for HCB and PeCB as well as for polychlorinated biphenyls where biota and PS were conducted alongside were calculated and found to rarely exceed unity for cod (Gadus morhua), a fish species with a TL of approximately 4.

• Mcgovern, Maeve; Warner, Nicholas Alexander; Borgå, Katrine; Evenset, Anita; Carlsson, Pernilla & Skogsberg, Emelie [Show all 10 contributors for this article] (2022). Is Glacial Meltwater a Secondary Source of Legacy Contaminants to Arctic Coastal Food Webs? Environmental Science and Technology. ISSN 0013-936X. 56(10), p. 6337–6348. doi: 10.1021/acs.est.1c07062. Full text in Research Archive Show summary

  Climate change-driven increases in air and sea temperatures are rapidly thawing the Arctic cryosphere with potential for remobilization and accumulation of legacy persistent organic pollutants (POPs) in adjacent coastal food webs. Here, we present concentrations of selected POPs in zooplankton (spatially and seasonally), as well as zoobenthos and sculpin (spatially) from Isfjorden, Svalbard. Herbivorous zooplankton contaminant concentrations were highest in May [e.g., ∑polychlorinated biphenyls (8PCB); 4.43, 95% CI: 2.72–6.3 ng/g lipid weight], coinciding with the final stages of the spring phytoplankton bloom, and lowest in August (∑8PCB; 1.6, 95% CI: 1.29–1.92 ng/g lipid weight) when zooplankton lipid content was highest, and the fjord was heavily impacted by sediment-laden terrestrial inputs. Slightly increasing concentrations of α-hexachlorocyclohexane (α-HCH) in zooplankton from June (1.18, 95% CI: 1.06–1.29 ng/g lipid weight) to August (1.57, 95% CI: 1.44–1.71 ng/g lipid weight), alongside a higher percentage of α-HCH enantiomeric fractions closer to racemic ranges, indicate that glacial meltwater is a secondary source of α-HCH to fjord zooplankton in late summer. Except for α-HCH, terrestrial inputs were generally associated with reduced POP concentrations in zooplankton, suggesting that increased glacial melt is not likely to significantly increase exposure of legacy POPs in coastal fauna.

• Mcgovern, Maeve; Borgå, Katrine; Heimstad, Eldbjørg Sofie; Ruus, Anders; Christensen, Guttorm & Evenset, Anita (2022). Small Arctic rivers transport legacy contaminants from thawing catchments to coastal areas in Kongsfjorden, Svalbard. Environmental Pollution (1987). ISSN 0269-7491. 304. doi: 10.1016/j.envpol.2022.119191. Full text in Research Archive Show summary

  Decades of atmospheric and oceanic long-range transport from lower latitudes have resulted in deposition and storage of persistent organic pollutants (POPs) in Arctic regions. With increased temperatures, melting glaciers and thawing permafrost may serve as a secondary source of these stored POPs to freshwater and marine ecosystems. Here, we present concentrations and composition of legacy POPs in glacier- and permafrost-influenced rivers and coastal waters in the high Arctic Svalbard fjord Kongsfjorden. Targeted contaminants include polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs) and chlordane pesticides. Dissolved (defined as fraction filtered through 0.7 μm GF/F filter) and particulate samples were collected from rivers and near-shore fjord stations along a gradient from the heavily glaciated inner fjord to the tundra-dominated catchments at the outer fjord. There were no differences in contaminant concentration or pattern between glacier and tundra-dominated catchments, and the general contaminant pattern reflected snow melt with some evidence of pesticides released with glacial meltwater. Rivers were a small source of chlordane pesticides, DDTs and particulate HCB to the marine system and the particle-rich glacial meltwater contained higher concentrations of particle associated contaminants compared to the fjord. This study provides rare insight into the role of small Arctic rivers in transporting legacy contaminants from thawing catchments to coastal areas. Results indicate that the spring thaw is a source of contaminants to Kongsfjorden, and that expected increases in runoff on Svalbard and elsewhere in the Arctic could have implications for the contamination of Arctic coastal food-webs.

• Haarr, Ane; Mwakalapa, Eliezer B.; Lyche, Jan Ludvig; Mmochi, Aviti J.; Polder, Anuschka & Ruus, Anders [Show all 7 contributors for this article] (2021). Spatial Variation in Contaminant Occurrence in Marine Fishes and Prawns from Coastal Tanzania. Environmental Toxicology and Chemistry. ISSN 0730-7268. 41(2), p. 321–333. doi: 10.1002/etc.5254. Full text in Research Archive Show summary

  There are limited data on organic contaminants in marine biota from coastal Tanzania, especially on the occurrence of industrial-use contaminants such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The present study, performed in 2018–2019 in coastal Tanzania and Zanzibar Island, aimed at assessing spatial variation in the occurrence of PCBs; brominated flame retardants (BFRs), including PBDEs; and organochlorine pesticides, including dichlorodiphenyltrichloroethane (DDT), among three locations that differ in degree of anthropogenic activity. Analyzed samples included edible tissues of marine fishes and prawns representing different trophic levels and habitats. The results indicate a mainland–island difference, with fishes and prawns collected on Zanzibar having significantly lower PCB and DDT concentrations but higher concentrations of hexachlorobenzene compared to the two mainland locations. The highest contaminant concentrations were found in fishes and prawns collected around central Dar es Salaam harbor, with median ΣPCBs ranging from 22.3 to 577 ng/g lipid weight and ΣDDTs from 22.7 to 501 ng/g lipid weight, suggesting local sources. Concentrations of PBDEs were similar among locations, suggesting more diffuse sources. None of the “newer-type” BFRs, including compounds introduced as replacements for PBDEs, were detected in the present study. Stable isotope values of carbon (δ13C) and nitrogen (δ15N) varied among locations, and the relationship between contaminants and δ15N varied among locations and habitat (pelagic/demersal). Concentrations measured in the present study are below European guidelines for human consumption of fishes and prawns. However, industrial-use contaminants should be monitored in developing countries because they are contaminants of emerging concern as a result of increasing industrialization and global trade of used products and wastes.

• Grung, Merete; Meland, Sondre; Ruus, Anders; Ranneklev, Sissel; Fjeld, Eirik & Kringstad, Alfhild [Show all 9 contributors for this article] (2021). Occurrence and trophic transport of organic compounds in sedimentation ponds for road runoff. Science of the Total Environment. ISSN 0048-9697. 751. doi: 10.1016/j.scitotenv.2020.141808. Full text in Research Archive Show summary

  Sedimentation ponds have been shown to accumulate several groups of contaminants, most importantly polycyclic aromatic compounds (PACs) and metals. But also, other urban organic pollutants have shown to be present, including polybrominated diphenyl ethers (PBDEs), organophosphate compounds (OPCs) and benzothiazoles (BTs). This investigation aimed at determining the occurrence of these four groups of contaminants in sedimentation ponds and determine their transport from water/sediment to organisms. PACs, including alkylated PACs, PBDEs; OPCs and BTs were determined in water, sediment, plants, dragonfly larvae and fish from two sedimentation ponds and one reference site. Fish were analysed for PAC metabolites. Overall, higher concentrations of all four pollutant groups were detected in water and sediment from sedimentation ponds compared to two natural lakes in rural environments (reference sites). The concentration difference was highest in sediments, and >20 higher concentration was measured in sedimentation ponds (3.6–4.4 ng/g ww) compared to reference (0.2 ng/g ww) for sum BDE6. For PACs and PBDEs a clear transport from water/sediment to organisms were observed. Fish were the highest trophic level organism (3.5–5) in our study, and all four pollutant groups were detected in fish. For PBDEs a trophic biomagnification (TMF) was found both in sedimentation ponds and reference, but higher concentrations in all matrices were measured in sedimentation ponds. TMF was not calculated for PACs since they are metabolised by vertebrates, but a transfer from water/sediment to organisms was seen. For BTs and OPCs, no consistent transfer to plants and dragonfly larvae could be seen. One OPC and two BTs were detected in fish, but only in fish from sedimentation ponds. It is therefore concluded that sedimentation ponds are hotspots for urban and traffic related contaminants, of which especially PACs and PBDEs are transferred to organisms living there.

• Haarr, Ane; Mwakalapa, Eliezer B; Mmochi, Aviti J; Lyche, Jan L; Ruus, Anders & Othman, Halima [Show all 8 contributors for this article] (2021). Seasonal rainfall affects occurrence of organohalogen contaminants in tropical marine fishes and prawns from Zanzibar, Tanzania. Science of the Total Environment. ISSN 0048-9697. 774. doi: 10.1016/j.scitotenv.2021.145652. Full text in Research Archive Show summary

  Seasonal differences in precipitation may affect contaminant dynamics in tropical coastal regions due to terrestrial runoff of contaminants to the marine environment after the rainy seasons. To assess the effect of seasonal rainfall on occurrence of organohalogen contaminants in a coastal ecosystem, marine fishes and prawns were collected off the coast of Zanzibar, Tanzania in January and August 2018, representing pre- and post-rainy season, respectively. Samples were analyzed for organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and emerging BFRs, as well as the dietary descriptors stable isotopes of carbon (δ13C) and nitrogen (δ15N). Across all species and seasons, mean contaminant concentrations ranged from below limit of detection (LOD) to 129 ng/g lipid weight (lw) ΣPCBs; 5.6–336 ng/g lw ΣOCPs; and < LOD –22.1 ng/g lw ΣPBDEs. Most of the emerging BFRs were below LOD. Contaminant concentrations generally increased with higher pelagic carbon signal (δ13C) and higher relative trophic position (δ15N). The ratio of DDE/ΣDDTs in fishes and prawns was lower in August than in January, suggesting runoff of non-degraded DDT into the marine system during or after the seasonal rainfall. Contaminant patterns of OCPs and PCBs, and concentrations of BFRs, differed between seasons in all species. A higher relative concentration-increase in lower halogenated, more mobile PCB and PBDE congeners, compared to higher halogenated congeners with lower mobility, between January and August aligns with a signal and effect of terrestrial runoff following the rainy season.

• Allan, Ian John; Vrana, Branislav; Weert, Jasperien de; Kringstad, Alfhild; Ruus, Anders & Christensen, Guttorm [Show all 8 contributors for this article] (2021). Passive sampling and benchmarking to rank HOC levels in the aquatic environment. Scientific Reports. 11. doi: 10.1038/s41598-021-90457-3. Full text in Research Archive Show summary

  The identification and prioritisation of water bodies presenting elevated levels of anthropogenic chemicals is a key aspect of environmental monitoring programmes. Albeit this is challenging owing to geographical scales, choice of indicator aquatic species used for chemical monitoring, and inherent need for an understanding of contaminant fate and distribution in the environment. Here, we propose an innovative methodology for identifying and ranking water bodies according to their levels of hydrophobic organic contaminants (HOCs) in water. This is based on a unique passive sampling dataset acquired over a 10-year period with silicone rubber exposures in surface water bodies across Europe. We show with these data that, far from point sources of contamination, levels of hexachlorobenzene (HCB) and pentachlorobenzene (PeCB) in water approach equilibrium with atmospheric concentrations near the air/water surface. This results in a relatively constant ratio of their concentrations in the water phase. This, in turn, allows us to (i) identify sites of contamination with either of the two chemicals when the HCB/PeCB ratio deviates from theory and (ii) define benchmark levels of other HOCs in surface water against those of HCB and/or PeCB. For two polychlorinated biphenyls (congener 28 and 52) used as model chemicals, differences in contamination levels between the more contaminated and pristine sites are wider than differences in HCB and PeCB concentrations endorsing the benchmarking procedure.

• Ruus, Anders; Allan, Ian J; Bæk, Kine & Borgå, Katrine (2021). Partitioning of persistent hydrophobic contaminants to different storage lipid classes. Chemosphere. ISSN 0045-6535. 263. doi: 10.1016/j.chemosphere.2020.127890. Full text in Research Archive Show summary

  Lipids generally represent the major matrix contributing to the absorptive capacity for hydrophobic organic contaminants in aquatic ecosystems. The aim of the present study was to determine whether contaminants partition to a different degree to the different storage lipid classes: wax ester (WE) and triacylglycerol (TAG). This was undertaken by studying experimentally the partitioning of organochlorine compounds between lipids (WE or TAG) and silicone rubber phase. Our results indicate that hydrophobic compounds have a slightly higher affinity for WE than for TAG. The findings thus corroborate earlier suggestions that contaminants accumulate to a greater extent in food webs with a higher reliance of on WE, such as in the Arctic. This knowledge is of interest since it implies that possible changes in planktonic community species composition, and thereby possible changes in the lipid composition, may have consequences for accumulation of hydrophobic contaminants in apex predators. However, the magnitude of these consequences remains unknown, and there may well be other factors of importance for previously observed higher accumulation of contaminants in Arctic systems. Thus, we have here identified aspects regarding partitioning of contaminants to lipids that need further scrutiny, and there is a need for further quantitative estimates of the suggested difference in absorptive capacities for hydrophobic contaminants between WE and TAG.

