Publications

• Carvalho, Cintia Oliveira; Gromstad, William; Dunthorn, Micah; Karlsen, Hans Erik; Schrøder-Nielsen, Audun & Ready, Jonathan Stuart [Show all 10 contributors for this article] (2024). Harnessing eDNA metabarcoding to investigate fish community composition and its seasonal changes in the Oslo fjord. Scientific Reports. ISSN 2045-2322. 14(1). doi: 10.1038/s41598-024-60762-8.
• Möllerke, Anton; Montes Vidal, Diogo; Leinaas, Hans Petter & Schulz, Stefan (2024). Socialane, a Nonaprenyl Terpene Hydrocarbon Surface Lipid from the Collembola Hypogastrura socialis. Chemistry - A European Journal. ISSN 0947-6539. doi: 10.1002/chem.202400272.
• Durant, Joël; Holt, Rebecca Emma & Langangen, Øystein Ole Gahr (2024). Large biomass reduction effect on the relative role of climate, fishing, and recruitment on fish population dynamics. Scientific Reports. ISSN 2045-2322. 14(1). doi: 10.1038/s41598-024-59569-4. Full text in Research Archive Show summary

  Many species around the world have collapsed, yet only some have recovered. A key question is what happens to populations post collapse. Traditionally, marine fish collapses are linked to overfishing, poor climate, and recruitment. We test whether the effect on biomass change from these drivers remains the same after a collapse. We used a regression model to analyse the effect of harvesting, recruitment, and climate variability on biomass change before and after a collapse across 54 marine fish populations around the world. The most salient result was the change in fishing effect that became weaker after a collapse. The change in sea temperature and recruitment effects were more variable across systems. The strongest changes were in the pelagic habitats. The resultant change in the sensitivity to external drivers indicates that whilst biomass may be rebuilt, the responses to variables known to affect stocks may have changed after a collapse. Our results show that a general model applied to many stocks provides useful insights, but that not all stocks respond similarly to a collapse calling for stock-specific models. Stocks respond to environmental drivers differently after a collapse, so caution is needed when using pre-collapse knowledge to advise on population dynamics and management.

• Ferreira, Sofia; Langangen, Øystein Ole Gahr; Yaragina, Nathalia A.; Prokopchuk, Irina P. & Durant, Joël (2024). How the spatio-temporal overlap of cod, haddock, and capelin larvae affects their recruitment in the Norwegian–Barents Sea system. Marine Ecology Progress Series. ISSN 0171-8630. 734, p. 79–90. doi: 10.3354/meps14564. Full text in Research Archive
• Vogt, Rolf David; Garmo, Øyvind Aaberg; Austnes, Kari; Kaste, Øyvind; Haaland, Ståle Leif & Sample, James Edward [Show all 10 contributors for this article] (2024). Factors Governing Site and Charge Density of Dissolved Natural Organic Matter. Preprints. ISSN 2310-287X. doi: 10.20944/preprints202404.0533.v1.
• Langangen, Øystein Ole Gahr & Durant, Joël (2024). Persistence of fish populations to longer, more intense, and more frequent mass mortality events. Global Change Biology. ISSN 1354-1013. 30(3), p. 1–10. doi: 10.1111/gcb.17251. Full text in Research Archive
• Cristi, Antonia; Law, Cliff S.; Pinkerton, Matt; Lopes dos Santos, Adriana; Safi, Karl & Gutiérrez-Rodríguez, Andres (2024). Environmental driving forces and phytoplankton diversity across the Ross Sea region during a summer–autumn transition. Limnology and Oceanography. ISSN 0024-3590. doi: 10.1002/lno.12526.
• Carlsen, Eira Catharine Lødrup; Hjelset, Sverre; Gomes, Tania; Igartha, Amaia; Sørensen, Lisbet & Booth, Andy [Show all 8 contributors for this article] (2024). Synthetic and natural rubber associated chemicals drive functional and structural changes as well as adaptations to antibiotics in in vitro marine microbiomes. Ecotoxicology and Environmental Safety. ISSN 0147-6513. 273. doi: 10.1016/j.ecoenv.2024.116134.
• Colls, Miriam; Viza, Aida; Zufiarre, Aitziber; Camacho-Santamans, Alba; Laini, Alex & González-Ferreras, Alexia Maria [Show all 85 contributors for this article] (2024). Impacts of diffuse urban stressors on stream benthic communities and ecosystem functioning: A review. Limnetica. ISSN 0213-8409. 43(1), p. 89–108. doi: 10.23818/limn.43.07.
• Pérez, Géraldine; O'Leary, Bethan C.; Allegri, Elena; Casal, Gema; Cornet, Cindy C. & de Juan, Silvia [Show all 18 contributors for this article] (2024). A conceptual framework to help choose appropriate blue nature-based solutions. Journal of Environmental Management. ISSN 0301-4797. 352. doi: 10.1016/j.jenvman.2023.119936.
• Trégarot, Ewan; D'Olivo, Juan Pablo; Botelho, Andrea Zita; Cabrito, Andrea; Cardoso, Gabriel O. & Casal, Gema [Show all 21 contributors for this article] (2024). Effects of climate change on marine coastal ecosystems – A review to guide research and management. Biological Conservation. ISSN 0006-3207. 289. doi: 10.1016/j.biocon.2023.110394.
• Andvik, Clare; Bories, Pierre; Harju, Mikael; Borgå, Katrine; Jourdain, Eve & Karoliussen, Richard [Show all 9 contributors for this article] (2023). Phthalate contamination in marine mammals off the Norwegian coast. Marine Pollution Bulletin. ISSN 0025-326X. 199. doi: 10.1016/j.marpolbul.2023.115936. Full text in Research Archive Show summary

  Phthalates are used in plastics, found throughout the marine environment and have the potential to cause adverse health effects. In the present study, we quantified blubber concentrations of 11 phthalates in 16 samples from stranded and/or free-living marine mammals from the Norwegian coast: the killer whale (Orcinus orca), sperm whale (Physeter macrocephalus), long-finned pilot whale (Globicephala melas), white-beaked dolphin (Lagenorhynchus albirostris), harbour porpoise (Phocoena phocoena), and harbour seal (Phoca vitulina). Five compounds were detected across all samples: benzyl butyl phthalate (BBP; in 50 % of samples), bis(2-ethylhexyl) phthalate (DEHP; 33 %), diisononyl phthalate (DiNP; 33 %), diisobutyl phthalate (DiBP; 19 %), and dioctyl phthalate (DOP; 13 %). Overall, the most contaminated individual was the white-beaked dolphin, whilst the lowest concentrations were measured in the killer whale, sperm whale and long-finned pilot whale. We found no phthalates in the neonate killer whale. The present study is important for future monitoring and management of these toxic compounds.

• Burgunter-Delamare, Bertille; Rousvoal, Sylvie; Legeay, Erwan; Tanguy, Gwenn; Fredriksen, Stein & Boyen, Catherine [Show all 7 contributors for this article] (2023). The Saccharina latissima microbiome: Effects of region, season, and physiology. Frontiers in Microbiology. ISSN 1664-302X. 13, p. 1–16. doi: 10.3389/fmicb.2022.1050939. Full text in Research Archive
• Möllerke, Anton; Bello, Jan; Leinaas, Hans Petter & Schulz, Stefan (2023). Cyclopropane Hydrocarbons from the Springtail Vertagopus sarekensis─A New Class of Cuticular Lipids from Arthropods. Journal of natural products. ISSN 0163-3864. 87(1), p. 85–97. doi: 10.1021/acs.jnatprod.3c00789. Full text in Research Archive
• Caillon, Coline; Pernet, Fabrice; Lutier, Mathieu & Di Poi, Carole (2023). Differential reaction norms to ocean acidification in two oyster species from contrasting habitats. Journal of Experimental Biology. ISSN 0022-0949. 226(23), p. 1–11. doi: 10.1242/jeb.246432.
• Silva, Andreia Sofia Jorge; Kristiansen, Silje Marie; Sengupta, Sagnik; van Gestel, Cornelis A. M.; Leinaas, Hans Petter & Borgå, Katrine (2023). Using dietary exposure to determine sub-lethal effects from imidacloprid in two springtail (Collembola) species. Ecotoxicology. ISSN 0963-9292. 32, p. 1209–1220. doi: 10.1007/s10646-023-02715-x. Full text in Research Archive
• Bustnes, Jan Ove; Bårdsen, Bård-Jørgen; Moe, Børge; Herzke, Dorte; Ballesteros, Manuel & Fenstad, Anette [Show all 12 contributors for this article] (2023). Impacts of a warming climate on concentrations of organochlorines in a fasting high arctic marine bird: Direct vs. indirect effects? Science of the Total Environment. ISSN 0048-9697. 908. doi: 10.1016/j.scitotenv.2023.168096. Full text in Research Archive Show summary

  The present study examined how climate changes may impact the concentrations of lipophilic organochlorines (OCs) in the blood of fasting High Arctic common eiders (Somateria mollissima) during incubation. Polychlorinated biphenyls (PCBs), 1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p′-DDE), hexachlorobenzene (HCB) and four chlordane compounds (oxychlordane, trans-chlordane and trans- and cis-nonachlor) were measured in females at chick hatching (n = 223) over 11 years (2007–2017). Firstly, median HCB and p,p′-DDE concentrations increased ~75 % over the study period, whereas median chlordane concentrations doubled (except for oxychlordane). PCB concentrations, in contrast, remained stable over the study period. Secondly, both body mass and clutch size were negatively associated with OC levels, suggesting that females with high lipid metabolism redistributed more OCs from adipose tissue, and that egg production is an important elimination route for OCs. Thirdly, the direct climate effects were assessed using the mean effective temperature (ET: air temperature and wind speed) during incubation, and we hypothesized that a low ET would increase redistribution of OCs. Contrary to expectation, the ET was positively correlated to most OCs, suggesting that a warmer climate may lead to higher OCs levels, and that the impact of ET may not be direct. Finally, potential indirect impacts were examined using the Arctic Oscillation (AO) in the three preceding winters (AOwinter 1–3) as a proxy for potential long-range transport of OCs, and for local spring climate conditions. In addition, we used chlorophyll a (Chla) as a measure of spring primary production. There were negative associations between AOwinter 1 and HCB, trans-chlordane and trans-nonachlor, whereas oxychlordane and cis-chlordane were negatively associated with Chla. This suggests that potential indirect climate effects on eiders were manifested through the food chain and not through increased long-range transport, although these relationships were relatively weak.

• Gerland, Sebastian; Ingvaldsen, Randi Brunvær; Reigstad, Marit; Sundfjord, Arild; Bogstad, Bjarte & Chierici, Melissa [Show all 41 contributors for this article] (2023). Still Arctic? — The changing Barents Sea. Elementa: Science of the Anthropocene. ISSN 2325-1026. 11(1), p. 1–62. doi: 10.1525/elementa.2022.00088. Full text in Research Archive Show summary

  The Barents Sea is one of the Polar regions where current climate and ecosystem change is most pronounced. Here we review the current state of knowledge of the physical, chemical and biological systems in the Barents Sea. Physical conditions in this area are characterized by large seasonal contrasts between partial sea-ice cover in winter and spring versus predominantly open water in summer and autumn. Observations over recent decades show that surface air and ocean temperatures have increased, sea-ice extent has decreased, ocean stratification has weakened, and water chemistry and ecosystem components have changed, the latter in a direction often described as “Atlantification” or “borealisation,” with a less “Arctic” appearance. Temporal and spatial changes in the Barents Sea have a wider relevance, both in the context of large-scale climatic (air, water mass and sea-ice) transport processes and in comparison to other Arctic regions. These observed changes also have socioeconomic consequences, including for fisheries and other human activities. While several of the ongoing changes are monitored and quantified, observation and knowledge gaps remain, especially for winter months when field observations and sample collections are still sparse. Knowledge of the interplay of physical and biogeochemical drivers and ecosystem responses, including complex feedback processes, needs further development.

• Cembella, Allan; Klemm, Kerstin; John, Uwe; Karlson, Bengt; Arneborg, Lars & Clarke, Dave [Show all 12 contributors for this article] (2023). Emerging phylogeographic perspective on the toxigenic diatom genus Pseudo-nitzschia in coastal northern European waters and gateways to eastern Arctic seas: Causes, ecological consequences and socio-economic impacts. Harmful Algae. ISSN 1568-9883. 129. doi: 10.1016/j.hal.2023.102496. Full text in Research Archive Show summary

  The diatom Pseudo-nitzschia H. Peragallo is perhaps the most intensively researched genus of marine pennate diatoms, with respect to species diversity, life history strategies, toxigenicity, and biogeographical distribution. The global magnitude and consequences of harmful algal blooms (HABs) of Pseudo-nitzschia are particularly significant because of the high socioeconomic impacts and environmental and human health risks associated with the production of the neurotoxin domoic acid (DA) among populations of many (although not all) species. This has led to enhanced monitoring and mitigation strategies for toxigenic Pseudo-nitzschia blooms and their toxins in recent years. Nevertheless, human adaptive actions based on future scenarios of bloom dynamics and proposed shifts in biogeographical distribution under climate-change regimes have not been implemented on a regional scale. In the CoCliME (Co-development of climate services for adaptation to changing marine ecosystems) program these issues were addressed with respect to past, current and anticipated future status of key HAB genera such as Pseudo-nitzschia and expected benefits of enhanced monitoring. Data on the distribution and frequency of Pseudo-nitzschia blooms in relation to DA occurrence and associated amnesic shellfish toxin (AST) events were evaluated in a contemporary and historical context over the past several decades from key northern CoCliME Case Study areas. The regional studies comprised the greater North Sea and adjacent Kattegat-Skagerrak and Norwegian Sea, eastern North Atlantic marginal seas and Arctic gateways, and the Baltic Sea. The first evidence of possible biogeographical expansion of Pseudo-nitzschia taxa into frontier eastern Arctic gateways was provided from DNA barcoding signatures. Key climate change indicators, such as salinity, temperature, and water-column stratification were identified as drivers of upwelling and advection related to the distribution of regional Pseudo-nitzschia blooms. The possible influence of changing variables on bloom dynamics, magnitude, frequency and spatial and temporal distribution were interpreted in the context of regional ocean climate models. These climate change indicators may play key roles in selecting for the occurrence and diversity of Pseudo-nitzschia species within the broader microeukaryote communities. Shifts to higher temperature and lower salinity regimes predicted for the southern North Sea indicate the potential for high-magnitude Pseudo-nitzschia blooms, currently absent from this area. Ecological and socioeconomic impacts of Pseudo-nitzschia blooms are evaluated with reference to effects on fisheries and mariculture resources and coastal ecosystem function. Where feasible, effective adaptation strategies are proposed herein as emerging climate services for the northern CoCLiME region.

• Heuschele, Jan David; Andersen, Tom; Walseng, Bjørn & Hessen, Dag Olav (2023). Assessing climatic and spatial variables influencing zooplankton richness for space-for-time predictions. Freshwater Biology. ISSN 0046-5070. 69(1), p. 64–73. doi: 10.1111/fwb.14193. Full text in Research Archive Show summary

  1. The macroecological drivers of freshwater diversity are accredited geographical, spatial and climatic variables, but also to productivity, ecosystem age and landscape history. Locally diversity is also influenced by the dispersal ability of species. Here we evaluated how spatial and climatic variables influence species richness and macroecological patterns in Cladocera and Copepoda. We also discuss whether a space-for-time approach is suitable to predict the community's response to the current rapid warming of lakes. 2. We use the presence-absence of pelagic and littoral microcrustaceans in 1465 Norwegian lakes with a wide range of latitudinal, longitudinal, and altitudinal gradients, as well as a wide span in lake areas, to evaluate how spatial and climatic factors influence zooplankton diversity in two major groups: Cladocera and Copepoda. 3. Longitude and latitude per se were poor predictors of zooplankton richness, but a combination of spatial and ecological predictors gave a good spatial prediction of cladoceran and copepod richness. These two groups did, however, not differ in their spatial distribution, with a strikingly fixed proportion of copepods close to 0.3, suggesting no obvious Allee- effects regarding the mode of reproduction (asexual vs sexual). 4. Since temperature alone was a poor predictor of species richness for both groups and dispersal constraints can make it very difficult to estimate a new richness equilibrium under a future climate, space-for-time predictions may have limited value for assessing future patterns of microcrustacean diversity. 5. Based on a quite unique dataset in terms of the sheer number of sites, spatial gradients, and inclusion of littoral species, our study demonstrates that assessments on how changing climate will shape and modulate zooplankton communities in the future are problematic. biogeography, dispersal, diversity, lakes, micro-crustaceans

• Dinh, van Khuong; Albini, Dania; Orr, James A.; Macaulay, Samuel J.; Rillig, Matthias C. & Borgå, Katrine [Show all 7 contributors for this article] (2023). Winter is coming: Interactions of multiple stressors in winter and implications for the natural world. Global Change Biology. ISSN 1354-1013. 29(24), p. 6834–6845. doi: 10.1111/gcb.16956.
• Ngo, Van Manh; Dinh, van Khuong; Chau, Bich Lien & Luc, Diep Minh (2023). Tank colours do not change the effects of extreme temperatures on the productive parameters, but skeletal deformities of golden trevally. Fisheries and Aquatic Sciences (FAS). ISSN 2234-1749. 26(8), p. 461–469. doi: 10.47853/FAS.2023.e39. Full text in Research Archive
• Pham, Hung Quoc; Van Bui, Canh; Doan, Nam Xuan & Dinh, van Khuong (2023). Density effects on a tropical copepod Acartia sp.: Implications as live feed in aquaculture. Journal of the World Aquaculture Society. ISSN 0893-8849. p. 1–12. doi: 10.1111/jwas.13020. Full text in Research Archive
• Bjorbækmo, Marit Frederikke Markussen; Brodie, Juliet; Krabberød, Anders Kristian; Logares, Ramiro; Fuss, Janina & Fredriksen, Stein [Show all 9 contributors for this article] (2023). 18S rDNA gene metabarcoding of microeukaryotes and epi-endophytes in the holobiome of seven species of large brown algae. Journal of Phycology. ISSN 0022-3646. 59(5), p. 859–878. doi: 10.1111/jpy.13377. Full text in Research Archive Show summary

  Brown algae (Phaeophyceae) are habitat-forming species in coastal ecosystems and include kelp forests and seaweed beds that support a wide diversity of marine life. Host-associated microbial communities are an integral part of phaeophyte biology, and whereas the bacterial microbial partners have received considerable attention, the microbial eukaryotes associated with brown algae have hardly been studied. Here, we used broadly targeted “pan-eukaryotic” primers (metabarcoding) to investigate brown algal-associated eukaryotes (the eukaryome). Using this approach, we aimed to investigate the eukaryome of seven large brown algae that are important and common species in coastal ecosystems. We also aimed to assess whether these macroalgae harbor novel eukaryotic diversity and to ascribe putative functional roles to the host-associated eukaryome based on taxonomic affiliation and phylogenetic placement. We detected a significant diversity of microeukaryotic and algal lineages associated with the brown algal species investigated. The operational taxonomic units (OTUs) were taxonomically assigned to 10 of the eukaryotic major supergroups, including taxonomic groups known to be associated with seaweeds as epibionts, endobionts, parasites, and commensals. Additionally, we revealed previously unrecorded sequence types, including novel phaeophyte OTUs, particularly in the Fucus spp. samples, that may represent fucoid genomic variants, sequencing artifacts, or undescribed epi-/endophytes. Our results provide baseline data and technical insights that will be useful for more comprehensive seaweed eukaryome studies investigating the evidently lineage-rich and functionally diverse symbionts of brown algae.

• 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.

• Marquardt, Miriam; Goraguer, Lucie Hélène Marie; Assmy, Philipp Kurt Wolf; Bluhm, Bodil Annikki Ulla Barbro; Aaboe, Signe & Down, Emily [Show all 12 contributors for this article] (2023). Seasonal dynamics of sea-ice protist and meiofauna in the northwestern Barents Sea. Progress in Oceanography. ISSN 0079-6611. 218. doi: 10.1016/j.pocean.2023.103128. Full text in Research Archive Show summary

  The rapid decline of Arctic sea ice makes understanding sympagic (ice-associated) biology a particularly urgent task. Here we studied the poorly known seasonality of sea-ice protist and meiofauna community composition, abundance and biomass in the bottom 30 cm of sea ice in relation to ice properties and ice drift trajectories in the northwestern Barents Sea. We expected low abundances during the polar night and highest values during spring prior to ice melt. Sea ice conditions and Chlorophyll a concentrations varied strongly seasonally, while particulate organic carbon concentrations were fairly stable throughout the seasons. In December to May we sampled growing first-year ice, while in July and August melting older sea ice dominated. Low sea-ice biota abundances in March could be related to the late onset of ice formation and short time period for ice algae and uni- and multicellular grazers to establish themselves. Pennate diatoms, such as Navicula spp. and Nitzschia spp., dominated the bottom ice algal communities and were present during all seasons. Except for May, ciliates, dinoflagellates, particularly of the order Gymnodiales, and small-sized flagellates were co-dominant. Ice meiofauna (here including large ciliates and foraminifers) was comprised mainly of harpacticoid copepods, copepod nauplii, rotifers, large ciliates and occasionally acoels and foraminifers, with dominance of omnivore species throughout the seasons. Large ciliates comprised the most abundant meiofauna taxon at all ice stations and seasons (50–90%) but did not necessarily dominate the biomass. While ice melt might have released and reduced ice algal biomass in July, meiofauna abundance remained high, indicating different annual cycles of protist versus meiofauna taxa. In May highest Chlorophyll a concentrations (29.4 mg m-2) and protist biomass (107 mg C m-2) occurred, while highest meiofauna abundance was found in August (23.9 × 103 Ind. m-2) and biomass in December (0.6 mg C m-2). The abundant December ice biota community further strengthens the emerging notion of an active biota during the dark Arctic winter. The data demonstrated a strong and partially unexpected seasonality in the Barents Sea ice biota, indicating that changes in ice formation, drift and decay will significantly impact the functioning of the ice-associated ecosystem.

• Nam, Pham Viet; Hich, Tran Vy; van Hoa, Nguyen; Dinh, van Khuong; Minh, Nguyen Cong & Trung, Trang Si (2023). Additive biocomponents from catfish by-products enhance the growth of shrimp Litopenaeus vannamei. Fisheries and Aquatic Sciences (FAS). ISSN 2234-1749. 26(6), p. 367–379. doi: 10.47853/FAS.2023.e31. Full text in Research Archive
• Holme, Jørn Andreas; Vondráček, Jan; Machala, Miroslav; Lagadic-Gossmann, Dominique; Vogel, Christoph F.A & Le Ferrec, Eric [Show all 8 contributors for this article] (2023). Lung cancer associated with combustion particles and fine particulate matter (PM2.5) - The roles of polycyclic aromatic hydrocarbons (PAHs) and the aryl hydrocarbon receptor (AhR). Biochemical Pharmacology. ISSN 0006-2952. 216. doi: 10.1016/j.bcp.2023.115801. Full text in Research Archive
• Fontaine, Laurent; Pin, Lorenzo; Savio, Domenico; Friberg, Nikolai; Kirschner, Alexander K. T. & Farnleitner, Andreas H. [Show all 7 contributors for this article] (2023). Bacterial bioindicators enable biological status classification along the continental Danube river. Communications Biology. ISSN 2399-3642. 6. doi: 10.1038/s42003-023-05237-8. Full text in Research Archive
• Thiele, Stefan; Vader, Anna; Thomson, Stuart; Saubrekka, Karoline; Petelenz-Kurdziel, Elzbieta Anna & Müller, Oliver [Show all 8 contributors for this article] (2023). Seasonality of the bacterial and archaeal community composition of the Northern Barents Sea. Frontiers in Microbiology. ISSN 1664-302X. 14. doi: 10.3389/fmicb.2023.1213718. Full text in Research Archive Show summary

  The Barents Sea is a transition zone between the Atlantic and the Arctic Ocean. The ecosystem in this region is highly variable, and a seasonal baseline of biological factors is needed to monitor the effects of global warming. In this study, we report the results from the investigations of the bacterial and archaeal community in late winter, spring, summer, and early winter along a transect through the northern Barents Sea into the Arctic Ocean east of Svalbard using 16S rRNA metabarcoding. Winter samples were dominated by members of the SAR11 clade and a community of nitrifiers, namely Cand. Nitrosopumilus and LS-NOB (Nitrospinia), suggest a prevalence of chemoautotrophic metabolisms. During spring and summer, members of the Gammaproteobacteria (mainly members of the SAR92 and OM60(NOR5) clades, Nitrincolaceae) and Bacteroidia (mainly Polaribacter, Formosa, and members of the NS9 marine group), which followed a succession based on their utilization of different phytoplankton-derived carbon sources, prevailed. Our results indicate that Arctic marine bacterial and archaeal communities switch from carbon cycling in spring and summer to nitrogen cycling in winter and provide a seasonal baseline to study the changes in these processes in response to the effects of climate change.

• Eriksen, Elke; Madsen, Anne Mette; Afanou, Komlavi Anani; Straumfors, Anne; Eiler, Alexander & Graff, Pål (2023). Occupational exposure to inhalable pathogenic microorganisms in waste sorting. International Journal of Hygiene and Environmental Health. ISSN 1438-4639. 253. doi: 10.1016/j.ijheh.2023.114240. Full text in Research Archive Show summary

  This study assessed microorganisms in personal inhalable work air samples aiming to identify potential human pathogens, and correlate exposure to adverse health outcomes in waste workers. Full-shift personal exposure was measured in six different waste sorting plants. Microbial concentrations in inhalable air samples were analysed using MALDI-TOF MS for cultivable, and next generation sequencing (NGS) for non-cultivable microorganisms. Concentrations of bacterial and fungal CFUs varied substantially within and between waste sorting plants, ranging from no identifiable organisms to a maximum concentration in the order of 105 CFU/m3. Bacillus and Staphylococcus were among the most abundant bacterial genera, whilst fungal genera were dominated by Aspergillus and Penicillium. Approximately 15% of all identified species were human pathogens classified in risk group 2, whereas 7% belonged to risk group 1. Furthermore, significant correlations between concentrations of fungi in risk group 1 and self-reported adverse symptoms, such as wheezing were identified in exposed workers. The combination of culture-based methods and NGS facilitated the investigation of infectious microbial species with potential pathophysiological properties as well as non-infectious biological agents in inhalable work air samples and thereby contributed to the risk assessment of occupational exposure in waste sorting.

