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• Bodin, Johanna Eva; Berg, Paul Ragnar; Dalen, Knut Tomas; Duale, Nur; Granquist, Erik Georg & Jevnaker, Anne-Marthe Ganes [Show all 19 contributors for this article] (2026). Guidance on the scientific information required for risk assessment of genetically modified animals intended for field trials in Norway. VKM Report. 2026(7), p. 1–68. Full text in Research Archive Show summary

  The Norwegian Environment Agency has tasked The Norwegian Scientific Committee for Food and Environment (VKM) with developing generic guidance documents for environmental risk assessment of genetically modified organisms (GMOs) to be used in field trials. GMOs used in limited field trials may have effect on the environment, and human and animal health. All experiments involving the use of GMOs in field trails for research require approval under the Norwegian Gene Technology Act. The Norwegian Environment Agency is the decision-making authority for deliberate release of GM plants in field trials. VKM performs health and environmental risk assessments (ERAs) of GMOs for the Norwegian Environment Agency. This guidance document is intended as a support for applicants seeking approval for field trials under the Gene Technology Act and identifies the scientific documentation and data necessary to facilitate an ERA of a genetically modified animal (GM animal) conducted by VKM. The risk assessments conducted by VKM generally follow the step-by-step approach outlined in EU Directive 2001/18/EC on the deliberate release of genetically modified organisms into the environment, starting with hazard identification, hazard characterization, exposure characterization and risk characterization. The Gene Technology Act and the Regulations on impact assessment under the Gene Technology Act implements directive 2001/18/EC into Norwegian legislation. Appendix 2 of the Regulation contain the principles for environmental risk assessment, which corresponds to the principles of Annex II in the Directive. The European Food Safety Authority (EFSA) has developed further guidance on the risk assessment of genetically modified organisms based on Annex II. ERAs of GM animals involve the collection, assessment and, where appropriate, generation of information on a GM animal to determine its potential impacts on the environment and on human and animal health, compared with non-GM animals or appropriate comparators. VKM performs risk assessments that include the following six steps: hazard identification, hazard characterisation, exposure characterisation, risk characterisation, risk reducing measures, and overall risk evaluation of the use of the GM animal in a field trial. Applicants should identify the scientific documentation and data necessary for VKM to perform an ERA based on these steps. Applicants should also consider general risk reducing measures in relation to the identified risks, taking into consideration the type of GM animal, the intended management regime (confinement), the scale of the field trial, the characteristics of the genetic modification, the characteristics of the identified hazard(s), and the potential consequences for the environment and for human and animal health. This document provides guidance for the assessment of the potential environmental effects of GM animals, based on data from the required molecular characterisation, consideration of the potential impacts of the modified characteristics of the GM animal, and any risk mitigating measures implemented in the event of escape of GM animals into the environment during field trials. The guidance is intended as a dynamic document to be amended in accordance with future scientific and regulatory developments.

• Velle, Gaute; Bryn, Anders; Kausrud, Kyrre; Kirkendall, Lawrence R.; Malmstrøm, Martin & Sandercock, Brett Kevin [Show all 12 contributors for this article] (2026). Cumulative impacts from co-occurring non-native species. VKM Report. 2026(03), p. 1–80. Full text in Research Archive Show summary

  This report examines how co-occurring non-native species can interact to create cumulative impacts on ecosystems. Non-native species may interact in additive, antagonistic, or synergistic ways. Through literature review, we found theoretical foundations and empirical examples showing that such interactions often occur. Synergistic interactions are of particular concern. Certain ecosystems appear particularly susceptible, including agricultural landscapes, urban environments, riparian systems, shipping-influenced marine areas, and islands with naïve fauna. We conclude that cumulative effects are ecologically important, and that it would be beneficial to incorporate multispecies interactions into risk assessments of non-native species in Norway.

• Hoff, Siv Nam Khang; Maurstad, Marius Filomeno; Tørresen, Ole K.; Araya, Robin Aasegg; Berg, Paul R. & Præbel, Kim [Show all 8 contributors for this article] (2026). Rapid genome modifications including chromosomal fusions and large-scale inversions are key features in Arctic codfish species. Genome Biology. ISSN 1474-7596. 27. doi: 10.1186/s13059-026-03975-6. Full text in Research Archive Show summary

  Genome evolvability involves activation of transposable elements (TEs) that result in novel genomic rearrangements, including translocations, deletions, duplications, as well as larger structural reorganizations, such as chromosomal inversions and fusions. These genomic modifications contribute to raw genetic variability in which selection can act upon, and thus, promote local adaptation. Results Using a comparative genomics framework combined with the generation of six chromosome-level gadid reference genomes, including the cold-water adapted polar cod ( Boreogadus saida ) and Arctic cod ( Arctogadus glacialis ), we uncover an array of larger and smaller chromosomal reorganizations within this lineage. For the two Arctic codfishes, we detect lineage-specific chromosomal fusions, i.e., five in polar cod vs. eight in Arctic cod, resulting in a reduced number of chromosomes found to be associated with their geographical distribution. For the same species, we identify a high number of partly overlapping chromosomal inversions where a majority (especially within breakpoint regions) display an overrepresentation of specific TE families, accompanied by signatures of high degree of conservation. We further demonstrate involvement of miniature inverted-repeat transposable elements (MITEs) in the expansion of the well-known antifreeze glycoprotein genes in polar cod, and that the three gene clusters were localized in association with chromosomal rearrangements on chromosomes 1, 2, and 14. Conclusions We characterize how the Gadidae lineage has undergone massive genomic modifications — potentially via activation of TEs — throughout their evolutionary history, and particularly for the more Arctic species. These genomic reorganizations have likely played an important role in divergence processes and adaptation to freezing environmental conditions.