• Eklo, Ole Martin; Boahene, Nana Yaa; Holth, Tor Fredrik; Klein, Michael; Dirven, Hubert & Engeset, Dagrun [Show all 9 contributors for this article] (2021). Establishing the representativeness of available surface water scenarios for plant protection products in environmental risk assessment in Norway. Opinion of the Panel on Plant protection Products of the Norwegian Scientific Committee for Food and Environment. VKM Report. Full text in Research Archive
• Knudtzon, Nina C; Thorstensen, Helene; Ruus, Anders; Helberg, Morten; Bæk, Kine & Enge, Ellen Katrin [Show all 7 contributors for this article] (2021). Maternal transfer and occurrence of siloxanes, chlorinated paraffins, metals, PFAS and legacy POPs in herring gulls (Larus argentatus) of different urban influence. Environment International. ISSN 0160-4120. 152. doi: 10.1016/j.envint.2021.106478. Full text in Research Archive Show summary

  Urban herring gulls (Larus argentatus) are exposed to contaminants from aquatic, terrestrial and anthropogenic sources. We aim to assess if differences in urbanisation affect ecological niche and contaminant concentrations in female herring gulls. Furthermore, we investigated maternal transfer from mothers to eggs for all the target compounds, including chlorinated paraffins (CPs) and cyclic volatile methyl siloxane (cVMSs), which to our knowledge have not been assessed in herring gulls previously. We compare concentrations of legacy and emerging contaminants and metals in blood and eggs between two herring gull colonies located 51 km apart, in the urban influenced Norwegian Oslofjord. While both colonies are within an urbanised area, the inner fjord is more so, as it is surrounded by Oslo, the capital and largest city in Norway Stable isotopes of carbon and nitrogen indicated a more marine ecological niche in the outer than the inner fjord colony, although with overlap. Persistent organic pollutant (POP) concentrations were similar in the inner and outer fjord colonies, while the short-chained chlorinated paraffins (SCCP), which are recently added to the Stockholm convention and contaminants of emerging concern (CECs) varied, with higher concentrations of SCCP and the cVMS decamethylcyclopentasiloxane (D5) in females and eggs of the inner fjord colony. Per- and polyfluorinated substances (PFAS) concentrations were higher in the outer fjord colony, likely linked to releases from a point-source (airport and waste management facility with open access to food waste). In blood, chlorinated paraffins contributed most the total lipophilic contaminants (inner: 78%, outer: 56%), while polychlorinated biphenyls (PCBs) were the most abundant lipophilic contaminants in eggs (inner: 62%, outer: 46%). Dechloranes and brominated flame retardants (BFRs) were detected in few samples. Maternal transfer, assessed by egg to blood ratios, of cVMSs were similar to the POPs with mean log ratio 0.39 (D5), while it was lower for SCCPs, with log ratios-0.77. Our results indicate comparable POP exposure of the herring gulls in the inner and outer Oslofjord, likely due to overlap in ecological niches between the colonies and wide distribution of POPs. The differences between the colonies in concentrations of PFAS, cVMS and CPs shows that point source exposures and urban influence may be more important than ecological niche for these compounds.

• Thorstensen, Helene; Ruus, Anders; Helberg, Morten; Bæk, Kine; Enge, Ellen Katrin & Borgå, Katrine (2020). Common Eider and Herring Gull as Contaminant Indicators of Different Ecological Niches of an Urban Fjord System. Integrated Environmental Assessment and Management (IEAM). ISSN 1551-3777. 17(2), p. 422–433. doi: 10.1002/ieam.4340. Full text in Research Archive Show summary

  Seabirds like gulls are common indicators in contaminant monitoring. The herring gull (Larus argentatus) is a generalist with a broad range of dietary sources, possibly introducing a weakness in its representativeness of aquatic contamination. To investigate the herring gull as an indicator of contamination in an urban‐influenced fjord, the Norwegian Oslofjord, we compared concentrations of a range of lipophilic and protein‐associated organohalogen contaminants (OHCs), Hg, and dietary markers in blood (n = 15), and eggs (n = 15) between the herring gull and the strict marine‐feeding common eider (Somateria mollissima) in the breeding period of May 2017. Dietary markers showed that the herring gull was less representative of the marine food web than the common eider. We found higher concentrations of lipophilic OHCs (wet weight and lipid weight) and Hg (dry weight) in the blood of common eider (mean ± SE ∑PCB = 210 ± 126 ng/g ww, 60 600 ± 28 300 ng/g lw; mean Hg = 4.94 ± 0.438 ng/g dw) than of the herring gull (mean ± SE ∑PCB = 19.0 ± 15.6 ng/g ww, 1210 ± 1510 ng/g lw; mean Hg = 4.26 ± 0.438 ng/g dw). Eggs gave opposite results; higher wet weight and lipid weight OHC concentrations in the herring gull (mean ± SE ∑PCB = 257 ± 203 ng/g ww, 3240 ± 2610 ng/g lw) than the common eider (mean ± SE ∑PCB = 18.2 ± 20.8 ng/g ww, 101 ± 121 ng/g lw), resulting in higher OHC maternal transfer ratios in gulls than eiders. We suggest that the matrix differences are due to fasting during incubation in the common eider. We suggest that in urban areas, herring gull might not be representative as an indicator of marine contamination but rather urban contaminant exposure. The common eider is a better indicator of marine pollution in the Oslofjord. The results are influenced by the matrix choice, as breeding strategy affects lipid dynamics regarding the transfer of lipids and contaminants to eggs and remobilization of contaminants from lipids to blood during incubation, when blood is drawn from the mother. Our results illustrate the benefit of a multispecies approach for a thorough picture of contaminant status in urban marine ecosystems. Integr Environ Assess Manag 2020;00:1–12. © 2020 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC)

• Jourdain, Eve; Andvik, Clare; Karoliussen, Richard; Ruus, Anders; Vongraven, Dag & Borgå, Katrine (2020). Isotopic niche differs between seal and fish-eating killer whales (Orcinus orca) in northern Norway. Ecology and Evolution. 10(9), p. 4115–4127. doi: 10.1002/ece3.6182. Full text in Research Archive Show summary

  Ecological diversity has been reported for killer whales (Orcinus orca) throughout the North Atlantic but patterns of prey specialization have remained poorly understood. We quantify interindividual dietary variations in killer whales (n = 38) sampled throughout the year in 2017–2018 in northern Norway using stable isotopic nitrogen (δ15N: 15N/14N) and carbon (δ13C: 13C/12C) ratios. A Gaussian mixture model assigned sampled individuals to three differentiated clusters, characterized by disparate nonoverlapping isotopic niches, that were consistent with predatory field observations: seal‐eaters, herring‐eaters, and lumpfish‐eaters. Seal‐eaters showed higher δ15N values (mean ± SD: 12.6 ± 0.3‰, range = 12.3–13.2‰, n = 10) compared to herring‐eaters (mean ± SD: 11.7 ± 0.2‰, range = 11.4–11.9‰, n = 19) and lumpfish‐eaters (mean ± SD: 11.6 ± 0.2‰, range = 11.3–11.9, n = 9). Elevated δ15N values for seal‐eaters, regardless of sampling season, confirmed feeding at high trophic levels throughout the year. However, a wide isotopic niche and low measured δ15N values in the seal‐eaters, compared to that of whales that would eat solely seals (δN‐measured = 12.6 vs. δN‐expected = 15.5), indicated a diverse diet that includes both fish and mammal prey. A narrow niche for killer whales sampled at herring and lumpfish seasonal grounds supported seasonal prey specialization reflective of local peaks in prey abundance for the two fish‐eating groups. Our results, thus, show differences in prey specialization within this killer whale population in Norway and that the episodic observations of killer whales feeding on prey other than fish are a consistent behavior, as reflected in different isotopic niches between seal and fish‐eating individuals.

• Andvik, Clare Margaret; Jourdain, Eve; Ruus, Anders; Lyche, Jan Ludvig; Karoliussen, Richard & Borgå, Katrine (2020). Preying on seals pushes killer whales from Norway above pollution effects thresholds. Scientific Reports. 10. doi: 10.1038/s41598-020-68659-y. Full text in Research Archive Show summary

  Killer whales (Orcinus orca) are at risk from high levels of biomagnifying pollutants, such as polychlorinated biphenyls (PCBs) and mercury (Hg). Previous toxicological risk assessments for the Norwegian killer whale population have assumed fish as the primary prey source, and assessed the population as below established effect thresholds. However, some individuals have recently been identified to also feed on seals. This study is the first to quantify levels of pollutants in seal-eating killer whales from northern Norway, and to measure Hg levels in the skin of killer whales worldwide. We found higher levels of all pollutants in seal-eating than fish-eating killer whales, including the emerging brominated flame retardants pentabromoethylbenzene (PBEB), pentabromotoluene (PBT) and hexabromobenzene (HBB). Sum polychlorinated biphenyls (ΣPCBs) in the blubber of seal-eaters (n = 7, geometric mean = 46 µg/g l.w.) were four times higher than fish-eaters (n = 24, geometric mean = 11 µg/g l.w.), which pushed all seal-eating individuals above multiple thresholds for health effects. Total Hg levels in skin of seal-eaters (n = 10, arithmetic mean = 3.7 µg/g d.w.) were twice as high as in fish-eaters (n = 28, arithmetic mean = 1.8 µg/g d.w.). Our results indicate that by feeding on higher trophic prey, the Norwegian killer whale population is at higher risk of health effects from pollution than previously assumed.

• Ono, Kotaro; Knutsen, Halvor; Olsen, Esben M; Ruus, Anders; Hjermann, Dag Ø & Stenseth, Nils Chr (2019). Possible adverse impact of contaminants on Atlantic cod population dynamics in coastal ecosystems. Proceedings of the Royal Society of London. Biological Sciences. ISSN 0962-8452. 286(1908), p. 1–9. doi: 10.1098/rspb.2019.1167. Full text in Research Archive Show summary

  While many in-laboratory ecotoxicological studies have shown the adverse impact of pollutants to the fitness of an individual, direct evidence from the field on the population dynamics of wildlife animals has been lacking. Here, we provide empirical support for a negative effect of pollution on Atlantic cod (Gadus morhua) population dynamics in coastal waters of Norway by combining unique time series of juvenile cod abundance, body size, environmental concentration of toxic contaminants and a spatially structured population dynamics model. The study shows that mercury concentration might have decreased the reproductive potential of cod in the region despite the general decline in the environmental concentration of mercury, cadmium and hexachlorobenzene since the implementation of national environmental laws. However, some cod populations appeared to be more resistant to mercury pollution than others, and the strength and shape of mercury effect on cod reproductive potential was fjord-specific. Additionally, cod growth rate changed at scales smaller than fjords with a gradient related to the exposure to the open ocean and offshore cod. These spatial differences in life-history traits emphasize the importance of local adaptation in shaping the dynamics of local wildlife populations. Finally, this study highlights the possibility to mitigate pollution effects on natural populations by reducing the overall pollution level, but also reveals that pollution reduction alone is not enough to rebuild local cod populations. Cod population recovery probably requires complementary efforts on fishing regulation and habitat restoration.