• Shi, Yingying; Wei, Zhipeng; Xu, Yaofei; Lu, Xiang & Ruan, Aidong (2023). Effects of electrochemical intervention on the remediation of black-odorous water: insights into microbial community dynamics and functional shifts in sediments. Water Science and Technology. ISSN 0273-1223. 87(11), p. 2776–2792. doi: 10.2166/wst.2023.169. Full text in Research Archive
• Buttay, Lucie; Ohlberger, Jan Philipp & Langangen, Øystein Ole Gahr (2023). Management strategies can buffer the effect of mass mortality in early life stages of fish. Journal of Applied Ecology. ISSN 0021-8901. 60(10), p. 2056–2065. doi: 10.1111/1365-2664.14489. Full text in Research Archive Show summary

  1. Mass mortality (MM) events affecting early life stages of fish can have strong and long-term consequences for population abundance and demography as well as the economic activity supported by exploited stocks. Adaptive fishery manage-ment may help mitigate economic impacts and ensure sustainable resource use following a MM event. 2. Using a state-space life cycle model, we simulated ‘what-if’ scenarios of MM on Northeast Arctic cod (Gadus morhua) eggs and larvae. We compared the expected catches, total stock biomass (TSB), and interannual variability in catches over a period of 10 years after the simulated disturbance. We further evaluated a range of management mitigation strategies, namely reductions in fishing mortality of varying duration (1–10 years) and intensity (no fishing reduction to full ban). 3. A large range of reductions in fishing led to an increase in expected catches over 10 years compared to no reductions, especially when applied immediately after the perturbation and when the cod population was characterized by a high mean age and high TSB. Severe fishing reductions can increase catches substantially but are associated with high interannual variability. Fishing reductions of moder-ate intensity applied between 1 and 4 years would allow to increase catches with only a slight increase in interannual variability. 4. Our findings demonstrate the potential benefits of an adaptive approach to fish-eries management and highlight that mitigation actions may ensure the sustain-able exploitation of fish stocks in the wake of unexpected disturbances. 5. Synthesis and application. Mass mortality events during early life stages of fish can potentially have substantial and long-term effects on the population. Mitigation is more efficient when the affected population has a diverse age structure and when the mitigation strategy is applied immediately after the perturbation. Severe re-duction in fishing mortality is an efficient measure to increase the expected aver-age catch but is associated with high interannual variability. Fishing reduction of moderate intensity applied during 1–4 years after the event also increases the expected average catch with only slightly higher interannual variability in catches.

• Durant, Joël; Holt, Rebecca Emma; Ono, Kotaro & Langangen, Øystein Ole Gahr (2023). Predatory walls may impair climate warming-associated population expansion. Ecology. ISSN 0012-9658. 104(9), p. 1–8. doi: 10.1002/ecy.4130. Full text in Research Archive Show summary

  Climate change has a profound impact on species distribution and abundanceglobally, as well as local diversity, which affects ecosystem functioning. In par-ticular, changes in population distribution and abundance may lead tochanges in trophic interactions. Although species can often shift their spatialdistribution when suitable habitats are available, it has been suggested thatpredator presence can be a constraint on climate-related distribution shifts.We test this using two well-studied and data-rich marine environments.Focusing on a pair of sympatric fishes, Atlantic haddock Melanogrammus aeglefinus and cod Gadus morhua, we study the effect of the presence andabundance of the latter on the former distribution. We found that the distribu-tion of cod and increased abundance may limit the expansion of haddock tonew areas and could consequently buffer ecosystem changes due to climatechange. Though marine species may track the rate and direction of climateshifts, our results demonstrate that the presence of predators may limit theirexpansion to thermally suitable habitats. By integrating climatic and ecologicaldata at scales that can resolve predator–prey relationships, this analysis dem-onstrates the usefulness of considering trophic interactions to gain a morecomprehensive understanding and to mitigate the effects of climate change onspecies distributions.

• Zheng, Xiaoqi; Lu, Yonglong; Ma, Cuimei; Yuan, Jingjing; Stenseth, Nils Christian & Hessen, Dag Olav [Show all 10 contributors for this article] (2023). Greenhouse gas emissions from extractive industries in a globalized era. Journal of Environmental Management. ISSN 0301-4797. 343, p. 1–10. doi: 10.1016/j.jenvman.2023.118172.
• Xu, Xiangbo; Xu, Yan; Li, Jing; Lu, Yonglong; Jenkins, Alan & Ferrier, Robert C. [Show all 16 contributors for this article] (2023). Coupling of crop and livestock production can reduce the agricultural GHG emission from smallholder farms. iScience. ISSN 2589-0042. 26(6), p. 1–13. doi: 10.1016/j.isci.2023.106798. Full text in Research Archive
• Gormley, Kate; Hague, Emily; Andvik, Clare Margaret; DaCosta, Valentina; Davies, Abigail & Diz, Daniela [Show all 8 contributors for this article] (2023). First port of call: a horizon scanning workshop for sustainable Arctic marine infrastructure. The Polar Journal. ISSN 2154-896X. 13(1), p. 146–162. doi: 10.1080/2154896X.2023.2205243. Full text in Research Archive
• Wei, Jing; Fontaine, Laurent; Valiente Parra, Nicolas; Dörsch, Peter; Hessen, Dag Olav & Eiler, Alexander (2023). Trajectories of freshwater microbial genomics and greenhouse gas saturation upon glacial retreat. Nature Communications. ISSN 2041-1723. 14. doi: 10.1038/s41467-023-38806-w. Full text in Research Archive
• Broch, Catharina & Heuschele, Jan David (2023). Zoobooth: A portable, open-source and affordable approach for repeated size measurements of live individual zooplankton. Heliyon. ISSN 2405-8440. 9(5). doi: 10.1016/j.heliyon.2023.e15383. Full text in Research Archive
• Kaartvedt, Stein; Christiansen, Svenja & Titelman, Josefin (2023). Mid-summer fish behavior in a high-latitude twilight zone. Limnology and Oceanography. ISSN 0024-3590. 68(7), p. 1654–1669. doi: 10.1002/lno.12374. Full text in Research Archive
• Holme, Jørn Andreas; Låg, Marit; Skuland, Tonje Schwach; Parenicová, Martina; Ciganek, Miroslav & Penciková, Katerina [Show all 13 contributors for this article] (2023). Characterization of elements, PAHs, AhR-activity and pro-inflammatory responses of road tunnel-derived particulate matter in human hepatocyte-like and bronchial epithelial cells. Toxicology in Vitro. ISSN 0887-2333. 90, p. 1–13. doi: 10.1016/j.tiv.2023.105611. Full text in Research Archive
• Paus-Knudsen, Julie Sørlie; Sveinsson, Henrik Andersen; Grung, Merete; Borgå, Katrine & Nielsen, Anders (2023). The Neonicotinoid Imidacloprid Impairs Learning, Locomotor Activity Levels, and Sucrose Solution Consumption in Bumblebees (Bombus terrestris). Environmental Toxicology and Chemistry. ISSN 0730-7268. 42(6), p. 1337–1345. doi: 10.1002/etc.5611. Full text in Research Archive Show summary

  Bumblebees carry out the complex task of foraging to provide for their colonies. They also conduct pollination, an ecosystem service of high importance to both wild plants and entomophilous crops. Insecticides can alter different aspects of bumblebee foraging behavior, including the motivation to leave the hive, finding the right flowers, handling flowers, and the ability to return to the colony. In the present study, we assessed how the neonicotinoid imidacloprid affects bumblebees' foraging behavior after exposure to four different treatment levels, including field-realistic concentrations (0 [control], 1, 10, and 100 μg/L), through sucrose solution over 9 days. We observed the behavior of several free-flying bumblebees simultaneously foraging on artificial flowers in a flight arena to register the bees' complex behavior postexposure. To conduct a detailed assessment of how insecticides affect bumblebee locomotor behavior, we used video cameras and analyzed the recordings using computer vision. We found that imidacloprid impaired learning and locomotor activity level when the bumblebees foraged on artificial flowers. We also found that imidacloprid exposure reduced sucrose solution intake and storage. By using automated analyses of video recordings of bumblebee behavior, we identified sublethal effects of imidacloprid exposure at field-realistic doses. Specifically, we observed negative impacts on consumption of sucrose solution as well as on learning and locomotor activity level. Our results highlight the need for more multimodal approaches when assessing the sublethal effects of insecticides and plant protection products in general.

• 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.

• Vereide, Emilie Hernes; Mihaljevic, Marina; Browman, Howard; Fields, David M.; Agersted, Mette Dalgaard & Titelman, Josefin [Show all 7 contributors for this article] (2023). Effects of airgun discharges used in seismic surveys on development and mortality in nauplii of the copepod Acartia tonsa. Environmental Pollution. ISSN 1566-0745. 327. doi: 10.1016/j.envpol.2023.121469. Full text in Research Archive Show summary

  Seismic surveys are conducted worldwide to explore for oil and gas deposits and to map subsea formations. The airguns used in these surveys emit low-frequency sound waves. Studies on zooplankton responses to airguns report a range of effects, from none to substantial mortality. A field experiment was conducted to assess mortality and naupliar body length of the calanoid copepod Acartia tonsa when exposed to the discharge of two 40-inch airguns. Nauplii were placed in plastic bags and attached to a line at a depth of 6 m. For each treatment, three bags of nauplii were exposed to one of three treatments for 2.5 h: Airgun array discharge, a boat control, or a silent control. After exposure, nauplii were kept in filtered seawater in the laboratory without food. Immediate mortality in the nauplii was approximately 14% compared to less than 4% in the silent and boat control. Similarly, there was higher mortality in the airgun exposed nauplii up to six days after exposure compared to the control treatments. Nearly all of the airgun exposed nauplii were dead after four days, while >50% of the nauplii in the control treatments were alive at six days post-exposure. There was an interaction between treatment and time on naupliar body length, indicating lower growth in the nauplii exposed to the airgun discharge (growth rates after 4 days: 1.7, 5.4, and 6.1 μm d−1 in the airgun exposed, silent control, and boat control, respectively). These experiments indicate that the output of two small airguns affected mortality and growth of the naupliar stages of Acartia tonsa in close vicinity to the array.

• Haarr, Ane; Nipen, Maja; Mwakalapa, Eliezer Brown; Borgen, Anders; Mmochi, Aviti J. & Borgå, Katrine (2023). Chlorinated paraffins and dechloranes in free-range chicken eggs and soil around waste disposal sites in Tanzania. Chemosphere. ISSN 0045-6535. 329, p. 1–11. doi: 10.1016/j.chemosphere.2023.138646. Full text in Research Archive Show summary

  Electronic waste is a source of both legacy and emerging flame retardants to the environment, especially in regions where sufficient waste handling systems are lacking. In the present study, we quantified the occurrence of short- and medium chain chlorinated paraffins (SCCPs and MCCPs) and dechloranes in household chicken (Gallus domesticus) eggs and soil collected near waste disposal sites on Zanzibar and the Tanzanian mainland. Sampling locations included an e-waste facility and the active dumpsite of Dar es Salaam, a historical dumpsite in Dar es Salaam, and an informal dumpsite on Zanzibar. We compared concentrations and contaminant profiles between soil and eggs, as free-range chickens ingest a considerable amount of soil during foraging, with potential for maternal transfer to the eggs. We found no correlation between soil and egg concentrations or patterns of dechloranes or CPs. CPs with shorter chain lengths and higher chlorination degree were associated with soil, while longer chain lengths and lower chlorination degree were associated with eggs. MCCPs dominated the CP profile in eggs, with median concentrations ranging from 500 to 900 ng/g lipid weight (lw) among locations. SCCP concentrations in eggs ranged from below the detection limit (LOD) to 370 ng/g lw. Dechlorane Plus was the dominating dechlorane compound in all egg samples, with median concentrations ranging from 0.5 to 2.8 ng/g lw. SCCPs dominated in the soil samples (400–21300 ng/g soil organic matter, SOM), except at the official dumpsite where MCCPs were highest (65000 ng/g SOM). Concentrations of dechloranes in soil ranged from below LOD to 240 ng/g SOM, and the dominating compounds were Dechlorane Plus and Dechlorane 603. Risk assessment of CP levels gave margins of exposure (MOE) close to or below 1000 for SCCPs at one location.

• Monteith, Donald T.; Henrys, Peter A.; Hruška, Jakub; de Wit, Heleen; Krám, Pavel & Moldan, Filip [Show all 12 contributors for this article] (2023). Long-term rise in riverine dissolved organic carbon concentration is predicted by electrolyte solubility theory. Science Advances. ISSN 2375-2548. 9(3). doi: 10.1126/sciadv.ade3491. Full text in Research Archive Show summary

  The riverine dissolved organic carbon (DOC) flux is of similar magnitude to the terrestrial sink for atmospheric CO2, but the factors controlling it remain poorly determined and are largely absent from Earth system models (ESMs). Here, we show, for a range of European headwater catchments, that electrolyte solubility theory explains how declining precipitation ionic strength (IS) has increased the dissolution of thermally moderated pools of soluble soil organic matter (OM), while hydrological conditions govern the proportion of this OM entering the aquatic system. Solubility will continue to rise exponentially with declining IS until pollutant ion deposition fully flattens out under clean air policies. Future DOC export will increasingly depend on rates of warming and any directional changes to the intensity and seasonality of precipitation and marine ion deposition. Our findings provide a firm foundation for incorporating the processes dominating change in this component of the global carbon cycle in ESMs.

• Opdal, Anders Martin Frugård; Andersen, Tom; Hessen, Dag Olav; Lindemann, Christian & Aksnes, Dag Lorents (2023). Tracking freshwater browning and coastal water darkening from boreal forests to the Arctic Ocean. Limnology and Oceanography Letters. ISSN 2378-2242. 8(4), p. 611–619. doi: 10.1002/lol2.10320. Full text in Research Archive
• Morrissey, Christy; Fritsch, Clémentine; Fremlin, Katharine; Adams, William; Borgå, Katrine & Brinkmann, Markus [Show all 11 contributors for this article] (2023). Advancing exposure assessment approaches to improve wildlife risk assessment. Integrated Environmental Assessment and Management. ISSN 1551-3777. doi: 10.1002/ieam.4743. Show summary

  The exposure assessment component of a Wildlife Ecological Risk Assessment aims to estimate the magnitude, frequency, and duration of exposure to a chemical or environmental contaminant, along with characteristics of the exposed population. This can be challenging in wildlife as there is often high uncertainty and error caused by broad-based, interspecific extrapolation and assumptions often because of a lack of data. Both the US Environmental Protection Agency (USEPA) and European Food Safety Authority (EFSA) have broadly directed exposure assessments to include estimates of the quantity (dose or concentration), frequency, and duration of exposure to a contaminant of interest while considering “all relevant factors.” This ambiguity in the inclusion or exclusion of specific factors (e.g., individual and species-specific biology, diet, or proportion time in treated or contaminated area) can significantly influence the overall risk characterization. In this review, we identify four discrete categories of complexity that should be considered in an exposure assessment—chemical, environmental, organismal, and ecological. These may require more data, but a degree of inclusion at all stages of the risk assessment is critical to moving beyond screening-level methods that have a high degree of uncertainty and suffer from conservatism and a lack of realism. We demonstrate that there are many existing and emerging scientific tools and cross-cutting solutions for tackling exposure complexity. To foster greater application of these methods in wildlife exposure assessments, we present a new framework for risk assessors to construct an “exposure matrix.” Using three case studies, we illustrate how the matrix can better inform, integrate, and more transparently communicate the important elements of complexity and realism in exposure assessments for wildlife. Modernizing wildlife exposure assessments is long overdue and will require improved collaboration, data sharing, application of standardized exposure scenarios, better communication of assumptions and uncertainty, and postregulatory tracking.

• Bachmann, Lutz; Beermann, Jan; Brey, Thomas; de Boer, Hugo; Dannheim, Jennifer & Edvardsen, Bente [Show all 20 contributors for this article] (2023). The role of systematics for understanding ecosystem functions: Proceedings of the Zoologica Scripta Symposium, Oslo, Norway, 25 August 2022. Zoologica Scripta. ISSN 0300-3256. 52(3), p. 187–214. doi: 10.1111/zsc.12593. Full text in Research Archive
• Sengupta, Sagnik; Leinaas, Hans Petter; van Gestel, Cornelis A.M.; Jager, Tjalling; Rundberget, Thomas & Borgå, Katrine (2023). High sensitivity to dietary imidacloprid exposure in early life stages of Folsomia quadrioculata (Collembola) populations from contrasting climates. Agriculture, Ecosystems & Environment. Applied Soil Ecology. ISSN 0929-1393. 187. doi: 10.1016/j.apsoil.2023.104880. Full text in Research Archive Show summary

  Survival of early life stages is critical for population growth. Understanding the vulnerability of these sensitive stages can therefore improve ecological risk predictions. The globally-used neonicotinoid insecticide imidacloprid does not degrade easily in soil and occurs at concentrations potentially toxic to non-target soil organisms, such as Collembola. Here, we studied the effects of dietary exposure to imidacloprid on the survival of juveniles in an arctic and a temperate population of Folsomia quadrioculata (Collembola), a commonly-occurring litter-dwelling species in the Northern Hemisphere. The exposure lasted from <24 h to 30 days since hatching at 15 °C. We assessed whether (1) the arctic population of the test species with faster development rates could be more vulnerable than the temperate population, (2) cumulative mortality could increase substantially with exposure time, and (3) the mortality risk experienced during the juvenile stage could be greater than that experienced by the adults. We found a strong concentration-dependent decline in survival in both populations, with small but significantly different LC50s, despite large differences in multiple life-history traits. Applying a General Unified Threshold model for Survival (GUTS) showed a low threshold for effects, slow damage dynamics, a 6–11-fold decrease in LC50 from 14 to 30 days of exposure, and saturation of damage at the three highest concentrations. In addition, exposure starting soon after hatching caused much more mortality than that starting in the adult stages. Our findings suggest that toxicity tests not emphasizing the neonate stages or not lasting long enough can underestimate the implications for populations of naturally abundant non-target organisms.

• Kohlbach, Doreen; Goraguer, Lucie; Bodur, Yasemin V.; Müller, Oliver; Amargant Arumí, Martí & Blix, Katalin [Show all 23 contributors for this article] (2023). Earlier sea-ice melt extends the oligotrophic summer period in the Barents Sea with low algal biomass and associated low vertical flux. Progress in Oceanography. ISSN 0079-6611. 213. doi: 10.1016/j.pocean.2023.103018. Full text in Research Archive Show summary

  The decrease in Arctic sea-ice extent and thickness as a result of global warming will impact the timing, duration, magnitude and composition of phytoplankton production with cascading effects on Arctic marine food-webs and biogeochemical cycles. Here, we elucidate the environmental drivers shaping the composition, abundance, biomass, trophic state and vertical flux of protists (unicellular eukaryotes), including phytoplankton, in the Barents Sea in late August 2018 and 2019. The two years were characterized by contrasting sea-ice conditions. In August 2018, the sea-ice edge had retreated well beyond the shelf break into the Nansen Basin (>82◦N), while in 2019, extensive areas of the northwestern Barents Sea shelf (>79◦N) were still ice-covered. These contrasting sea-ice conditions resulted in marked interannual differences in the pelagic protist community structure in this area. In August 2018, the protist community was in a post-bloom stage of seasonal succession characterized by oligotrophic surface waters and dominance of small-sized phytoplankton and heterotrophic protists (predominantly flagellates and ciliates) at most stations. In 2019, a higher contribution of autotrophs and large-celled phytoplankton, particularly diatoms, to total protist biomass compared to 2018 was reflected in higher chlorophyll a concentrations and suggested that the protist community was still in a late bloom stage at some stations. It is noteworthy that particularly diatoms contributed a considerably higher proportion to the protist biomass at the ice-covered stations in both years compared to the open-water stations. This pattern was also evident in the higher vertical protist biomass flux in 2019, dominated by dinoflagellates and diatoms, compared to 2018. Our results suggest that the predicted transition toward an ice-free Barents Sea will lengthen the oligotrophic summer period with low algal biomass and associated low vertical flux.

• Matek, Antonija; Bosak, Sunčica; Supraha, Luka; Neeley, Aimee; Višić, Hrvoje & Cetinić, Ivona [Show all 7 contributors for this article] (2023). Phytoplankton diversity and chemotaxonomy in contrasting North Pacific ecosystems. PeerJ. ISSN 2167-8359. 11, p. 1–30. doi: 10.7717/peerj.14501. Full text in Research Archive
• Cui, Haotian; Lu, Yonglong; Zhou, Yunqiao; He, Guizhen; Song, Shuai & Yang, Shengjie [Show all 15 contributors for this article] (2023). Carbon flow through continental-scale ground logistics transportation. iScience. ISSN 2589-0042. 26(1), p. 1–18. doi: 10.1016/j.isci.2022.105792. Full text in Research Archive
• Nowicki, Robynne; Borgå, Katrine; Gabrielsen, Geir W. & Varpe, Øystein (2023). Energy content of krill and amphipods in the Barents Sea from summer to winter: variation across species and size. Polar Biology. ISSN 0722-4060. 46, p. 139–150. doi: 10.1007/s00300-023-03112-0. Full text in Research Archive Show summary

  Arctic zooplankton develop large energy reserves, as an adaptation to strong seasonality, making them valuable prey items. We quantified the energy content (kJ g−1 dry weight) of abundant krill (arcto-boreal, Thysanoessa inermis and boreal, Meganyctiphanes norvegica) and amphipods (Arctic, Themisto libellula and sub-Arctic-boreal, Themisto abyssorum) in the Barents Sea in late summer (August) and early winter (December). Variation in energy content was attributed to species-specific traits and body size categories, the latter in part as a proxy for ontogeny. T. inermis had the highest energy content, (Aug: 26.8 ± 1.5 (SD) kJ g−1) and remained similar from summer to winter. Energy content increased in M. norvegica and decreased in both amphipod species, with the lowest energy content being in T. abyssorum (Dec: 17.8 ± 0.8 kJ g−1). The effect of body size varied between species, with energy content increasing with size in T. inermis and T. libellula, and no change with size in M. norvegica and T. abyssorum. The reproductive stages of T. libellula differed in energy content, being highest in gravid females. Energy content varied with species’ dependence on energy storage. Our findings highlight how phylogenetically and morphologically similar prey items cannot necessarily be considered equal from a predator´s perspective. Energetically, the northern T. inermis was higher quality compared to the more southern M. norvegica, and mostly so during summer. Ecological models and management strategies should consider such variation in prey quality, especially as Arctic borealization is expected to change species composition and the energetic landscape for predators.

• Crapart, Camille Marie; Finstad, Anders Gravbrøt; Hessen, Dag Olav; Vogt, Rolf David & Andersen, Tom (2023). Spatial predictors and temporal forecast of total organic carbon levels in boreal lakes. Science of the Total Environment. ISSN 0048-9697. 870. doi: 10.1016/j.scitotenv.2023.161676. Full text in Research Archive Show summary

  Browning of Fennoscandian boreal lakes is raising concerns for negative ecosystem impacts as well as reduced drinking water quality. Declined sulfur deposition and warmer climate, along with afforestation, other climate impacts and less outfield grazing, have resulted in increased fluxes of Total Organic Carbon (TOC) from catchments to freshwater, and subsequently to coastal waters. This study assesses the major governing factors for increased TOC levels among several catchment characteristics in almost 5000 Fennoscandian lakes and catchments. Normalized Difference Vegetation Index (NDVI), a proxy for plant biomass, and the proportions of peatland in the catchment, along with surface runoff intensity and nitrogen deposition loading, were identified as the main spatial predictors for lake TOC concentrations. A multiple linear model, based on these explanatory variables, was used to simulate future TOC concentration in surface runoff from coastal drainage basins in 2050 and 2100, using the forecasts of climatic variables in two of the Shared Socio-economic Pathways (SSP): 1-2.6 (+2 °C) and 3-7.0 (+4,5 °C). These scenarios yield contrasting effects. SSP 1-2.6 predicts an overall decrease of TOC export to coastal waters, while SSP 3-7.0 in contrast leads to an increase in TOC export.

• Bekkby, Trine; Torstensen, Ragnhild Ryther Grimm; Grünfeld, Lars Andreas Holm; Gundersen, Hege; Fredriksen, Stein & Rinde, Eli [Show all 12 contributors for this article] (2023). ‘Hanging gardens’—comparing fauna communities in kelp farms and wild kelp forests. Frontiers in Marine Science. ISSN 2296-7745. 10. doi: 10.3389/fmars.2023.1066101. Full text in Research Archive Show summary

  A growing need for food is causing increased interest for seaweed farming globally. This requires knowledge of the industry’s effects on the marine environment. We therefore aimed to explore the communities hosted by a kelp farm compared to that of wild kelp forests. The study was performed in mid-western Norway. Kelp associated fauna were collected from farmed kelp (Saccharina latissima and Alaria esculenta), in wild kelp forests (S. latissima, A. esculenta and Laminaria hyperborea), and from fauna traps in the water column. The study showed that the kelp farm had lower taxa abundance and richness and a lower biodiversity than the wild kelp forests. Nonetheless, the farmed kelp hosted many associated species, with communities different from what was found on ropes without kelp (i.e., in the water column). The fauna communities among the farmed kelp were more similar to what was found in the wild L. hyperborea kelp forest than to its wild counterparts. The difference between the fauna communities of ‘old’ and ‘young’ farmed kelp (grown for 3 and 7 months, respectively) was not significant, but the fauna was dominated by the isopod species Idotea pelagica in the young forest and by amphipods, mainly belonging to the genus Caprella, in the older. The study contributes to our knowledge of kelp farms’ ecological role in the marine environment, which is of importance for today’s management as well as for ensuring a sustainable future development of the kelp farming industry.

• Andvik, Clare Margaret; Haug, Tore; Lyche, Jan Ludvig & Borgå, Katrine (2023). Emerging and legacy contaminants in common minke whale from the Barents sea. Environmental Pollution. ISSN 1566-0745. 319. doi: 10.1016/j.envpol.2023.121001. Full text in Research Archive
• Osman, Omneya Ahmed; Andersson, Johan; Martin Sanchez, Pedro Maria & Eiler, Alexander (2022). National eDNA-based monitoring of Batrachochytrium dendrobatidis and amphibian species in Norway. Metabarcoding and Metagenomics. ISSN 2534-9708. 6, p. 305–317. doi: 10.3897/mbmg.6.85199. Full text in Research Archive
• Lundsør, Elisabeth; Lømsland, Evy Rigmor; Johnsen, Torbjørn Martin; Engesmo, Anette; King, Andrew Luke & Staalstrøm, Andre [Show all 11 contributors for this article] (2022). Marine phytoplankton community data and corresponding environmental properties from eastern Norway, 1896–2020. Scientific Data. ISSN 2052-4463. 9. doi: 10.1038/s41597-022-01869-3. Full text in Research Archive
• Šigutová, Hana; Dolný, Aleš; Samways, Michael J.; Hardersen, Sönke; Max Barbosa Oliveira Junior, José & Juen, Leandro [Show all 8 contributors for this article] (2022). Odonata as indicators of pollution, habitat quality, and landscape disturbance. In Córdoba-Aguilar, Alex; Beatty, Christopher & Bried, Jason T. (Ed.), Dragonflies and Damselflies: Model Organisms for Ecological and Evolutionary Research. Oxford University Press. ISSN 9780192898623. p. 371–384. doi: 10.1093/oso/9780192898623.003.0026.
• Rusch, Johannes; Strand, David; Laurendz, Charlotte; Andersen, Tom; Johnsen, Stein Ivar & Edsman, Lennart [Show all 7 contributors for this article] (2022). Exploring the eDNA dynamics of the host-pathogen pair Pacifastacus leniusculus (Decapoda) and Aphanomyces astaci (Saprolegniales) under experimental conditions. NeoBiota. ISSN 1619-0033. 79, p. 1–29. doi: 10.3897/NEOBIOTA.79.82793. Full text in Research Archive
• Langangen, Øystein Ole Gahr; Ohlberger, Jan Philipp; Stige, Leif Christian; Patin, Rémi; Buttay, Lucie & Stenseth, Nils Christian [Show all 8 contributors for this article] (2022). Effects of early life mass mortality events on fish populations. Fish and Fisheries. ISSN 1467-2960. 24(1), p. 176–186. doi: 10.1111/faf.12718. Full text in Research Archive
• Skjæraasen, Jon Egil; Karlsen, Ørjan; Langangen, Øystein Ole Gahr; Meier, Sonnich; Dunlop, Katherine Mary & van der Meeren, Terje [Show all 14 contributors for this article] (2022). Attraction of cod Gadus morhua from coastal spawning grounds to salmon farms. Aquaculture Environment Interactions. ISSN 1869-215X. 14, p. 229–242. doi: 10.3354/aei00440. Full text in Research Archive Show summary

  Wild fish aggregate at aquaculture net-pens, but the underlying mechanisms are not fully understood. This study examined how salmon farms attract coastal Atlantic cod Gadus morhua from their inshore spawning grounds. Acoustic receivers were deployed at 5 known cod spawning grounds and 6 salmon Salmo salar farms located at varying distances from these grounds in a mid-Norway study site. Cod were caught at each spawning ground annually from 2017-2019, fitted with acoustic transmitters and released (n = 535). A total of 289 tagged cod (54%) were detected at the salmon farms, with more cod detected at farms closest to the focal spawning grounds and at operational farms. The latter result is likely linked to the availability of feeding opportunities at farm locations. Those cod that were detected by the receivers spent less time at farms farther from their release locations. For the farm-associated cod, 70% were detected for <1 wk at the farms. However, 48 cod spent >1 mo close to the farms, with 1 individual staying 720 d underneath the farm. A total of 135 cod visited 2 or more farms, with farms in proximity more connected in terms of inter-farm movement. Some of the cod utilizing these local spawning grounds likely have considerable dietary input from salmon feed.