• Andrews, Adam Jon; Christie, Hartvig C; Præbel, Kim; Brandner, Melissa Michelle; Torstensen, Ragnhild Ryther Grimm & Lewis, Larisa [Show all 10 contributors for this article] (2025). Combining environmental DNA and traditional sampling to assess the role of kelp aquaculture as an artificial habitat in Norway. Frontiers in Marine Science. 12. doi: 10.3389/fmars.2025.1717725. Full text in Research Archive Show summary

  Kelp aquaculture is expanding rapidly in the temperate Atlantic, yet its ecological role as an artificial habitat remains poorly understood. This study assessed the biodiversity associated with wave-exposed kelp farms in coastal Norway using both environmental DNA (eDNA) and traditional sampling methods. Fish and invertebrate communities were surveyed at two kelp farms and compared to nearby natural kelp forests and pelagic control sites. Results from gill-net fishing, camera observations, and invertebrate sampling revealed lower species richness and abundance at kelp farms compared to natural habitats. eDNA analyses (12S and CO1 markers) showed few differences in community composition between sites, and no species were identified as significantly associated with kelp farms. Traditional sampling detected the presence of the amphipod Caprella mutica in the kelp farms, indicating that seaweed farmers can play roles in alien species spread. Overall, kelp farms supported distinct but less diverse communities than natural kelp forests, being more similar to pelagic control sites. Finally, eDNA provided limited insights compared to traditional methods. These findings suggest that kelp farms currently provide limited habitat provisioning in Norway, likely as a result of how and where kelp aquaculture is currently performed. We suggest the need for population-level assessments for species like Atlantic lumpfish (Cyclopterus lumpus) that commonly use kelp farms as habitats, and locally based assessments in collaboration with authorities to define nature-positive or -negative outcomes to balance ecological and economic goals in the growing seaweed aquaculture industries of the Atlantic.

• Kirkendall, Lawrence R.; Flø, Daniel; Malmstrøm, Martin; Nielsen, Anders; Berg, Paul Ragnar & Bryn, Anders [Show all 13 contributors for this article] (2025). Assessment of the risks of negative impact on biodiversity in Norway from import and keeping of the Turkestan cockroach (Periplaneta lateralis). Scientific Opinion of the Panel on Biodiversity of the Norwegian Scientific Committee for Food and Environment. VKM Report. 2025(07), p. 1–45. doi: https:/vkm.no/english/riskassessments/allpublications/lowriskassociatedwiththeimportandkeepingofturkestancockroach.4.78f38f6a1972b767482b0170.html. Full text in Research Archive Show summary

  VKM has assessed the potential risk to Norwegian biodiversity associated with the import of the Turkestan cockroach, Periplaneta lateralis, as live food for hobby animals. Populations of the cockroach are nearly always found in or near buildings, and non-native populations have never been observed in natural environments. No previous observations of P. lateralis have been reported for Norway and it is very unlikely the species will be able to establish and spread into Norwegian nature due to the low winter temperatures and short summers. Furthermore, VKM find that there is low risk associated with the potential effects on biodiversity, if it against all odds, were to establish in Norway. Therefore, VKM concludes that there is low risk associated with import and keeping of P. lateralis in relation to its potential negative effect on Norwegian biodiversity.

• Helmerson, Cecilia; Durant, Joël; Hoff, Siv Nam Khang; Brieuc, Marine Servane Ono; Berg, Paul Ragnar & Jorde, Per Erik [Show all 14 contributors for this article] (2025). A century of anthropogenic perturbations impact genomic signatures of the iconic migratory Atlantic cod. Science Advances. 11(31). doi: 10.1126/sciadv.adp3342. Full text in Research Archive Show summary

  Anthropogenic stressors have led to marked ecosystem perturbations, including population declines and shifts in habitat range for key marine fish species. Understanding how these changes affect genome-wide characteristics, causing long-term evolutionary responses, is still in its infancy. Genome-wide retrospective assessment of the iconic migratory Atlantic cod ( Gadus morhua ) from the Barents Sea, unraveled varying degree of admixture with the nonmigratory coastal ecotype throughout the 20th century, and intriguingly more intensified during recent decades. These genomic changes were supported by an increased number of individuals displaying the heterozygous state of the chromosomal inversion coupled to migratory behavior in Atlantic cod. Ecological models and genome-wide scans identified that some of the observed frequency shifts, coupled to neural development, metabolic, and growth regulation, covaried with intensified fisheries, reduced generation time, and ocean warming. Our results demonstrate how anthropogenic perturbations impact the dynamics between two well-known ecotypes of Atlantic cod and thus, their genomic signatures, with potential implications for future management programs.