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• Alexander, Jan; Kvalem, Helen Engelstad; Mariussen, Espen; Schlabach, Martin; Steffensen, Inger-Lise Karin & Hannisdal, Rita [Show all 12 contributors for this article] (2025). Protokoll: Krav til konsekvensutredning ved planlegging av vindkraftprosjekter for å hindre forurensning av drikkevann. VKM Bulletin. VKM Bulletin(VKM Bulletin 2025: 03), p. 1–10. Full text in Research Archive Show summary

  VKM skal lage oversikt over hvilke krav som bør stilles til konsekvensutredninger ved planlegging av nye vindkraftprosjekter. Det er laget en protokoll som beskriver hvordan VKM vil gå frem for å løse oppdraget. Bakgrunn for oppdraget Et vindkraftverk kan forurense omgivelsene både under etablering, drift og avvikling. Dersom området ligger innenfor et vanntilsigsområde for drikkevann, kan det utgjøre en forurensningsfare for drikkevannet. Mattilsynet er høringsinstans når vindkraftverk skal etableres, og de ønsker en oversikt over hvilke krav som bør stilles til konsekvensutredningene. Dette er en bestilling fra Mattilsynet, som fører tilsyn med drikkevann. Om protokollen VKM har utarbeidet en protokoll for hvordan vi skal løse oppdraget som går på å utarbeide krav til informasjon om, og risikovurdering av farene ved søknad om etablering av vindkraftverk. Protokollen favner bruk av kjemiske stoffer og annen aktuell forurensing som kan utgjøre en risiko for drikkevann gjennom hele vindkraftverkets livsløpssyklus (anlegg, drift, vedlikehold og avvikling)

• Milne, Stephanie; Andvik, Clare Margaret; Jourdain, Eve Marie; Karoliussen, Richard; Vongraven, Dag & Øien, Nils Inge [Show all 8 contributors for this article] (2024). Temporal trends of dietary patterns and mercury in Norwegian killer whales from contrasting ecosystem states. Full text in Research Archive
• Lee, Kiah Jane Oland; Jourdain, Eve Marie; Remili, Anaïs; Andvik, Clare Margaret; Fagerlund, Carl Johan Ludwig & McKinney, Melissa [Show all 8 contributors for this article] (2024). Profiling the diet of Norwegian killer whales through quantitative fatty acid signature analysis (QFASA) and mercury accumulation. Full text in Research Archive
• Andvik, Clare Margaret; Jourdain, Eve Marie; Dulgheriu, Daniela; Lyche, Jan Ludvig; Karoliussen, Richard & Ruus, Anders [Show all 7 contributors for this article] (2024). Blubber Cortisol Levels in Norwegian Killer Whales: Accounting for Individual Variation is Vital in Assessing Stress Responses to Whale Watching. Full text in Research Archive
• Jourdain, Eve Marie; Borgå, Katrine; Ruus, Anders & Andvik, Clare Margaret (2023). Spekkhoggerflokken trues av gammel gift. Forskerne følger dem tett. [Journal]. Titan.uio.no. Full text in Research Archive
• Schultze, Sabrina; Langva, Hilde K.; Knudtzon, Nina Cathrine; Chatzigeorgiou, Marios; Rundberget, Jan Thomas & Brooks, Steven [Show all 11 contributors for this article] (2023). Increases in Terrestrial Dissolved Organic Matter Will Not Increase Feeding Related Uptake of a common Lipid Soluble Contaminant In coastal Filter Feeders. Full text in Research Archive
• Schultze, Sabrina; Langva, Hilde K.; Knudtzon, Nina Cathrine; Chatzigeorgiou, Marios; Rundberget, Jan Thomas & Brooks, Steven [Show all 11 contributors for this article] (2023). Terrestrial dissolved organic matter is not an efficent vector for lipohilic contaminants in filter feeders. Full text in Research Archive
• Fagerlund, Carl Johan Ludwig; Jourdain, Eve Marie; Andvik, Clare Margaret; Yuan, Bo; Ruus, Anders & Borgå, Katrine (2023). Understanding mercury and chlorinated paraffins biomagnification by identifying dietary patterns in killer whales in Norway. Full text in Research Archive
• Andvik, Clare Margaret; Jourdain, Eve Marie; Ruus, Anders & Borgå, Katrine (2023). Effect of multiple stressors on Norwegian killer whales (MULTIWHALE). Full text in Research Archive
• Andvik, Clare Margaret; Jourdain, Eve Marie; Ruus, Anders & Borgå, Katrine (2023). Effect of multiple stressors on Norwegian killer whales (MULTIWHALE). Full text in Research Archive
• Ruus, Anders; Xie, Li; Petersen, Karina; Færgestad, Eline Mosleth; Heimstad, Eldbjørg Sofie & Harju, Mikael [Show all 7 contributors for this article] (2022). Characterisation and evaluation of the environmental risk of stormwater emissions from Oslo, Norway. Full text in Research Archive
• Petersen, Karina; Xie, Li; Wolf, Raoul; Ruus, Anders; Færgestad, E. M. & Tollefsen, Knut-Erik (2022). Characterisation of cumulative risk of pollutants to marine organisms in Sørfjorden, Norway. Full text in Research Archive
• Schultze, Sabrina; Langva, Hilde K.; Nina, Knudtzon; Chatzigeorgiou, Marios; Rundberget, Thomas & Brooks, Steven [Show all 11 contributors for this article] (2022). Effect of terrestrial and aquatic dissolved organic matter on uptake of teflubenzuron in mussels and ascidians. Full text in Research Archive
• Petersen, Karina; Xie, Li; Wolf, Raoul; Ruus, Anders; Færgestad, E. M. & Tollefsen, Knut-Erik (2022). Characterisation of cumulative risk of pollutants to marine organisms in Sørfjorden, Norway. Full text in Research Archive
• Ruus, Anders; Xie, Li; Wolf, Raoul; Petersen, Karina; Færgestad, E. M. & Heimstad, Eldbjørg Sofie [Show all 8 contributors for this article] (2022). Characterisation of cumulative risk of contaminants to organisms exposed to stormwater in Oslo, Norway. Full text in Research Archive
• Petersen, Karina; Xie, Li; Wolf, Raoul; Ruus, Anders; Færgestad, E. M. & Heimstad, Eldbjørg Sofie [Show all 8 contributors for this article] (2022). Characterisation of cumulative risk of pollutants to marine organisms in Sørfjorden, Norway. Full text in Research Archive
• Ruus, Anders; Xie, Li; Wolf, Raoul; Petersen, Karina; Færgestad, E. M. & Heimstad, Eldbjørg Sofie [Show all 8 contributors for this article] (2022). Characterisation of cumulative risk of contaminants to organisms exposed to stormwater in Oslo, Norway. Full text in Research Archive
• Hancke, Kasper; Gundersen, Hege; Borgersen, Gunhild; d'Auriac, Marc Anglès; Ruus, Anders & Andersen, Guri Sogn [Show all 7 contributors for this article] (2022). Det Nordiske blått karbonbudsjettet. Full text in Research Archive
• Gundersen, Hege; Hancke, Kasper; Borgersen, Gunhild; d'Auriac, Marc Anglès; Ruus, Anders & Andersen, Guri Sogn [Show all 7 contributors for this article] (2022). Det Nordiske Blått karbon-prosjektet. Full text in Research Archive
• Schultze, Sabrina; Andersen, Tom; Knudtzon, Nina Cathrine; Ruus, Anders; Rundberget, Jan Thomas & Brooks, Steven [Show all 9 contributors for this article] (2021). Effect of terrestrial and aquatic dissolved organic matter on uptake rates of teflubenzuron in blue mussels (M. edulis). Full text in Research Archive
• Rodriguez, Simon; Borgå, Katrine; Gomes, Tania; Lillicrap, Adam David; Martins, Samantha Eslava & Ruus, Anders [Show all 7 contributors for this article] (2021). Antifoulants, Veterinary Medicinal Products and Organic Material can affect marine sediment organisms, but to what extent? - ANTIVENOM. Full text in Research Archive
• Rodriguez, Simon; Borgå, Katrine; Gomes, Tania; Lillicrap, Adam David; Petersen, Karina & Ruus, Anders [Show all 7 contributors for this article] (2021). Antifoulants, veterinary medicinal products and organic material can affect marine sediment organisms, but to what extent? – ANTIVENOM. Full text in Research Archive
• Knudtzon, Nina Cathrine; Thorstensen, Helene; Ruus, Anders; Helberg, Morten; Bæk, Kine & Enge, Ellen Katrin [Show all 7 contributors for this article] (2021). Maternal Transfer and Occurrence of Siloxanes, Chlorinated Paraffins and Legacy POPs in Herring Gulls (Larus argentatus) of Different Urban Influence. Full text in Research Archive
• Hancke, Kasper; Gundersen, Hege; Borgersen, Gunhild; d'Auriac, Marc Anglès; Ruus, Anders & Andersen, Guri Sogn [Show all 7 contributors for this article] (2020). The Nordic Blue Carbon Project: Updates on the marine carbon cycle and estimates of an overall budget for carbon capture, export and storage in Nordic blue forests. Full text in Research Archive
• Thorstensen, H. S.; Ruus, Anders; Helberg, Morten; Bæk, Kine; Enge, Ellen Katrin & Borgå, Katrine (2020). Herring gull and common eider as indicators of contaminants in an urban fjord. Full text in Research Archive
• Andvik, Clare Margaret; Jourdain, Eve Marie; Ruus, Anders; Lyche, Jan Ludvig; Karoliussen, Richard & Borgå, Katrine (2020). At risk: Preying on seals pushes killer whales from Norway above pollution effects thresholds. Full text in Research Archive
• Ruus, Anders; Helberg, Morten; Knudtzon, Nina Cathrine; Bæk, Kine; Enge, Ellen Katrin & Borgå, Katrine (2020). Emerging and legacy contaminants in two urban herring gull colonies. Full text in Research Archive
• Ruus, Anders; Helberg, Morten; Bæk, Kine; Enge, Ellen Katrin & Borgå, Katrine (2020). Common eider and herring gull as indicators of contaminants in an urban fjord system. Full text in Research Archive
• Ruus, Anders; Wolf, Raoul; Petersen, Karina & Tollefsen, Knut-Erik (2020). CHARACTERISATION OF CUMULATIVE RISK OF CONTAMINANTS TO ORGANISMS EXPOSED TO STORMWATER IN OSLO, NORWAY. Full text in Research Archive
• Moe, Jannicke; Ruus, Anders; Hjermann, Dag Øystein & Macken, Ailbhe Lisette (2020). A Bayesian Network Model for Assessment of Chemical Status in Fjords Affected by Aluminium Smelters. Full text in Research Archive
• Petersen, Karina; Wolf, Raoul; Ruus, Anders & Tollefsen, Knut-Erik (2020). Characterisation of cumulative risk of pollutants to marine organisms in Sørfjorden, Norway. Full text in Research Archive
• Ruus, Anders; Wolf, Raoul; Petersen, Karina & Tollefsen, Knut-Erik (2020). Characterisation of cumulative risk of contaminants to organisms exposed to stormwater in Oslo, Norway. Full text in Research Archive
• Beyer, Jonny; Walday, Mats Gunnar; Ruus, Anders; Yakushev, Evgeniy; Jartun, Morten & Lusher, Amy L. [Show all 7 contributors for this article] (2026). Miljøforurensning fra Fritidsbåtvrak i Oslofjorden. Norsk institutt for vannforskning (NIVA). ISSN 9788257779474. Full text in Research Archive Show summary

  Oslofjorden inneholder tusenvis av fritidsbåtvrak, de fleste av glassfiber, noe som vekker bekymring for utslipp av mikroplast og olje, PAH, tungmetaller, antibegroingsmidler, bromerte flammehemmere og andre miljøgifter. På oppdrag fra Handelens Miljøfond har NIVA utviklet et kunnskapsgrunnlag og en forenklet miljørisikovurderingsmodell basert på et representativt «typevrak». Vi har også laget et interaktivt vrakkart og modellert spredningen av mikroplast i fjorden. Risikovurderingen viser at utlekkinger av forurensning fra enkeltvrak påvirker hovedsakelig nærområdet, men den samlede effekten av mange vrak over tid kan være mer bekymringsfull. Dette gjelder særlig for nedbrytning av glassfibermaterialer til mikroplast, selv om kunnskapen om langtidsvirkninger fra slik forurensning fortsatt er svært begrenset. Vrakbåter på bunnen kan også fungere som kunstige rev og gi lokale økologiske fordeler, men samtidig også tiltrekke organismer til områder med høyere forurensning. NIVA anbefaler bedre kartlegging av dyptliggende vrak i Oslofjorden og integrering av mikroplast fra vrak i bredere miljørisikovurderinger. Vår forenklede tilnærming/metode for miljørisikovurdering kan også ytterligere forbedres/valideres for bruk som verktøy innen tiltaksrettet miljørisikovurdering og håndtering av marine fritidsbåtvrak.