• Lundsør, Elisabeth; Eikrem, Wenche; Stige, Leif Christian; Engesmo, Anette; Gran-Stadniczeñko, Sandra & Edvardsen, Bente (2022). Changes in phytoplankton community structure over a century in relation to environmental factors. Journal of Plankton Research. ISSN 0142-7873. 44(6), p. 854–871. doi: 10.1093/plankt/fbac055. Full text in Research Archive Show summary

  Changes in phytoplankton abundance and biomass during the period 1933–2020 were examined by statistical modeling using data from the Inner Oslofjorden phytoplankton database. The phytoplankton abundances increased with eutrophication from 1930s to 1970s, but with the implementation of sewage cleaning measures and a resulting reduction in nutrient releases, the phytoplankton abundance has since then decreased significantly. The onset of the seasonal blooms has started progressively later during the last 15 years, especially the spring bloom. The delayed spring bloom co-occurred with increasing temperature in winter and spring. The diatom biomass decreased more than that of dinoflagellates and other microeukaryotes. The diatom genus Skeletonema dominated the spring bloom and was found to be the key taxa in explaining these changes in abundance and phenology. Extensive summer blooms of the coccolithophore Emiliania huxleyi, which has been characteristic for the inner Oslofjorden, has also gradually decreased during the last decades, along with reducing eutrophication. Dinoflagellates have not had the same reduction in abundance as the other groups. Despite an increasing proportion of dinoflagellates compared with other taxa, there are no clear indications of increased occurrence of toxic algal blooms in inner Oslofjorden. However, the introduction of new “toxin-producing” species may cause concern.

• Supraha, Luka; Klemm, Kerstin; Gran-Stadniczeñko, Sandra; Hörstmann, Cora; Vaulot, Daniel & Edvardsen, Bente [Show all 7 contributors for this article] (2022). Diversity and biogeography of planktonic diatoms in Svalbard fjords: The role of dispersal and Arctic endemism in phytoplankton community structuring. Elementa: Science of the Anthropocene. ISSN 2325-1026. 10(1). doi: 10.1525/elementa.2021.00117. Full text in Research Archive Show summary

  Understanding the processes that shape the community structure of Arctic phytoplankton is crucial for predicting responses of Arctic ecosystems to the ongoing ocean warming. In particular, little is known about the importance of phytoplankton dispersal by the North Atlantic Current and the prevalence and maintenance of Arctic endemism. We investigated the diversity and biogeography of diatoms from five Svalbard fjords and the Hausgarten observatory (Fram Strait) by combining diatom cultivation and 18S rRNA gene metabarcoding. In total, 50 diatom strains were isolated from the area during the HE492 cruise in August 2017. The strains were identified taxonomically using molecular and morphological approaches, and their biogeographic distribution was mapped using the local metabarcoding dataset and a global compilation of published metabarcoding datasets. Biogeographic analysis was also conducted for the locally most abundant diatom metabarcoding amplicon sequence variants. The biogeographic analyses demonstrated that Arctic diatoms exhibit three general biogeographic distribution types: Arctic, Arctic-temperate, and cosmopolitan. At Hausgarten and in outer Isfjorden on the west coast of Svalbard, the communities were dominated by genotypes with Arctic-temperate and cosmopolitan distribution. Diatom communities in nearby Van Mijenfjorden, inner Isfjorden and Kongsfjorden were dominated by genotypes with Arctic-temperate distribution, and cosmopolitan species were less abundant. The genotypes endemic to the Arctic had lower abundance on the west coast of Svalbard. The two northernmost fjords (Woodfjorden and Wijdefjorden) had a higher abundance of genotypes endemic to the Arctic. Our results demonstrate that the diatom communities in the Svalbard area consist of genotypes endemic to the Arctic, and genotypes with broader biogeographic distribution, all of which are further structured by local environmental gradients. Finer biogeographic patterns observed within Arctic-temperate and cosmopolitan genotypes suggest that certain genotypes can be used as indicators of increasing influence of Atlantic waters on the phytoplankton community structure in the Svalbard area.

• Konestabo, Heidi Sjursen; Birkemoe, Tone; Leinaas, Hans Petter; van Gestel, Cornelis A.M.; Sengupta, Sagnik & Borgå, Katrine (2022). Pesticide effects on the abundance of springtails and mites in field mesocosms at an agricultural site. Ecotoxicology. ISSN 0963-9292. 31(9), p. 1450–1461. doi: 10.1007/s10646-022-02599-3. Full text in Research Archive
• Borgå, Katrine; McKinney, Melissa A.; Routti, Heli Anna Irmeli; Fernie, Kim J.; Giebichenstein, Julia & Hallanger, Ingeborg G. [Show all 7 contributors for this article] (2022). The influence of global climate change on accumulation and toxicity of persistent organic pollutants and chemicals of emerging concern in Arctic food webs. Environmental Science: Processes & Impacts. ISSN 2050-7887. 24(10), p. 1544–1576. doi: 10.1039/d1em00469g. Full text in Research Archive Show summary

  This review summarizes current understanding of how climate change-driven physical and ecological processes influence the levels of persistent organic pollutants (POPs) and contaminants of emerging Arctic concern (CEACs) in Arctic biota and food webs. The review also highlights how climate change may interact with other stressors to impact contaminant toxicity, and the utility of modeling and newer research tools in closing knowledge gaps on climate change-contaminant interactions. Permafrost thaw is influencing the concentrations of POPs in freshwater ecosystems. Physical climate parameters, including climate oscillation indices, precipitation, water salinity, sea ice age, and sea ice quality show statistical associations with POPs concentrations in multiple Arctic biota. Northward range-shifting species can act as biovectors for POPs and CEACs into Arctic marine food webs. Shifts in trophic position can alter POPs concentrations in populations of Arctic species. Reductions in body condition are associated with increases in levels of POPs in some biota. Although collectively understudied, multiple stressors, including contaminants and climate change, may act to cumulatively impact some populations of Arctic biota. Models are useful for predicting the net result of various contrasting climate-driven processes on POP and CEAC exposures; however, for some parameters, especially food web changes, insufficient data exists with which to populate such models. In addition to the impact of global regulations on POP levels in Arctic biota, this review demonstrates that there are various direct and indirect mechanisms by which climate change can influence contaminant exposure, accumulation, and effects; therefore, it is important to attribute POP variations to the actual contributing factors to inform future regulations and policies. To do so, a broad range of habitats, species, and processes must be considered for a thorough understanding and interpretation of the consequences to the distribution, accumulation, and effects of environmental contaminants. Given the complex interactions between climate change, contaminants, and ecosystems, it is important to plan for long-term, integrated pan-Arctic monitoring of key biota and ecosystems, and to collect ancillary data, including information on climate-related parameters, local meteorology, ecology, and physiology, and when possible, behavior, when carrying out research on POPs and CEACs in biota and food webs of the Arctic.

• Allesson, Lina; Valiente Parra, Nicolas; Dörsch, Peter; Andersen, Tom; Eiler, Alexander & Hessen, Dag Olav (2022). Drivers and variability of CO2:O2 saturation along a gradient from boreal to Arctic lakes. Scientific Reports. ISSN 2045-2322. 12. doi: 10.1038/s41598-022-23705-9. Full text in Research Archive
• Rieder, Jessica; Martin Sanchez, Pedro Maria; Osman, Omneya A.; Adrian-Kalchhauser, Irene & Eiler, Alexander (2022). Detecting aquatic pathogens with field-compatible dried qPCR assays. Journal of Microbiological Methods. ISSN 0167-7012. 202. doi: 10.1016/j.mimet.2022.106594. Full text in Research Archive
• Klemm, Kerstin; Cembella, Allan; Clarke, Dave; Cusack, Caroline; Arneborg, Lars & Karlson, Bengt [Show all 11 contributors for this article] (2022). Apparent biogeographical trends in Alexandrium blooms for northern Europe: identifying links to climate change and effective adaptive actions. Harmful Algae. ISSN 1568-9883. 119, p. 1–19. doi: 10.1016/j.hal.2022.102335. Full text in Research Archive
• Le, Minh Hoang; Dinh, van Khuong; Vo, Xuan Thi & Pham, Hung Quoc (2022). Direct and delayed synergistic effects of extreme temperature, metals and food limitation on tropical reef-associated fish juveniles. Estuarine, Coastal and Shelf Science. ISSN 0272-7714. 278. doi: 10.1016/j.ecss.2022.108108.
• Dinh, van Khuong; Konestabo, Heidi Sjursen; Borgå, Katrine; Hylland, Ketil; Macaulay, Samuel J. & Jackson, Michelle C [Show all 8 contributors for this article] (2022). Interactive Effects of Warming and Pollutants on Marine and Freshwater Invertebrates. Current Pollution Reports. ISSN 2198-6592. 8, p. 341–359. doi: 10.1007/s40726-022-00245-4. Full text in Research Archive
• Dupont, Nicolas; Vikebø, Frode Bendiksen & Langangen, Øystein Ole Gahr (2022). Assessing the patchiness of early life stage of a fish stock (Gadus morhua) and its contribution to the stock recruitment. Frontiers in Marine Science. ISSN 2296-7745. 9, p. 1–10. doi: 10.3389/fmars.2022.932169. Full text in Research Archive
• Truong, Kiem N.; Vu, Ngoc-Anh; Doan, Nam X.; Bui, Canh V.; Le, Minh Hoang & Vu, Thi Thuy Minh [Show all 7 contributors for this article] (2022). Transgenerational exposure to marine heatwaves ameliorates the lethal effect on tropical copepods regardless of predation stress. Ecology and Evolution. ISSN 2045-7758. 12(8). doi: 10.1002/ece3.9149. Full text in Research Archive
• Durant, Joël; Ono, Kotaro & Langangen, Øystein Ole Gahr (2022). Empirical evidence of nonlinearity in bottom up effect in a marine predator-prey system. Biology Letters. ISSN 1744-9561. 18(11). doi: 10.1098/rsbl.2022.0309. Full text in Research Archive Show summary

  Strength of species interaction may have profound effects on population dynamics. Empirical estimates of interaction strength is often based on the assumption that the interaction strengths are constant. Barents Sea cod and capelin are two fish populations for which such interaction has been acknowledged and used, under the assumption of constant interaction strength, when studying their population dynamics. However, species interaction can often be non-linear in marine ecosystems and might profoundly change our understanding of food chains. Analysing 37 years long survey time series in the Arcto-Boreal Barents Sea with a state-space modelling framework, we demonstrate that the effect of capelin on cod is not linear but shifts depending on capelin abundance: while capelin is beneficial for cod population at high abundance, below the threshold, it becomes less important for cod. Our analysis therefore shows the importance of investigating non-linearity in species interaction and may contribute to an improved understanding on species assemblages.

• Dierkes, Jutta; Dietrich, Stefan; Abraham, Klaus; Monien, Bernhard H.; McCann, Adrian & Borgå, Katrine [Show all 7 contributors for this article] (2022). Stable isotope ratios of nitrogen and carbon as biomarkers of a vegan diet. European Journal of Nutrition. ISSN 1436-6207. p. 1–9. doi: 10.1007/s00394-022-02992-y. Full text in Research Archive
• Sobradillo Benguria, Beatriz; Christiansen, Svenja; Røstad, Anders & Kaartvedt, Stein (2022). Individual daytime swimming of mesopelagic fishes in the world's warmest twilight zone. Deep Sea Research Part I: Oceanographic Research Papers. ISSN 0967-0637. 190. doi: 10.1016/j.dsr.2022.103897. Full text in Research Archive
• Guðmundsson, Guðmundur; Cedhagen, Tomas & Andersen, Tom (2022). Taxonomy and distribution of recent species of the subfamily Nodosariinae (Foraminifera) in Icelandic waters. European Journal of Taxonomy. ISSN 2118-9773. 824, p. 1–74. doi: 10.5852/ejt.2022.824.1827. Full text in Research Archive
• Nilsen, Ina; Hansen, Cecilie; Kaplan, Isaac; Holmes, Elizabeth & Langangen, Øystein Ole Gahr (2022). Exploring the role of Northeast Atlantic cod in the Barents Sea food web using a multi-model approach. Fish and Fisheries. ISSN 1467-2960. 23(5), p. 1083–1098. doi: 10.1111/faf.12671. 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.

• Kiko, Rainer; Picheral, Marc; Antoine, David; Babin, Marcel; Berline, Léo & Biard, Tristan [Show all 42 contributors for this article] (2022). A global marine particle size distribution dataset obtained with the Underwater Vision Profiler 5. Earth System Science Data. ISSN 1866-3508. 14, p. 4315–4337. doi: 10.5194/essd-14-4315-2022. Full text in Research Archive
• Christiansen, Svenja; Langangen, Øystein Ole Gahr; Titelman, Josefin; Vøllestad, Leif Asbjørn & Kaartvedt, Stein (2022). Three-dimensional swimming behavior and activity of a mesopelagic fish. Limnology and Oceanography. ISSN 0024-3590. 67, p. 2677–2690. doi: 10.1002/lno.12230. Full text in Research Archive
• Grytting, Vegard Sæter; Refsnes, Magne Arnold; Låg, Marit; Erichsen, Eyolf; Røhr, Torkil Sørlie & Snilsberg, Brynhild [Show all 8 contributors for this article] (2022). The importance of mineralogical composition for the cytotoxic and pro-inflammatory effects of mineral dust. Particle and Fibre Toxicology. ISSN 1743-8977. 19(1). doi: 10.1186/s12989-022-00486-7. Full text in Research Archive
• Oczkowski, Michał; Wilczak, Jacek; Dziendzikowska, Katarzyna; Øvrevik, Johan; Myhre, Oddvar & Lankoff, Anna [Show all 8 contributors for this article] (2022). Dietary Intervention with Blackcurrant Pomace Protects Rats from Testicular Oxidative Stress Induced by Exposition to Biodiesel Exhaust. Antioxidants. ISSN 2076-3921. 11(8). doi: 10.3390/antiox11081562. Full text in Research Archive
• Kaartvedt, Stein; Christiansen, Svenja; Røstad, Anders & Aksnes, Dag Lorents (2022). Mesopelagic fishes in a hurry at low latitudes. Marine Ecology Progress Series. ISSN 0171-8630. 694, p. 149–156. doi: 10.3354/meps14114.
• Suarez, Carolina; Sedlacek, Christopher J.; Gustavsson, David J. I.; Eiler, Alexander; Modin, Oskar & Hermansson, Malte [Show all 7 contributors for this article] (2022). Disturbance-based management of ecosystem services and disservices in partial nitritation-anammox biofilms. npj Biofilms and Microbiomes. ISSN 2055-5008. 8(1). doi: 10.1038/s41522-022-00308-w. Full text in Research Archive
• Valiente Parra, Nicolas; Eiler, Alexander; Allesson, Lina; Andersen, Tom; Clayer, Francois & Crapart, Camille Marie [Show all 13 contributors for this article] (2022). Catchment properties as predictors of greenhouse gas concentrations across a gradient of boreal lakes. Frontiers in Environmental Science. ISSN 2296-665X. 10. doi: 10.3389/fenvs.2022.880619. Full text in Research Archive
• Ribeiro, Pedro Miguel de Azevedo; Næss, Tonje; Dahle, Geir; Asplin, Lars; Meland, Kenneth & Fredriksen, Stein [Show all 7 contributors for this article] (2022). Going With the Flow – Population Genetics of the Kelp Saccharina latissima (Phaeophyceae, Laminariales). Frontiers in Marine Science. ISSN 2296-7745. 9. doi: 10.3389/fmars.2022.876420. Full text in Research Archive
• Yadetie, Fekadu; Brun, Nadja Rebecca; Giebichenstein, Julia; Dmoch, Katarzyna; Hylland, Ketil & Borgå, Katrine [Show all 8 contributors for this article] (2022). Transcriptome responses in copepods Calanus finmarchicus, Calanus glacialis and Calanus hyperboreus exposed to phenanthrene and benzo[a]pyrene. Marine Genomics. ISSN 1874-7787. 65, p. 1–13. doi: 10.1016/j.margen.2022.100981. Full text in Research Archive
• Planque, Benjamin; Aarflot, Johanna Myrseth ; Buttay, Lucie; Carroll, JoLynn; Fransner, Sara Filippa Krusmynta & Hansen, Cecilie [Show all 17 contributors for this article] (2022). A standard protocol for describing the evaluation of ecological models. Ecological Modelling. ISSN 0304-3800. 471. doi: 10.1016/j.ecolmodel.2022.110059. Full text in Research Archive Show summary

  Numerical models of ecological systems are increasingly used to address complex environmental and resource management questions. One challenge for scientists, managers, and stakeholders is to appraise how well suited these models are to answer questions of scientific or societal relevance, that is, to perform, communicate, or access transparent evaluations of ecological models. While there have been substantial developments to support standardised descriptions of ecological models, less has been done to standardise and to report model evaluation practices. We present here a general protocol designed to guide the reporting of model evaluation. The protocol is organised in three major parts: the objective(s) of the modelling application, the ecological patterns o relevance and the evaluation methodology proper, and is termed the OPE (objectives, patterns, evaluation) protocol. We present the 25 questions of the OPE protocol which address the many aspects of the evaluation process and then apply them to six case studies based on a diversity of ecological models. In addition to standardising and increasing the transparency of the model evaluation process, we find that going through the OPE protocol helps modelers to think more deeply about the evaluation of their models. From this last point, we suggest that it would be highly beneficial for modelers to consider the OPE early in the modelling process, in addition to using it as a reporting tool and as a reviewing tool. Standardisation Best practice Ecological patterns Skill assessment Transparency

• Heuschele, Jan David; Lode, Torben; Konestabo, Heidi Sjursen; Titelman, Josefin; Andersen, Tom & Borgå, Katrine (2022). Drivers of copper sensitivity in copepods: A meta-analysis of LC50s. Ecotoxicology and Environmental Safety. ISSN 0147-6513. 242. doi: 10.1016/j.ecoenv.2022.113907. Full text in Research Archive
• John, Uwe; Supraha, Luka; Gran-Stadniczeñko, Sandra; Bunse, Carina; Cembella, Allan & Eikrem, Wenche [Show all 13 contributors for this article] (2022). Spatial and biological oceanographic insights into the massive fish-killing bloom of the haptophyte Chrysochromulina leadbeateri in northern Norway. Harmful Algae. ISSN 1568-9883. 118. doi: 10.1016/j.hal.2022.102287. Full text in Research Archive Show summary

  A bloom of the fish-killing haptophyte Chrysochromulina leadbeateri in northern Norway during May and June 2019 was the most harmful algal event ever recorded in the region, causing massive mortalities of farmed salmon. Accordingly, oceanographic and biodiversity aspects of the bloom were studied in unprecedented detail, based on metabarcoding and physico-chemical and biotic factors related with the dynamics and distribution of the bloom. Light- and electron-microscopical observations of nanoplankton samples from diverse locations confirmed that C. leadbeateri was dominant in the bloom and the primary cause of associated fish mortalities. Cell counts by light microscopy and flow cytometry were obtained throughout the regional bloom within and adjacent to five fjord systems. Metabarcoding sequences of the V4 region of the 18S rRNA gene from field material collected during the bloom and a cultured isolate from offshore of Tromsøy island confirmed the species identification. Sequences from three genetic markers (18S, 28S rRNA gene and ITS region) verified the close if not identical genetic similarity to C. leadbeateri from a previous massive fish-killing bloom in 1991 in northern Norway. The distribution and cell abundance of C. leadbeateri and related Chrysochromulina species in the recent incident were tracked by integrating observations from metabarcoding sequences of the V4 region of the 18S rRNA gene. Metabarcoding revealed at least 14 distinct Chrysochromulina variants, including putative cryptic species. C. leadbeateri was by far the most abundant of these species, but with high intraspecific genetic variability. Highest cell abundance of up to 2.7 × 107 cells L 􀀀 1 of C. leadbeateri was found in Balsfjorden; the high cell densities were associated with stratification near the pycnocline (at ca. 12 m depth) within the fjord. The cell abundance of C. leadbeateri showed positive correlations with temperature, negative correlation with salinity, and a slightly positive correlation with ambient phosphate and nitrate concentrations. The spatio-temporal succession of the C. leadbeateri bloom suggests independent initiation from existing pre-bloom populations in local zones, perhaps sustained and supplemented over time by northeastward advection of the bloom from the fjords

• Skuland, Tonje Schwach; Grytting, Vegard Sæter; Låg, Marit; Jørgensen, Rikke Bramming; Snilsberg, Brynhild & Leseman, Daan L.A.C. [Show all 12 contributors for this article] (2022). Road tunnel-derived coarse, fine and ultrafine particulate matter: physical and chemical characterization and pro-inflammatory responses in human bronchial epithelial cells. Particle and Fibre Toxicology. ISSN 1743-8977. 19. doi: 10.1186/s12989-022-00488-5. Full text in Research Archive
• Henderiks, Jorijntje; Sturm, Daniela; Supraha, Luka & Langer, Gerald (2022). Evolutionary Rates in the Haptophyta: Exploring Molecular and Phenotypic Diversity. Journal of Marine Science and Engineering (JMSE). ISSN 2077-1312. 10(6). doi: 10.3390/jmse10060798. Full text in Research Archive
• Wang, You-Ren; Buchmann, Nina; Hessen, Dag Olav; Stordal, Frode; Erisman, Jan Willem & Vollsnes, Ane Victoria [Show all 8 contributors for this article] (2022). Disentangling effects of natural and anthropogenic drivers on forest net ecosystem production. Science of the Total Environment. ISSN 0048-9697. 839. doi: 10.1016/j.scitotenv.2022.156326. Full text in Research Archive
• 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.

• 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.

• Baden, Susanne; Fredriksen, Stein; Christie, Hartvig C; Eriander, Louise; Gustafsson, Camilla & Holmer, Marianne [Show all 9 contributors for this article] (2022). Effects of depth and overgrowth of ephemeral macroalgae on a remote subtidal NE Atlantic eelgrass (Zostera marina) community. Marine Pollution Bulletin. ISSN 0025-326X. 177. doi: 10.1016/j.marpolbul.2022.113497. Full text in Research Archive Show summary

  We conducted a short-term field sampling complemented with time integrating stable isotope analysis to holistically investigate status and ecological interactions in a remote NE Atlantic Zostera marina meadow. We found high nutrient water concentrations, large biomass of fast-growing, ephemeral macroalgae, low abundance, and biodiversity of epifauna and a food web with thornback ray (Raja clavata) as intermediate and cod (Gadus morhua) as top predator. We observed no variation with increasing depth (3.5–11 m) except for decreasing shoot density and biomass of Zostera and macroalgae. Our results indicate that the Finnøya Zostera ecosystem is eutrophicated. During the past three to four decades, nutrients from aquaculture have steadily increased to reach 75% of anthropogenic input while the coastal top predator cod has decreased by 50%. We conclude that bottom-up regulation is a predominant driver of change since top-down regulation is generally weak in low density and exposed Zostera ecosystems such as Finnøya.

• Nipen, Maja; Vogt, Rolf David; Bohlin-Nizzetto, Pernilla; Borgå, Katrine; Mwakalapa, Eliezer Brown & Borgen, Anders Røsrud [Show all 10 contributors for this article] (2022). Increasing Trends of Legacy and Emerging Organic Contaminants in a Dated Sediment Core From East-Africa. Frontiers in Environmental Science. ISSN 2296-665X. 9. doi: 10.3389/fenvs.2021.805544. Full text in Research Archive Show summary

  Temporal trends of industrial organic contaminants can show how environmental burdens respond to changes in production, regulation, and other anthropogenic and environmental factors. Numerous studies have documented such trends from the Northern Hemisphere, while there is very limited data in the literature from sub-Saharan Africa. We hypothesized that the temporal trends of legacy and contemporary industrial contaminants in sub-Saharan Africa could greatly differ from the regions in which many of these chemicals were initially produced and more extensively used. For this purpose, a dated sediment core covering six decades from a floodplain system in urban Dar es Salaam, Tanzania, was analysed. The samples were analysed for selected legacy persistent organic pollutants (POPs) [polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs)] and chemicals of emerging concern (CECs) [alternative brominated flame retardants (aBFRs), chlorinated paraffins (CPs), and dechloranes]. All groups of chemicals showed a steep increase in concentrations towards the uppermost sediment layers reflecting the more recent years. Concentrations of the individual compound groups in surface sediment were found in the order CPs >> aBFRs ∼ ∑25PBDEs > dechloranes ∼ ∑32PCBs. Time trends for the individual compounds and compound groups differed, with ∑32PCBs showing presence in sediments since at least the early 1960s, while some CECs first occurred in sediments corresponding to the last decade. Investigations into potential drivers for the observed trends showed that socioeconomic factors related to growth in population, economy, and waste generation have contributed to increasing concentrations of PBDEs, aBFRs, CPs, and Dechlorane Plus. Further monitoring of temporal trends of industrial organic contaminants in urban areas in the Global South is recommended.