• Hindar, Kjetil; Bodin, Johanna Eva; Dalen, Knut Tomas; Duale, Nur; Garseth, Åse Helen & Malmstrøm, Martin [Show all 14 contributors for this article] (2025). Overview of methods for production of sterile salmonids, their applicability in aquaculture and possible implications to wild salmon populations and biodiversity in Norway. VKM Report. 2025(02), p. 1–92. doi: https:/vkm.no/risikovurderinger/allevurderinger/steriloppdrettsfiskeffekterpabiologiskmangfold.4.6b6641cb18a179b6780ab2db.html. Full text in Research Archive Show summary

  VKM has assessed the positive and negative effects on biodiversity were sterile salmon to be used in Norwegian aquaculture. Triploidisation is assessed as the most effective method for sterilising fish, but it can affect the welfare and health of the fish. Several other techniques for producing sterile salmon are being tested, but it is too early to determine whether they can be used in large-scale farming. This is the key message in a knowledge summary VKM has prepared for the Norwegian Environment Agency. Background Escaped farmed salmon poses a major threat to wild salmon in Norway. hey can interbreed with wild salmon, genetically alter them, and make the populations less adaptable and more vulnerable to disease and environmental changes. A possible solution to the problem may be to use sterile salmon in farming. To date, only triploidisation has been tested. Newly fertilised eggs are given a hydrostatic pressure shock, thereby retaining an extra set of chromosomes which render the fish sterile. This method is currently the only one tested on a large scale. Triploidisation is effective but can also pose health and welfare challenges to fish. Methods VKM has reviewed available scientific literature regarding methods that can be used to produce sterile salmon. VKM has assessed whether these methods work as well, or better, than triploidy and whether they are likely to have fewer negative effects on fish welfare. Assessments have also been made of whether farmed fish treated with other sterilisation methods pose a greater or lesser threat to wild salmon than traditional farmed salmon. VKM has looked at the possibilities for further development of the triploidisation technique and has also assessed various methods currently being tested for producing sterile fish. Some of these are still at the laboratory-testing stage, while others are approaching trials with release into sea-pens. VKM has grouped the different methods based on whether they cause permanent changes in the genome (so-called "knock-out" of important genes) or whether the changes only result in temporary blocking or downregulation of gene expression (so-called "knock-down"). Results VKM concludes that triploidisation remains the most effective method and that there are possibilities to further develop this methodology through targeted breeding and adjustments in how the fish are kept. These measures can potentially solve the challenges for fish health and welfare. Using pure triploid female lines can also reduce some of the other challenges by preventing spawning interactions in rivers and reducing disease transmission to wild salmon. Alternative sterilisation methods, such as gene editing, vaccination, and temporary downregulation of proteins for gonad development using antisense oligomers and egg immersion, are promising but still under development. VKM assesses that methods causing permanent changes in the genome of diploid fish have a higher inherent risk than methods that only affect gene expression. Hope in egg-bathing Perhaps the most promising technique for safe production of sterile salmon is to add synthetic oligonucleotides to the eggs at an early stage, thereby preventing germ cell development without causing any inheritable changes. Such oligonucleotides can be injected into the eggs or absorbed by the eggs through bathing (immersion) in a special solution. "Especially the method involving targeted 'tools,' such as oligonucleotides that prevent germ cell development and can be added to the eggs in a water bath, seems promising," says Johanna Bodin, member of the Panel for Genetically Modified organisms and spokesperson for the report. (...)

• Nielsen, Anders; Hatteland, Bjørn Arild; Hermansen, Jo Skeie; Kirkendall, Lawrence Richard; Rasmussen, Claus & Seljetun, Kristin Opdal [Show all 17 contributors for this article] (2024). Risks posed by managed honey bees (Apis mellifera) to wild pollinators in Norway. Scientific Opinion of the Panel on Biodiversity of the Norwegian Scientific Committee for Food and Environment. VKM Report. 2024(4), p. 1–135. Full text in Research Archive Show summary