• Ruus, Anders & Ranneklev, Sissel Brit (2026). Vurdering av miljøkonsekvens – endring av grenseverdier for utslipp fra Boliden Odda AS. Norsk institutt for vannforskning (NIVA). ISSN 9788257779542. Full text in Research Archive Show summary

  I forbindelse med ombygging av eksisterende Hg vannrenseanlegg har Boliden Odda intensjon om å søke Miljødirektoratet om utvidede grenser for utslipp av noen metaller i en periode, før ombyggingen og påfølgende optmalisering er ferdig. Her vurderes konsekvenser for miljøet av en slik utvidelse. Det gis en utredning av hva de økte mengdene representer, samt hva konsentrasjonene i ønsket årsmiddelgrense representerer, for Sørfjorden som resipient. Mer spesifkt gis en kort redegjørelse for overvåking og tilstand i Sørfjorden. Tilleggsmengden av metaller Boliden Odda ønsker tillatelse til å slippe ut i en toårsperiode (utover nåværende konsesjon) settes i perspektv med eksisterende utslipp og tillatelser til Sørforden, samt med andre tilførsler til fjorden. Mengdene settes også i perspektiv med den eksisterende mengde metaller i sedimentene. Det gis også en beskrivelse av fortynninger av utslippet i resipienten, med sammenligninger med grenseverdiene i Vannforskriften.

• Ruus, Anders; Grung, Merete; Bæk, Kine; Rundberget, Thomas; Beylich, Bjørnar & Hanssen, Linda [Show all 8 contributors for this article] (2026). Environmental Contaminants in an Urban Fjord, 2025. Norsk institutt for vannforskning (NIVA). ISSN 9788257779498. Full text in Research Archive Show summary

  This report presents data from the last year of a 5-year period of the Urban Fjord programme. The programme started in 2013 and has since been altered/advanced. In 2025 the programme covers sampling and analyses of sediment, polychaetes, krill, shrimps, blue mussels, herring, cod, eider, and herring gull from the Inner Oslofjord. A total of 230 single compounds/isomers were analysed, and frequent detection was found of specific PFAS compounds (e.g. PFOS) in most matrices, certain QACs in several matrices (ATAC-C22 in all matrices), specific benzothiazoles in eider blood, LCCPs in certain matrices, certain siloxanes in most matrices, metals in all matrices and PCBs in all matrices. Biomagnification was observed for 24 PCB congeners, LCCPs and D4 (siloxane; lipid wt. basis). Furthermore, biomagnification was observed for PFOSA, ATAC-C20 and ATAC-C22, as well as for the metals As and Hg (wet wt. basis).

• Ruus, Anders & Mengeot, Caroline (2026). Overvåking av kystvann i vannområde Hardanger 2025. Norsk institutt for vannforskning (NIVA). ISSN 9788257779184. Full text in Research Archive Show summary

  Overvåkingen av kystvann i vannområdet Hardanger i 2025 viste følgende: Mhp. de fysisk-kjemiske kvalitetselementene viste oksygen(minimum-)konsentrasjoner god (S22Sør og S1/4) til moderat (Lind1 og S7/2) tilstand. Siktedypet tilsvarte moderat tilstand på alle disse fire stasjonene. Vannregionspesifikke stoffer (Zn) i vann overskred grenseverdien i overflatevann på alle stasjonene hvor vann er analysert (Lind1, Sø7/2, S22Sør og S1/4). Ingen av de undersøkte prioriterte stoffer oversteg grenseverdiene i overflatevann. Konsentrasjonene av kvikksølv i blåskjell var for høye til å klassifisere kjemisk tilstand som god, på samtlige stasjoner hvor blåskjell er analysert. Konsentrasjoner av fluorid i sjøvann var oftest lavere enn kvantifiseringsgrensen (i hovedsak <0,50 mg/L). Konsentrasjoner av fluorid i blåskjell var lave (gjennomsnitt av triplikater 1,26 –2,12 mg/kg våtvekt). Det ble observert lave konsentrasjoner av thallium i prøver av overflatevann, kun konsentrasjoner ≤0,05 µg/L Tl. Thallium ble funnet i blåskjell i gjennomsnittskonsentrasjoner på 0,002-0,007 mg/kg våtvekt.

• Ruus, Anders; Borgersen, Gunhild; Grung, Merete; Mannvik, Hans Petter & Palerud, Rune (2025). Utredning for etablering av grenseverdier, tilstandsklasser og risikovurdering for sediment - petroleumsvirksomhet til havs. Norsk institutt for vannforskning (NIVA). ISSN 9788257778880. Full text in Research Archive Show summary

  Miljødirektoratet har ønsket å få utredet mulighetene for etablering av grenseverdier, tilstandsklasser og risikoveileder for forurenset sediment fra petroleumsvirksomhet til havs. Resultatene fra dette arbeidet skal gi Miljødirektoratet et grunnlag for å senere vurdere en eventuell utlysning av oppdrag om faktisk utarbeidelse av hhv. grenseverdier og tilstandsklasser for sediment til havs, samt en risikoveileder for forurenset sediment til havs. Det konkluderes i denne utredningen med at det bør være mulig å komme frem til grenseverdier, tilstandsklasser og risikoveileder og her presenteres relevant kunnskap og faglige råd for veien mot dette. Når det gjelder kunnskap om bunndyrsamfunn, er datagrunnlaget omfattende og anses som tilstrekkelig til å utarbeide grenseverdier og tilstandsklasser basert på allerede innsamlede data.

• Schøyen, Merete; Grung, Merete; Lund, Espen; Hjermann, Dag Øystein; Ruus, Anders & Øxnevad, Sigurd [Show all 15 contributors for this article] (2025). Contaminants in coastal waters 2024: Miljøgifter i kystområdene 2024. Norsk institutt for vannforskning (NIVA). ISSN 9788257778965. Full text in Research Archive Show summary

  The Norwegian environmental monitoring programme “Contaminants in coastal waters” (Miljøgifter i kystområdene - MILKYS) examines the levels, trends, and effects of contaminants annually in biota along the Norwegian fjords and coastline including Svalbard. The 2024 investigation included analyses of more than 180 different contaminants or biological effect methods (BEM) in five species (blue mussel, cod, dogwhelk, common periwinkle, and common eider). The contaminants measured include metals, TBT, PCBs, PAHs, PBDEs, PFAS, HBCDs, chlorinated paraffins, siloxanes, and pesticides. BEM includes imposex (VDSI) and intersex (ISI), PAH-metabolites, ALA-D, and EROD. The 2024 optional monitoring also included sediment cores (Oslo, Bergen, and Tromsø) and alternative species (whiting, pollack, and haddock) for cod in the Inner Oslofjord. In this report, 37 contaminants and in addition, BEM were chosen for in-depth presentations. EQSs (Environmental Quality Standards) were exceeded in blue mussel (16%), cod (37%), and common eider (22%) expressed as datapoints (contaminants x stations). Contaminants above EQSs were mercury (Hg), sumPCB7, and sumBDE6. PROREFs (Norwegian provisional high reference contaminant concentrations) were exceeded in blue mussel (35%) and cod (11%) expressed as datapoints (contaminants x stations), and exceedances were higher in mussel (10-20x PROREF) than for cod (5-10x PROREF). Significant downward time trends for specific contaminants/effects dominated both recent (≤10 years) and whole period (>10 years) where trends could be statistically detected. The OSPAR method for time trends, HARSAT was used. The highest occurrences of upward whole and recent trends were found for blue mussel in the Inner Oslofjord, and for cod at Lista and Sandnessjøen. Biological effect parameters showed no effects of TBT in snail, but confirmed exposure to PAH and lead in cod. The additional monitoring showed that sediments from the Inner Oslofjord had higher frequency of exceedances of EQS than close to Bergen and Tromsø. Whiting seems to be the most appropriate species for monitoring as an alternative to cod, compared to pollack and haddock, based on biology and comparisons of contaminant levels in the Inner Oslofjord.

• Ruus, Anders; Grung, Merete; Bæk, Kine; Rundberget, Thomas; Vogelsang, Christian & Beylich, Bjørnar [Show all 12 contributors for this article] (2025). Environmental Contaminants in an Urban Fjord, 2024 – Emphasis on Alna River. Norsk institutt for vannforskning (NIVA). ISSN 9788257778552. Full text in Research Archive Show summary

  This report presents data from the fourth year of a 5-year period of the Urban Fjord programme. The programme started in 2013 and has since been altered/advanced. In 2024 the programme covers sampling and analyses of water, water moss, invertebrates, and trout from Alna River, as well as stormwater from Eastern Oslo City. A sampling campaign was also conducted for source tracing of chlorhexidine, dichloromethane and trichloromethane previously found in Alna River. A total of 240 single compounds/isomers were analyzed, and frequent detection was found of specifc PFAS compounds in aqueous phases, other specifc PFAS compounds in trout liver, UV-compounds and certain QACs in the particulate fraction of stormwater, certain benzothiazoles in stormwater (dissolved and/or particulate fraction) , chlorinated paraffns (MCCP and LCCP) in biota, certain siloxanes in nearly all matrices, metals in all matrices, and PCBs in biota. Biomagnifcation was only observed for a couple of the PCB congeners. However, as expected, biomagnifcation was observed for mercury and PFOS. Biomagnifcation of silver was observed when trout was represented by liver samples, but not muscle samples. The source tracing showed the presence of the compounds at several stations

• Ruus, Anders; Borgersen, Gunhild & Mengeot, Caroline (2025). Overvåking av kystvann i vannområde Hardanger 2024. Norsk institutt for vannforskning (NIVA). ISSN 9788257778071. Full text in Research Archive Show summary

  Overvåkingen av kystvann i vannområdet Hardanger i 2024 viste følgende: Bløtbunnsfauna viste god til moderat (kun Sø7/2) tilstand. Mhp. de fysiskkjemiske kvalitetselementene viste oksygen(minimum-) konsentrasjoner god (S22Sør og S1/4) til moderat (Lind1 og S7/2) tilstand. Siktedypet tilsvarte moderat tilstand på alle disse fire stasjonene. Vannregionspesifikke stoffer (Zn) i vann overskred grenseverdien på stasjonene Lind1, Sø7/2, S22Sør og S1/4. Det ble også registrert overskridelser av grenseverdier for vannregionspesifikke stoffer i sediment på samtlige stasjoner hvor sediment er analysert. Dette begrenser økologisk tilstand til moderat. Også prioriterte stoffer i sediment oversteg grenseverdiene og førte til at god kjemisk tilstand ikke ble oppnådd på alle stasjoner hvor sediment er analysert. Ingen av de undersøkte prioriterte stoffer oversteg grenseverdiene i overflatevann. Konsentrasjonene av kvikksølv i blåskjell var for høye til å klassifisere kjemisk tilstand som god, på samtlige stasjoner hvor blåskjell er analysert. Kvikksølv i brosme fra ytre Sørfjorden var også for høy til å klassifiseres som god kjemisk tilstand. Konsentrasjoner av fluorid i sjøvann var oftest lavere enn kvantifiseringsgrensen på 0,50 mg/L. Konsentrasjoner av fluorid i blåskjell var lave (<1 – 1,75 mg/kg våtvekt). Det ble observert lave konsentrasjoner av thallium i prøver av overflatevann, og for det meste konsentrasjoner ≤0,05 μg/L Tl. Tl kunne ikke detekteres i blåskjell (kvantifiseringsgrense: 0,1 mg/kg vv). I brosme var gjennomsnittskonsentrasjonen av Tl 0,002 mg/kg våtvekt.

• Jonsson, Henrik; Staalstrøm, Andre; Eek, Espen; Norling, Magnus; Ruus, Anders & Dillinger, Benno (2024). Forprosjekt Ren Frier. Norsk institutt for vannforskning (NIVA). ISSN 9788257776732. Full text in Research Archive Show summary

  Rapporten benytter simuleringer til å utrede bidraget som f.eks. skipstrafikk inkl. oppankringsaktivitet, har på spredning av dioksinforbindelser fra sjøbunnen i Frierfjorden, samt effekten av tiltak i havne- og oppankringsområder. Et av de viktigste funnene i prosjektet er at skipsaktivitet i Frierfjorden fører til fire ganger høyere partikkelkonsentrasjon i vannsøylen utenfor Herøya havn enn hva som er normalt bakgrunnsnivå i fjorden. Et forandret sjøtrafikkbilde er simulert ved å endre partiklenes resuspensjonsrate inkl. konsentrasjonen av organiske partikler (POC) i vannsøylen. Simuleringene viser at oppvirvlet sediment fordeles over et stort område og derfor har begrenset virkning på sedimentene i andre delområder av Frierfjorden. Skipstrafikk gir derimot en signifikant økning i mengden oppvirvlede dioksinforbindelser i vannmassene, noe som utgjør en økt risiko for eksponering og opptak i marine organismer. Simulering av tiltak (tildekking eller mudring) viser begrenset effekt på konsentrasjoner i sedimentene, men betydelig effekt på mengden resuspenderte partikler i vannmassene. Tiltak i Herøya havn er identifisert å gi størst virkning på mengden resuspenderte partikler i vannmassene utenfor selve tiltaksområdet.