• Nater, Chloe Rebecca; Stubberud, Marlene Wæge; Langangen, Øystein Ole Gahr; Rustadbakken, Atle; Moe, S. Jannicke & Ergon, Torbjørn [Show all 8 contributors for this article] (2022). Towards a future without stocking: harvest and river regulation determine long-term population viability of migratory salmonids. Climate Research (CR). ISSN 0936-577X. 86, p. 37–52. doi: 10.3354/cr01644. Full text in Research Archive Show summary

  Freshwater species are particularly vulnerable to emerging threats linked to climate change because they are often already heavily impacted by habitat destruction, pollution, and exploitation. For many harvested populations of freshwater fish, these combined impacts have been mitigated for decades through stocking with captive-bred individuals. However, stocking may lead to loss of genetic variation, which may be crucial for adaptation under climate change. Exploration of sustainable alternatives is therefore paramount. We used a female-based integral projection model (IPM) to assess the consequences of terminating a long-term stocking programme for a population of landlocked, migratory brown trout Salmo trutta, and to evaluate relative effectiveness of alternative management strategies involving harvest regulations and river habitat improvement. The IPM classified individuals by body size, life history stage, and location relative to a hydropower dam, and was parameterised with 50 yr of individual-based data, supplemented with literature values. Model simulations indicated a strong population decline of 22-29% per year without stocking, much of which was attributed to high harvest mortality. Consequently, drastic reductions in fishing pressure were predicted to be necessary to ensure population viability without stocking. Mitigation measures reducing mortality associated with the hydropower dam or restoring spawning areas could further contribute to population viability when combined with changes in harvest regulations. Our results thus emphasise that large changes in management strategies, such as termination of long-term stocking programmes, require a thorough assessment of potential consequences and alternative mitigation strategies using data and models, or, at the very least, a precautionary approach under consideration of on-going climate change. Migratory salmonid · Salmo trutta · Integral projection model · Harvest · Fishing · Stocking · Dam · Hydropower · Trout

• Truong, Kiem N. & Dinh, van Khuong (2021). Agent Orange: Half-Century Effects On The Vietnamese Wildlife Have Been Ignored. Environmental Science and Technology. ISSN 0013-936X. 55(22), p. 15007–15009. doi: 10.1021/acs.est.1c06613.
• Ringvold, Halldis; Guðmundsson, G. & Andersen, Tom (2021). Starfish (Asteroidea, Echinodermata) from Iceland; spatial distribution and abundance. Deep Sea Research Part I: Oceanographic Research Papers. ISSN 0967-0637. 176, p. 1–15. doi: 10.1016/j.dsr.2021.103605. Full text in Research Archive
• Halle, Louise L.; Palmqvist, Annemette; Kampmann, Kristoffer; Jensen, Anders; Hansen, Tobias & Khan, Farhan (2021). Tire wear particle and leachate exposures from a pristine and road-worn tire to Hyalella azteca: Comparison of chemical content and biological effects. Aquatic Toxicology. ISSN 0166-445X. 232, p. 1–9. doi: 10.1016/j.aquatox.2021.105769.
• 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.

• Peña, Viviana; Bélanger, David; Gagnon, Patrick; Richards, Joseph L.; Gall, Line Le & Hughey, Jeffery R. [Show all 23 contributors for this article] (2021). Lithothamnion (Hapalidiales, Rhodophyta) in the changing Arctic and Subarctic: DNA sequencing of type and recent specimens provides a systematics foundation. European journal of phycology. ISSN 0967-0262. 56(4), p. 468–493. doi: 10.1080/09670262.2021.1880643. Full text in Research Archive Show summary

  Coralline red algae in the non-geniculate genera Clathromorphum, Phymatolithon and Lithothamnion are important benthic ecosystem engineers in the photic zone of the Arctic and Subarctic. In these regions, the systematics and biogeography of Clathromorphum and Phymatolithon have mostly been resolved whereas Lithothamnion has not, until now. Seventy-three specific and infraspecific names were given to Arctic and Subarctic Lithothamnion specimens in the late 19th and early 20th century by Frans R. Kjellman and Mikael H. Foslie. DNA sequences from 36 type specimens, five historical specimens, and an extensive sampling of recent collections resulted in the recognition of four Arctic and Subarctic Lithothamnion species, L. glaciale, L. lemoineae, L. soriferum and L. tophiforme. Three genes were sequenced, two plastid-encoded, rbcL and psbA, and the mitochondrial encoded COI-5P; rbcL and COI-5P segregated L. glaciale from L. tophiforme but psbA did not. Partial rbcL sequences obtained from type collections enabled us to correctly apply the earliest available names and to correctly place the remainder in synonymy. We were unable to sequence another 22 type specimens, but all of these are more recent names than those that are now applied. It is difficult to identify these species solely on morpho-anatomy as they can all occur as encrusting corallines or as maerl (rhodoliths). We demonstrate the importance of sequencing historical type specimens by showing that the recently proposed North-east Atlantic L. erinaceum is a synonym of one of the earliest published Arctic species of Lithothamnion, L. soriferum, itself incorrectly placed in synonymy under L. tophiforme based on morpho-anatomy. Based on sequenced specimens, we update the distributions and ecology of these species.

• Trapp, Aubrey; Heuschele, Jan David & Selander, Erik (2021). Eavesdropping on plankton—can zooplankton monitoring improve forecasting of biotoxins from harmful algae blooms? . Limnology and Oceanography. ISSN 0024-3590. 66(9), p. 3455–3471. doi: 10.1002/lno.11891. Full text in Research Archive
• Jager, Tjalling; Heuschele, Jan David; Lode, Torben & Borgå, Katrine (2021). Analysing individual growth curves for the copepod Tigriopus brevicornis, while considering changes in shape. Journal of Sea Research. ISSN 1385-1101. 174(102075). doi: 10.1016/j.seares.2021.102075. Full text in Research Archive
• Egge, Elianne Dunthorn; Elferink, Stephanie; Vaulot, Daniel; John, Uwe; Bratbak, Gunnar & Larsen, Aud [Show all 7 contributors for this article] (2021). An 18S V4 rDNA metabarcoding dataset of protist diversity in the Atlantic inflow to the Arctic Ocean, through the year and down to 1000 m depth. Earth System Science Data. ISSN 1866-3591. 13, p. 4913–4928. doi: 10.5194/essd-13-4913-2021.
• Lode, Torben; Heuschele, Jan David; Andersen, Tom; Titelman, Josefin; Hylland, Ketil & Borgå, Katrine (2021). Density-Dependent Metabolic Costs of Copper Exposure in a Coastal Copepod. Environmental Toxicology and Chemistry. ISSN 0730-7268. 40(9), p. 2538–2546. doi: 10.1002/etc.5141. Full text in Research Archive
• Langbehn, Tom; Aksnes, Dag Lorents; Kaartvedt, Stein; Fiksen, Øyvind; Ljungström, Anna Jeja Gabriella & Jørgensen, Christian (2021). Poleward distribution of mesopelagic fishes is constrained by seasonality in light. Global Ecology and Biogeography. ISSN 1466-822X. 31(3), p. 546–561. doi: 10.1111/geb.13446. Full text in Research Archive
• Hylland, Ketil; Bellas, Juan; Giltrap, Michelle & Brooks, Steven (2021). How can we quantify and manage the impact of chemical pollution in the oceans? ICES Scientific Reports. ISSN 2618-1371. 3(102). doi: 10.17895/ices.pub.5446. Show summary

  Chemical pollution is ubiquitous in the world’s oceans and affects marine organisms. Pollutants in marine ecosystems include trace metals and organic pollutants such as pesticides, industrial chemicals, pharmaceuticals and personal care products, household chemicals, chemicals released from transport and chemicals associated with solid waste or effluents. The substances of major concern are persistent, bioaccumulative and/or have high or specific toxicity to marine organisms. Although the extent to which contaminants accumulate in organisms is clearly important, not least from the perspective of human consumption, the relationship between the concentration of one or more contaminants in tissues of an organism and health impact is not straightforward. To quantify the impact of chemical pollutants on marine organisms there is therefore a need to quantify their toxicity in the field. Chemical pollutants are known to cause effects on populations of marine organisms, e.g. endocrine disruption caused by the antifouling agent tributyltin in gastropods, reproductive failure in Baltic grey seal (Halichoerus grypus) and in European killer whale (Orcinus orca), the latter two associated with accumulation of polychlorinated biphenyls, PCBs. Important mechanisms of toxicity in marine organisms are carcinogenicity, genotoxicity, neurotoxicity, immunotoxicity, cardiotoxicity, endocrine disruption, reproductive toxicity and developmental toxicity. Methods to quantify carcinogenicity, genotoxicity, neurotoxicity, endocrine disruption, reproductive toxicity and developmental toxicity have to varying extents been included in monitoring programmes in European countries over the past decades. The methods in use have been chosen for their ability to distinguish between effects from contaminant exposure and the influence of other environmental processes. For most of them, there is an understanding of the mechanism of toxicity and the relationship between exposure and response is known. Over the past two decades, ICES working groups have developed a list of recommended methods, as well as criteria by which to assess data for the different methods and species. In parallel, activities have been established to ensure the quality and consistency of effect data from national and international monitoring programmes. The range of organisms used in monitoring programmes does not represent the full marine biodiversity. Progress has however been made to allow intercomparison of effect responses between species through developing species-specific assessment guidelines. Society needs to know the extent to which chemicals affect the oceans. New substances, for which there are no or limited effects data, are continuously being introduced, and a combination of methods will need to be used to identify and quantify health impacts caused by chemical pollutants. The following are recommendations for national and international monitoring programmes. 1. Full adoption of the ’biological effects methods’ monitoring approach within the integrated chemical-biological monitoring and assessment framework for accurate and realistic assessment of chemical pollution and its impacts, including the effects of chemical mixtures. 2. Inclusion of robust monitoring methods that quantify the most important toxicity mechanisms: carcinogenicity, genotoxicity, neurotoxicity, immunotoxicity, cardiotoxicity, and endocrine disruptiony. 3. Develop and implement quality assurance programs and intercalibration exercises to ensure comparability of data between laboratories, and to promote free accessibility of data. 4. Continue to bring in new evidence of biological effects of chemical pollution into national and international regulatory frameworks.

• Durant, Joël; Aarvold, Leana & Langangen, Øystein Ole Gahr (2021). Stock collapse and its effect on species interactions: Cod and herring in the Norwegian-Barents Seas system as an example. Ecology and Evolution. ISSN 2045-7758. 11, p. 16993–17004. doi: 10.1002/ece3.8336. Full text in Research Archive Show summary

  Both the Norwegian Spring Spawning herring (Clupea harengus) and the Northeast Arctic (NEA) cod (Gadus morhua) are examples of strong stock reduction and decline of the associated fisheries due to overfishing followed by a recovery. Cod and herring are both part of the Barents Sea ecosystem, which has experienced major warming events in the early (1920–1940) and late 20th century. While the collapse or near collapse of these stocks seems to be linked to an instability created by overfishing and climate, the difference of population dynamics before and after is not fully understood. In particular, it is unclear how the changes in population dynamics before and after the collapses are associated with biotic interactions. The combination of the availability of unique long-term time series for herring and cod makes it a well-suited study system to investigate the effects of collapse. We examine how species interactions may differently affect the herring and cod population dynamic before and after a collapse. Particularly we explore, using a GAM modeling approach, how herring could affect cod and vice versa. We found that the effect of cod biomass on herring that was generally positive (i.e., covariation) became negative after the collapse (i.e., predation or competition). Likewise a change occurred for the cod, the juvenile herring biomass that had no effect before the collapse had a negative effect after. Our results indicate that the population collapses may alter the inter-specific interactions and response to abiotic environmental changes. While the stocks are at similar abundance levels before and after the collapses, the system is potentially different in its functioning and may require different management action.

• Jourdain, Eve Marie; Goh, Tiffany; Kuningas, Sanna; Similä, Tiu; Vongraven, Dag & Karoliussen, Richard [Show all 8 contributors for this article] (2021). Killer whale (Orcinus orca) population dynamics in response to a period of rapid ecosystem change in the eastern North Atlantic. Ecology and Evolution. ISSN 2045-7758. 11, p. 17289–17306. doi: 10.1002/ece3.8364. Full text in Research Archive Show summary

  This study investigates survival and abundance of killer whales (Orcinus orca) in Norway in 1988–2019 using capture–recapture models of photo-identification data. We merged two datasets collected in a restricted fjord system in 1988–2008 (Period 1) with a third, collected after their preferred herring prey shifted its wintering grounds to more exposed coastal waters in 2012–2019 (Period 2), and investigated any differences between these two periods. The resulting dataset, spanning 32 years, comprised 3284 captures of 1236 whales, including 148 individuals seen in both periods. The best-supported models of survival included the effects of sex and time period, and the presence of transients (whales seen only once). Period 2 had a much larger percentage of transients compared to Period 1 (mean = 30% vs. 5%) and the identification of two groups of whales with different residency patterns revealed heterogeneity in recapture probabilities. This caused estimates of survival rates to be biased downward (females: 0.955 ± 0.027 SE, males: 0.864 ± 0.038 SE) compared to Period 1 (females: 0.998 ± 0.002 SE, males: 0.985 ± 0.009 SE). Accounting for this heterogeneity resulted in estimates of apparent survival close to unity for regularly seen whales in Period 2. A robust design model for Period 2 further supported random temporary emigration at an estimated annual probability of 0.148 (± 0.095 SE). This same model estimated a peak in annual abundance in 2015 at 1061 individuals (95% CI 999–1127), compared to a maximum of 731 (95% CI 505–1059) previously estimated in Period 1, and dropped to 513 (95% CI 488–540) in 2018. Our results indicate variations in the proportion of killer whales present of an undefined population (or populations) in a larger geographical region. Killer whales have adjusted their distribution to shifts in key prey resources, indicating potential to adapt to rapidly changing marine ecosystems.

• Stubberud, Marlene Wæge; Nater, Chloe Rebecca; Vindenes, Yngvild; Vøllestad, Leif Asbjørn & Langangen, Øystein Ole Gahr (2021). Low impact of first-time spawners on population growth in a brown trout population. Climate Research (CR). ISSN 0936-577X. 86, p. 65–78. doi: 10.3354/cr01645. Full text in Research Archive Show summary

  For species with individual variation in reproductive success, experience in breeding and the distribution of different breeders is important for population productivity and viability. Human impacts, such as climate change and harvesting, can alter this distribution and thus population dynamics. Here, we investigated the effect of spawning experience on population growth in a population of migratory brown trout Salmo trutta subject to stressors including migration barriers, harvesting, and climate change. We described the population dynamics with a structured integral projection model that differentiates between first-time and repeat spawners. We then took a scenario-based approach to test to which extent spawning experience has a positive effect on the population growth of brown trout by running 3 different model simulations: a baseline scenario with no changes to the reproductive output of the population, a non-selective scenario in which the reproductive output of all spawners was reduced, and a selective scenario where the reproductive output of only first-time spawners was reduced. We found that the reproductive output of repeat spawners is more important than that of first-time spawners for population growth, in line with other studies. Moreover, the contribution of first-time spawners to the population growth through their own survival is more important than their contribution to growth through reproduction. To ensure the continued existence of the study population, survival of first-time spawners and reproductive success of repeat spawners should be prioritised. More generally, including breeding experience adds more mechanistic detail, which ultimately can aid management and conservation efforts. Integral projection model · Iteroparity · Spawning experience · Management · Selective harvesting · Population dynamics · Brown trout · Salmo trutta · Dam

• Skjæraasen, Jon Egil; Karlsen, Ørjan; Langangen, Øystein Ole Gahr; van der Meeren, Terje; Keeley, Nigel B. & Myksvoll, Mari Skuggedal [Show all 12 contributors for this article] (2021). Impact of salmon farming on Atlantic cod spatio-temporal reproductive dynamics. Aquaculture Environment Interactions. ISSN 1869-215X. 13, p. 399–412. doi: 10.3354/AEI00415. Full text in Research Archive
• Dupont, Nicolas; Durant, Joël; Gjøsæter, Harald; Langangen, Øystein Ole Gahr & Stige, Leif Christian (2021). Effects of sea ice cover, temperature and predation on the stock dynamics of the key Arctic fish species polar cod Boreogadus saida. Marine Ecology Progress Series. ISSN 0171-8630. 677, p. 141–159. doi: 10.3354/meps13878. Show summary

  Climate change has large effects on population dynamics of fish species in high latitude ecosystems. Arctic fish stocks experience multiple pressures with changing abiotic living conditions and increased competition and predation from boreal species. However, there are many unknowns regarding how environmental change influences the dynamics of those populations. Here, we focused on the Barents Sea polar cod, a pan-Arctic zooplanktivorous key fish species physiologically and ecologically adapted to the presence of sea ice. We developed an age-resolved Bayesian state-space model of the dynamics of polar cod based on 30 yr of survey data (1986-2015). Using this model, we quantified how inter-annual changes in abundance were associated with abiotic variables (temperature and sea ice cover) and biotic variables (prey biomasses and a predation index). Using the model output, we used a hindcast scenario approach to investigate to which degree the observed variations in total population size were related to the abiotic or biotic variables. Our results showed that variation in abundance of young polar cod (ages 0 and 1) was best explained by abiotic variables while variation in the older age groups (ages 3 and 4) was best explained by predation. Hindcast scenarios showed that the abiotic variables had a more evident effect than predation on population dynamics, but none of the variables we considered could explain the drastic population decline observed in recent years. Our work shows the advantages of studying age-specific responses as a stepping stone to understand changes at the population level.

• Nipen, Maja; Vogt, Rolf David; Bohlin-Nizzetto, Pernilla; Borgå, Katrine; Mwakalapa, Eliezer Brown & Borgen, Anders [Show all 11 contributors for this article] (2021). Spatial trends of chlorinated paraffins and dechloranes in air and soil in a tropical urban, suburban, and rural environment. Environmental Pollution. ISSN 1566-0745. 292. doi: 10.1016/j.envpol.2021.118298. Full text in Research Archive Show summary

  There are large knowledge gaps concerning environmental levels and fate of many organic pollutants, particularly for chemicals of emerging concern in tropical regions of the Global South. In this study, we investigated the levels of chlorinated paraffins (CPs) and dechloranes in air and soil in rural, suburban, and urban regions in and around Dar es Salaam, Tanzania. Samples were also collected near the city's main municipal waste dumpsite and an electronic waste (e-waste) handling facility. In passive air samples, short chain CPs (SCCPs) dominated, with an average estimated concentration of 22 ng/m3, while medium chain CPs (MCCPs) had an average estimated concentration of 9 ng/m3. The average estimated air concentration of ∑dechloranes (Dechlorane Plus (DP) + Dechlorane 602 + Dechlorane 603) was three to four orders of magnitudes lower, 2 pg/m3. In soil samples, MCCPs dominated with an average concentration of 640 ng/g dw, followed by SCCPs with an average concentration of 330 ng/g dw, and ∑dechloranes with an average concentration of 0.9 ng/g dw. In both air and soil, DP was the dominating dechlorane compound. Urban pulses were observed for CPs and dechloranes in air and soil. CPs were in addition found in elevated levels at the municipal waste dumpsite and the e-waste handling facility, while DPs were found in elevated levels at the e-waste handling facility. This suggests that waste handling sites represent important emission sources for these pollutants. Investigations into seasonal trends and environmental fate of CPs and dechloranes showed that monsoonal rain patterns play a major role in governing air concentrations and mobility, particularly for the less volatile MCCPs and dechloranes. This study is the first to report levels of CPs in air from sub-Saharan Africa, and DP, Dechlorane 602, and Dechlorane 603 in soil from sub-Saharan Africa.

• Gundersen, Madeleine S.; Vadstein, Olav; Bakke, Ingrid; Andersen, Tom & Morelan, Ian (2021). The effect of periodic disturbances and carrying capacity on the significance of selection and drift in complex bacterial communities. ISME Communications. ISSN 2730-6151. doi: 10.1038/s43705-021-00058-4. Full text in Research Archive
• Valiente Parra, Nicolas; Jirsa, Franz; Hein, Thomas; Wanek, Wolfgang; Prommer, Judith & Bonin, Patricia [Show all 7 contributors for this article] (2021). The role of coupled DNRA-Anammox during nitrate removal in a highly saline lake. Science of the Total Environment. ISSN 0048-9697. 806(3), p. 1–14. doi: 10.1016/j.scitotenv.2021.150726. Full text in Research Archive
• Humborstad, Odd Børre; Eliassen, Lasse Krøger; Siikavuopio, Sten Ivar; Løkkeborg, Svein; Ingólfsson, Ólafur Arnar & Hjelset, Ann Merete (2021). Catches in abandoned snow crab (Chionoecetes opilio) pots in the Barents Sea. Marine Pollution Bulletin. ISSN 0025-326X. 173(Part A), p. 1–7. doi: 10.1016/j.marpolbul.2021.113001. Full text in Research Archive Show summary

  During a 2018 retrieval cruise for abandoned snow crab (Chionoecetes opilio) pots in the Barents Sea, approximately 8600 pots abandoned 1.5 years earlier were recovered. Forty-three percent of a subsample of 1000 pots contained snow crabs, with an average of three crabs per pot. Most of the crabs were alive (~98%) and dominated by large males. Pinch injuries and limb loss were common and tended to decline with increasing crab size. Reflex testing showed that the crabs were vital (i.e. the crabs moved their legs, chelipeds and maxillipeds when stimulated), which was supported by a relatively high meat content. However, energy reserves in the digestive glands (hepatopancreas reserves) were low, indicating overall energy deficiencies. Our results indicate considerable unaccounted mortality due to self-baiting, continued catch and cannibalism. The findings demonstrate that snow crab pots which are lost or abandoned in the Barents Sea fishery maintain huge potential for ghost-fishing impacts.

• Sandaa, Ruth-Anne; Saltvedt, Marius Rydningen; Dahle, Håkon; Wang, Haina; Våge, Selina & Blanc-Mathieu, Romain [Show all 11 contributors for this article] (2021). Adaptive evolution of viruses infecting marine microalgae (haptophytes), from acute infections to stable coexistence. Biological Reviews. ISSN 1464-7931. 97(1), p. 179–194. doi: 10.1111/brv.12795. Full text in Research Archive
• Fontaine, Laurent; Khomich, Maryia; Andersen, Tom; Hessen, Dag Olav; Rasconi, Serena & Davey, Marie Louise [Show all 7 contributors for this article] (2021). Multiple thresholds and trajectories of microbial biodiversity predicted across browning gradients by neural networks and decision tree learning. ISME Communications. ISSN 2730-6151. 1. doi: 10.1038/s43705-021-00038-8. Show summary

  Ecological association studies often assume monotonicity such as between biodiversity and environmental properties although there is growing evidence that nonmonotonic relations dominate in nature. Here, we apply machine-learning algorithms to reveal the nonmonotonic association between microbial diversity and an anthropogenic-induced large-scale change, the browning of freshwaters, along a longitudinal gradient covering 70 boreal lakes in Scandinavia. Measures of bacterial richness and evenness (alpha-diversity) showed nonmonotonic trends in relation to environmental gradients, peaking at intermediate levels of browning. Depending on the statistical methods, variables indicative for browning could explain 5% of the variance in bacterial community composition (beta-diversity) when applying standard methods assuming monotonic relations and up to 45% with machine- learning methods taking non-monotonicity into account. This non-monotonicity observed at the community level was explained by the complex interchangeable nature of individual taxa responses as shown by a high degree of nonmonotonic responses of individual bacterial sequence variants to browning. Furthermore, the nonmonotonic models provide the position of thresholds and predict alternative bacterial diversity trajectories in boreal freshwater as a result of ongoing climate and land-use changes, which in turn will affect entire ecosystem metabolism and likely greenhouse gas production.

• Kristiansen, Silje Marie; Borgå, Katrine; Rundberget, Jan Thomas & Leinaas, Hans Petter (2021). Effects on Life-History Traits of Hypogastrura viatica (Collembola) Exposed to Imidacloprid Through Soil or Diet. Environmental Toxicology and Chemistry. ISSN 0730-7268. 40(11), p. 3111–3122. doi: 10.1002/etc.5187. Full text in Research Archive Show summary

  Collembola (springtails) are important members of soil communities worldwide by contributing to degradation of organic matter. In nature, Collembola might be exposed to the neonicotinoid insecticide imidacloprid, which is fairly persistent in soil. We exposed the widespread Hypogastrura viatica to imidacloprid through soil or food and monitored the animals during exposure and a post exposure period. We recorded effects on life-history traits affecting individual fitness, that is, mortality, behavioral activity, several reproduction traits, and molting frequency. Exposure through soil led to a concentration-dependent mortality, while the mortality from dietary exposure possibly reflected reduced feeding activity. The body burden of imidacloprid in the Collembola did not differ between treatments. We found no sign of recovery in behavioral activity following exposure in either experiment. The egg production of H. viatica was not significantly affected by imidacloprid at 0.01 mg/kg dry soil but showed a tendency to reduce number of eggs per batch and reduced hatching success. At higher concentrations, reproduction was close to, or completely, stopped. The molting frequency decreased during exposure, while in the post exposure period, we saw milder effects at the highest concentrations, suggesting elimination through molting or reduced toxic response as a result of reduced feeding activity. Overall, H. viatica was more sensitive to imidacloprid than previously studied Collembola, which highlights the importance of considering species sensitivities when risk-assessing soil environments.

• Melsom, Arne; Kvile, Kristina Øie; Dagestad, Knut Frode; Brostrøm, Gøran & Langangen, Øystein (2021). Exploring drift simulations from ocean circulation experiments: Application to cod eggs and larval drift. Climate Research (CR). ISSN 0936-577X. 86, p. 145–162. doi: 10.3354/cr01652. Full text in Research Archive Show summary

  Drift models are commonly used to study the transport of early life stages of fish and other marine organisms. Various approaches may be applied to examine the distribution and variability of ocean trajectory pathways. In the present study, we compare results using passive Eulerian tracers and Lagrangian float trajectories that are embedded in numerical models. We supplement this analysis by applying an offline model for drift computations. The contrasts in the results from the various configurations are mainly due to differences in drift depth. Simulations were performed using horizontal resolutions of 4 and 0.8 km. The higher-resolution experiment gives somewhat more realistic results for the drift time from Lofoten to the Tromsøflaket bank at the southwestern entrance of the Barents Sea. Furthermore, differences in results between simulation years are much larger than the differences that arise from the choice of model configuration. Climate variability at high latitudes on a multi-decadal time scale is dominated by large interannual variability superimposed on an underlying moderate warming trend. We conclude that a properly configured offline drift model using hourly or 2-hourly results from a simulation with a horizontal resolution of 1 km or finer is the best approach for investigations of trajectory pathways. The flexibility of an offline drift model is also highly advantageous in biological contexts, as it easily allows for a variety of ways in which behavioural characteristics can be parameterized, including descriptions that are defined after the ocean circulation simulation has been executed.

• Crapart, Camille Marie; Andersen, Tom; Hessen, Dag Olav; Valiente Parra, Nicolas & Vogt, Rolf David (2021). Factors Governing Biodegradability of Dissolved Natural Organic Matter in Lake Water. Water. ISSN 2073-4441. 13(16). doi: 10.3390/w13162210. Full text in Research Archive
• Aarønes, Malin Røyset; Paus-Knudsen, Julie Sørlie; Nielsen, Anders; Rundberget, Thomas & Borgå, Katrine (2021). Within-Body Distributions and Feeding Effects of the Neonicotinoid Insecticide Clothianidin in Bumblebees (Bombus terrestris). Environmental Toxicology and Chemistry. ISSN 0730-7268. 40(10), p. 2781–2790. doi: 10.1002/etc.5154. Full text in Research Archive Show summary

  Bumblebees can be exposed to neonicotinoid pesticides through nectar and pollen collected from treated crops, which can cause lethal and sublethal effects in these nontarget pollinators. However, the body distribution of the compound after exposure to neonicotinoids in bumblebees is not well studied. Bumblebee colonies (Bombus terrestris, n = 20) were exposed to field-realistic concentrations of clothianidin through artificial nectar (3.6–13 µg/L) for 9 d. Comparison of the nominal with the measured exposure in nectar indicated good compliance, confirming the applicability of the method. When quantified, clothianidin showed a concentration-dependent occurrence in the head and body of workers (head: <0.2–2.17 µg/kg; body: <0.2–3.17 µg/kg), and in the body of queens (<0.2–2.49 µg/kg), although concentrations were below those measured in the nectar (bioaccumulation factor = 0.2). Exposure to clothianidin did not affect mortality nor brood production, nor did it have a statistically significant effect on nectar consumption and size of food storage. However, visual inspection suggests higher nectar consumption of nectar with low clothianidin content compared with nectar with no or high clothianidin content. Our results show that dietary clothianidin is taken up in bumblebees, but does not bioaccumulate to elevated levels compared with exposure. Still, clothianidin may elicit responses that affect feeding behavior of the pollinator B. terrestris, although our endpoints were not significantly affected.