  Det er hovedkonklusjonen i en risikovurdering Vitenskapskomiteen for mat og miljø (VKM) har gjort for Miljødirektoratet. For biearter som er avhengige av én eller få plantearter for å overleve, vurderes risikoen som høyere (medium) på grunn av mulig konkurranse med honningbier om ressursene. Dette gjelder arter som rødknappsandbie. Også for humler i ensartede landskaper med begrensede blomsterressurser vurderes risikoen som medium. Oppdrag På oppdrag fra Miljødirektoratet har VKM oppsummert den tilgjengelige faglitteraturen om sammenhenger mellom hold av honningbier og deres effekter på ville pollinerende insekter, og vurdert om birøkt kan utgjøre en risiko for ville pollinatorer i Norge. VKM har også identifisert og vurdert effekten av mulige risikoreduserende tiltak. Risiko VKM har identifisert tre potensielle farer knyttet til hold av honningbier og vurdert risikoen for negative effekter på ville pollinatorer som følge av disse: Konkurranse om blomsterressurser. VKM vurderer at hold av honningbier medfører medium risiko for enkelte biearter som er avhengige av én eller få plantearter for å overleve, som rødknappsandbie og humler i ensartede landskaper med begrensede blomsterressurser. Dette skyldes mulig konkurranse om disse ressursene. For alle andre ville pollinerende insekter i Norge, vurderes risikoen fra konkurranse om blomsterressurser som lav. Spredning av patogener og parasitter. VKM vurderer at risikoen for spredning av patogener og parasitter til ville pollinerende insekter som følge av hold av honningbier er lav, delvis som følge av dagens høye hygienestandarder i norsk birøkt. Indirekte effekter som følge av endringer i plantesamfunn og predatorpopulasjoner. VKM vurderer at risikoen for at honningbier påvirker sammensetningen av plantesamfunn på en slik måte at tilgjengeligheten av blomsterressurser for ville pollinatorer reduseres, er lav. VKM vurderer også at risikoen for at predatorer av honningbier påvirker ville pollinatorer negativt er lav, da geithams er den eneste potensielle predatoren, og forekommer i lave antall og innenfor begrensede områder. Risikoreduserende tiltak VKM har identifisert og vurdert effekten av tre typer risikoreduserende tiltak som kan redusere den mulige negative effekten hold av honningbier har på ville pollinatorer i Norge: Forvaltning av blomsterressurser. Å redusere antallet honningbier eller øke mengden blomsterressurser i et område, kan minske konkurransen om blomsterressurser. Etablering av blomsterstriper og skjøtsel av stedegen flora er mulige tiltak. Kartlegging av blomsterressurser kan brukes til å anslå bæreevnen i et område og veilede plasseringen av bikuber. Fremme god helse hos honningbier. God helse blant honningbier reduserer risikoen for spredning av sykdommer og parasitter til ville pollinatorer. Risikoen for spredning av sykdommer fra honningbier til ville pollinatorer vurderes som lav i Norge, som følge av godt hygienearbeid blant norske birøktere, og effektiv overvåking fra Mattilsynet. Økt kunnskap om blomsterressurser og behovene til ville pollinatorer. Økt kunnskap om tilgjengeligheten av blomsterressurser og fødebehovene til ville pollinatorer vil kunne veilede plassering av bikuber og slik redusere potensialet for konkurranse mellom honningbier og ville pollinerende insekter.

• Velle, Gaute; Berg, Paul Ragnar; Järnegren, Johanna; Malmstrøm, Martin; Bryn, Anders & Hindar, Kjetil [Show all 12 contributors for this article] (2024). Assessment of risks posed by the import of live crabs intended for human consumption. Scientific Opinion of the Panel on Biodiversity of the Norwegian Scientific Committee for Food and Environment. VKM Report. 2024(09), p. 1–99. Full text in Research Archive Show summary

  The Norwegian Environment Agency asked VKM to evaluate the risks to biodiversity associated with the importation of eight species of live crabs intended for human consumption. Background Invasive crab species represent a significant threat to biodiversity globally due to their omnivory, adaptability to diverse habitats, high reproductive output, and aggressive behaviour. The Norwegian Environment Agency has raised concerns about the potential ecological risks posed by the import of live crabs to Norway intended for human consumption. This report provides a risk assessment of eight species of crabs that could have negative effects on native biodiversity. The species include Chinese mitten crab (Eriocheir sinensis), Japanese mitten crab (E. japonica), blue crab (Callinectes sapidus), Atlantic rock crab (Cancer irroratus), Asian paddle crab (Charybdis japonica), common moon crab (Matuta victor), African blue swimming crab (Portunus segnis), and Harris mud crab (Rhithropanopeus harrisii). Three of the assessed species were recently confiscated at Norway's border. This suggests a market demand that could increase the frequency of introductions to Norway. Methods VKM established a working group with expertise in invertebrates and risk assessment. The group searched scientific literature for information on the taxonomy, natural history, invasiveness, and ecology for each crab species. If scientific literature was lacking, supplemental google searches allowed for a broader understanding of species with limited research or on the use and transportation of live crabs as food. The assessment utilized the EICAT framework (Environmental Impact Classification for Alien Taxa) to identify potential mechanisms by which each species could harm native biodiversity, should imported specimens become established in Norwegian nature. Key mechanisms include competition, predation, pathogen transmission, and hybridization. The relevant mechanisms were analysed for each species by rating the potential magnitude of impact on biodiversity from minimal to massive. The likelihood of each impact was assessed from very unlikely to very likely. A combination of magnitude of impact and likelihood resulted in final risk levels ranging from low and medium to possibly high and high. Confidence levels for each assessment were also categorized as low, medium, or high based on expert opinion. Results The potential hazards evaluated under the EICAT framework include competition, predation, and transmission of disease for all species, grazing for four species and structural impacts on the ecosystem for three species. The conditions required for crabs imported live for human consumption to reach a natural ecosystem in Norway include a commercial demand for crabs, survival during transport and handling, and the possibility of release or escape. If these conditions for reaching a natural ecosystem are met, the species must then be capable of establishment in the new ecosystem. There are several examples of species imported live for human consumption becoming established in the wild, most likely due to intentional release. The risk assessments indicate varied levels of risk across the five hazards. Competition from E. sinensis or E. japonica was assessed to pose a high risk, while competition from C. sapidus, C. irroratus, M. victor, P. segnis, or R. harrisii was assessed to pose a medium risk. Predation by E. sinensis or E. japonica was assessed to pose a high risk and predation from R. harrisii, C. sapidus, C. irroratus, M. victor, or P. segnis was assessed to pose a medium risk. Transmission of disease from either E. sinensis or E. japonica was assessed to pose a high risk, while there was a possibly high risk of disease transmission from C. irroratus. The diseases of highest concern include the crayfish plague (Aphanomyces astaci) and gaffkaemia (Aerococcus viridans var. homari). Finally, there was a moderate risk of ......