• Schøyen, Merete; Grung, Merete; Lund, Espen; Hjermann, Dag Øystein; Ruus, Anders & Øxnevad, Sigurd [Show all 14 contributors for this article] (2024). Contaminants in coastal waters 2023. Norsk institutt for vannforskning (NIVA). ISSN 9788257777593. Full text in Research Archive Show summary

  The Norwegian environmental monitoring programme “Contaminants in coastal waters” (Miljøgifter i kystområdene - MILKYS) examines the levels, trends, and effects of contaminants annually in biota along the Norwegian fjords and coastline including Svalbard. The 2023 investigation included analyses of more than 180 different contaminants or biological effect methods (BEM) in five species (blue mussel, cod, dogwhelk, common periwinkle, and common eider). The contaminants measured include metals, TBT, PCBs, PAHs, PBDEs, PFAS, HBCDs, chlorinated paraffins, siloxanes, and pesticides. BEM include imposex (VDSI) and intersex (ISI), PAH-metabolites, ALA-D, and EROD. In this report, 37 contaminants and in addition, BEM were chosen for in-depth presentation. EQSs (Environmental Quality Standards) were exceeded in blue mussel (21 %), cod (36 %) and common eider (25 %) expressed as datapoints (contaminants x stations). Contaminants above EQSs were mercury (Hg), sumPCB7 and sumBDE6. The sum of exceedances (sum of risk quotients) was highest in cod from the Inner Oslofjord. PROREFs (Norwegian provisional high reference contaminant concentrations) were exceeded in blue mussel (42 %) and cod (15 %) expressed as datapoints (contaminants x stations), and exceedances were higher in mussel (up to >20x PROREF) than for cod (5-10x PROREF). The sum of PROREFratio above background levels were highest in blue mussel from Gressholmen followed by Akershuskaia in the harbour of the Inner Oslofjord. Significant downward time trends for specific contaminants/effects dominated both recent (≤ 10 years) and whole period (>10 years) where trends could be statistically detected, still some significant upward trends were observed for contaminants exceeding EQS and/or PROREF. A recently published OSPAR method was used for trends, and the highest occurrence of upward whole and recent trends were found for blue mussel in the Inner Oslofjord, and for cod at Lista and Sandnessjøen. BEM (biomarker analysis) showed no effects of TBT in snail but confirm exposure of PAH and lead in cod. Cod health parameters varied among stations, with lowest rank (lowest health condition) in cod from the Inner Oslofjord.

• Schøyen, Merete; Lund, Espen; Hjermann, Dag Øystein; Ruus, Anders; Beylich, Bjørnar & Jenssen, Marthe Torunn Solhaug [Show all 12 contributors for this article] (2024). Contaminants in coastal waters of Norway 2020. Norsk institutt for vannforskning (NIVA). ISSN 9788257777388. Full text in Research Archive Show summary

  The monitoring programme “Contaminants in coastal waters of Norway” (Miljøgifter i norske kystområder - MILKYS) examines levels, trends and effects of contaminants in biota. The 2020-investigation included analyses of more than 176 different contaminants or biological effect parameters in six species (blue mussel, cod, dogwhelk, common periwinkle, flounder and common eider). The contaminants measured includes metals (Hg, Cd, Pb, Cu, Zn, Ag, As, Ni, Cr and Co), tributyltin (TBT), organochlorines (e.g. PCBs (PCB-7), DDT, HCB, OCS and QCB), PAHs, polybrominated diphenyl ethers (PBDEs), perfluorinated alkylated substances (PFAS), hexabromocyclododecane (α-, γ- and β HBCD), chlorinated paraffins (SCCP, MCCP) and siloxanes (D4, D5 and D6). Biological effects parameters include imposex (VDSI) and intersex (ISI), OH-pyrene metabolites as a marker of PAH-exposure, ALA-D as a marker of exposure to lead, and EROD as a marker to exposure to planar PCBs, PAHs and dioxines. In this report, 30 contaminants or biological effects parameters were chosen for statistical analyses of 739 time series (short-term trends for the last 10 years). Of these, there were statistically significant trends in 96 cases: 67 (9.1 %) were downwards and 29 (3.9 %) upwards. The dominance of downward trends indicated that contamination was decreasing. The downward trends were primarily associated with metals, α-HBCD and PBDEs, and the upward trends with metals. Of the 2020-medians for all 739 time series, 380 cases could be classified against EQS, of which 264 (35.7 %) were below the EQS and 116 (15.7 %) were above. Of the 739 time series, 644 cases could be classified using Norwegian provisional high reference contaminant concentrations (PROREF). Of these, 447 (69.4 %) were below PROREF. The remaining 197 (30.6 %) cases exceeded PROREF: 105 (16.3 %) by a factor of less than two, 57 (8.9 %) by a factor between two and five, 30 (4.7 %) by a factor between five and 10, three (0.5 %) by a factor between 10 and 20, and two (0.3 %) by a factor greater than 20. Some cases warrant special concern, such as high concentrations of several organic contaminants in cod liver from the Inner Oslofjord.

• Schøyen, Merete; Grung, Merete; Lund, Espen; Hjermann, Dag Øystein; Ruus, Anders & Øxnevad, Sigurd [Show all 13 contributors for this article] (2024). Contaminants in coastal waters 2021. Norsk institutt for vannforskning (NIVA). ISSN 9788257777395. Full text in Research Archive Show summary

  The Norwegian environmental monitoring programme “Contaminants in coastal waters” (Miljøgifter i kystområdene - MILKYS) examines levels, trends, and effects of contaminants in biota. The 2021 investigation included analyses of more than 180 different contaminants or biological effect parameters in five species (blue mussel, cod, dogwhelk, common periwinkle, and common eider). The contaminants measured include metals, TBT, PCBs, PAHs, PBDEs, PFAS, HBCDs, chlorinated paraffins, siloxanes, and pesticides. Biological effect parameters investigated include imposex (VDSI) and intersex (ISI), PAH-metabolites, ALA-D, and EROD. In this report, 27 contaminants and in addition, biological effect parameters were chosen for in-depth presentation. EQSs (environmental quality standard) were exceeded in samples of blue mussel (21%), cod (36%), and eider (23%). Contaminants above EQSs were sumPBDE6, mercury (Hg), sumPCB7, and fluoranthene. PROREF (Norwegian provisional high reference contaminant concentration) was exceeded for 35% in blue mussel and 11% in cod, and exceedances were higher in mussel (up to >20x PROREF) than cod (2-5x PROREF). Even though decreasing time trends dominated both long-term (>10 years) and short-term (≤ 10 years) where trends could be detected, notably increasing trends were observed which are discussed here. Notably increasing short-term trends for blue mussel were lead (Pb), chromium (Cr), arsenic (As) and some PCBs, and for cod were mercury (Hg), and silver (Ag). (Revidert utgave av rapport nr. 7784-2022)

• Schøyen, Merete; Grung, Merete; Lund, Espen; Hjermann, Dag Øystein; Ruus, Anders & Øxnevad, Sigurd [Show all 13 contributors for this article] (2024). Contaminants in coastal waters 2022. Norsk institutt for vannforskning (NIVA). ISSN 9788257776480. Full text in Research Archive Show summary

  The Norwegian environmental monitoring programme “Contaminants in coastal waters” (Miljøgifter i kystområdene - MILKYS) examines the levels, trends, and effects of contaminants annually in biota along the Norwegian fjords and coastline including Svalbard. The 2022 investigation included analyses of more than 180 different contaminants or biological effect parameters in five species (blue mussel, cod, dogwhelk, common periwinkle, and common eider). The contaminants measured include metals, TBT, PCBs, PAHs, PBDEs, PFAS, HBCDs, chlorinated paraffins, siloxanes, and pesticides. Biological effect parameters investigated include imposex (VDSI) and intersex (ISI), PAH-metabolites, ALA-D, and EROD. In this report, 37 contaminants and in addition, biological effect parameters were chosen for in-depth presentation. EQSs (Environmental Quality Standards) were exceeded in blue mussel (15%) and cod (36%) expressed as datapoints (contaminants x stations). Contaminants above EQSs were mercury (Hg), sumPCB7, sumPBDE6, and MCCP. The sum of exceedances (sum of risk quotients) was highest in cod from the Inner Oslofjord. PROREFs (Norwegian provisional high reference contaminant concentrations) were exceeded in blue mussel (38%) and cod (9%) expressed as datapoints (contaminants x stations), and exceedances were higher in mussel (up to 10-20x PROREF) than cod (5-10x PROREF). The sum of PROREFratio above background levels were highest in blue mussel from Akershuskaia in the harbour of the Inner Oslofjord. Significant decreasing time trends for specific contaminants/effects dominated both long-term (> 10 years) and short-term (≤ 10 years) where trends could be detected, still some significant increasing trends were observed for contaminants exceeding EQS and/or PROREF. Notably significant increasing short-term trends were found for lead (Pb), chromium (Cr), and some PCBs in blue mussel, and for mercury, and silver (Ag) in cod.

• Frigstad, Helene; Ramon, Paula; Borgersen, Gunhild; Engesmo, Anette; Staalstrøm, Andre & Naustvoll, Lars Johan [Show all 22 contributors for this article] (2024). Tilstandsrapport for Oslofjorden. Norsk institutt for vannforskning (NIVA). ISSN 9788257777739. Full text in Research Archive Show summary

  I 2021 la regjeringen frem en helhetlig tiltaksplan som viser regjeringens viktigste prioriteringer for å gjøre Oslofjorden ren, rik og tilgjengelig for alle fram mot 2026. Tilstandsrapport for Oslofjorden, ledet av NIVA i samarbeid med HI, NINA, NMBU og UiO, gir en oversikt over miljøtilstanden i Oslofjorden de siste 5-10 årene og utviklingen de siste 10-50 årene. Oslofjorden har opplevd negativ utvikling på grunn av blant annet forurensing, overfiske og bygging i strandnære områder. Klimaendringer forventes å forverre situasjonen ytterligere. Økologisk tilstand viser forbedring i Indre Oslofjord, men forverring i Ytre Oslofjord og Skagerrak. For miljøgifter er det ofte overskridelser av grenseverdier for kjemisk tilstand. Blåskjell, dyreplankton, sjøpattedyr, fisk og sjøfugler er viktige indikatorer på fjordens helse, men det er registret nedgang i mange arter, spesielt for torskebestanden. Utbredelse av stortareskog, sukkertareskog og ålegressenger er redusert, og det er økt forekomst av lurv. Flere arter og naturtyper er regnet som truet og rødlistet. Det er registrert flere fremmede arter, som utgjør en økologisk risiko i Oslofjorden.

• Ruus, Anders; Grung, Merete; Bæk, Kine; Rundberget, Thomas; Vogelsang, Christian & Beylich, Bjørnar [Show all 11 contributors for this article] (2024). Environmental Contaminants in an Urban Fjord, 2023. Norsk institutt for vannforskning (NIVA). ISSN 9788257777319. Full text in Research Archive Show summary

  This report presents data from the third year of a new 5-year period of the Urban Fjord programme. The programme started in 2013 and has since been altered/advanced. In 2023 the programme covers sampling and analyses of sediment, blue mussels and cod from the Inner Oslofjord, as well as water and trout from Alna River. In addition, samples of stormwater, and waste water from Bekkelaget wastewater treatment plant, are analysed. A total of ∼230 single compounds/isomers were analysed, and frequent detection was found of specific PFAS compounds in aqueous phases, other specific PFAS compounds in fish liver, certain QACs in particulate phases, certain benzothiazoles in aqueous phases, chlorinated paraffins (MCCP in particular) in sediment and biota, certain siloxanes in biota and particulate phases, metals in all matrices, and PCBs in sediment and biota.