• Kolano, Pawel; Borgå, Katrine & Nielsen, Anders (2021). Temperature sensitive effects of the neonicotinoid Clothianidin on bumblebee (Bombus terrestris) foraging behaviour. Journal of Pollination Ecology. ISSN 1920-7603. 28(11), p. 138–152. doi: 10.26786/1920-7603(2021)633. Full text in Research Archive Show summary

  Pollinating insects are an inherent part of most terrestrial ecosystems as they provide a crucial service for most angiosperms, including numerous important crops. A decrease in pollinator populations can therefore have severe consequences for both natural ecosystems and agricultural yields. Pesticide usage has been pointed out as one of the drivers behind pollinator declines. Globally, neonicotinoids are one of the most commonly used insecticides and studies have shown that exposure at sub-lethal levels can alter foraging behaviour, ultimately negatively affecting survival. Using a custom-made bumblebee colony monitoring system, we examined how the number and duration of foraging bouts of bumblebees (Bombus terrestris) on an individual level, and hive growth rate, was affected by exposure to low (6.5 µg/L) and high (10.6 µg/L) sub-lethal concentrations of the neonicotinoid clothianidin via nectar. We also examined possible interaction between clothianidin exposure and abiotic factors (temperature and precipitation), and its impact on foraging bout number and duration. Exposure to sublethal concentrations of clothianidin increased foraging bout duration in bumblebees. Furthermore, the foraging bout duration decreased with increasing temperature at both exposure concentrations, whereas the unexposed control group was not affected by temperature. Neither number of foraging bouts nor the daily rhythm of foraging bout duration was affected by clothianidin exposure or temperature. The foraging bout duration decreased with increasing precipitation in both exposed and non-exposed groups. However, we did not find any interaction between precipitation and exposure, suggesting that precipitation does not affect toxicity. Our study shows the importance of semi-natural experiments and accounting for ambient factors when assessing the risk that pesticide exposure may present to pollinators. We conclude that the effect of clothianidin exposure on bumblebee foraging behaviour is temperature sensitive and that local climatic conditions and future climate change scenarios should be considered in risk assessments of clothianidin and other insecticides.

• Kaartvedt, Stein; Ugland, Karl I.; Heuschele, Jan David & Solberg, Ingrid (2021). Coordinated gas release among the physostomous fish sprat (Sprattus sprattus). Scientific Reports. ISSN 2045-2322. 11(1). doi: 10.1038/s41598-021-92585-2. Full text in Research Archive Show summary

  Previous experimental studies suggest that the production of sound associated with expelling gas from an open swimbladder may play a role in communication. This would suggest non-random gas release. We used deployed echosounders to study patterns of gas release among a ford population of sprat (Sprattus sprattus). The echosounder records concurrently revealed individual fsh and their release of gas. The gas release primarily occurred at night, partly following recurrent temporal patterns, but also varying between nights. In testing for non-randomness, we formulated a datadriven simulation approach. Non-random gas release scaled with the length of the analyzed time intervals from 1 min to 6 h, and above 30 min the release events in more than 50% of the intervals were signifcantly connected.

• Andvik, Clare Margaret; Jourdain, Eve; Lyche, Jan Ludvig; Karoliussen, Richard & Borgå, Katrine (2021). High Levels of Legacy and Emerging Contaminants in Killer Whales (Orcinus orca) from Norway, 2015 to 2017. Environmental Toxicology and Chemistry. ISSN 0730-7268. 40(7), p. 1848–1858. doi: 10.1002/etc.5064. Full text in Research Archive Show summary

  Little is known of the movement or presence of unregulated, emerging contaminants in top predators. The aim of the present study was to conduct the first screening of legacy and emerging contaminants in multiple tissues of killer whales (Orcinus orca) from Norway and investigate tissue partitioning and maternal transfer. Blubber was collected from 8 killer whales in 2015 to 2017, in addition to muscle from 5 of the individuals, and kidney, liver, heart, and spleen from a neonate. We screened for 4 unregulated brominated flame retardants and found pentabromotoluene (PBT) and hexabromobenzene (HBB) at low levels in the blubber of all individuals (median PBT 0.091 ng/g lipid wt, median HBB 1.4 ng/g lipid wt). Levels of PBT and HBB (wet wt) were twice as high in the blubber than the muscle for each individual, confirming preferential accumulation in lipid-rich tissues. Perfluoroalkyl substances and total mercury levels were lower in the neonate than adults, suggesting less efficient maternal transfer of these substances. Polychlorinated biphenyl levels in blubber exceeded the threshold for onset of physiological effects (9 µg/g lipid wt) in 7 of the 8 whales, including the neonate. The presence of PBT and HBB in the neonate is the first evidence of maternal transfer of these unregulated contaminants in marine mammals. Our results are relevant for the continued environmental monitoring of contaminants in the Arctic. Environ Toxicol Chem 2021;40:1850–1860. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

• Christiansen, Svenja; Klevjer, Thor Aleksander; Røstad, Anders; Aksnes, Dag Lorents & Kaartvedt, Stein (2021). Flexible behaviour in a mesopelagic fish (Maurolicus muelleri). ICES Journal of Marine Science. ISSN 1054-3139. 78(5), p. 1623–1635. doi: 10.1093/icesjms/fsab075. Full text in Research Archive
• Gopakumar, Anjali; Giebichenstein, Julia; Raskhozheva, Evgeniia & Borgå, Katrine (2021). Mercury in Barents Sea fish in the Arctic polar night: Species and spatial comparison. Marine Pollution Bulletin. ISSN 0025-326X. 169, p. 1–8. doi: 10.1016/j.marpolbul.2021.112501. Full text in Research Archive
• Midthaug, Hilde Karin; Hitchcock, Daniel James; Bustnes, Jan Ove; Polder, Anuschka; Descamps, Sebastien & Tarroux, Arnaud [Show all 8 contributors for this article] (2021). Within and between breeding-season changes in contaminant occurrence and body condition in the Antarctic breeding south polar skua. Environmental Pollution (1987). ISSN 0269-7491. 284, p. 1–9. doi: 10.1016/j.envpol.2021.117434. Full text in Research Archive Show summary

  The Antarctic ecosystem represents a remote region far from point sources of pollution. Still, Antarctic marine predators, such as seabirds, are exposed to organohalogen contaminants (OHCs) which may induce adverse health effects. With increasing restrictions and regulations on OHCs, the levels and exposure are expected to decrease over time. We studied south polar skua (Catharacta maccormiciki), a top predator seabird, to compare OHC concentrations measured in whole blood from 2001/2002 and 2013/2014 in Dronning Maud Land. As a previous study found increasing organochlorine concentrations with sampling day during the 2001/2002 breeding season, suggesting dietary changes, we investigated if this increase was repeated in the 2013/2014 breeding season. In addition to organochlorines, we analyzed hydroxy-metabolites, brominated contaminants and per- and polyfluoroalkyl substances (PFAS) in 2013/2014, as well as dietary descriptors of stable isotopes of carbon and nitrogen, to assess potential changes in diet during breeding. Lipid normalized concentrations of individual OHCs were 63%, 87% and 105% higher for hexachlorobenzene (HCB), 1,1-dichloro-2,2-bis (p- chlorophenyl)ethylene (p,p’-DDE), and ∑Polychlorinated biphenyls (PCBs), respectively, in 2013/2014 compared to 2001/2002. South polar skuas males in 2013/2014 were in poorer body condition than in 2001/ 2002, and with higher pollutant levels. Poorer body condition may cause the remobilization of contaminants from stored body reserves, and continued exposure to legacy contaminants at overwintering areas may explain the unexpected higher OHC concentrations in 2013/2014 than 2001/2002. Concentrations of protein-associated PFAS increased with sampling day during the 2013/2014 breeding season, whereas the lipid-soluble chlorinated pesticides, PCBs and polybrominated diphenyl ether (PBDEs) showed no change. OHC occurrence was not correlated with stable isotopes. The PFAS biomagnification through the local food web at the colony should be investigated further. Organic pollutants Seabirds PFAS PCB HCB Mirex Catharacta maccormicki

• 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.

• Langangen, Øystein & Stige, Leif Christian (2021). Shedding light on the link between the spatial distribution of eggs and survival in Northeast Arctic cod. Fisheries Oceanography. ISSN 1054-6006. 30, p. 429–436. doi: 10.1111/fog.12528. Full text in Research Archive
• Volpe, Charlotte; Vadstein, Olav; Andersen, Geir & Andersen, Tom (2021). Nanocosm: A well plate photobioreactor for environmental and biotechnological studies. Lab on a Chip. ISSN 1473-0197. 21(10), p. 2027–2039. doi: 10.1039/d0lc01250e. Full text in Research Archive
• Hasle, Gunnar; Leinaas, Hans Petter; Heier, Lise; Garcia, Aïda Lopez & Røed, Knut (2021). Mitochondrial DNA in Ixodus ricinus (Acari: Ixodidae) on birds reflects ticks’ transportation routes to Lista, Norway. Ticks and Tick-borne Diseases. ISSN 1877-959X. 12(1), p. 1–7. doi: 10.1016/j.ttbdis.2020.101553.
• Pin, Lorenzo; Eiler, Alexander; Fazi, Stefano & Friberg, Nikolai (2021). Two different approaches of microbial community structure characterization in riverine epilithic biofilms under multiple stressors conditions: Developing molecular indicators. Molecular Ecology Resources. ISSN 1755-098X. 21(4), p. 1200–1215. doi: 10.1111/1755-0998.13341. Full text in Research Archive Show summary

  Microbial communities are major players in the biogeochemical processes and ecosystem functioning of river networks. Despite their importance in the ecosystem, biomonitoring tools relying on prokaryotes are still lacking. Only a few studies have employed both metabarcoding and quantitative techniques such as catalysed reported deposition fluorescence in situ hybridization (CARD‐FISH) to analyse prokaryotic communities of epilithic biofilms in river ecosystems. We intended to investigate the efficacy of both techniques in detecting changes in microbial community structure associated with environmental drivers. We report a significant correlation between the prokaryotic community composition and pH in rivers from two different geographical areas in Norway. Both CARD‐FISH and metabarcoding data were following the pattern of the environmental variables, but the main feature distinguishing the community composition was the regional difference itself. Beta‐dispersion analyses on both CARD‐FISH abundance and metabarcoding data revealed higher accuracy of metabarcoding to differentiate regions and river systems. The CARD‐FISH results showed high variability, even for samples within the same river, probably due to some unmeasured microscale ecological variability which we could not resolve. We also present a statistical method, which uses variation coefficient and overall prevalence of taxonomic groups, to detect possible biological indicators among prokaryotes using metabarcoding data. The development of new prokaryotic bioindicators would benefit from both techniques used in this study, but metabarcoding seems to be faster and more reliable than CARD‐FISH for large scale bio‐assessment.

• 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.

• 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.

• Climent, Estela; Gotor, Raul; Tobias, Charlie; Bell, Jeremy; Martin-Sanchez, Pedro Maria & Rurack, Knut (2020). Dip Sticks Embedding Molecular Beacon-functionalized Core Mesoporous Shell Particles for the Rapid on-site Detection of Microbiological Fuel Contamination. ACS Sensors. ISSN 2379-3694. doi: 10.1021/acssensors.0c01178. Show summary

  Microbial contamination of fuels by fungi and bacteria presents risks of corrosion and fuel system fouling. In this work, a rapid test for the determination of microbial genomic DNA from aqueous fuel extracts is presented. It combines test strips coated with polystyrene core/mesoporous silica shell particles, to the surface of which modified fluorescent molecular beacons are covalently grafted, with a smartphone detection system. In the hairpin loop, the beacons incorporate a target sequence highly conserved in all bacteria, corresponding to a fragment of the 16S ribosomal RNA gene, which is also present to a significant extent in the 18S rRNA gene of fungi, allowing for broadband microbial detection. In the developed assay, the presence of genomic DNA extracts from bacteria and fungi down to ca. 20–50 μg L–1 induced a distinct fluorescence response. The optical read-out was adapted for on-site monitoring by combining a 3D-printed case with a conventional smartphone, taking advantage of the sensitivity of contemporary complementary metal oxide semiconductor (CMOS) detectors. Such an embedded assembly allowed to detect microbial genomic DNA in aqueous extracts down to ca. 0.2–0.7 mg L–1 and presents an important step toward the on-site uncovering of fuel contamination in a rapid and simple fashion.

• Barreto, A.; Carvalho, A.; Silva, D.; Pinto, E.; Almeida, A. & Paíga, P. [Show all 13 contributors for this article] (2020). Effects of single and combined exposures of gold (nano versus ionic form) and gemfibrozil in a liver organ culture of Sparus aurata. Marine Pollution Bulletin. ISSN 0025-326X. 160, p. 1–12. doi: 10.1016/j.marpolbul.2020.111665. Full text in Research Archive
• Villanger, Gro Dehli; Øvrevik, Johan; Aase, Heidi & Myhre, Oddvar (2020). Early-Life Environmental Toxic Influences on Neural Development. In Xia, Yankai (Eds.), Early-life Environmental Exposure and Disease. Springer. ISSN 978-981-15-3796-7. p. 141–159. doi: 10.1007/978-981-15-3797-4_8.
• Kilias, Estelle S.; Junges, Leandro; Supraha, Luka; Leonard, Guy; Metfies, Katja & Richards, Thomas A. (2020). Chytrid fungi distribution and co-occurrence with diatoms correlate with sea ice melt in the Arctic Ocean. Communications Biology. ISSN 2399-3642. 3, p. 1–13. doi: 10.1038/s42003-020-0891-7.
• Kiko, Rainer; Brandt, Peter; Christiansen, Svenja; Faustmann, Jannik; Kriest, Iris & Rodrigues, Elizandro [Show all 8 contributors for this article] (2020). Zooplankton-mediated fluxes in the eastern tropical North Atlantic. Frontiers in Marine Science. ISSN 2296-7745. 7. doi: 10.3389/fmars.2020.00358. Full text in Research Archive
• Hoving, Henk-Jan T.; Neitzel, Philipp; Hauss, Helena; Christiansen, Svenja; Kiko, Rainer & Robison, Bruce H. [Show all 8 contributors for this article] (2020). In situ observations show vertical community structure of pelagic fauna in the eastern tropical North Atlantic off Cape Verde. Scientific Reports. ISSN 2045-2322. 10. doi: 10.1038/s41598-020-78255-9. Full text in Research Archive
• Heuschele, Jan David; Lode, Torben; Andersen, Tom & Titelman, Josefin (2020). The Hidden Dimension: Context‐Dependent Expression of Repeatable Behavior in Copepods . Environmental Toxicology and Chemistry. ISSN 0730-7268. 39(5), p. 1017–1026. doi: 10.1002/etc.4688. Full text in Research Archive
• Lode, Torben; Heuschele, Jan David; Andersen, Tom; Titelman, Josefin; Hylland, Ketil & Borgå, Katrine (2020). Contrasting Effects of Predation Risk and Copper on Copepod Respiration Rates. Environmental Toxicology and Chemistry. ISSN 0730-7268. 39(9), p. 1765–1773. doi: 10.1002/etc.4804. Full text in Research Archive
• Mazzoni, Michela; Ferrario, Claudia; Bettinetti, Roberta; Piscia, Roberta; Cicala, Davide & Volta, Pietro [Show all 9 contributors for this article] (2020). Trophic Magnification of Legacy (PCB, DDT and Hg) and Emerging Pollutants (PFAS) in the Fish Community of a Small Protected Southern Alpine Lake (Lake Mergozzo, Northern Italy). Water. ISSN 2073-4441. 12(6), p. 1–17. doi: 10.3390/w12061591. Full text in Research Archive

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• Jemterud, Torkild; Bjorå, Charlotte Sletten; Sletsjøe, Arne Bernhard & Garvang, Even Sletteng (2024). Abels tårn. [Radio]. NRK P2.
• Wahl, Andreas; Lie-Jensen, Anette Christensen & Kline, Simon Hasselø (2024). Jøss?! #141 - Biespy, avskyelig snømann som bonde og fulle menns interesse for fastbundet dame (Podcast).
• Thrane, Jan-Erik (2023). NIVA is frontrunner in the tech race - Modern and innovative methods for environmental monitoring.
• Opdal, Anders Martin Frugård; Andersen, Tom; Hessen, Dag Olav; Lindemann, Christian & Aksnes, Dag Lorents (2023). Tracking freshwater browning and coastal water darkening from boreal forests to the Arctic Ocean.
• Delsett, Lene Liebe; Skogvoll, Vidar; Kline, Simon Hasselø & Jemterud, Torkild (2023). Abels tårn 18. august. [Radio]. NRK P2.
• Ahme, Antonia; Happe, Anika; Striebel, Maren; Olsson, Markus; Giesler, Jakob & Kline, Simon Hasselø [Show all 7 contributors for this article] (2023). Thermal performance assay of a plankton community from Helgoland Roads for an indoor mesocosm experiment in March 2022. PANGAEA. Data Publisher for Earth & Environmental Science. doi: 10.1594/PANGAEA.961508.
• Ahme, Antonia; Happe, Anika; Striebel, Maren; Olsson, Markus; Kühne, Nancy & Giesler, Jakob [Show all 16 contributors for this article] (2023). Temperature effects on a plankton community from Helgoland Roads tested in an indoor mesocosm experiment in March 2022. PANGAEA. Data Publisher for Earth & Environmental Science. doi: 10.1594/PANGAEA.961155.
• Giebichenstein, Julia; Warner, Nicholas Alexander; Routti, Heli Anna Irmeli; Harju, Mikael; Varpe, Øystein & Andersen, Tom [Show all 8 contributors for this article] (2023). Emerging contaminant accumulation in an Arctic marine food web.
• Mariussen, Espen; Skuland, Tonje Schwach; Dahlman, Hans Jørgen; Låg, Marit & Øvrevik, Johan (2023). An Approach to Test Effects on Secondary Organs via Lung Cells Exposed at the Air Liquid Interphase. Annals of Work Exposures and Health. ISSN 2398-7308. 67(S1), p. i59–i59.
• Dinh, van Khuong (2023). Science for use talk - Seasonal and climate change effects on pollution accumulation and effects in the Arctic marine food web.
• Nowicki, Robynne; Borgå, Katrine; Gabrielsen, Geir Wing & Varpe, Øystein (2023). Exploring seasonal energetics of Barents Sea macrozooplankton and the impact of borealization.
• Nowicki, Robynne; Borgå, Katrine; Gabrielsen, Geir Wing; Søreide, Janne & Varpe, Øystein (2023). Seasonal Dynamics of Body Condition and Energy Content of Polar Cod (Boreogadus saida).
• Giebichenstein, Julia; Harju, Mikael; Varpe, Øystein; Gabrielsen, Geir Wing; Andersen, Tom & Borgå, Katrine (2023). Across the Seasons: Persistent Organic Pollutants in an Arctic Pelagic Food Web.
• Eikrem, Wenche; Vader, Anna; Hofgaard, Antje & Edvardsen, Bente (2023). Phytoplankton in the Arctic Ocean - Species Composition and Biomass during the Nansen Legacy Arctic basin cruise, 24 Aug-26 Sep 202. Show summary

  At the southern-most station along the S-N transect, P7, the pelagic protist community was characterized by both high diversity and abundance. Large diatom species dominated the community, and large dinoflagellates and Phaeocystis pouchetii were also abundant. Moving north and into the ice, the protist community in the water column changed. Smaller organisms and heterotrophic species became more prominent. The larger diatom species became much scarcer but were still present. The community in the ice cores was dominated by pennate diatoms, but dinoflagellates and in particular the heterotrophic species were also abundant. In addition, green flagellates, cryptomonads, chrysophytes, and haptophytes were frequent. The sea-ice showed the highest chlorophyll-a values and had larger cells. In the melt ponds the salinity was low, but variable (2.8-5.7). The chlorophyll-a values there were low, and the species composition varied, and the taxa present were associated with brackish and freshwater as well as a benthic lifestyle.

• Saubrekka, Karoline; Vader, Anna; Supraha, Luka & Edvardsen, Bente (2023). Diversity and distribution of Arctic protists in pelagic and sympagic habitats in the northern Barents Sea as revealed by metabarcoding. Show summary

  Protists play crucial roles in the marine ecosystems and in a rapidly changing Arctic it is important to reveal who are there, when and where, for future research and management. The aim of this study was to describe and compare the composition of protist communities in sea ice and pelagic habitats from samples collected in the northern Barents Sea along a transect in August 2018 with low sea-ice extent and 2019 with high sea-ice extent. Metabarcoding targeting the 18S rRNA gene revealed 3682 unique amplicon sequence variants (ASVs), a proxy for species, and clear difference in ASV composition in ice and pelagic habitats. The pelagic community showed interannual differences. In 2018 the community was dominated by dinoflagellates and nano- and pico-plankton such as Micromonas polaris. In 2019 a community with more centric diatoms was observed at ice edge stations. Members of the class Chrysophyceae dominated in melt ponds, whereas communities within the ice were dominated by dinoflagellates and pennate diatoms. The community changed from top to bottom of the ice cores and the diversity was higher in thick than thin ice. Just below the ice, dinoflagellate ASVs dominated together with Phaeocystis. Our results indicate that protist communities are distinct and specialized by habitat. With further ocean warming, pelagic communities may shift towards smaller flagellates, and thinning of the sea ice may lead to a loss of habitats and diversity.

• Edvardsen, Bente; Supraha, Luka; Egge, Elianne Dunthorn & Saubrekka, Karoline (2023). Diversity and distribution of marine protists in the Arctic explored by a polyphasic approach.
• Edvardsen, Bente (2023). Biodiversity of microalgae in Scandinavian marine waters.
• Saubrekka, Karoline; Vader, Anna; Supraha, Luka; Andersen, Tom & Edvardsen, Bente (2023). Diversity and Distribution of Arctic Protists in Pelagic and Sympagic Habitats in the Northern Barents Sea as Revealed by Metabarcoding.
• Edvardsen, Bente (2023). On the track of causes for fish-killing algal blooms. Show summary

  Harmful algal blooms (HABs) in marine, brackish and fresh waters resulting in fish-kills occur worldwide and may lead to great economic and ecological losses, as well as suffering for the fish. Farmed fish in pens and ponds are especially prone as they cannot escape from the blooms. Many ichthyotoxic blooms are sporadic events and the causes and triggering factors of these HABs are often poorly understood. Knowledge on the responsible algae and their physiology, ecology and environmental factors promoting their growth are required to understand these events. Bloom formation may also be linked to their toxicity through a relaxation of the top-down control from grazers, pathogens or competitors. We thus also need to understand how toxin production or toxicity are affected by various environmental factors to be able to understand causes of HABs. Knowledge about the responsible toxin(s) and their mode of action may however be limited and difficult to quantify. In this presentation I will compare ichthyotoxic haptophytes and look at similarities and differences in their bloom formation, ecology, physiology and toxicity in order to better understand causes for some of these blooms, especially of the little studied species Chrysochromulina leadbeateri.

• Edvardsen, Bente; Fon, Mathias; Reitzel, Helene; Šupraha, Luka; Andersen, Tom & Uhlig, Silvio (2023). Growth preferences of the haptophyte Chrysochromulina leadbeateri forming ichthyotoxic blooms in fjords in N Norway. Show summary

  Microalgal flagellates of the genera Chrysochromulina and Prymnesium may form extensive blooms in marine and brackish waters causing fish kills. Chrysochromulina leadbeateri blooms caused massive fish kills in fish farms in Northern Norway in May 1991 and 2019. More than 14 500 tons of farmed salmon died in 2019. Cultures from both blooms were used in physiological experiments to investigate possible causes for the blooms. Growth experiments with varying salinity, temperature and irradiance in a facultative design were performed. Highest growth rates were obtained at temperatures 11-15 oC and salinities 25-30, and the tolerance range for growth were between 4-15 oC and salinities 20-34. Under optimal conditions, growth rates increased with irradiance (up to 100 µmol photons m-2 s-1). During the bloom in 2019, highest C. leadbeateri concentrations were found in waters with slightly reduced salinity (32-33) and sea surface temperatures around 7oC. Strains from the blooms in 1991 and 2019 were identical in the 18S rRNA gene. This ribotype appears to have a cold water-Arctic geographical distribution based on the metaPR2 metabarcoding datasets, whereas other ribotypes of C. leadbeateri in this dataset show a cosmopolitan or temperate-warm water distribution. We suggest that C. leadbeateri consists of several ribotypes with different growth preferences and that the toxic blooms in Northern Norway were formed by a ribotype adapted to cold waters with slightly reduced salinity and can tolerate rather high irradiances. Possible causes for the ichthyotoxic blooms will be discussed.

• Dupont, Nicolas; Durant, Joël; Langangen, Øystein Ole Gahr & Stige, Leif Christian (2023). Effects of abrupt ecological change on the Barents Sea Arctic food-web: predictions from a food-web state-space model.
• Dupont, Nicolas; Durant, Joël; Langangen, Øystein Ole Gahr & Stige, Leif Christian (2023). Survival of adult polar cod (Boreogadus saida) in the context of “borealization” of the Barents Sea .
• Vereide, Emilie Hernes; de Jong, Karen; Mihaljevic, Marina; Fields, David M.; Titelman, Josefin & Browman, Howard [Show all 9 contributors for this article] (2023). ZoopSeis- The effects of seismic surveys on zooplankton .
• Vereide, Emilie Hernes; de Jong, Karen; Utne-Palm, Anne Christine; Titelman, Josefin; Browman, Howard & Mihaljevic, Marina [Show all 8 contributors for this article] (2023). ZoopSeis- Zooplankton og seismikk.
• Wahl, Andreas; Lie-Jensen, Anette Christensen & Kline, Simon Hasselø (2023). Jøss?! #136 - Zombieplankton, vettug grunn til å drikke tiss og drukningsdød i verdensrommet (Podcast).
• Larsen, Thomas ostenfeld; Wang, Xinhui; Fon, Mathias; Andersen, Aaron John Christian; Hansen, Per Juel & Uhlig, Silvio [Show all 8 contributors for this article] (2023). Insights into the chemistry of microalgal toxins involved in recent northern European fish killing events.
• Fon, Mathias; Supraha, Luka; Andersen, Tom; Uhlig, Silvio & Edvardsen, Bente (2023). Using high-throughput techniques to understand the growth of the fish-killing haptophyte Chrysochromulina leadbeateri in northern Norway.
• Samdal, Ingunn Anita; Uhlig, Silvio; Solhaug, Anita; Fon, Mathias; Gilbert, Dorothea & Ivanova, Lada [Show all 15 contributors for this article] (2023). Toxic microalgae in Norwegian waters - Uncovering fish-killing mechanisms of phytoplankton from Scandinavian waters.
• Ziegler, Amanda; Jørgensen, Lis Lindal; Bluhm, Bodil Annikki Ulla Barbro; Giebichenstein, Julia; Borgå, Katrine & Ricardo de Freitas, Thaise (2023). The effect of ice-free summer conditions on benthic food web structure in the Barents Sea. Show summary

  Reduced Arctic sea-ice cover has been shown to alter phytoplankton community composition and reduce the magnitude of vertical flux, thereby reducing the strength of pelagic-benthic coupling. It is predicted that Arctic shelf ecosystems, like the Barents Sea, will transition into sub-polar-like ecosystems under future climatic conditions. However, few studies have provided a benthic perspective to the question of how ice-free conditions in the Arctic will affect food web structure. In this study, we aim to test whether ice-free summer conditions in the Barents Sea and adjacent Nansen Basin alter benthic food web structure and the strength of pelagic benthic coupling. To do so, we used bulk stable isotopes of carbon and nitrogen measured in food sources and benthic consumers, demersal fish, and zooplankton collected during summers with contrasting sea-ice conditions: August 2018 – low sea-ice extent and August 2019 – high sea-ice extent. We compared benthic food web structure across three oceanographically distinct regions from the sea-ice free central Barents Sea shelf and the seasonally ice-free northern Barents Sea shelf to the slope extending into the Nansen Basin. The results of this work will not only improve our understanding of the impact that Arctic sea-ice loss has on benthic communities but provide additional insight to the resiliency of Arctic benthic food webs.