• Kirkendall, Lawrence Richard; Kausrud, Kyrre Linné; Malmstrøm, Martin; Berg, Paul Ragnar; Bryn, Anders & Hindar, Kjetil [Show all 12 contributors for this article] (2024). Assessment of risks posed by import of live medicinal leeches to biodiversity in Norway. Scientific Opinion of the Panel on Biodiversity of the Norwegian Scientific Committee for Food and Environment. VKM Report. 2024(07), p. 1–66. Full text in Research Archive Show summary

  The Norwegian Environment Agency has asked VKM to evaluate the risks to biodiversity associated with the import of two species of leeches to Norway, Hirudo medicinalis and H. verbana (so-called medicinal leeches). In addition, they ask that the project group suggest mitigating measures that could reduce any potential risks, should import of the two species be granted. Background Bloodsucking leeches have been employed by humans for millennia. The two species Hirudo medicinalis and H. verbana have dominated the trade in medicinal leeches in Europe. Overcollection combined with loss or degradation of freshwater habitats led to a precipitous decline in European populations by the 1800s and led to a corresponding increase in imports from Turkey, North Africa, Russia and the Middle East. By the turn of the 19th century, the demand for live leeches in Europe had tapered off as contemporary medicine developed, only to have a small resurgence over the last decades as live leeches became recognized as useful for a variety of medical and cosmetic procedures, and to be the source of bioactive molecules of interest to medical researchers. As traditional medicine in Asia also uses a variety of leech products, there is a robust global market for live leeches and leech derivatives that is being met mostly by leech aquaculture, where the live leech trade seems dominated by H. verbana. There is increasing interest in commercializing production and sale of three similar leech species, H. orientalis from Central Asia, H. sulukii from a small region in Turkey, and H. troctina from North Africa. Hirudo medicinalis has been used medicinally in Norway since at least the Middle Ages when they were used by barber-surgeons for bloodletting. Leeches have been dispensed by apothecaries up until the end of the 1950s. Phylogeographic studies have treated the species as native to southern Norway and the Norwegian Biodiversity Information Centre has numerous records of H. medicinalis, with recent records primarily from the eastern coast of southern Norway. The Norwegian Red List for Species categorizes H. medicinalis as being of Least Concern in Norway. Hirudo verbana naturally occurs in southern Europe and has not been observed in Scandinavia so far (see map in Figure 2). Methods for the risk assessment VKM established a small working group with expertise in invertebrates and risk assessment. Our group combed the scientific literature and relevant websites for information on the taxonomy, natural history, ecology, and medical uses of medicinal leeches broadly and H. medicinalis and H. verbana specifically. The project group contacted major leech providers in Europe and North America to learn more about leech production and sale. Using the EICAT (Environmental Impact Classification for Alien Taxa) system developed by the IUCN, The project group identified those mechanisms (“hazards”) through which these two species could affect native biodiversity in Norway should imported specimens become established in Norwegian nature, and characterized the risk related to each of these hazards. The project group then conducted a semi-quantitative risk assessment for the species according to four categories: Low, Medium, Possibly high, and High risk. Hazards: how likely, how impactful, and overall risks In our report, VKM regard H. medicinalis as a native species, since it is so treated by Hirudo experts and is widespread in Norway. The project group regards H. verbana as non-native to Norway. The potential hazards from the EICAT system that could be associated with introducing one or both species include predation and parasitism, competition, disease transmission, and hybridization. ................................ .................................... Conclusions VKM concludes that the overall risk to biodiversity in Norway from importing live H. medicinalis and H. verbana is low.