• Ruus, Anders & Mengeot, Caroline (2024). Overvåking av kystvann i vannområde Hardanger 2023. Norsk institutt for vannforskning (NIVA). ISSN 9788257776855. Full text in Research Archive Show summary

  Overvåkingen av kystvann i vannområdet Hardanger i 2023 viste følgende: Mhp. de fysisk-kjemiske kvalitetselementene viste oksygen(minimum-) konsentrasjoner moderat tilstand på stasjonene Sø7/2 og Lind1 og god tilstand på stasjonene S22Sør og S1/4. Siktedypet tilsvarte dårlig tilstand på stasjon Sø7/2 og moderat tilstand på stasjonene Lind1 og S22Sør. Vannregionspesifikke stoffer i vann (metaller; særlig sink) oversteg grenseverdiene på alle stasjoner hvor vann ble analysert (Lind1, Sø7/2, S22Sør og S1/4). Det var maksimalverdi (MAC-EQS; 6 μg/L) som ble oversteget ved flere anledninger og det var vanskelig å klassifisere årsgjennomsnittlig konsentrasjon av sink, grunnet høy kvantifikasjonsgrense i 2023. Ingen analyserte prioriterte stoffer oversteg grenseverdiene (EQS) i overflatevann. Konsentrasjoner av kvikksølv i blåskjell var derimot for høye til å klassifisere kjemisk tilstand som god på samtlige stasjoner hvor blåskjell ble analysert. Kvikksølv i brosme fra ytre Sørfjorden var også for høy til å klassifiseres som god kjemisk tilstand. Konsentrasjoner av fluorid i sjøvann var oftest lavere enn kvantifiseringsgrensen på 0,50 mg/L. gjennomsnittlige konsentrasjoner av fluorid i blåskjell var lave (1,22-3,25 mg/kg våtvekt). Det ble observert lave konsentrasjoner av thallium i prøver av overflatevann, og for det meste konsentrasjoner ≤0,05 μg/L Tl. Tl ble funnet i blåskjell i gjennomsnittskonsentrasjoner på 0,002-0,005 mg/kg våtvekt.

• Gundersen, Cathrine Brecke; Nipen, Maja; Reid, Malcolm James; Ruus, Anders; Rostkowski, Pawel & Blévin, Pierre [Show all 17 contributors for this article] (2024). Screening Programme 2023. Norsk institutt for vannforskning (NIVA). ISSN 9788257777463. Full text in Research Archive Show summary

  The 2023 Screening Programme aimed to investigate the presence of emerging environmental concerning substances 1) at so-called “hot spot” locations, and 2) in marine top predators. Part 1 covered emerging substances that were considered for EU regulation; persistent, mobile and toxic; identified as problematic (Sweden); and UV-stabilizers. Sampling sites were a wastewater treatment plant, indoor dust, agricultural soils, and consumer products. Part 2 covered substances found in the 2021 Screening Programme as well as selected through the LIfeAPEX project. Additionally, in part 2, several classical legacy contaminants were included. A unique sample set was assembled with different types of tissue from whales (killer whale, sperm whale, fin whale, humpback whale, white beaked dolphin, and harbor porpoise) and sharks (greenland shark, porbeagle shark, and spiny dogfish). Highlights from the results in part 1 covered a high detection frequency and concentrations of one phthalate (CAS 6422-86-2) and two UV-stabilizers (CAS 154702-15-5 and 103597-45-1). In part 2, only a small number of the emerging substances were identified, while many of the legacy substances were found at high levels.

• Ruus, Anders & Mengeot, Caroline (2023). Overvåking av kystvann i vannområde Hardanger 2022. Norsk institutt for vannforskning (NIVA). ISSN 9788257775667. Full text in Research Archive Show summary

  Overvåkingen av kystvann i vannområdet Hardanger i 2022 viste følgende: Mhp. de fysisk-kjemiske kvalitetselementene viste oksygen(minimum-) konsentrasjoner moderat tilstand på stasjon Lind1 og god tilstand på stasjonene Sø7/2 og S22Sør. Siktedypet tilsvarte dårlig tilstand på samtlige av disse tre stasjonene. Vannregionspesifikke stoffer i vann (metaller; særlig sink) oversteg grenseverdiene (EQS) på alle stasjoner hvor vann ble analysert (Lind1, Sø7/2, S22Sør og S1/4). Ingen analyserte prioriterte stoffer oversteg grenseverdiene (EQS) i overflatevann. Konsentrasjoner av kvikksølv i blåskjell var derimot for høye til å klassifisere kjemisk tilstand som god på samtlige stasjoner hvor blåskjell ble analysert. Konsentrasjoner av fluorid i sjøvann var i hovedsak lavere enn kvantifiseringsgrensen på 1,5 mg/L. gjennomsnittlige konsentrasjoner av fluorid i blåskjell var lave (1,53- 2,24 mg/kg våtvekt). Det ble kun observert konsentrasjoner av thallium på ≤0,05 μg/L i overflatevann. Tl ble funnet i blåskjell i gjennomsnittskonsentrasjoner på 0,003-0,005 mg/kg våtvekt.

• Mariussen, MS; Strøm, V; Valseth, ÅA; Vennemo, K; Bjorbækmo, Marit & Chen, Wenting [Show all 16 contributors for this article] (2023). Mariussen MS, Strøm V, Valseth ÅA, Vennemo K, Bjorbækmo MFM, Chen W, Furuseth IS, Bekkby T, Berg PR, Saesin P, Staalstrøm A, Walday MG, Kaste Ø, Ruus A, Hess-Erga O-K, Langaas S. Mulighetskartlegging for kystbaserte næringer i Viken – Indre Oslofjord og Drammensfjorden. Vista Analyse Report 2023/11. ISBN 978-82-8126-623-0. https://www.vista-analyse.no/site/assets/files/7886/va-rapport_2023- 11_mulighetskartlegging_for_kystbaserte_naeringer_i_viken.pdf. Vista Analyse . Full text in Research Archive
• Ruus, Anders; Grung, Merete; Jartun, Morten; Bæk, Kine; Rundberget, Thomas & Beylich, Bjørnar [Show all 10 contributors for this article] (2023). Environmental Contaminants in an Urban Fjord, 2022. Norsk institutt for vannforskning (NIVA). ISSN 9788257776091. Full text in Research Archive Show summary

  This report presents data from the second year of a new 5-year period of the Urban Fjord programme. The programme started in 2013 and has since been altered/advanced. In 2022 the programme covers sampling and analyses of sediment, polychaetes, krill, shrimps, blue mussels, herring, cod, eider, and herring gull from the Inner Oslofjord. In addition, samples of Harbour seals from the Outer Oslofjord are analysed. A total of ~300 single compounds/isomers were analysed, and frequent detection was found of certain PFAS compounds (such as PFOS) in most matrices, certain QACs in sediment, MCCPs in most matrices (also SCCPs in birds and seals, as well as LCCPs in seals), D5 (siloxane) in all matrices, certain PBDEs (such as BDE 100) in most matrices, PCBs in all matrices, BCPS (phenolic) in seals and certain metals in all matrices. Biomagnification was observed for 28 PCB congeners and 6 PBDEs (lipid wt. basis). Furthermore, biomagnification was observed for 5 PFAS compounds, as well as for the metals As, Ag and Hg (wet wt. basis).

• Jartun, Morten; Økelsrud, Asle; Bæk, Kine; Rundberget, Thomas; Øxnevad, Sigurd & Ruus, Anders [Show all 11 contributors for this article] (2023). Monitoring of environmental contaminants in freshwater food webs (MILFERSK) 2022. Norsk institutt for vannforskning (NIVA). ISSN 9788257776114. Full text in Research Archive Show summary

  Samples of a benthic food chain in Lake Mjøsa have been collected, and the concentrations of emerging contaminants such as Siloxanes, PFAS, UV-compounds, Quaternary Ammonium Compounds, Musks, Benzothiazoles and Chlorinated paraffins in addition to legacy contaminants such as Mercury, other Metals and PBDEs have been determined. For comparison, samples of the top predator brown trout have been collected and analysed from Lake Femunden, a rural counterpart to the more urban Lake Mjøsa.

• Ruus, Anders; Oughton, Deborah H; Beylich, Bjørnar; Saesin, Pipatthra; Borgersen, Gunhild & Jerome, Simon Mark [Show all 9 contributors for this article] (2023). Kartlegging av radioaktive stoffer i Oslofjorden. Norsk institutt for vannforskning (NIVA). ISSN 9788257776206. Full text in Research Archive Show summary

  DSA har ønsket å undersøke om utslipp av radioaktive stoffer fra helsesektoren kan gjenfinnes i miljøet og om I-131 tas opp og/eller oppkonsentrerer i Oslofjorden. Det ble ikke funnet I-131 eller Tc-99m i biota i detekterbare mengder. Dette tyder på lavt opptak, og liten tilknyttet risiko for organismer i Oslofjorden. Lave konsentrasjoner av Tc-99m og I-131 ble målt i noen vannprøver, samt I-131 i noen sediment prøver. Lu-177 ble ikke detektert i noen prøver. Disse observasjonene er ikke i konflikt med strømningsmønsteret i området, men partiklene skal også rekke å sedimentere til bunnen, tidsnok til at deteksjon er mulig (I-131 har halveringstid på 8 døgn). Selv med fordeling av prøvene over fire ulike prøveinnsamlingstidspunkter ble det for lang tid mellom prøvetaking og måling, med så lave konsentrasjoner av kortlevde radionuklider. Med så lave nivåer må man i fremtiden ta sikte på færre prøver og enda kortere tid mellom prøvesamling og måling, kanskje ved å fokusere på et mindre geografisk område. Resultatene gir et innblikk i situasjonen før en forventet økning i bruk av nukleærmedisin ved sykehusene.

• Mariussen, Espen; Alexander, Jan; Dahl, Lisbeth; Kvalem, Helen Engelstad; Olsen, Ann-Karin Hardie & Schlabach, Martin [Show all 11 contributors for this article] (2023). Protocol for risk assessment of grilled and barbequed food. Norwegian Scientific Committee for Food and Environment . Full text in Research Archive
• Ruus, Anders; Grung, Merete; Jartun, Morten; Bæk, Kine; Rundberget, Thomas & Vogelsang, Christian [Show all 12 contributors for this article] (2022). Environmental Contaminants in an Urban Fjord, 2021. Norsk institutt for vannforskning (NIVA). ISSN 9788257774981. Full text in Research Archive Show summary

  This report presents data from the first year of a new 5-year period of the Urban Fjord programme. The programme started in 2013 and has since been altered/advanced. In 2021 the programme covers sampling and analyses of stormwater, river water, effluent from a wastewater treatment plant (inputs to the fjord), fjord sediment, blue mussel, cod and (river) trout, all from the Inner Oslofjord area. A total of 260 single compounds/isomers were analysed and frequent detection was found of benzothiazoles in abiotic aqueous phases, UV-compounds in most matrices, metals in all matrices, PBDEs in biota, chlorinated paraffins in all matrices and PCBs in biota and abiotic particle phases. Four

• Jonsson, Henrik; Ruus, Anders & Staalstrøm, Andre (2022). Vurdering av miljøeffekter fra utslipp av thallium til sjø fra Boliden Odda. Norsk institutt for vannforskning (NIVA). ISSN 9788257774660. Full text in Research Archive Show summary

  Rapporten gir en samlet miljøvurdering av Bolidens utslipp av thallium (Tl) til Sørfjorden. Utslippet forventes utelukkende å gå til sjø som vannløselig Tl(I), men selv tett opp mot utslippet ligger Tl(I) lavere enn PNEC marin i vannprøver. Målte vannkonsentrasjoner er omtrent som forventet basert på utslippskonsentrasjon og modellert fortynning av utslippet. Tl(I) sedimenterer hovedsakelig i vannvolumet øst for Eitrheimsneset. Det er ikke identifisert Tl(I) over PNEC sediment på stasjoner i Sørfjorden, men spesiering av thallium i sediment er fortsatt usikker. Beregninger gir en forventning om at 13% av totalt thallium i sedimenter foreligger som biotilgjengelig Tl(I). Thalliumanalyser i blåskjell og tang viser at Tl(I) har begrenset bioakkumuleringspotensial omtrent som andre tungmetaller. Vurderingen viser at spill fra lossing av sink-konsentrat på kai er en viktig kilde til thalliumforurensing i Sørfjorden. Som konklusjon er det i 2021 ikke framkommet data som peker i retning at thalliumutslippet gir toksiske effekter i biota. Analyser i vann- og sedimentprøver viser derimot, at utslippet fra Boliden kan spores over store deler av Sørfjorden. Noen inngangsdata som er brukt i vurderingen, særlig spesiering av thallium i sediment, bør imidlertid revurderes.