• Jensen, Thomas Correll; Schartau, Ann Kristin; Majaneva, Markus; Veraart, A.J.; Hessen, Dag Olav & Eiler, Alexander [Show all 8 contributors for this article] (2023). Bird impacts on biological communities in Arctic ponds.
• Langbehn, Tom; Ljungström, Anna Jeja Gabriella; Fiksen, Øyvind; Aksnes, Dag; Kaartvedt, Stein & Jørgensen, Christian (2023). Model evidence for photic barriers to poleward range shifts.
• Kwasniewski, Slawomir; Altenburger, Andreas; Assmy, Philipp Kurt Wolf; Bluhm, Bodil Annikki Ulla Barbro; Dabrowska, Anna Maria & Edvardsen, Bente [Show all 25 contributors for this article] (2023). Biodiversity in the northern Barents Sea and adjacent Nansen Basin – towards an updated inventory. Show summary

  Biodiversity patterns shape and drive ecosystem processes and functions in the global ocean. Given the changing climate and recent agreements to protect ocean regions, current estimates of biodiversity must be assembled. Here, we present new estimates and spatial patters of taxon richness from microbes to mammals from a shelf-to-basin transect in the northern Barents Sea and southern Nansen Basin from seasonal sampling in 2018-2022 by the Nansen Legacy project. We find that estimates of taxon richness are higher on the shelf than in the basin for pelagic protists, zooplankton, and benthic macrobenthos, nematodes, and prokaryotes, but not for sympagic protists. Taxon richness varied seasonally for pelagic prokaryotes, protists, and zooplankton, but little for sympagic meiofauna, benthic prokaryotes and macrobenthos. Unsurprisingly, taxon richness was generally highest for single-celled taxa. Taxon-rich groups included: sympagic diatoms; pelagic prokaryotes (e.g., Alphaproteobacteria), diatoms, dinoflagellates, copepods; and benthic prokaryotes (with abundant taxa, e.g., Candidatus nitrosopumilus and Woesia), nematodes, and polychaetes. Unexpectedly absent - though known from earlier studies - were, for example, nematodes in sea ice. Ironically, at top (and perhaps other) trophic levels species richness is likely to be enhanced regionally for some time, while losses of Arctic (endemic) species will impact global biodiversity, and potentially Arctic ecosystem functioning

• Marquardt, Miriam; Goraguer, Lucie Hélène Marie; Assmy, Philipp Kurt Wolf; Bluhm, Bodil Annikki Ulla Barbro; Patrohay, Evan & Aaboe, Signe [Show all 12 contributors for this article] (2023). Seasonal dynamics of sea ice protists and meiofauna in the northwestern Barents Sea in relation to sea ice properties . Show summary

  The rapid decline of Arctic sea-ice including that in the Barents Sea makes understanding sympagic biology an urgent task. Seasonal ice sampling (2019-2022) as part of the Nansen Legacy project focused on ice biota composition and abundance in the bottom 30cm of Barents Sea ice in relation to ice properties. In December and May we sampled growing first-year ice, while in July and August melting, older sea ice dominated, overall agreeing with ice trajectories. Abiotic ice conditions and Chla varied strongly seasonally, while POC values were unexpectedly homogenous. Low ice biota abundances in March could be related to late ice formation resulting in a short time for biota to build up biomass. Pennate diatoms dominated the bottom ice algal communities in all seasons, with highest biomass in May. Outside May, small-sized flagellates were co-dominant. Overall, ice meiofauna was comprised of harpacticoid copepods, copepod nauplii and rotifers, foraminiferans and highly abundant ciliates. While melting ice had released ice algal biomass in July, abundance of secondary producers remained high, indicating different life history traits. Unexpectedly abundant communities occurred in December, further strengthened the notion of an active biota in the dark Arctic winter. The data demonstrated a strong and partly unexpected seasonality in the ice biota, indicating that changing timing of ice formation and melt will significantly impact composition and phenology of sympagic communities.

• 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.
• 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.
• Sjøtun, Kjersti; Fredriksen, Stein; Gabrielsen, Tove M.; Husa, Vivian; Goecke, Franz Ronald Saavedra & Le Gall, Line [Show all 9 contributors for this article] (2023). Mapping and DNA barcoding the brown algal diversity within the orders Ectocarpales, Ralfsiales and Sphacelariales in Norway.
• Marquardt, Miriam; Assmy, Philipp; Edvardsen, Bente; Goraguer, Lucie Hélène Marie; Gradinger, Rolf Rudolf & Patrohay, Evan [Show all 9 contributors for this article] (2023). Seasonal dynamics of sea ice protists and meiofauna in the northern Barents Sea. Show summary

  The declining Arctic sea ice makes understanding sympagic biology a urgent task, including the Northern Barents Sea, which is highly influenced by ice loss and increased Atlantic inflow. A seasonal ice sampling effort (2019-2022) as part of the Nansen Legacy project focused on the poorly known ice biota composition and abundance in the bottom 30cm of Barents Sea ice in relation to season, hydrography and ice properties. We expected low abundances during the polar night and highest values during the spring prior to ice melt. From December and March, ice thickness increased while melting dominated in summer. Pennate diatoms, such as Navicula and Nitzschia spp., were dominating the bottom ice protist communities during all periods, while small-sized dinoflagellates were co-dominant. Ice meiofauna was comprised of harpacticoid copepods, copepod nauplii, rotifers, occasional visitors such as acoels and foraminiferans and highly abundant ciliates (50-90 %; total abundances). Surprisingly, active December communities occurred in higher than expected abundances. Low abundances in March could be related to later on-set of ice formation and reduced time for biota to establish. Maximum meiofauna abundances in May reflect a late spring bloom development. In August despite ice melting meiofauna abundances were still high. The data demonstrated a strong and partially unexpected seasonality in the ice biota, indicating that changing timing of ice formation and decay will significantly impact the current sea ice biology.

• Marquardt, Miriam; Goraguer, Lucie Hélène Marie; Assmy, Philipp; Bluhm, Bodil; Aaboe, Signe & Down, Emily [Show all 12 contributors for this article] (2023). Seasonal dynamics of sea ice protists and meiofauna in the Northern Barents Sea. .
• Heuschele, Jan David; Lode, Torben; Bruserud, Hilde; Brochmann, Solveig; Dingstad, Trym R & Wolf, Raoul [Show all 7 contributors for this article] (2023). Development of splash pool populations under copper and predation risk exposure in field conditions.
• Dijkstra, Jildou; Schott, Schott; Thomsen, Nele; Lutier, Mathieu; Dinh, van Khuong & Reinardy, Helena Christine [Show all 7 contributors for this article] (2023). Influence of ocean warming and acidification on Arctic zooplankton during the polar night.
• Borgå, Katrine; McKinney, Melissa A.; Giebichenstein, Julia; Dinh, van Khuong; Bårnås Gravelle, Amalie Marie & Heuschele, Jan David [Show all 10 contributors for this article] (2023). The influence of climate change on accumulation and toxicity of pollutants in Arctic marine food webs.
• Andvik, Clare Margaret; Jourdain, Eve Marie; Borgen, Anders; Haug, Tore; Karoliussen, Richard & Borgå, Katrine (2023). Short, Medium and Long-chain Chlorinated Paraffins and Dechloranes in Marine Mammals from Norway.
• Planque, Benjamin; Aarflot, Johanna Myrseth; Buttay, Lucie; Carroll, JoLynn; Fransner, Sara Filippa Krusmynta & Eide, Cecilie Hansen [Show all 17 contributors for this article] (2023). A standard protocol for describing the evaluation of ecological models.
• Heuschele, Jan David; Lode, Torben; Bruserud, Hilde; Brochmann, Solveig; Røil Dingstad, Trym & Wolf, Raoul [Show all 7 contributors for this article] (2023). The population development of splash pool organisms under copper and predation risk exposure in field conditions.
• Durant, Joël; Ono, Kotaro & Langangen, Øystein Ole Gahr (2023). Empirical evidence of non-linearity in the interaction between fish stocks in the Barents Sea. Show summary

  The strength of species interactions can have a significant impact on population dynamics. Empirical estimates of interaction strength are often based on the assumption that the interaction strength is constant. Several fish species interact in the Barents Sea and their population dynamics are typically modelled under the assumption of constant interaction strength. However, interactions between species are often non-linear in marine ecosystems and this could fundamentally change our understanding of food webs’ functioning. Here, we present two examples of such nonlinear interactions in the Barents Sea, between cod Gadus morhua and capelin Mallotus villosus, and between cod and haddock Melanogrammus aeglefinus. Analysis of long survey time series in the Arcto-boreal Barents Sea within a state-space modelling framework showed that the effect of capelin on cod is not linear but varies with capelin abundance. Similarly, interactions between cod and haddock have changed over the past two decades due to rising ocean temperatures, altering the equilibrium abundances and the dynamics of the system. Our analyses demonstrate that long-term climate change in the Arcto-boreal system leads to differences in equilibrium conditions for species communities and demonstrates the importance of investigating nonlinearities in species interactions, leading to a better understanding of species communities and species assemblages.

• Bekkby, Trine; Torstensen, Ragnhild Ryther Grimm; Grünfeld, Lars Andreas Holm; Gundersen, Hege; Fredriksen, Stein & Rinde, Eli [Show all 12 contributors for this article] (2023). Hanging gardens - do floating kelp farm communities resemble natural kelp forests? Show summary

  The interest in seaweed cultivation is increasing globally, which requires knowledge of the potential effect of seaweed production on the marine environment, both negative and positive. We therefore wanted to study the fauna communities found in a kelp farm and compare these with what is found in natural kelp forests with the aim of finding out if a kelp farm ecosystem resembles that of natural kelp forests. The field work was conducted in north-western Norway, just before the kelp was harvested in the spring. Fauna traps were deployed and kelp plants scraped in the kelp farm (both in the sugar kelp, Saccharina latissima, and the winged kelp, Alaria esculenta, part), in natural sugar kelp, winged kelp and tangle kelp (Laminaria hyperborea) forests and in the water masses. The potential effect of the duration of the growth period of the farmed sugar kelp on the associated community was also analysed. The study shows that a kelp farm has lower taxa richness and fewer individuals than natural kelp forests, but indicates that the farm still has an ecological function as a habitat. However, the communities in the farm are more similar to the natural kelp forest surrounding the farm than with the natural kelp forest of similar species. The result from this study contributes with important knowledge of kelp farms ecological role in the marine environment, which is important both for today’s management and for the planned growth of the industry.

• Jensen, Thomas Correll; Schartau, Ann Kristin; Majaneva, Markus; Hessen, Dag Olav; Eiler, Alexander & Loonen, Maarten J.J.E. [Show all 7 contributors for this article] (2023). Bird impacts on biological communities in Arctic ponds – preliminary results.
• Chen, An; Fon, Mathias; Edvardsen, Bente; Uhlig, Silvio & Solhaug, Anita (2023). Evaluation of toxicity of the microagla Chrysochromulina leadbeateri using the Atlantis salmon gill epithelial cell line ASG-10.
• Eliassen, Lasse Krøger; Humborstad, Odd Børre; Hjelset, Ann Merete; Hustad, Anette; Løkkeborg, Svein & Martinsen, Gustav [Show all 8 contributors for this article] (2022). Catches in abandoned snow crab pots in the Barents Sea.
• Goksøyr, Anders; Eide, Marta; Brun, Nadja Rebecca; Yadetie, Fekadu; Zhang, Xiaokang & Hylland, Ketil [Show all 14 contributors for this article] (2022). Complex mixture and omics responses in Atlantic cod: a time- and dose-response study.
• Dinh, van Khuong (2022). Impacts of environmental pollution and climate change on marine life.
• Edvardsen, Bente (2022). Mikroalger i Arktis - hvor unike er de?
• Edvardsen, Bente (2022). DNA-strekkoding – et verktøy for gjennkjenning av arter.
• Edvardsen, Bente (2022). Planteplankton i Oslofjorden, endringer og mulige årsaker.
• Edvardsen, Bente; Supraha, Luka & Egge, Elianne Dunthorn (2022). Diversity and distribution of marine protists in the Arctic explored by a polyphasic approach.
• Giebichenstein, Julia; Warner, Nicholas Alexander; Varpe, Øystein; Gabrielsen, Geir W.; Andersen, Tom & Borgå, Katrine (2022). Chlorinated paraffins in Polar cod and capelin from the Barents Sea during the Arctic spring bloom.
• Gravelle, Amalie M.; Dinh, van Khuong; Titleman, Josefin; Søreide, Janne & Borgå, Katrine (2022). Transgenerational effects of ocean acidification, elevated temperature and pyrene on the growth and development of the Arctic copepod Calanus glacialis.
• Edvardsen, Bente (2022). Metabarcoding and Systematics of Protists in the Ocean to Understand Ecosystem Functioning.
• Edvardsen, Bente (2022). Exploration of protist diversity and distribution in the ocean by a polyphasic approach.
• Dupont, Nicolas; Durant, Joël; Langangen, Øystein Ole Gahr & Stige, Leif Christian (2022). Change in the Barents Sea Arctic food-web dynamic based on biotic and abiotic environmental factors.
• Dinh, van Khuong; Titleman, Josefin; Søreide, Janne; Hylland, Ketil & Borgå, Katrine (2022). Long-Term Effects of Warming and Pyrene on Calanus hyperboreus.
• Borgå, Katrine; McKinney, Melissa A.; Routti, Heli Anna Irmeli; Fernie, Kim J.; Giebichenstein, Julia & Hallanger, Ingeborg G. [Show all 7 contributors for this article] (2022). The influence of global climate change on accumulation and toxicity of persistent organic pollutants and chemicals of emerging concern in Arctic food webs.
• Borgå, Katrine; McKinney, Melissa A.; Routti, Heli Anna Irmeli; Fernie, Kim J.; Giebichenstein, Julia & Hallanger, Ingeborg G. [Show all 7 contributors for this article] (2022). The influence of global climate change on accumulation and toxicity of persistent organic pollutants and chemicals of emerging concern in Arctic food webs.
• Bekkby, Trine; Torstensen, Ragnhild Ryther Grimm; Grünfeld, Lars Andreas Holm; Gundersen, Hege; Fredriksen, Stein & Rinde, Eli [Show all 12 contributors for this article] (2022). Hanging gardens - do floating kelp farm communities resemble natural kelp forests?
• Vereide, Emilie Hernes; de Jong, Karen; Titelman, Josefin; Browman, Howard; Agersted, Mette Dalgaard & Mihaljevic, Marina [Show all 7 contributors for this article] (2022). Seismikkens påvirkning på dyreplankton.
• Vereide, Emilie Hernes; de Jong, Karen; Titelman, Josefin; Browman, Howard; Agersted, Mette Dalgaard & Mihaljevic, Marina [Show all 7 contributors for this article] (2022). The Effects of Seismic Surveys on Zooplankton – Small animals meet loud noise.
• Vereide, Emilie Hernes; de Jong, Karen; Titelman, Josefin; Browman, Howard; Fields, David M. & Agersted, Mette Dalgaard [Show all 7 contributors for this article] (2022). Impacts of Airgun Blasts Used in Seismic Surveys - Small Effects in Small Copepods.
• Vereide, Emilie Hernes; de Jong, Karen; Titelman, Josefin; Browman, Howard; Fields, David M. & Agersted, Mette Dalgaard [Show all 7 contributors for this article] (2022). Impacts of Airgun Blasts Used in Seismic Surveys - Small Effects in Small Copepods .
• Lode, Torben; Dingstad, Trym R; Heuschele, Jan David & Borgå, Katrine (2022). Effect of historic aquaculture activity on copepod sensitivity to combined copper and predation risk exposure.
• Sengupta, Sagnik; Leinaas, Hans Petter; van Gestel, Cornelis A.M. & Borgå, Katrine (2022). Interaction of neonicotinoid exposure and temperature on the life-history traits of the widely distributed Collembola Folsomia quadrioculata. .
• Edvardsen, Bente & Eikrem, Wenche (2022). Haptophyte taxonomy.
• Edvardsen, Bente; Supraha, Luka; Egge, Elianne Dunthorn & John, Uwe (2022). Harmful haptophyte blooms in Norway - bloom dynamics and ecology, with special focus on the Chrysochromulina leadbeateri blooms.
• Carlsen, Eira Catharine Lødrup; Hylland, Ketil; Gomes, Tania; Sørensen, Lisbet; Booth, Andrew & Eiler, Alexander (2022). Plastic leachates as drivers for bacterial community structure and functioning, including antibiotic resistance.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• Heuschele, Jan David; Dinh, Khuong V.; Lode, Torben; Jager, Tjalling & Borgå, Katrine (2022). Copper sensitivity in three common Arctic copepods. .
• Haarr, Ane; Mwakalapa, Eliezer; Nipen, Maja; Mmochi, Aviti & Borgå, Katrine (2022). Emerging Contaminants in Household Chicken Eggs and Soil Around Waste Disposal Sites in Tanzania.
• 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.
• Giebichenstein, Julia; Warner, Nicholas Alexander; Varpe, Øystein; Andersen, Tom; Gabrielsen, Geir W. & Borgå, Katrine (2022). Chlorinated paraffins in polar cod and capelin from the Barents Sea.
• Parmentier, Frans-Jan; Hessen, Dag Olav & Wang, You-Ren (2022). Ekstremoppvarmingen av Arktis gir økte CO2-utslipp. Dagens næringsliv. ISSN 0803-9372. p. 31–31.
• Gundersen, Madeleine S.; Morelan, Ian; Bakke, Ingrid; Andersen, Tom & Vadstein, Olav (2022). Disturbances increase selection – whereas stability promotes stochastic assembly in bacterial communities.
• Moazami, Therese Nitter; Hilt, Bjørn; Sørås, Kirsti; Svendsen, Kristin V Hirsch; Refsnes, Magne Arnold & Dahlman, Hans Jørgen [Show all 9 contributors for this article] (2022). Korttidseksponering for steinmineraler brukt i asfalt kan påvirke lungefunksjonog lungeinflammasjon hos friske, unge mennesker . Yrkeshygienikeren. ISSN 0802-2763.
• Gundersen, Madeleine S.; Morelan, Ian; Andersen, Tom; Bakke, Ingrid & Vadstein, Olav (2022). Bacterial community assembly during disturbances.
• Hancke, Kasper; Gundersen, Hege; Borgersen, Gunhild; Anglès d'Auriac, Marc; Ruus, Anders & Andersen, Guri Sogn [Show all 7 contributors for this article] (2022). Det Nordiske blått karbonbudsjettet.
• Gundersen, Hege; Hancke, Kasper; Borgersen, Gunhild; Anglès d'Auriac, Marc; Ruus, Anders & Andersen, Guri Sogn [Show all 7 contributors for this article] (2022). Det Nordiske Blått karbon-prosjektet.
• Hylland, Ketil (2022). Comment to Christina Rudén "The precautionary principle in regulatory toxicology".
• 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).
• Vereide, Emilie Hernes; Titelman, Josefin; Browman, Howard; Agersted, Mette Dalgaard; Mihaljevic, Marina & Fields, David M. [Show all 7 contributors for this article] (2021). Effects of airgun blasts used in seismic surveys on mortality and growth in the copepod Acartia tonsa.
• 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.
• 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.
• Wang, You-Ren (2021). Evaluating global and regional land warming trends in the past decades with both MODIS and ERA5-Land land surface temperature data.
• Descamps, Sebastien; Moreau, Sebastien; Tarroux, Arnaud; Lorentsen, Svein-Håkon; Bustnes, Jan Ove & Yoccoz, Nigel [Show all 9 contributors for this article] (2021). Svarthamaren seabirds, sentinels of the Southern Ocean. Fram Forum. ISSN 1893-5532. 10.
• Giebichenstein, Julia (2021). The Arctic's invisible pollution.
• Giebichenstein, Julia (2021). An Arctic expedition.
• Giebichenstein, Julia (2021). How do Arctic animals stay warm? .
• Giebichenstein, Julia (2021). What does an Arctic scientist do?
• Giebichenstein, Julia (2021). Skype a scientist. Virtual meeting with school classes from the U.S. - "An Arctic expedition" .
• Giebichenstein, Julia (2021). Skype a scientist. Virtual meeting with school classes from the U.S. - "How do Arctic animals stay warm?" .
• Giebichenstein, Julia (2021). Expedition in die Arktis .
• Giebichenstein, Julia (2021). The Arctics invisible pollution - Polar Pint of Science.
• Saubrekka, Karoline (2021). The hidden forest in the Arctic.
• Jortveit, Andreas; Dinh, van Khuong; Borgå, Katrine; Titelman, Josefin & Søreide, Janne (2021). Sensitivity of the Early Life Stages of the Arctic Copepod C. Glacialis to Multiple Stressors: Multi-Dimensional Interactions of Ocean Acidification, Warming and Pyrene.
• Gravelle, Amalie M.; Dinh, van Khuong; Titelman, Josefin; Søreide, Janne; Jortveit, Andreas & Borgå, Katrine (2021). Transgenerational Effects of Warming, Ocean Acidification and Polycyclic Aromatic Hydrocarbons on a Key Arctic Copepod Calanus glacialis.
• Legacy, Nansen; Nowicki, Robynne; Giebichenstein, Julia; Dörr, Jakob Simon & Gawinski, Christine (2021). Nansen Legacy Polar Pint of Science in Oslo, Bergen, Tromsø and Longyearbyen 2021 Oct 11.
• Giebichenstein, Julia (2021). Skype a scientist. Virtual meeting with school classes from the U.S. - "What does an Arctic scientist do?" .
• Hylland, Ketil (2021). Seminar om sprøytemidler. [Internet]. Økologisk Norge - streamet seminar.
• Hylland, Ketil (2021). Kjemisk-syntetiske sprøytemidler: Det store eksperimentet. Ren Mat.
• Hylland, Ketil (2021). Forskning kobler stoff som gjør plast mykt til risiko for tidlig død. Forskning.no. ISSN 1891-635X.
• Hylland, Ketil (2021). Hvor farlig er egentlig sprøytemidler (aka plantevernmidler)?
• Yadetie, Fekadu; Brun, Nadja Rebecca; Vieweg, Ireen; Nahrgang, Jasmine; Giebichenstein, Julia & Dmoch, Kasia [Show all 10 contributors for this article] (2021). Genomic responses to pollutants in Arctic fish and copepod species.
• Dinh, van Khuong; Titelman, Josefin; Søreide, Janne; Hylland, Ketil & Borgå, Katrine (2021). Long-term effects of warming and pyrene on Calanus hyperboreus.
• Kaartvedt, Stein & Hylland, Ketil (2021). Oslofjorden er langt fra død. Dagens næringsliv. ISSN 0803-9372.
• Hylland, Ketil (2021). Fiskesamfunn og miljøgiftsituasjonen i fjorden.
• Hylland, Ketil (2021). EDs - how different is wildlife to humans?
• Dupont, Nicolas; Durant, Joël; Gjøsæter, Harald; Langangen, Øystein Ole Gahr & Stige, Leif Christian (2021). Using time series to predict the future: quantifying the effects of borealization on polar cod (Boreogadus saida).
• Düsedau, Luisa; Fredriksen, Stein; Brand, Markus; Savoie, Amanda; Jungblut, Simon & Molis, Markus [Show all 10 contributors for this article] (2021). Macroalgal biodiversity and biomass of Kongsfjorden through time and space . Show summary

  Macroalgae are major primary producers and ecosystem engineers along rocky shores of the Arctic. With Svalbard being a hotspot of global warming, macroalgal species distribution and biomass is undergoing rapid changes, presumably affecting all associated life forms. The overall retreat of the yearly ice cover is only the centerpiece in a complex interplay of environmental drivers noticeably altering light availability, disturbance regimes and nutrient supply for Arctic seaweeds. Between 1996/1998 and 2012/2013 ecosystem changes were observed at our study site Hansneset in Kongsfjorden, as algal biomass in the littoral zone doubled and the macroalgal biomass peak, as well as the lower distribution limit of most dominating kelp species, shifted upwards by several meters. In summer 2021, we seek to complement these datasets. Our interdisciplinary group will repeat the quantitative monitoring study to examine how the community pattern of seaweeds and their associated fauna has changed since the last expedition. In detail, we will quantify macroalgal biomass and biodiversity, the age structure and fertility of kelp species, and the biomass and biodiversity of associated animals along a depth gradient between 0 and 15 m. Incorporated into the European Horizon 2020 project FACE-IT and two associated Svalbard Science Forum field grants, our superior aim is to analyse the response of benthic macroalgal assemblages to observed cryosphere changes in a broad context. In this talk, we will share the first results from this year’s field samplings and show how abundances, biomass and species diversity of macroalgae have changed over the last decades at our investigation site and what this means in general for the development of macroalgae on Arctic coasts.