• Järnegren, Johanna; Gulliksen, Bjørn; Husa, Vivian; Malmstrøm, Martin; Oug, Eivind & Berg, Paul Ragnar [Show all 16 contributors for this article] (2023). Assessment of risk and risk-reducing measures related to the introduction and dispersal of the invasive alien carpet tunicate Didemnum vexillum in Norway. VKM Report. 2023(7), p. 1–124. Full text in Research Archive Show summary

  Didemnum vexillum is colonial sea squirt, a marine species which originates from the northwest Pacific; it was first recorded in Norway in November 2020. Didemnum vexillum is an alien species, meaning that it is a species that has been transferred from its original region to other regions of the world through human activity, and it had not previously been recorded in Norwegian waters. The species is regarded as having great invasive potential and having strong negative ecological effects on biodiversity. It is also considered to pose a risk to marine industries such as shipping and aquaculture, with possible major negative economic impacts.

• Nielsen, Anders; Kirkendall, Lawrence Richard; Stenberg, Johan A.; Wendell, Per Hans Micael; Berg, Paul Ragnar & Bryn, Anders [Show all 13 contributors for this article] (2023). Risk assessment of the predatory mite Stratiolaelaps scimitus for biological control of varroa mites in beehives. Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment. VKM Report. 2023(6), p. 1–29. Full text in Research Archive Show summary

  Key words: apiculture, biological control, Norwegian Environment Agency, Norwegian Scientific Committee for Food and Environment, predatory mites, risk assessment, varroa Introduction The Norwegian Environment Agency (NEA) have asked the Norwegian Scientific Committee for Food and Environment for an assessment of adverse impacts on biodiversity concerning import and release of the predatory mite Stratiolaelaps scimitus as measure against varroa mites (Varroa destructor) in apiaries. The predatory mite is already in use in Norwegian greenhouses and polytunnels as a biological control agent against dark-winged fungus gnats in a various of plant cultures. The NEA has received an application for a new type of use: to combat varroa mites in apiaries. Background Varroa destructor (the varroa mite) is a species of parasitic mite that feeds externally on honeybees; it is considered one of the major threats to beekeeping world-wide due to its parasitic behaviour and because it acts as a vector for several viral and bacterial bee pathogens. Beekeepers in North America have begun experimenting with introducing Stratiolaelaps scimitus, a commercially available predaceous mite originally used for biocontrol in greenhouses and polytunnels, to control varroa mites, and several studies on the use of the mite in this context have been published recently. The Norwegian Environment Agency has asked VKM to assess the risk to biological diversity in Norway associated with this new use of S. scimitus, and to assess the effects of climate change on any risks that are proposed. Stratiolaelaps scimitus is a tiny (0.5 mm), soil-dwelling predaceous mite that in nature feeds on a wide variety of soil invertebrates, including fly larvae, nematodes, nymphs of thrips, potworms (oligochaetes), springtails, and other mites. For over three decades, Stratiolaelaps scimitus has been produced commercially and the species is now used globally for biological control. The mite is applied to control a wide variety of organisms harmful to food production or to the production of ornamental plants, but especially to combat infestations of fungus gnat larvae, spider mites, flower thrips, and certain plant-feeding nematodes. The species is already used as a biocontrol agent in Norway in greenhouses, open plastic polytunnels used for protecting crops, and in various indoor plantings and fungiculture. Methods VKM established a project group with expertise in entomology, invasion ecology, honeybee behaviour and ecology, and risk analysis of biological control agents. The group conducted systematic literature searches and scrutinized the relevant literature that was found. In the absence of Norwegian studies, VKM relied on literature from other countries. Results and conclusions This VKM assessment concludes with medium confidence that introducing S. scimitus for use in beehives would not significantly increase the probability of establishment and spread of S. scimitus above that of its current use. We point out that there is no evidence that continuous use of S. scimitus in Norway, over decades, has led to its establishment outside of enclosures, including open polytunnels. The optimal temperature for development and reproduction is far higher than what is normally observed in Norway (~28 °C). Although lethal temperature has been reported to be as low as –5.2 °C, we still conclude that S. scimitus would not be able to establish permanent populations in Norway, not even in the southern part of the country as such temperatures are expected to occur in some years throughout the country. Future climate change is not believed to alter this conclusion, since periods with lethally cold temperatures are expected to still occur in the future.

• Nilsen, Erlend Birkeland; Braastad, Bjarne Olai; Dale, Svein; Dervo, Børre Kind; Kausrud, Kyrre Linné & Kirkendall, Lawrence Richard [Show all 18 contributors for this article] (2023). Assessment of the risks posed by domestic cats (Felis catus) to biodiversity and animal welfare in Norway. Scientific Opinion of the Panel on Biodiversity of the Norwegian Scientific Committee for Food and Environment. VKM Report. 2023(23), p. 1–228. Full text in Research Archive Show summary

  VKM has evaluated to what extent keeping of cats pose a risk to biodiversity in Norway. Risks were assessed separately for threats to biodiversity from direct predation, indirect (non-lethal) effects, competition with other wildlife and spread of infectious organisms. VKM also assessed the risk of reduced animal welfare related to the keeping of domestic cats, both for the cats and their prey. In addition, VKM has assessed a range of risk-reducing measures aimed at minimizing the risk for negative impacts on biodiversity and animal welfare. Overall, VKM find that the risk of negative impact on vulnerable birds and red-listed mammalian species are high under certain conditions. VKM also find that there is a considerable risk associated with increased spread of infectious organisms from cats to wildlife and other domestic species. Some of these infectious organisms may also infect humans. With respect to mitigation measures, VKM concludes that measures focused on limiting cats’ access to prey populations are likely to yield the most positive outcomes in terms of mitigating the adverse impact on biodiversity.