• Ruus, Anders; Borgersen, Gunhild; Mengeot, Caroline & Kristiansen, Trond (2022). Overvåking av kystvann i vannområde Hardanger 2021. Norsk institutt for vannforskning (NIVA). ISSN 9788257774585. Full text in Research Archive Show summary

  Overvåkingen av kystvann i vannområdet Hardanger i 2021 viste følgende: Bløtbunnsfauna viste god til svært god tilstand på samtlige stasjoner. Mhp. de fysisk-kjemiske kvalitetselementene viste oksygen(minimum-)konsentrasjon moderat tilstand på stasjonene Lind1 og S22Sør, og dårlig tilstand på Sø7/2. Siktedypet på disse stasjonene tilsvarte moderat tilstand på stasjon Lind1 og dårlig tilstand på Sø7/2 og S22Sør. Vannregionspesifikke stoffer i vann (metaller; særlig sink) og særlig i sediment (metaller; sink, arsen og kobber, samt PAH-forbindelser) oversteg i mange tilfeller grenseverdiene (EQS) og vil dermed begrense økologisk tilstand til maksimalt moderat tilstand på de fleste stasjoner. Også prioriterte stoffer i sediment (metaller og PAHforbindelser) oversteg grenseverdiene (EQS) og førte til at god kjemisk tilstand ikke ble oppnådd på de fleste stasjoner. I sjøvann var det kun bly, blant de prioriterte stoffene, som oversteg grenseverdien på stasjon S16. Konsentrasjoner av kvikksølv i blåskjell var også for høye til å klassifisere kjemisk tilstand som god på samtlige stasjoner hvor blåskjell ble analysert. På stasjon Sø10 ble høyeste konsentrasjon av fluorid i ufiltrert sjøvann fra 2 m dyp målt til 1300 μg/L i mai. Med unntak av en målt thalliumkonsentrasjon på 0,06 μg/L Tl på stasjon Sø7/2 i januar 2021, ble det kun observert konsentrasjoner ≤0,05 μg/L Tl i sjøvann i Sørfjorden.

• Jartun, Morten; Økelsrud, Asle; Bæk, Kine; Ruus, Anders; Rundberget, Thomas & Vogelsang, Christian [Show all 14 contributors for this article] (2022). Environmental contaminants in freshwater food webs, 2021. Norsk institutt for vannforskning (NIVA). ISSN 9788257775308. Full text in Research Archive Show summary

  This report presents monitoring data from freshwater food webs and abiotic samples from Lake Mjøsa and Femunden within the Milfersk programme. Studies and monitoring of legacy and emerging contaminants have been carried out through this programme for several years, focusing on the pelagic food web. This is the first report in the monitoring program focusing on a benthic food chain (Chironomids, ruffe, roach and perch) in addition to inputs to Lake Mjøsa by analysis of lake sediments, surface waters, stormwater, effluent and sludge from a wastewater treatment plant (WWTP). The analytical programme includes the determination of a total of ̴ 260 single components.

• Ruus, Anders; Hjermann, Dag Øystein; Håvardstun, Jarle; Øxnevad, Sigurd & Macken, Ailbhe (2022). ESPIAL - Data review and evaluation of historical data (WP1). Norsk institutt for vannforskning (NIVA). ISSN 9788257775117. Full text in Research Archive Show summary

  The present report details the outcome of work package 1 of ESPIAL, with the aim of compiling the historical data from previous surveys at the aluminium sites in a common database and further to analyse the data. A graphical data displaying tool was developed as a custom interactive tool for data visualisations and was designed to be intuitive and user friendly. The main outcomes and findings of this work package can be summarized as follows: Polycyclic aromatic hydrocarbons (PAHs) constitute most data in the database; There is a decent amount of data on sediment samples in the data base, however these do not form time series; Most time series available in the data base are on blue mussel from Sunndal and northern horsemussel from Årdal; Most time series show a declining tendency; All statistically significant PAH time trends show declining concentrations; The database is likely not complete, and more data could be available; The graphical data displaying tool is a promising aid for instant insight in concentrations and time series of different analytes in environmental samples, historically collected in the vicinity of the smelters; The graphical data displaying tool makes it possible to view concentrations and trends in relation to the EQSs, giving insight in chemical status and sites of interest, in terms of possible need of remedial action or natural recovery.

• Jonsson, Henrik; Ruus, Anders & Staalstrøm, Andre (2022). Miljøkonsekvensvurdering av kjølevannsutslipp til Frierfjorden fra Vianode Herøya. Norsk institutt for vannforskning (NIVA). ISSN 9788257774677. Full text in Research Archive Show summary

  Vianode AS søker om etablering av ny virksomhet i Herøya industripark for produksjon av karbon-baserte anoder. NIVA leverer her delutredningen på bedriftens miljøpåvirkning i Frierfjorden. Delutredningen er del i en full konsekvensutredning av omsøkte tiltak på Herøya. Beregninger viser begrenset sedimentoppvirvling fra etablering av ny utslippsledning i Frierfjorden sammenlignet med oppvirvling fra skipstrafikk i området. Oppvirvlet sediment forventes avsatt svært lokalt, og beregninger viser at biotilgjengelig fraksjon av miljøgifter i sedimentene er svært lav. Sedimentoppvirvling øker med økende utslippsdyp/rørlengde, og minst miljøbelastning i anleggsfasen vil derfor komme fra et utslipp tett opp mot kai på Herøya. Modellering av et kjølevannsutslipp fra Vianode til Frierfjorden viser bedre innblanding, og dermed lavere overtemperatur i resipienten med økende utslippsdyp. Et ferskvannsbasert system gir bedre innblanding, og dermed lavere overtemperatur i resipienten sammenlignet med et sjøvannsbasert system. Bedre innblanding og lavere overtemperatur oppnås også med økt utslippshastighet, enten ved å redusere diameteren på utslippsrøret, eller ved å øke vannraten. Et utslipp med plumen rettet oppover mot sjøoverflaten vil begrense miljøbelastningen i driftsfasen. Biologiske effekter i driftsfasen forventes da å være begrenset til små tap av i første rekke fiskeegg og larver innenfor plumens primærfortynningssone. Modelleringer viser at primærfortynningssonen vil strekke seg opptil 34m fra utslippet.

• Green, Norman Whitaker; Schøyen, Merete; Hjermann, Dag Øystein; Øxnevad, Sigurd; Ruus, Anders & Grung, Merete [Show all 14 contributors for this article] (2022). Contaminants in coastal waters of Norway 2019. Norsk institutt for vannforskning (NIVA). ISSN 9788257774776. Full text in Research Archive Show summary

  This monitoring programme examines levels, trends and effects of contaminants in biota along the coast of Norway. The 2019- investigation included analyses of more than 176 different contaminants or biological effect parameters in six species (blue mussel, dogwhelk, common periwinkle, cod, flounder and common eider). The contaminants measured includes metals (Hg, Cd, Pb, Cu, Zn, Ag, As, Ni, Cr and Co), tributyltin (TBT), organochlorines (e.g. PCBs (PCB-7), DDT, HCB, OCS and QCB), PAHs, polybrominated diphenyl ethers (PBDEs), and perfluorinated alkylated substances (PFAS), as well as contaminants that have recently received much attention such as hexabromocyclododecane (HBCD), chlorinated paraffins (SCCP, MCCP) and siloxanes (D4, D5 and D6). Biological effects parameters includes the imposex parameter VDSI, OH-pyrene metabolites, ALA-D and EROD. In the report, 30 contaminants or biological effects parameters were chosen for statistical analyses of 670 time series (last 10 years). Of these, there were statistically significant trends in 100 cases: 72 were downwards and 28 upwards. The upward trends were associated with metals (67.9 %), primarily Cr (14.3 %). The downwards trends for TBT-concentrations and effect parameter VDSI confirmed that the legislation banning the use of TBT has been effective. Of the 2019-medians (last year) for all 670 time series, there were 346 cases that could be classified against EQS, of which 232 (67.1 %) were below the EQS and 114 (32.9 %) were above the EQS. Of the 2019-medians for the 670 time series, 582 cases could be classified using Norwegian provisional high reference contaminant concentrations (PROREF). Of these, 407 were below PROREF and 175 exceeded PROREF: 82 by a factor of less than two, 51 by a factor between two and five, 31 by a factor between five and 10, four by a factor between 10 and 20, and seven by a factor greater than 20. Some cases warrant special concern, such as high concentrations of several organic contaminants in cod liver from the Inner Oslofjord. Results of analyses of stable isotopes of carbon and nitrogen are presented to investigate the role of food origin and trophic levels for observed concentrations of contaminants. Results from supplementary studies that investigated geographical trends in contaminants and trophic levels are also presented.

• Green, Norman Whitaker; Schøyen, Merete; Hjermann, Dag Øystein; Øxnevad, Sigurd; Ruus, Anders & Lusher, Amy [Show all 13 contributors for this article] (2021). Contaminants in coastal waters of Norway 2017. Norsk institutt for vannforskning (NIVA). ISSN 9788257773151. Full text in Research Archive Show summary

  This programme examines the levels, trends and effects of contaminants in biota along the coast of Norway. The 2017-investigation included analyses of 93 different contaminants or biological effect parameters in five species (blue mussel, dogwhelk, common periwinkle, cod and the common eider). The contaminants include metals (Hg, Cd, Pb, Cu, Zn, Ag, As, Ni, Cr and Co), tributyltin (TBT), organochlorines (e.g. PCBs, DDT), PAHs, polybrominated diphenyl ethers (PBDEs), perfluorinated alkylated substances (PFAS) as well as contaminants that have recently received much attention such as hexabromocyclododecane (HBCDs), chlorinated paraffins (SCCP, MCCP), bisphenol A (BPA), tetrabrombisphenol A (TBBPA), alkyphenols and siloxanes. Biological effects parameters included VDSI, OH-pyrene metabolites, ALA-D and EROD. In the report, 30 representative substances or parameters were chosen for analyses of 809 time series (last 10 years). Of these there were statistically significant trends in 193 cases: 83 were downwards and 35 upwards. The dominance of downward trends indicated that contamination is decreasing for the measured substances. The downwards trends for TBT-concentrations and effect parameter (VDSI) confirmed that the legislation banning the use of TBT has been effective. Of the 2017-medians (last year) for all 809 time series, there were 262 cases that could be classified against EQS, of which 157 (59.9 %) were below the EQS and 105 (40.1 %) were above the EQS. All of the 2017-medians from the 809 time series could be classified using a provisional high reference concentrations (PROREF). Of these 578 were below PROREF and 231 exceeded PROREF: 148 by a factor of less than two, 61 by a factor between two and five, 13 by a factor between five and 10, seven by a factor between 10 and 20, and two by a factor greater than 20. Some cases warrant special concern, such as high concentrations of several organic contaminants in cod liver from the Inner Oslofjord. High concentrations of DDE in mussels from the Sørfjord were related to earlier use of DDT as pesticide in orchards along the fjord. The influence of fish length on contaminant concentration was examined. Results of analyses of stable isotopes of carbon and nitrogen are presented to investigate the role of food origin and trophic levels for observed contaminant concentrations. In addition microplastics were investigated in blue mussel collected in 2016 and 2017.