• Hylland, Ketil (2021). Microplastics and sediment-dwelling organisms.
• Kolano, Pawel; Borgå, Katrine & Nielsen, Anders (2021). Med strekkode på ryggen avslørte humlene hvordan insektmiddel påvirker atferden. NTB.
• Kolano, Pawel; Borgå, Katrine & Nielsen, Anders (2021). Med strekkode på ryggen avslørte humlene hvordan insektmiddel påvirker atferden. Titan.uio.no.
• Kroglund, Ingvild Buran; Ciesielski, Tomasz Maciej; Østnes, Jan Eivind; Borgå, Katrine & Jaspers, Veerle (2021). Metals and other elements in adult and nestling tawny owls from central Norway.
• 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.
• Lönn-Stensrud, Jessica; Skattebu, Julie; Gadmar, Tone Charlotte & Konestabo, Heidi Sjursen (2021). From black screens to success.
• Bechmann, Marianne; Thrane, Jan-Erik; Kværnø, Sigrun & Turtumøygard, Stein (2021). Eutrofiering av Mjøsa – kartlegging av årsaksforhold og kilder til fosfor i delnedbørfelt: Gudbrandsdalslågen. NIBIO POP. ISSN 2464-1170. 7(13). Full text in Research Archive Show summary

  Gudbrandsdalslågen er Mjøsas største tilløpselv og er avgjørende både for vannkvaliteten og den økologiske dynamikken i Mjøsa. Vannkvaliteten i Lågen er bedret sammenliknet med 1970- og 80-tallet, og til tross for mye jordbruk og bebyggelse i hele Gudbrandsdalen er den økologiske tilstanden god eller svært god med hensyn til eutrofiering langs mesteparten av elva. Det er imidlertid indikasjoner på at både transport og konsentrasjon av fosfor og nitrogen har økt det siste tiåret, bl.a. som følge av hyppigere flommer. De menneskeskapte tilførslene av fosfor til Gudbrandsdalslågen kommer fra jordbruket i tillegg til avløp. Jordbruket i nedbørfeltet til Lågen er dominert av grasdyrking og husdyrproduksjon. Over de siste 20 årene har det vært en liten nedgang i antall melkekyr, men for øvrig har husdyrtettheten vært ganske stabil. Bruk av fosforfri mineralgjødsel i tillegg til husdyrgjødsel er et viktig tiltak for å redusere fosforavrenningen, særlig der jordas fosforstatus er høy. Konsentrasjoner av E. coli i elva indikerer at avløp eller husdyrgjødsel bidrar til næringsstoffavrenningen og tiltak for disse kildene bør prioriteres. Miljøovervåkingen av Mjøsa, samt algeoppblomstringen i 2019, indikerer at innsjøen ikke tåler særlig større næringsstoffbelastning. Opprettholdelse av god vannkvalitet i Mjøsa er avhengig av målrettede tiltak i de ulike vassdragene som har utløp i Mjøsa. Dette faktaarket omhandler årsaksforhold, kilder og tiltak for redusert fosforavrenning fra nedbørfeltet til Gudbrandsdalslågen.

• Bechmann, Marianne; Thrane, Jan-Erik; Kværnø, Sigrun & Turtumøygard, Stein (2021). Eutrofiering av Mjøsa – kartlegging av årsaksforhold og kilder til fosfor i delnedbørfelt: Gausa. NIBIO POP. ISSN 2464-1170. 7(12). Full text in Research Archive Show summary

  Gausa har vært betydelig påvirket av både avløp, husdyrhold og arealavrenning fra jordbruket. Over tid har vannkvaliteten blitt bedre, og den økologiske tilstanden har vært god eller svært god med hensyn til eutrofiering i nedre deler av elva de siste årene. Lokalt i vassdraget er derimot den økologiske tilstanden fortsatt moderat. Beregninger for 2016 viser at hovedkildene til de menneskeskapte tilførslene av fosfor til elva er jordbruk og avløp. Avløp er den største kilden til biotilgjengelig fosfor. Fortsatt opprydding i spredt avløp er derfor det viktigste tiltaket for å bedre vannkvaliteten i elva. Jordbruket i Gausas nedbørfelt er dominert av grasdyrking og husdyrproduksjon. Fosforstatus i dyrket mark er høy og dette medfører risiko for avrenning av fosfor. Redusert fosforgjødsling er et viktig tiltak for å redusere fosforavrenningen fra jordbruksarealene. Konsentrasjoner av E. coli i elva indikerer at avløp eller husdyrgjødsel bidrar til næringsstoffavrenningen og tiltak for disse kildene bør prioriteres. Miljøovervåkingen av Mjøsa, samt algeoppblomstringen i 2019, indikerer at innsjøen ikke tåler særlig større næringsstoffbelastning. Opprettholdelse av god vannkvalitet i Mjøsa er avhengig av målrettede tiltak i de ulike vassdragene som har utløp i Mjøsa. Dette faktaarket omhandler årsaksforhold, kilder og tiltak for redusert fosforavrenning fra nedbørfeltet til Gausa.

• Bechmann, Marianne; Thrane, Jan-Erik; Kværnø, Sigrun & Turtumøygard, Stein (2021). Eutrofiering av Mjøsa – kartlegging av årsaksforhold og kilder til fosfor i delnedbørfelt: Skanselva og Bausbakkelva. NIBIO POP. ISSN 2464-1170. 7(11). Full text in Research Archive Show summary

  Skanselva og Bausbakkelva har vært betydelig påvirket av både avløp, husdyrhold og arealavrenning fra jordbruket. Det foreligger få nyere undersøkelser av økologisk tilstand med hensyn til eutrofiering, men den er trolig moderat i midtre og nedre deler av begge elvene. Beregninger for 2016 viser at hovedkildene til det menneskeskapte tapet av fosfor er jordbruk og avløp. Avløp er den største kilden til biotilgjengelig fosfor. Fortsatt oppgradering av spredt avløp er derfor det viktigste tiltaket for å bedre vannkvaliteten i elvene. I jordbruket har det over de siste 20 årene skjedd endringer som kan ha påvirket vannkvaliteten i elva og tilførslene til Mjøsa. Husdyrtettheten og fosforstatus i jorda har økt, noe som medfører økt risiko for fosforavrenning. Redusert fosforgjødsling generelt og bruk av fosforfri gjødsel på jord med høyt fosforinnhold er viktige tiltak for å redusere fosfortilførselen til elvene fra jordbruksarealene. Miljøovervåkingen av Mjøsa, samt algeoppblomstringen i 2019, indikerer at innsjøen ikke tåler særlig større næringsstoffbelastning. Opprettholdelse av god vannkvalitet i Mjøsa er avhengig av målrettede tiltak i de ulike vassdragene som har utløp i Mjøsa. Dette faktaarket omhandler årsaksforhold, kilder og tiltak for redusert fosforavrenning fra nedbørfeltene til Skanselva og Bausbakkelva.

• Bechmann, Marianne; Thrane, Jan-Erik; Kværnø, Sigrun & Turtumøygard, Stein (2021). Eutrofiering av Mjøsa – kartlegging av årsaksforhold og kilder til fosfor i delnedbørfelt: Heggshuselva. NIBIO POP. ISSN 2464-1170. 7(10). Full text in Research Archive Show summary

  Heggshuselva har vært betydelig påvirket av både avløp, husdyrhold og arealavrenning fra jordbruket. Det foreligger få nyere undersøkelser av vannmiljøet i elva, men økologisk tilstand med hensyn til eutrofiering er trolig moderat. Beregninger for 2016 viser at hovedkildene til de menneskeskapte tilførslene av fosfor er jordbruk og avløp. Avløp er den største kilden til biotilgjengelig fosfor. Fortsatt opprydding i spredt avløp er derfor det viktigste tiltaket for å bedre vannkvaliteten i elva. Det har likevel over de siste 20 årene skjedd endringer i jordbruket i nedbørfeltet som kan ha hatt positiv effekt på vannkvaliteten i elva og tilførslene til Mjøsa. Husdyrtettheten er redusert og det samme gjelder kornarealet, mens andelen av kornarealet som overvintret i stubb har økt. Fosforstatus i jordbruksjorda er imidlertid høy og har ikke endret seg de siste 20 årene. En fortsatt nedgang i husdyrtetthet med redusert spredning av husdyrgjødsel på jordbruksarealene vil føre til redusert fosforstatus i jorda og redusert avrenning av fosfor. Miljøovervåkingen av Mjøsa, samt algeoppblomstringen i 2019, indikerer at innsjøen ikke tåler særlig større næringsstoffbelastning. Opprettholdelse av god vannkvalitet i Mjøsa er avhengig av målrettede tiltak i de ulike vassdragene som har utløp i Mjøsa. Dette faktaarket omhandler årsaksforhold, kilder og tiltak for redusert fosforavrenning fra nedbørfeltet til Heggshuselva.

• Bechmann, Marianne; Thrane, Jan-Erik; Kværnø, Sigrun & Turtumøygard, Stein (2021). Eutrofiering av Mjøsa – kartlegging av årsaksforhold og kilder til fosfor i delnedbørfelt: Moelva og Tingnes-Brøttum. NIBIO POP. ISSN 2464-1170. 7(9). Full text in Research Archive Show summary

  Moelva og bekkene i området Tingnes-Brøttum har vært betydelig påvirket av både avløp, husdyrhold og arealavrenning fra jordbruket. Over tid har vannkvaliteten blitt bedre og de nyeste undersøkelsene viser stort sett god økologisk tilstand med hensyn til eutrofiering i Moelva. I området Tingnes-Brøttum er mange av bekkene trolig ikke i god økologisk tilstand. Beregninger for 2016 viser at hovedkildene til de menneskeskapte tilførslene av fosfor til vann er jordbruk og avløp. Avløp er den største kilden til biotilgjengelig fosfor. Fortsatt oppryffing i spredt avløp er derfor det viktigste tiltaket for å bedre vannkvaliteten. Over de siste 20 årene har det dessuten skjedd endringer i jordbruket som kan ha påvirket vannkvaliteten i elva og bekkene, og tilførslene til Mjøsa. Husdyrtettheten og fosforstatus i jorda har økt, og på kornarealene har det vært en svak nedgang i overvintring i stubb. Dette medfører økt risiko for fosforavrenning. Redusert fosforgjødsling, grasdekte vannveier i forsenkninger, og ‘ingen jordarbeiding om høsten’ vil derfor være viktige tiltak for å redusere fosfortilførslene til Mjøsa fra jordbruksarealene. Miljøovervåkingen av Mjøsa, samt algeoppblomstringen i 2019, indikerer at innsjøen ikke tåler særlig større næringsstoffbelastning. Opprettholdelse av god vannkvalitet i Mjøsa er avhengig av målrettede tiltak i de ulike elvene som har utløp i Mjøsa. Dette faktaarket omhandler årsaksforhold, kilder og tiltak for redusert fosforavrenning fra nedbørfeltet til Moelva og området Tingnes-Brøttum.

• Bechmann, Marianne; Thrane, Jan-Erik; Kværnø, Sigrun & Turtumøygard, Stein (2021). Eutrofiering av Mjøsa – kartlegging av årsaksforhold og kilder til fosfor i delnedbørfelt: Svartelva. NIBIO POP. ISSN 2464-1170. 7(8). Full text in Research Archive Show summary

  Svarteelva har vært betydelig påvirket av både avløp, husdyrhold og arealavrenning fra jordbruket. Over tid har vannkvaliteten blitt bedre, og i hovedelva og sideelva Fura er den økologiske tilstanden med hensyn til eutrofiering stort sett god. Lokalt i elva oppnås likevel ikke god økologisk tilstand. I sideelva Nordre Starelva er f.eks. den økologiske tilstanden dårlig til moderat. Beregninger for 2016 viser at hovedkildene til de menneskeskapte tilførslene av fosfor til vann er avløp og jordbruk. Avløp er den største kilden til biotilgjengelig fosfor. Fortsatt opprydding i spredt avløp er derfor det viktigste tiltaket for å bedre vannkvaliteten i elva. Over de siste 20 årene har det skjedd endringer i jordbruket som kan ha påvirket vannkvaliteten i elva og tilførslene til Mjøsa. Husdyrtettheten har økt og det har vært en halvering i areal med overvintring i stubb. Dessuten er fosforstatus i jordbruksjorda høy. Dette medfører økt risiko for fosforavrenning. Redusert fosforgjødsling, grasdekte vannveier i forsenkninger, og ‘ingen jordarbeiding om høsten’ vil derfor være viktige tiltak for å redusere fosfortilførslene til elva fra jordbruksarealene. Høye konsentrasjoner av E. coli i elva indikerer at avløp eller husdyrgjødsel bidrar til næringsstoffavrenningen og tiltak for disse kildene bør prioriteres. Miljøovervåkingen av Mjøsa, samt algeoppblomstringen i 2019, indikerer at innsjøen ikke tåler særlig større næringsstoffbelastning. Dette faktaarket omhandler årsaksforhold, kilder og tiltak for redusert fosforavrenning fra nedbørfeltet til Svartelva.

• Bechmann, Marianne; Thrane, Jan-Erik; Kværnø, Sigrun & Turtumøygard, Stein (2021). Eutrofiering av Mjøsa – kartlegging av årsaksforhold og kilder til fosfor i delnedbørfelt: Flagstadelva. NIBIO POP. ISSN 2464-1170. 7(7). Full text in Research Archive Show summary

  Flagstadelva har vært betydelig påvirket av både avløp, husdyrhold og arealavrenning fra jordbruket. Over tid har vannkvaliteten blitt bedre, men den økologiske tilstanden er fortsatt moderat med hensyn til eutrofiering i nedre deler av elva. Beregninger for 2016 viser at hovedkildene til de menneskeskapte tilførslene av fosfor til vann er avløp og jordbruk. Avløp er den største kilden til biotilgjengelig fosfor. Fortsatt opprydding i spredt avløp er derfor det viktigste tiltaket for å bedre vannkvaliteten i elva. Det har over de siste 20 årene skjedd endringer i jordbruket som kan ha påvirket vannkvaliteten i elva og tilførslene til Mjøsa. Husdyrtettheten og fosforstatus i jorda har økt, og på kornarealene har det vært en nedgang i overvintring i stubb. Dette medfører økt risiko for fosforavrenning. Redusert fosforgjødsling, grasdekte vannveier i forsenkninger, og ‘ingen jordarbeiding om høsten’ vil derfor være viktige tiltak for å redusere fosfortilførslene til elva fra jordbruksarealene. Høye konsentrasjoner av E. coli i elva i dag indikerer at avløp eller husdyrgjødsel bidrar til næringsstoffavrenningen og det er behov for tiltak for reduserte utslipp fra disse kildene. Miljøovervåkingen av Mjøsa, samt algeoppblomstringen i 2019, indikerer at innsjøen ikke tåler særlig større næringsstoffbelastning. Opprettholdelse av god vannkvalitet i Mjøsa er avhengig av målrettede tiltak i de ulike vassdragene som har utløp i Mjøsa. Dette faktaarket omhandler årsaksforhold, kilder og tiltak for redusert fosforavrenning fra nedbørfeltet til Flagstadelva, som renner ut i Åkersvika ved Hamar.

• Bechmann, Marianne; Thrane, Jan-Erik; Kværnø, Sigrun & Turtumøygard, Stein (2021). Eutrofiering av Mjøsa – kartlegging av årsaksforhold og kilder til fosfor i delnedbørfelt: Hunnselva. NIBIO POP. ISSN 2464-1170. 7(6). Full text in Research Archive Show summary

  Hunnselva har vært betydelig påvirket av både avløp, husdyrhold og arealavrenning fra jordbruket. Vannkvaliteten har blitt bedre sammenliknet med 1970, 1980 og 1990-tallet, men tilstanden med hensyn til eutrofiering er fortsatt moderat i nedre og midtre deler av elva. Avløp er den største kilden til biotilgjengelig fosfor. Fortsatt opprydding i spredt avløp er derfor det viktigste tiltaket for å bedre vannkvaliteten i elva. Beregninger fra 2016 viser at hovedkildene til det menneskeskapte fosfortapet er jordbruk og avløp. Jordbruksproduksjonen har endret seg lite i nedbørfeltet til Hunnselva over de siste 20 årene, og består av husdyr-, gras- og kornproduksjon. Fosforstatus i jorda er høy, og viser en svak økning i løpet av perioden. Dette medfører økt risiko for fosforavrenning. Redusert fosforgjødsling, grasdekte vannveier i forsenkninger, og ‘ingen jordarbeiding om høsten’ vil derfor være viktige tiltak for å redusere fosfortilførslene til elva fra jordbruksarealene. Miljøovervåkingen av Mjøsa, samt algeoppblomstringen i 2019, indikerer at innsjøen ikke tåler særlig større næringsstoffbelastning. Opprettholdelse av god vannkvalitet i Mjøsa er avhengig av målrettede tiltak i de ulike vassdragene som har utløp i Mjøsa. Dette faktaarket omhandler årsaksforhold,kilder og tiltak for redusert fosforavrenning fra nedbørfeltet til Hunnselva.

• Bekkby, Trine; Michael, Burrows; Cebrian, Emma; Fredriksen, Stein; Kotta, Jonne & Milanese, Martina [Show all 15 contributors for this article] (2021). COASTFRAG – Impact of habitat fragmentation and loss on coastal ecosystems and implications for sustainable management under climate change.
• Bekkby, Trine; Burrows, Michael; Cebrian, Emma; Fredriksen, Stein; Kotta, Jonne & Milanese, Martina [Show all 15 contributors for this article] (2021). COASTFRAG - Effekter av fragmentering og tap av habitater på økosystemer i kystsonen og betydningen for b ærekraftig forvaltning i en verden i endring.
• 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.
• Olsen, Thomas Meldahl; Augustsson, Ingrid Carita; Ravnås, Rodmar & Andersen, Tom (2020). Provenance on the Lange-Lysing mega-sequence on the Dønna Terrace: stratigraphic variability and lateral sandbody connectivity.
• Wang, You-Ren (2020). Probing trends of environmental changes with satellite remote sensing.
• Allesson, Lina; Andersen, Tom; Dörsch, Peter; Eiler, Alexander; Wei, Jing & Hessen, Dag Olav (2020). Corrigendum: Phosphorus Availability Promotes Bacterial DOC-Mineralization, but Not Cumulative CO2-Production (Front.Microbiol, (2020), 11, (569879), 10.3389/fmicb.2020.569879). Frontiers in Microbiology. ISSN 1664-302X. 11. doi: 10.3389/fmicb.2020.614974.
• Søbstad, Ingrid Holtan; Sælemyr, Lisbeth; Thorsen, Anders; Hylland, Ketil; Kögel, Tanja & Mortensen, Stein [Show all 7 contributors for this article] (2020). Nile Red and polarised light for visualization of microplastics in mussels (Mytilus spp.).
• Bellas, Juan; Hylland, Ketil & Thierry, Burgeot (2020). Editorial: New Challenges in Marine Pollution Monitoring. Frontiers in Marine Science. ISSN 2296-7745. 6. doi: 10.3389/fmars.2019.00820.
• 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.
• Mentzel, Sophie; Grung, Merete; Tollefsen, Knut-Erik; Stenrød, Marianne; Petersen, Karina & Moe, S. Jannicke (2020). A Bayesian Network approach to probabilistic risk assessment of pesticide mixtures .
• Mentzel, Sophie; Grung, Merete; Tollefsen, Knut-Erik; Stenrød, Marianne; Petersen, Karina & Moe, S. Jannicke (2020). Probabilistic risk assessment of pesticides for a Norwegian case study: A Bayesian Network approach .
• Mentzel, Sophie; Grung, Merete; Tollefsen, Knut-Erik; Stenrød, Marianne; Holten, Roger & Moe, S. Jannicke (2020). Probabilistic risk assessment of pesticides under future agricultural and climate scenarios: A Bayesian Network approach.
• Mentzel, Sophie; Grung, Merete; Tollefsen, Knut-Erik; Stenrød, Marianne; Petersen, Karina & Moe, S. Jannicke (2020). Probabilistic risk assessment of pesticides under future scenarios: A Bayesian Network approach.
• Mentzel, Sophie; Grung, Merete; Tollefsen, Knut-Erik; Stenrød, Marianne; Petersen, Karina & Moe, S. Jannicke (2020). A Bayesian network approach for probabilistic risk assessment of pesticides: expanding the binary outcome of risk assessment.
• Holme, Jørn Andreas; Låg, Marit; Øvrevik, Johan & Golestani, Karan (2020). Kan luftforurensning øke risikoen for covid-19? Tidsskrift for Den norske legeforening. ISSN 0029-2001. 140(18), p. 1–3. doi: 10.4045/tidsskr.20.0843.
• Giebichenstein, Julia; Gawinski, Christine & Jones, Elizabeth Marie (2020). Instagram account @nansenlegacyresearch.
• Nipen, Maja; Bohlin-Nizzetto, Pernilla; Borgen, Anders; Borgå, Katrine; Jørgensen, Susanne Jøntvedt & Mmochi, Aviti John [Show all 10 contributors for this article] (2020). Spatial trends of chlorinated paraffins and dechloranes in soil and air from Tanzania.
• 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.
• 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.
• Vogt, Yngve & Edvardsen, Bente (2020). Varmere hav endrer algesamfunnet i Arktis. Apollon : Forskningsmagasin for Universitetet i Oslo. ISSN 0803-6926.
• Vogt, Yngve & Borgå, Katrine (2020). Klimaendringer og miljøgifter er dårlig kombo. Apollon : Forskningsmagasin for Universitetet i Oslo. ISSN 0803-6926.
• Edvardsen, Bente; Supraha, Luka; Gran-Stadniczeñko, Sandra; Eikrem, Wenche & John, Uwe (2020). An in-depth study of Chrysochromulina leadbeateri bloom in northern Norway during spring 2019. Show summary

  The toxic algal bloom of the haptophyte Chrysochromulina leadbeateri in spring 2019 was the largest bloom of this species in Norwegian waters and worldwide ever recorded. Starting in the Vestfjorden area in northern Norway during early May and expanding north to Balsfjorden and Tromsø area, the bloom caused a major mortality of farmed salmon, with over 13 000 tonns of fish reported as lost during the outbreak. The C. leadbeateri bloom in northern Norway was studied in-depth in frame of a research cruise led by Alfred Wegener Institute (Germany) and in collaboration with the University of Oslo. The cruise focused on studies of phytoplankton diversity, distribution and functional ecology in several fjord systems along the northern Norwegian coast (Lofoten-Vesterålen area, Balsfjorden, Lyngen, Porsangerfjorden, Laksefjorden, Tanafjorden). Biological and environmental data collected during the cruise allowed for detailed analyses of the blooming organism, its distribution patterns in northern Norway, and its ecology. Cultures of C. leadbeateri isolated from the bloom were used to determine the morphology, taxonomic identity, and phylogenetic placement of the organism, and to compare it with a C. leadbeateri strain isolated from the previous major bloom in 1991. Metabarcoding data, light microscopy counts and flow cytometry data were used to map the distribution and abundance of the species along the coast of northern Norway, and correlate its distribution with biotic and abiotic parameters. Preliminary results show that the blooming organism is genetically identical in marker genes to the strain from the bloom in Vestfjorden in 1991. However, both strains and C. leadbeateri in field material exhibit significant intraspecific genetic variability. Biogeographic mapping shows that the bloom was most pronounced in the Balsfjorden area, with maximum cell concentration of over 27 million cells L-1. From an ecological perspective, C. leadbeateri abundance showed positive correlation with phosphate and nitrate, negative correlation with salinity and a slightly positive correlation with temperature. The results of our work provide a unique, in-depth insight into C. leadbeateri blooms, which may help in the monitoring, modelling and predicting similar events in the future. Ongoing work in our group focus on physiological and genetic profiling of the isolated C. leadbeateri strains with the aim to improve our understanding of factors triggering toxicity and bloom formation.

• Edvardsen, Bente (2020). Norsk algekultursamling (NORCCA) - en verdifull ressurs for innovasjon.
• 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 .
• Husson, Berengere; Eriksen, Elena; Jentoft, Sissel; Boge, Erling; Borgå, Katrine & Chierici, Melissa [Show all 36 contributors for this article] (2023). Polar cod connectivity cruise 2022 Cruise Report. UiT Norges arktiske universitet. ISSN 2703-7525.
• Nilsen, Ina; Eide, Cecilie Hansen; Olsen, Are; Langangen, Øystein Ole Gahr & Kaplan, Isaac (2023). Dealing with uncertainty in ecosystem models along three axes; resolution, forcing and projections. Universitetet i Bergen.
• Dankel, Eli; Supraha, Luka; Edvardsen, Bente; Eikrem, Wenche & Saubrekka, Karoline (2023). Arktiske kalkflagellater: et morfologisk og molekylært dypdykk i det nordlige Barentshavet. Universitetet i Oslo. Show summary

  Oppblomstringer av kalkflagellater utgjør et viktig fundament for næringskjeden i Barentshavet. Fjernanalyse med satellittbilder har de siste tiårene dokumentert at denne oppblomstringen beveger seg nordover i takt med økende klimaendringer. Det er likevel fortsatt uvisst hva som skjer på artsnivå. Å forstå hvordan forekomsten til den enkelte art forandrer seg i møte med endrede miljøbetingelser, som redusert is og økende temperatur, gjør at man enklere kan forutse hvordan fytoplanktonsamfunnet vil respondere på et fremtidig, varmere Arktis. For denne oppgaven ble det hentet inn vannprøver fra syv stasjoner på et sør-nord-transekt i Barentshavet i august 2018 og 2019 under tokt i regi av forskningsprosjektet Arven etter Nansen (AeN). 2018 var globalt et av de varmeste årene på mange tiår, og Barentshavet var dermed isfritt den sommeren. I 2019 derimot var større deler av Barentshavet dekket av is. Prøver tatt for både svepeelektronmikroskopi (scanning electron microscopy, forkortet «SEM») og metastrekkoding (metabarcoding) ble brukt i oppgaven slik at resultatene fra metodene kunne sammenlignes. Formålet med SEM var å utføre både en kvalitativ og kvantitativ analyse av kalkflagellater. Metastrekkoding ble brukt til sekvensering av 18S rRNA-genet. I SEM fant jeg i prøvene fra 2018 Emiliania huxleyi, Coccolithus pelagicus, Papposphaera sarion, Papposphaera arctica, Wigwamma annulifera og Porsildia acerviphora. Utenom Coccolithus pelagicus og Wigwamma annulifera, ble de samme artene funnet i 2019. I tillegg ble Syracosphaera Marginiporata funnet i prøver fra et AeN-tokt i november-desember 2019. Artene fra 2018 var hovedsakelig til stede på den sørligste stasjonen i transektet, mens artene fra 2019 generelt ble funnet på flere forskjellige stasjoner. Fra metastrekkoding ble det registrert 13 OTUer (Operational Taxonomic Units) som er bestemt til kalkflagellat-taksa. Ettersom det stort sett mangler referansesekvenser for arktiske kalkflagellater, ble de fleste OTUene kun klassifisert til klasse eller orden. OTUene var for det meste til stede i prøvene fra den sørligste, og de to nordligste stasjonene. Det ble ikke observert et nevneverdig mønster i sammenheng med isdekket. Det ble derimot både for SEM og metastrekkoding observert at de fleste artene var til stede på stasjoner som i ulik grad ble påvirket av Den nordatlantiske havstrømmen. Resultatene er likevel ikke holdbare nok til å trekke en konklusjon om hvordan kalkflagellatsamfunnet i Barentshavet vil se ut i fremtiden. Ettersom de fleste OTUene viste lav taksonomisk oppløsning, og alle celler funnet i SEM ble bestemt til artsnivå, anbefaler jeg at SEM forblir den foretrukne metoden for kvalitativ og kvantitativ analyse av kalkflagellater.