• Theissinger, Kathrin; Fernandes, Carlos; Formenti, Giulio; Bista, Iliana; Berg, Paul Ragnar & Bleidorn, Christoph [Show all 55 contributors for this article] (2023). How genomics can help biodiversity conservation. Trends in Genetics. ISSN 0168-9525. 39(7), p. 545–559. doi: 10.1016/j.tig.2023.01.005. Full text in Research Archive Show summary

  The availability of public genomic resources can greatly assist biodiversity assessment, conservation, and restoration efforts by providing evidence for scientifically informed management decisions. Here we survey the main approaches and applications in biodiversity and conservation genomics, considering practical factors, such as cost, time, prerequisite skills, and current shortcomings of applications. Most approaches perform best in combination with reference genomes from the target species or closely related species. We review case studies to illustrate how reference genomes can facilitate biodiversity research and conservation across the tree of life. We conclude that the time is ripe to view reference genomes as fundamental resources and to integrate their use as a best practice in conservation genomics.

• Kirkendall, Lawrence Richard; Bryn, Anders; Flø, Daniel; Malmstrøm, Martin; Velle, Gaute & Berg, Paul Ragnar [Show all 12 contributors for this article] (2023). Assessment of the risk to Norwegian biodiversity from private import and keeping of Northern Cardinal. Scientific Opinion of the Panel on Biodiversity of the Norwegian Scientific Committee for Food and Environment. VKM Report. 2023(18), p. 1–87. Full text in Research Archive Show summary

  VKM has evaluated the risk to biodiversity from allowing private import and keeping of the Northern Cardinal as a caged bird in Norway, for birds acquired through the bird trade. VKM has reviewed the invasion ecology of non-native birds in general and of the Northern Cardinal specifically. The assessment includes evaluation of various mechanisms that invasive birds generally have a negative impact through, and includes competition, hybridization, spread of pathogens and interactions with other alien species in Norway. VKM has also evaluated two different scenarios establishment and how climate change can influence both the negative impact and the likelihood of establishment. Overall, VKM finds that there is low risk in regards negative effects on biodiversity in Norway in regard to import and keeping of the Northern Cardinal.

• Hindar, Kjetil; Bodin, Johanna Eva; Duale, Nur; Jevnaker, Anne-Marthe Ganes; Garseth, Åse Helen & Malmstrøm, Martin [Show all 15 contributors for this article] (2023). Environmental risk assessment of genetically modified sterile VIRGIN® Atlantic salmon for use in research trials in aquaculture sea-cages. VKM Report. 2023:20, p. 1–94. Full text in Research Archive Show summary

  One of the substantial environmental challenges posed by the aquaculture industry is the escape of farmed Atlantic salmon (Salmo salar), which can mate with wild Atlantic salmon and alter the genetic composition of the wild populations. One potential solution to mitigate this issue is the cultivation of sterile salmon in aquaculture. Atlantic salmon can be made sterile by pressure or temperature treatment of newly fertilized eggs to produce triploids, which are functionally sterile due to their unpaired chromosomes. However, these triploids often perform poorly on commercial fish farms and the production of triploid salmon in Norway is put on hold due to welfare issues of the fish.

• Rueness, Eli Knispel; Asmyhr, Maria Gulbrandsen; Basic, Dean; Eldegard, Katrine; Janczak, Andrew M. & Pedersen, Hans Christian [Show all 19 contributors for this article] (2022). The release of common pheasants and grey partridges for pointing dog training- consequences for biodiversity, animal welfare and health. Scientific Opinion of the Panel on biodiversity of the Norwegian Scientific Committee for Food and Environment. VKM Report. Full text in Research Archive Show summary