• Green, Norman Whitaker; Schøyen, Merete; Øxnevad, Sigurd; Ruus, Anders; Hjermann, Dag Øystein & Severinsen, Gunnar [Show all 12 contributors for this article] (2021). Contaminants in coastal waters of Norway 2016. Norsk institutt for vannforskning (NIVA). ISSN 9788257773144. Full text in Research Archive Show summary

  This programme examines the levels, trends and effects of contaminants in biota along the coast of Norway. The 2016- investigation included analyses of 104 different contaminants or biological effect parameters in five types of samples (blue mussel, dog whelk, common periwinkle and cod). The contaminants include metals (Hg, Cd, Pb, Cu, Zn, Ag, As, Ni, Cr and Co), tributyltin (TBT), organochlorines (e.g. PCBs, DDT), PAHs, polybrominated diphenyl ethers (PBDEs), perfluorinated alkylated substances (PFAS) as well as contaminants that have recently received much attention such as hexabromocyclododecane (HBCDs), chlorinated paraffins (SCCP, MCCP), phosphorus flame retardants (PFRs), bisphenol A (BPA), tetrabrombisphenol A (TBBPA) and alkyphenols. Biological effects parameters included VDSI, OH-pyrene metabolites, ALA-D and EROD. In the report, 30 representative substances or parameters were chosen for analyses of 800 time series (last 10 years). Of these there were statistically significant trends in 135 cases: 107 were downwards and 28 upwards. The dominance of downward trends indicated that contamination is decreasing for the measured substances. The downwards trends for TBT-concentrations and effect parameter (VDSI) confirmed that the legislation banning the use of TBT has been effective. Of the 2016-medians for all 800 time series, there were 403 cases that could be classified against EQS, of which 254 (63 %) were below the EQS and 149 (37 %) were above the EQS. All of the 2016-medians from the 800 time series could be classified using a new concept denoted provisional high reference concentrations (PROREF). Of these 594 were below PROREF and 206 exceeded PROREF: 124 by a factor of less than two, 59 by a factor between two and five, 11 by a factor between five and 10, six by a factor between 10 and 20, and six by a factor greater than 20. Some cases warrant special concern, such as high concentrations of several organic pollutants in cod liver from the Inner Oslofjord. High concentrations of DDE in mussels from the Sørfjord were related to earlier use of DDT as pesticide in orchards along the fjord. The influence of fish length on contaminant concentration was examined. Results of analyses of stable isotopes of carbon and nitrogen are presented to investigate the role of food origin and trophic levels for observed contaminant concentrations.

• Ruus, Anders; Kristiansen, Trond; Mengeot, Caroline & Jonsson, Henrik (2021). Overvåking av kystvann i vannområde Hardanger 2020. Norsk institutt for vannforskning (NIVA). ISSN 9788257773458. Full text in Research Archive Show summary

  Overvåkingen av kystvann i vannområdet Hardanger i 2020 viste følgende: Oksygen ved største sondedyp (her antatt bunnvann) viste moderat tilstand på stasjonene Sø7/2, Lind1 og S22Sør. Siktedypet på disse stasjonene tilsvarte hhv. dårlig, moderat og dårlig tilstand. Vannregionspesifikke stoffer i vann (metaller; særlig sink) oversteg grenseverdiene (EQS) på alle stasjoner hvor vann ble analysert (Lind1, Sø7/2, S22Sør og S1/4). Også prioriterte stoffer (bly) oversteg grenseverdiene (EQS) i sjøvann på stasjon Sø7/2 og S22Sør og førte til at god kjemisk tilstand ikke ble oppnådd. Konsentrasjoner av kvikksølv i blåskjell var også for høye til å klassifisere kjemisk tilstand som god på samtlige stasjoner hvor blåskjell ble analysert. På stasjon Sø10 ble høyeste konsentrasjon av fluorid i ufiltrert sjøvann fra 2 m dyp målt til 600 μg/L. Thallium kunne detekteres i 2 av 14 sjøvannsprøver, men dette ble ikke bekreftet av parallelle analyser på annet laboratorium. Tl ble funnet i blåskjell i konsentrasjoner på 4-6 μg/kg.

• Frigstad, Helene; Gundersen, Hege; Andersen, Guri Sogn; Borgersen, Gunhild; Kvile, Kristina Øie & Krause-Jensen, Dorte [Show all 13 contributors for this article] (2021). Blue Carbon – climate adaptation, CO2 uptake and sequestration of carbon in Nordic blue forests. Results from the Nordic Blue Carbon Project. Nordic Council of Ministers. ISSN 9789289368612. Full text in Research Archive Show summary

  This report presents the main findings of the Nordic Blue Carbon Project (2017–2020) on the areal distribution and carbon budget of blue forests (kelp forests, seagrass meadows and rockweed beds) in the Nordic region. We have identified the main ecosystem effects of climate change and other human pressures on Nordic blue forests, tested the effect of moderating some of these pressures, and give scientific advice on management measures aimed at safeguarding these important coastal ecosystems for the future. Recently, there has been an increased focus on salt marshes as a blue forest habitat, however salt marshes were not covered in the Nordic Blue Carbon Project.

• Green, Norman Whitaker; Schøyen, Merete; Hjermann, Dag Øystein; Øxnevad, Sigurd; Ruus, Anders & Beylich, Bjørnar [Show all 14 contributors for this article] (2021). Contaminants in coastal waters of Norway 2018. Norsk institutt for vannforskning (NIVA). ISSN 9788257773168. Full text in Research Archive Show summary

  This programme examines the levels, trends and effects of contaminants in biota along the coast of Norway. The 2018-investigation included analyses of more than 133 different contaminants or biological effect parameters in five species (blue mussel, dogwhelk, common periwinkle, cod and the common eider). The contaminants include metals (Hg, Cd, Pb, Cu, Zn, Ag, As, Ni, Cr and Co), tributyltin (TBT), organochlorines (e.g. PCBs (PCB-7), DDT), PAHs, polybrominated diphenyl ethers (PBDEs), and perfluorinated alkylated substances (PFAS), as well as contaminants that have recently received much attention such as hexabromocyclododecane (HBCDs), chlorinated paraffins (SCCP, MCCP), bisphenol A (BPA), tetrabrombisphenol A (TBBPA), alkyphenols, siloxanes (D4, D5 and D6) and dechlorane plus. Biological effects parameters included VDSI, OHpyrene metabolites, ALA-D and EROD. In the report, 30 representative substances or parameters were chosen for analyses of 713 time series (last 10 years). Of these there were statistically significant trends in 102 cases: 79 were downwards and 23 upwards. The upward trends were also associated with metals (78.3 %), primarily Hg (17.4 %).The dominance of downward trends indicated that contamination is decreasing for the measured substances. The downwards trends for TBT-concentrations and effect parameter (VDSI) confirmed that the legislation banning the use of TBT has been effective. Of the 2018-medians (last year) for all 713 time series, there were 323 cases that could be classified against EQS, of which 203 (62.8 %) were below the EQS and 120 (37.2 %) were above the EQS. Of the 2018-medians for the 713 time series, 641 cases could be classified using Norwegian provisional high reference contaminant concentrations (PROREF). Of these, 463 were below PROREF and 173 exceeded PROREF: 117 by a factor of less than two, 45 by a factor between two and five, eight by a factor between five and 10, four by a factor between 10 and 20, and four by a factor greater than 20. Some cases warrant special concern, such as high concentrations of several organic contaminants in cod liver from the Inner Oslofjord. High concentrations of DDE in mussels from the Sørfjord were related to earlier use of DDT as pesticide in orchards along the fjord. Concentrations of an expanded list of PFAS in cod liver from the Inner Oslofjord sampled since 1990 are presented. Results of analyses of stable isotopes of carbon and nitrogen are presented to investigate the role of food origin and trophic levels for observed contaminant concentrations.

• Grung, Merete; Jartun, Morten; Bæk, Kine; Ruus, Anders; Rundberget, Thomas & Allan, Ian [Show all 12 contributors for this article] (2021). Environmental Contaminants in an Urban Fjord, 2020. Norsk institutt for vannforskning (NIVA). ISSN 9788257774103. Full text in Research Archive Show summary

  This programme, “Environmental Contaminants in an Urban Fjord” has covered sampling and analyses of sediment and organisms in a marine food web of the Inner Oslofjord, in addition to samples of blood and eggs from herring gull. The programme also included inputs of pollutants via surface water (stormwater), and effluent water and sludge from a wastewater treatment plant. The bioaccumulation potential of the contaminants in the Oslo fjord food web was evaluated. The exposure to/accumulation of the contaminants was also assessed in birds. A vast number of chemical parameters have been quantified, in addition to some biological effect parameters in cod, and the report serves as a status description of the concentrations of these chemicals in different compartments of the Inner Oslofjord marine ecosystem.

• Ruus, Anders; Beyer, Jonny & Green, Norman Whitaker (2021). Proposed Environmental Quality standards (EQS) for blue mussel (Mytilus edulis). Norsk institutt for vannforskning (NIVA). Full text in Research Archive Show summary

  The Norwegian Environment Agency recognizes the need to further develop Environmental Quality Standards (EQSs) under EU’s Water Framework Directive. As one step in this direction the Norwegian Institute for Water Research (NIVA) was tasked to propose EQSs for a selection of contaminants in blue mussel (Mytilus edulis). The proposed EQS are derived either from the current EQS for coastal water, using a bioconcentration factor (BCF) or bioaccumulation factor (BAF) that is most relevant for blue mussel, or from the current EQS for biota, e.g. by correcting for a lower trophic level than fish. EQS are proposed for 24 selected contaminants that included six metals, 16 PAH compounds and two perfluorinated alkylated substances. The practical applicability of a few are questionable.

• Ruus, Anders; Ranneklev, Sissel Brit; Golmen, Lars Gunder; Grung, Merete; Allan, Ian & Øxnevad, Sigurd (2020). Utredning av konsekvenser av uhellsutslipp av PAH fra Tizir Titanium & Iron AS. Norsk institutt for vannforskning (NIVA). ISSN 9788257772703. Full text in Research Archive Show summary

  Tizir Titanium & Iron AS hadde et uhellsutslipp av 217 kg PAH-forbindelser i løpet av 28 timer i juni 2020. Kortsiktige og langsiktige effekter av utslippet ble vurdert. Tidligere modellering av fortynning og spredning av bedriftens regulerte utslippspunkt ble benyttet. Beregnede konsentrasjoner av PAH-forbindelser i vannsøyle ved diffusor og ca. 1 km fra diffusor (nordvestlig retning) viste at grenseverdier for flere PAH-forbindelser ble oversteget i løpet av de 28 timene uhellsutslippet vedvarte. Beregnede kortvarige konsentrasjoner kan gi akutte toksiske effekter på organismer inntil 1 km fra diffusor. Blåskjell innsamlet ca. to måneder etter uhellsutslippet hadde tilsvarende konsentrasjoner av PAH som i blåskjell samlet inn i 2019. Konsentrasjonene var godt under grenseverdier gitt i vannforskriften. En konservativ og teoretisk beregning av tilførsler av PAH til sedimenter utenfor Tizir Titanium & Iron AS, indikerer at tilførslene av PAH er beskjedne i forhold til de eksiterende konsentrasjonene i sedimentene. NIVA kan ikke se at det noen tiltak som kan iverksettes for å motvirke konsekvenser av utslippet. En blåskjellstasjon ved Apold bør følges opp videre.

• Ruus, Anders; Bæk, Kine; Rundberget, Thomas; Allan, Ian; Beylich, Bjørnar & Vogelsang, Christian [Show all 10 contributors for this article] (2020). Environmental Contaminants in an Urban Fjord, 2019. Norsk institutt for vannforskning (NIVA). ISSN 9788257772901. Full text in Research Archive Show summary

  This programme, “Environmental Contaminants in an Urban Fjord” has covered sampling and analyses of sediment and organisms in a marine food web of the Inner Oslofjord, in addition to samples of blood and eggs from herring gull. The programme also included inputs of pollutants via surface water (storm water), and effluent water and sludge from a sewage treatment plant. The bioaccumulation potential of the contaminants in the Oslo fjord food web was evaluated. The exposure to/accumulation of the contaminants was also assessed in birds. A vast number of chemical parameters have been quantified, in addition to some biological effect parameters in cod, and the report serves as a status description of the concentrations of these chemicals in different compartments of the Inner Oslofjord marine ecosystem.

• Ruus, Anders; Ledang, Anna Birgitta & Kristiansen, Trond (2020). Overvåking av kystvann i vannområde Hardanger 2019. Norsk institutt for vannforskning (NIVA). ISSN 9788257772369. Full text in Research Archive Show summary

  Overvåkingen av kystvann i vannområdet Hardanger i 2019 viste følgende: Oksygen ved største sondedyp (her antatt bunnvann) viste moderat tilstand på stasjonene Sø7/2, Lind1 og S22Sør. Siktedypet på disse stasjonene tilsvarte også moderat tilstand. Vannregionspesifikke stoffer i vann (metaller; særlig sink) oversteg grenseverdiene (EQS) på alle stasjoner hvor vann ble analysert (Lind1, Sø7/2 og S22Sør). Også prioriterte stoffer (kadmium og bly) oversteg grenseverdiene (EQS) i sjøvann på stasjon S22Sør og førte til at god kjemisk tilstand ikke ble oppnådd. Konsentrasjoner av kvikksølv i blåskjell var også for høye til å klassifisere kjemisk tilstand som god på samtlige stasjoner hvor blåskjell ble analysert. På stasjon Sø10 ble høyeste konsentrasjon av fluorid i ufiltrert sjøvann fra 2 m dyp målt til 910 μg/L.

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