• Walbækken, Hanna Myhre; Eikrem, Wenche; Edvardsen, Bente; Saubrekka, Karoline & Hofgaard, Antje (2023). Dinoflagellate diversity in the Barents Sea: a comparative identification analysis. Universitetet i Oslo. Show summary

  An important group in the protist community in marine habitats are dinoflagellates. In this study the diversity of dinoflagellates in a transect of seven pelagic sea stations in the Northern Barents Sea in August 2018 and August 2019 was assessed. The two sampling periods were characterized with low and high sea-ice extent, respectively. I have studied the diversity and presence of dinoflagellate species in the sample transect using the molecular method DNA metabarcoding, and the morphological methods light microscopy (LM), and scanning electron microscopy (SEM). The results from species identification were used to observe and compare potential differences in the two sampling years. It was shown that the morphological methods were limited in identification success by little amount of material in several of the vertical net haul samples, resulting in some bias when these results were compared with DNA metabarcoding that revealed a high number of OTU (operational taxonomic unit) reads assigned to division Dinoflagellata. Species classification by DNA metabarcoding was shown to be limited by the availability of reference sequences in the curated protist ribosomal database PR2. It yielded a rough overview of the composition of dinoflagellate species in the sampling transect that could be closer examined with more time to study single OTUs. Identification done by LM and SEM revealed the presence of genera in certain stations that was not revealed in metabarcoding, and vice versa. I also found that Lugol’s solution functioned well for the preservation of cell structure for sample analysis in SEM. Climate change is shown to cause more and rapid alterations in the Arctic, and the loss of sea-ice is an important consequence of a warmer climate. Regarding interannual differences in 2018 and 2019, the morphological methods showed some differences in species composition with genus Protoperidinium more often identified in 2018 than other species, and the same for Gymnodiniales species in 2019. This could potentially show a shift in phytoplankton communities in a changing environment, although time-series are necessary to predict the future compositions of dinoflagellate species. As phytoplankton makes up the fundament for the Arctic food chain, studies of changing environmental conditions are valuable for ecological reasons.

• Edvardsen, Bente; Gryn, Khrystyna; Šupraha, Luka; Eikrem, Wenche & Saubrekka, Karoline (2023). Biodiversity and distribution of Arctic phytoplankton and ice algae. Universitetet i Oslo. Show summary

  The project aims to enhance our understanding of Arctic marine ecosystems by researching the diversity, distribution, and functioning of phytoplankton and ice algae in response to rapid environmental changes. The diversity and biogeography of phytoplankton and ice algae from the Barents Sea were studied by combining algal cultivation and 18S and 28S rRNA gene sequencing. During the Nansen legacy project cruise in August 2019 (AeN706), a total of 46 algal strains were isolated from stations along a S-N transect in the Barents Sea into the Arctic Ocean. The identifications obtained from DNA sequencing, phylogenetic analysis and morphological examination indicated the presence of common Arctic algal species, such as Attheya septentrionalis, Thalassiosira gravida, and Chaetoceros neogracilis, among the identified genotypes. Additionally, this study has also characterised potentially novel species or species that have not been adequately described before. Taxonomic identification of the strains was performed using molecular and morphological approaches, and the biogeographic distribution was mapped using a global compilation of published metabarcoding datasets. It was demonstrated by the biogeographic analyses that four general biogeographic distribution types exist for arctic phytoplankton and ice algae: polar, arctic, arctic-temperate, and cosmopolitan. Genotypes with arctic-temperate distribution was most common among the characterised strains, and genotypes endemic to the arctic was also found. Only two genotypes with cosmopolitan distribution and one genotype with polar distribution were discovered. The results highlight that the phytoplankton and ice algal communities in the Barents Sea and Arctic Ocean consist of genotypes endemic to the Arctic and genotypes with broader biogeographic distributions.

• Røsbak, Silje K.; Edvardsen, Bente; Eiler, Alexander; Saubrekka, Karoline & Fon, Mathias (2023). Mikrobielt samfunn i kulturer av Chrysochromulina leadbeateri og relaterte svepeflagellater undersøkt med metastrekkoding. Universitetet i Oslo. Show summary

  Skadelige marine algeoppblomstringer er et tilbakevendende problem over hele verden, der skadene har en påvirkning på økosystemer og lokal økonomi. Chrysochromulina leadbeateri var årsak til en massiv fiskedød i 2019, men mekanismene bak denne oppblomstringen er fortsatt ukjent. Målet med oppgaven var å undersøke bakteriediversiteten i kulturer av den fiske-giftige Chrysochromulina leadbeateri, og sammenligne denne mot andre beslektede svepeflagellater, både hos potensielt giftige og ikke-giftige arter. I tillegg til dette ble bakteriediversiteten av mikrobiomet mellom fastsittende bakterier på algecellene og frittlevende bakterier i kultur undersøkt. I denne oppgaven ble det prokaryote mikrobiomet i kulturer av tre stammer av Chryochromulina leadbeateri og 6 stammer av beslektede svepeflagellatarter analysert. Dette ble gjort ved metastrekkoding av det ribosomale 16S rRNA-genet. Det ble påvist et mangfoldig mikrobiom der hele bakteriedatasettet inneholdt 3 rekker, 14 ordener og 53 slekter. Bakteriesamfunnets sammensetning bestod hovedsakelig av medlemmer i rekken Proteobacteria etterfulgt av medlemmer av rekken Bacteroidota, og kun noen få ASVer i rekken Actinobacteria. Av de 14 ordenene var Rhodobacterales, Flavobacteriales, Caulobacterales, Rhiszobiales og Cytophagales de mest vanlige. Av de 53 slektene var Marivita (Rhodobacterales) den mest abundante, etterfulgt av Roseovarius (Rhodobacterales), Jannaschia (Rhodobacterales), Hoefla (Rhizobiales), Seohaeicola (Rhodobacterales), Hyphomonas (Rhodobacterales) og Sulfitobacter (Rhodobacterales). Taksonomisk fordeling av bakterieslekter mellom de potensielt giftige og ikke-giftige svepeflagellatene viste forskjeller, der de potensielt giftige hadde flest unike identifiserte bakterieslekter. Når det gjelder alfadiversitet (forskjeller innad i et samfunn) viser de to gruppene derimot ingen store forskjeller i mikrobiomet. Det ble funnet en svak signifikant sammenheng i mikrobiomets betadiversitet (forskjeller mellom samfunn) mellom kulturer av potensielt giftige og ikke-giftige svepeflagellater, der svepeflagellatens giftighet innen slekt hadde en svak effekt i denne studien. I tillegg viste slekten til svepeflagellaten til å ha en signifikant betydning for hvilke bakteriearter som ble funnet i algekulturer. Ved en sammenligning av fordelingen av bakterieslekter som er fastsittende til algecellen og frittlevende i algekultur, deler de to gruppene 80 % av bakterieslektene, og har dermed høy likhet. De frittlevende bakteriene har høyest antall ASVer, noe som indikerer at de fleste bakterie-typene lever fritt i kultur. Dette vises også ved de statistiske analysene, der alfadiversiteten for de IV frittlevende bakteriene i kultur har et signifikant rikere mikrobiom i forhold til fastsittende bakterier til algecellen. Betadiversiteten mellom fastsittende og frittlevende bakterier viser derimot ingen signifikante forskjeller, som vil si at mikrobiom-sammensetningen ikke kan forklares ut ifra om det er fastsittende på algecellene eller frittlevende i kultur.

• Tran, Jacquelynn Phuong-Vy; Edvardsen, Bente; Fon, Mathias; Heuschele, Jan David & Titelman, Josefin (2023). When hungry meets harmful: investigating the toxic relationship between haptophytes and copepods. Predatory induced defenses in Chrysochromulina leadbeateri. . Universitetet i Oslo. Show summary

  Harmful algal blooms are a recurring phenomenon all around the world, causing devastating effects including massive fish kills. A bloom of the toxic haptophyte, Chrysochromulina leadbeateri, in Northern Norway during May-June 2019 was the largest bloom ever recorded in that area causing massive mortalities of farmed salmon. While past C. leadbeateri blooms are known to cause such damage, relatively little is known about this toxic haptophyte, compared to other species. Some studies have investigated the bloom dynamics and abiotic factors influencing its toxicity, but little is known about the biotic influences. In particular, the predator-prey interactions with copepods. Past studies have found that when other species are directly exposed to predation threats (e.g. herbivorous copepods), the algae will respond by inducing and/or increasing toxicity potential as a defense mechanism. Those studies have focused on toxic diatoms and dinoflagellates producing shellfish toxins, but the potential for fish-killing algae to be influenced by predation pressure remains to be explored. In this thesis, I examined the biotic interactions between the toxic C. leadbeateri and the grazing Acartia sp. copepods. I first conducted a series of 3-day tolerance experiments, exposing Acartia sp. to different C. leadbeateri concentrations to answer: What is the threshold C. leadbeateri concentration that Acartia sp. can maintain survival and grazing? Then I conducted 3-day induction experiments, exposing C. leadbeateri to varying levels of grazing pressure, and in vitro tests using two fish cell lines to measure this potential grazing-induced toxicity to answer: Does the presence of copepod grazers affect toxicity in the ichthyotoxic haptophyte C. leadbeateri? Through the initial tolerance experiments, I determined that ca. 5 x 104 cells ml-1 of C. leadbeateri was the threshold concentration that enough Acartia sp. could survive and maintain feeding for the later toxicity induction experiments. Acartia sp. short-term tolerance to direct exposure to C. leadbeateri appeared to be concentration and time-dependent since the toxins need to be taken up by Acartia sp. to cause mortalities. Copepod grazing habits observed during the induction experiment appeared unaffected when C. leadbeateri was the only food source, as evidenced by fecal pellet production. However to accurately determine the effects of grazing on C. leadbeateri, future studies should observe grazing periodically with Acartia sp. exposed to different C. leadbeateri concentrations and non-toxic food alternatives. I examined whether the toxicity of C. leadbeateri was influenced by the presence of grazing copepods using in vitro tests on two fish (Rainbow trout and Atlantic salmon) cell lines to measure cell viability and light microscopy to look at morphological changes. I created different concentrations of algal extracts from crude C. leadbeateri material exposed to varying grazing levels. The different extracts were exposed to the gill cells in a microplate-based assay for 24 hours and at the endpoint, cell viability was measured using Alamar blue as an indicator dye. It seems that while increasing algal extract concentration decreases cell viability, extract made from C. leadbeateri exposed to increasing grazing pressure does not increase the negative effects on cell viability. The light micrographs of the gill cells suggest the same, but with some inclination that grazing pressure does affect some toxicity potential in C. leadbeateri. Unfortunately, with the lack of more independent trials, there is no statistical analyses to back up these claims. More experiments would allow for proper analyses and a potentially more conclusive statement about the relationship between copepod grazing and the toxicity potential of C. leadbeateri. This thesis can be used as a starting point for future research on the dynamics between toxic haptophytes and their copepod grazers.

• Reitzel, Helene; Edvardsen, Bente; Šupraha, Luka & Heuschele, Jan David (2023). The ichthyotoxic algae Chrysochromulina leadbeateri – an investigation into favorable conditions for growth and toxicity. . Universitetet i Oslo. Show summary

  Harmful algal blooms can be devastating to local ecosystems as well as have major impacts on economy and aquaculture. Chrysochromulina leadbeateri caused the death of an estimated seven and a half million farmed salmon in 2019, and the cause of this bloom is still unknown. While the growth and toxicity of other toxic prymnesiophytes have been examined, we still know little about optimal conditions for growth and toxicity of Chrysochromulina leadbeateri. In this thesis I have examined the growth of C. leadbeateri in controlled conditions, and how different salinities and temperatures affects the growth rate. I also examined the toxicity and whether or not I could induce it in a laboratory setting, and whether phosphorous limitation or other temperatures or salinities could play a role. I conducted three growth experiments. The first to establish a relationship between cell density and chlorophyll a fluorescence measurements. The second and third growth experiments were used to establish how different temperatures and salinities affected the strains of C. leadbeateri and how the different conditions affected growth rate as well as establish tolerance limits. Low temperatures and low salinities seemed to affect growth negatively, while optimum growth conditions were at 15°C and a salinity between 25 and 30. I recommend that the growth experiments are replicated with the inclusion of higher temperatures to establish where the upper temperature limit is, as well as repeat the temperatures used to get a better understanding of growth at 11°C as the equipment here had some flaws. I performed three Artemia bioassay experiments. The first showed that the cultures did not become more toxic after growing in phosphorous limited conditions compared to those that hadn’t. The second and third Artemia bioassay experiments were performed to see whether temperature or salinity played a role in inducing toxicity, as well as where in the growth phase the cultures were. Cultures that were in their stationary stage were toxic to Artemia nauplii, and this seemed to play a larger role in inducing toxicity than temperature or salinity.

• 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. ISSN 978-82-577-7609-1. 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).

• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wold, Anette; Goraguer, Lucie Hélène Marie & Wiktor, Jozef [Show all 7 contributors for this article] (2022). Ice algae biodiversity Nansen Legacy Q4. Norwegian Polar Institute.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wold, Anette; Goraguer, Lucie Hélène Marie & Wiktor, Jozef [Show all 7 contributors for this article] (2022). Ice algae biodiversity Nansen Legacy Q3. Norwegian Polar Institute.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wold, Anette; Goraguer, Lucie Hélène Marie & Wiktor, Jozef [Show all 8 contributors for this article] (2022). Ice algae biodiversity Nansen Legacy Q1. Norwegian Polar Institute.
• Assmy, Philipp; Wold, Anette; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wiktor, Jozef & Tatarek, Agnieszka [Show all 7 contributors for this article] (2022). Ice algae biodiversity Nansen Legacy JC2-2. Norwegian Polar Institute.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Goraguer, Lucie Hélène Marie; Wiktor, Józef & Tatarek, Agnieszka [Show all 7 contributors for this article] (2022). Ice algae biodiversity Nansen Legacy JC2-1. Norwegian Polar Institute.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wold, Anette; Goraguer, Lucie Hélène Marie & Wiktor, Jozef [Show all 7 contributors for this article] (2022). Ice algae biodiversity Nansen Legacy JC1. Norwegian Polar Institute.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wiktor, Józef; Tatarek, Agnieszka & Dabrowska, Anna Maria (2022). Phytoplankton biodiversity Nansen Legacy Q4. Norwegian Polar Institute.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wold, Anette; Goraguer, Lucie Hélène Marie & Wiktor, Józef [Show all 8 contributors for this article] (2022). Phytoplankton biodiversity Nansen Legacy Q3. Norwegian Polar Institute.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wold, Anette; Goraguer, Lucie Hélène Marie & Wiktor, Józef [Show all 8 contributors for this article] (2022). Phytoplankton biodiversity Nansen Legacy Q2. Norwegian Polar Institute.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wold, Anette; Goraguer, Lucie Hélène Marie & Wiktor, Jozef (2022). Phytoplankton biodiversity Nansen Legacy Q1. Norwegian Polar Institute.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wold, Anette; Wiktor, Jozef & Tatarek, Agnieszka [Show all 8 contributors for this article] (2022). Phytoplankton biodiversity Nansen Legacy JC2-2. Norwegian Polar Institute.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wold, Anette; Goraguer, Lucie Hélène Marie & Wiktor, Jozef [Show all 8 contributors for this article] (2022). Phytoplankton biodiversity Nansen Legacy JC2-1. Norwegian Polar Institute.
• MacKenzie, Kirsteen M.; Lydersen, Christian; Haug, Tore; Routti, Heli Anna Irmeli; Aars, Jon & Andvik, Clare Margaret [Show all 13 contributors for this article] (2022). Stable isotope (C&N) and dietary fatty acid compositions (>1%) for marine mammals in the European Arctic. Norwegian Polar Data Centre.
• Assmy, Philipp; Gradinger, Rolf Rudolf; Edvardsen, Bente; Wold, Anette; Goraguer, Lucie Hélène Marie & Wiktor, Jozef [Show all 7 contributors for this article] (2022). Phytoplankton biodiversity Nansen Legacy JC1. Norwegian Polar Institute.
• Gabrielsen, June Helen; Fredriksen, Stein & Bekkby, Trine (2022). Samfunn knyttet til kunstig substrat i båthavner i Oslofjorden. Et studium over sesong med fokus på fremmede arter. Universitetet i Oslo.
• Sanderson, Jack Jeffrey; Borgå, Katrine & Sengupta, Sagnik (2022). Effects of Imidacloprid on the Survival and Recruitment of Folsomia quadrioculata in Soil Microcosms. Universitetet i Oslo.
• Carlsen, Eira Catharine Lødrup; Eiler, Alexander; Hylland, Ketil & Gomes, Tania (2022). Double trouble: plastic leachates as drivers for increased adaptations to antibiotics? The effects of plastic leachates and ciprofloxacin on the sea urchin microbiome. Universitetet i Oslo.
• Jones, Elizabeth Marie; Reigstad, Marit; Espinel, Nadjejda; Gjerland, Audun; Goraguer, Lucie Hélène Marie & Hodal, helene [Show all 15 contributors for this article] (2022). JC2-1 Joint cruise part 1 2021 : Cruise Report. Septentrio Academic Publishing. ISSN 2703-7525. Show summary

  The Nansen Legacy Joint Cruise 2, part 1 (JC2-1) 12-29 July 2021, continued the investigation of the interannual variability during the late summer season. At the same time will the cruise provide a late summer reference for the seasonal investigation that was separated to late summer and polar night 2019, and winter and spring 2021. The transect represents an environmental gradient going through the northern Barents Sea, and included 7 process stations (P1-P7) lasting 10-39 hrs. Additional CTD stations (NLEG) were taken between the process stations to increase the hydrographic resolution on the transect. The work started at 76°N at the open Atlantic Water dominated station P1, was sea ice covered from station P4 at 79 45.00 °N and included deep water stations at the P7 station at 82°N in the Nansen Basin. The program included measurements and sampling from the atmosphere, sea ice, ocean and sea floor. Data collected includes several disciplines to map the physical environment, the chemical characterization and biological communities. Key parameters from the Nansen Legacy joint cruises were selected and included in this reduced sampling program, compared to the other joint cruises. An important aim was to characterize the northern Barents Sea to map the interannual variability, but also to see how the proceeding winter and spring conditions has impacted the environment and conditions this year. A third task is to carry out a shelf investigation that can complement the investigations in the deep Arctic Basin starting in late August. Tests and improvements of a modified pelagic trawl (Harstad) were carried out as preparations for the Arctic Basin cruise in late August 2021.

• Reigstad, Marit; Gabrielsen, Tove M.; Amargant-Arumi, Marti; Amundsen, Rita; Bluhm, Bodil & Bodur, Yasemin V. [Show all 37 contributors for this article] (2022). Seasonal Cruise Q3: Cruise Report . Septentrio Academic Publishing. ISSN 2703-7525. Show summary

  The Nansen Legacy Q3 cruise, 5-27 August 2019, initiated the seasonal investigations of the Nansen Legacy transect. The transect represent an environmental gradient going through the northern Barents Sea, and included 7 process stations (P1-P7) lasting 6-53 hrs. CTD stations were taken to increase the hydrographic resolution on the transect. The program included measurements and sampling from the atmosphere, sea ice, ocean and sea floor. Data collected ranged from physical observations, chemical, biological and geological data collection, and the aim was to link observations and measurements to improve our understanding of the systems involving both climate, human impacts and the ecosystems. Deployment of moorings and gliders extended the observational capacity in time and space, outside the cruise period.

• Gerland, Sebastian; Wold, Anette; Al-Habahbeh, Amalia Keck; Anglada Ortiz, Griselda; Amargant-Arumi, Marti & Bodur, Yasemin V. [Show all 35 contributors for this article] (2022). Seasonal Cruise Q1 2021: Cruise Report . Septentrio Academic Publishing. ISSN 2703-7525.
• Ludvigsen, Martin; Assmy, Philipp; Adams, Matthew James Samuel; Arumi, Marti A.; Mo-Bjørkelund, Tore & Bodur, Yasemin V. [Show all 35 contributors for this article] (2022). Seasonal cruise Q2 2021: Cruise Report . Septentrio Academic Publishing. ISSN 2703-7525. Show summary

  The spring season was the target for the Nansen Legacy cruise organized in late April and first half of May 2021 following the transect defined for this series of cruises to capture the variations of the year sampling physical, biological and chemical conditions in the ice and the sea. The transect went through both open water and ice. Seven process stations were visited (P1 through P7) together with smaller NLEG stations according to the program for the seasonal investigations. The first station (P1) was in open waters, while the remaining six main station had ice coverage of varying degree. Each of the process stations lasted 24 hours or more to allow a full diurnal cycle. Sampling included ice physics, ice samples, phytoplankton, zooplankton, marine chemistry and eco toxicology using acoustic, optical and robotics methods together with lab analyses of physical samples. Remote sensing data were also matched with in situ observations of both sea and ice conditions.

• Fransson, Agneta; Bluhm, Bodil; Arumi, Marti A.; Assmann, Karen; Gravelle, Amalie M. & Bratrein, Marius [Show all 34 contributors for this article] (2022). The Nansen Legacy Report Series. No. 30 - Joint Cruise 2-2 2021: Cruise report. UiT Norges arktiske universitet. ISSN 2703-7525.
• Utne-Palm, Anne Christine; de Jong, Karen; Pedersen, Geir; Klevjer, Thor A.; Titelman, Josefin & Strand, Espen [Show all 14 contributors for this article] (2022). Does seismic have an effect on zooplankton? - Field study at Ekofisk with RV Kristine Bonnevie. Havforskningsinstituttet. ISSN 1503-6294. Full text in Research Archive Show summary

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• Nøland, Helena; Fagerli, Camilla With; Bekkby, Trine & Fredriksen, Stein (2021). Endring i forekomst av blåskjell (Mytilus edulis) i Oslofjorden - Analyse av populasjoner over tid og mulige årsaker til variasjon. Universitetet i Oslo.
• Teksum, Mia Drazkowski; Konestabo, Heidi Sjursen; Borgå, Katrine & Birkemoe, Tone (2021). Assessing the exposure and effects of imidacloprid on the abundance of microarthropods in an agricultural soil community. Universitetet i Oslo.
• Rusch, Johannes; Vrålstad, Trude; Strand, David; Andersen, Tom & Hansen, Haakon (2021). Environmental DNA (eDNA) monitoring of two different freshwater host-pathogen complexes in the interface between nature and aquaculture. Universitetsforlaget. ISSN 1501-7710. 7710(2436).
• 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. ISSN 978-82-577-7410-3. 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.

• Ringvold, Halldis; Johnsen, Geir & Andersen, Tom (2021). Studies on Echinodermata from the NE Atlantic Ocean - Spatial distribution and abundance of Asteroidea, including taxonomic and molecular studies on Crossaster and Henricia genera - Value-chain results, including test fishery, biology, market and nutritional analysis on Parastichopus tremulus (Holothuroidea) from the Norwegian coast. NTNU. ISSN 978-82-326-6852-6. Show summary

  The phylum Echinodermata represent a large part of the marine benthic ecosystem biomass (up to 90%), and are also important in determining habitat structure for other species, and maintaining high species diversity in the marine ecosystems. The phylum contains five classes (Asteroidea, Holothuroidea, Ophiuroidea, Crinoidea and Echinoidea), of which studies on both asteroids and holothuroids from the NE Atlantic Ocean are presented here. With the establishment of nations Exclusive Economic Zone at the end of the 1970s, nations acquired scientific responsibility for a larger area than previously controlled as well as the jurisdiction to govern the use of their marine resources. Scarce knowledge on benthic fauna from the NE Atlantic Ocean (mainly before 1950), led to increased efforts in mapping biodiversity. In order to increase knowledge about invertebrates, including echinoderms, around the Faroe Islands, the «Marine benthic fauna of the Faroe Islands» (BIOFAR) programme was implemented. The programme conducted systematic sampling down to about 2400 m depth during the period between 1987 and 1990. Based on positive experience from BIOFAR, another programme, «Benthic Invertebrates of Icelandic Waters» (BIOICE), was formed a few years later, following somewhat the same principles. Data from both programmes, as well as a few other areas, are included in the studies on spatial distribution and abundance of Asteroidea, including taxonomic and molecular studies on Crossaster and Henricia genera, from the NE Atlantic Ocean. Also, holothuroids (sea cucumbers) are considered a delicacy on the Chinese market, with increasing demand from consumers. With increasing interest for a Norwegian fishery on Parastichopus tremulus, but with limited knowledge on fishery, biology, production and the Chinese market, several pilot projects were begun. These projects took place along the Norwegian coast between 2000 and 2006, with follow up scientific cruises. This doctoral thesis comprises three sub-aims, of which the first was to analyse distribution and abundance of asteroids from the NE Atlantic Ocean, using data obtained mainly from the Faroe Islands and Iceland. With the inclusion of asteroids from published literature, the total results show that 50 species have been recorded from the Faroe Islands, 64 from Iceland, and, although not included in these studies, 50 have been reported from nearby Norway, making Iceland the most species-rich area. Within the upper continental slope and the water mass transition zone, the most species-rich depth intervals from the Faroe Islands were identified with 33-34 species from 500-700 m depth. The two most species-rich depth intervals from Iceland showed only 23-24 species from 100-200 m and 400-500 m depth. All species showed different preferences regarding abundance-weighted depth- and temperature, although somewhat the same shallow-, intermediate- and deep-water species from the two programmes could be grouped. Non-metric Multidimensional Scaling (NMDS) from both programmes captured the same environmental gradients (depth and temperature). Asteroid accounts from the Faroe Islands and Iceland may become important basic reference data for future studies on climate change and shift in species distribution in these highly productive seas.

• Bekkby, Trine; Gabrielsen, June Helen; Rinde, Eli & Fredriksen, Stein (2021). Japansk spøkelseskreps og andre fremmede arter i Oslofjorden. NIVA. Show summary

  Våre undersøkelser i Oslofjorden viser forekomst av flere av de samme fremmede artene som det som er funnet i tidligere undersøkelser. Vi fant både stillehavsøsters, japansk spøkelseskreps, strømgarn, japansk sjølyng, djeveltunge og tøffelnegl. Flest arter og individer ble observert på den innerste stasjonen i indre Oslofjord (Oksval) og på Ula på vestsiden av ytre Oslofjord. På disse stasjonene ble det blant annet observert mye japansk spøkelseskreps, en art som har risikokategori Svært høy (SE) i Fremmedartslista. For første gang observert vi djeveltunge så langt inn som Horten (arten er tidligere observert på Ula), noe som mest sannsynlig betyr at denne arten er i ferd med å spre seg videre innover i fjorden. Vi anbefaler at det planlegges et program for overvåking av eksisterende fremmedarter og for tidlig varsling av dørstokkarter og andre nye arter i Oslofjorden. NIVA-notat 0412/21

• Bølling, Anette Kocbach; Aasvang, Gunn Marit; Låg, Marit; Refsnes, Magne Arnold; Øvrevik, Johan & Oftedal, Bente Margaret (2021). Konsentrasjons-responskurver for svevestøv: PM10. Folkehelseinstituttet. ISSN 978-82-8406-237-2. Full text in Research Archive
• Hjelset, Sverre; Eiler, Alexander; Hylland, Ketil & Gomes, Tania (2021). Weak toxicity of chemical additives extracted from car tire rubber on the microbiome of Atlantic cod and Norway pout. Universitetet i Oslo.
• 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 978-92-893-6861-2. 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.

• Gopakumar, Anjali & Borgå, Katrine (2020). Mercury Accumulation in fishes from North-East and North-West Barents Sea during the polar night. Universitetet i Oslo.
• Planque, Benjamin; Aarflot, Johanna Myrseth ; Buttay, Luice; Fransner, Filippa; Hansen, Cecilie & Husson, Berengere [Show all 15 contributors for this article] (2020). Best practices for ecological model evaluation II: Workshop Report. Septentrio Academic Publishing.
• Ingvaldsen, Randi Brunvær; Bluhm, Bodil; Aberle-Malzahn, Nicole; Amundsen, Rita; Ardelan, Murat Van & Bagøien, Espen [Show all 33 contributors for this article] (2020). Joint Cruise 1-2 2018: Cruise Report . Septentrio Academic Publishing.

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