  Background Since the late 1800s, an unknown number of common pheasants and grey partridges from captive bred stocks have been released in Norwegian nature. The birds are released to be used for training of pointing dogs. The import, keeping and release of gamebirds, as well as the management of release sites, have been largely unregulated. The consequences to biodiversity, animal health and welfare have not been investigated. The Norwegian Environment Agency (NEA) and the Norwegian Food Safety Authority (NFSA) have jointly requested the Norwegian Scientific Committee for Food and Environment (VKM) for a scientific opinion on the release of common pheasants and grey partridges for pointing dog training regarding consequences for biodiversity, animal welfare of the released birds and health of the released birds as well as wild birds to which pathogens may be transmitted. VKM was further asked to suggest risk reducing measures for biodiversity and animal welfare. Methods VKM established a project group with expertise within avian ecology, landscape ecology, population biology, wildlife veterinary medicine and animal welfare. The group conducted systematic literature searches, scrutinized the resulting literature, and supplemented by other relevant articles and reports. In the absence of Norwegian studies, VKM used literature from other countries where common pheasants and grey partridges (and in some cases other gamebirds), are released, as references. The project group applied observation data of common pheasants and grey partridges in Norway for the period 2000-2022, presented by the Norwegian Biodiversity Information Centre (NBIC). In the assessments, VKM assumed that the release of birds will be in the same order of magnitude as in previous years (a few thousand birds annually on a national level). The number of release sites and the density of released birds per site are unknown. Increasing the number and density of birds would also increase the probability of negative effects and the severity of the consequences. VKM assessed the impacts of released common pheasants and grey partridges on competition, predation, hybridization, transmission of disease, herbivory and indirect impacts through interactions with other species (predator abundance and pathogen-mediated competition). VKM also assessed the impact on biodiversity in a 50-year perspective. Furthermore, VKM discusses how the birds’ welfare might be impacted by rearing, transport, release and exposure to pointing dogs. Finally, VKM provides a list of relevant diseases and assessed their potential impact on animal health during transport, rearing and release. Results and conclusions VKMs assessment show that there are several risks to biodiversity, animal health, and animal welfare from the release of captive bred common pheasants and grey partridges in Norway. The risk of increased competition for food, particularly in winter, with birds with similar niches as common pheasants and grey partridges, is low on a national scale and moderat on a local scale. This is particularly so for yellowhammer, Emberiza citronella, a species categorized as vulnerable on the national red list due to its progressive population decline caused by reduced availability of food during winter. There is a moderate risk for predation on invertebrates and negative impacts on flora. Indirectly, activities connected to the release of birds may lead to moderate risks of altered predator abundance and disease-mediated competition. VKM concludes that the ecological impacts will be more severe for redlisted species present within the release areas for common pheasants and grey partridges. Repeated release of common pheasants and grey partridges can lead to high risk of disease transmission to wild birds. .............

• Nilsson, Pernille; Ravinet, Mark; Cui, Yujun; Berg, Paul Ragnar; Zhang, Yujiang & Guo, Rong [Show all 17 contributors for this article] (2022). Polygenic plague resistance in the great gerbil uncovered by population sequencing. PNAS Nexus. 1(5). doi: 10.1093/pnasnexus/pgac211. Full text in Research Archive
• Pampoulie, Christophe; Berg, Paul Ragnar & Jentoft, Sissel (2022). Hidden but revealed: After years of genetic studies behavioural monitoring combined with genomics uncover new insight into the population dynamics of Atlantic cod in Icelandic waters. Evolutionary Applications. 16(2), p. 223–233. doi: 10.1111/eva.13471. Full text in Research Archive Show summary

  Stock structure is of paramount importance for sustainable management of exploited resources. In that context, genetic markers have been used for more than two decades to resolve spatial structure of marine exploited resources and to fully fathom stock dynamics and interactions. While genetic markers such as allozymes and RFLP dominated the debate in the early era of genetics, technology advances have provided scientists with new tools every decade to better assess stock discrimination and interactions (i.e. gene flow). Here, we provide a review of genetic studies performed to understand stock structure of Atlantic cod in Icelandic waters, from the early allozyme approaches to the genomic work currently carried out. We further highlight the importance of the generation of a chromosome-anchored genome assembly together with whole-genome population data, which drastically changed our perception of the possible management units to consider. After nearly 60 years of genetic investigation of Atlantic cod structure in Icelandic waters, genetic (and later genomic) data combined with behavioural monitoring using Data Storage Tags shifted the attention from geographical population structures to behavioural ecotypes. This review also demonstrates the need for future research to further disentangle the impact of these ecotypes (and gene flow among them) on the population structure of Atlantic cod in Icelandic waters. It also highlights the importance of whole-genome data to unravel unexpected within-species diversity related to chromosomal inversions and associated supergenes, which are important to consider for future development of sustainable management programmes of the species within the North Atlantic.

• Ytrehus, Bjørnar; Bustnes, Jan Ove; Bårdsen, Bård-Jørgen; Eldegard, Katrine; Kausrud, Kyrre & Sandercock, Brett [Show all 17 contributors for this article] (2022). Assessment of risks to wildlife and animal welfare associated with Lodden, Sami traditional hunting of ducks in spring. Scientific Opinion of the Panel on Biodiversity of the Norwegian Scientific Committee for Food and Environment. VKM Report. Full text in Research Archive Show summary

  Background Spring hunting for ducks (Lodden in Northern Sami) is part of the Sami hunting and trapping culture. In Norway, this traditional hunting has been permitted in Kautokeino Municipality in accordance with the exception provision in the Wildlife Act Section 15, with quotas for males of several duck species. However, hunting in the spring may be in conflict with the Nature Diversity Act's principle for species management, saying (quote from Section 15): “Unnecessary harm and suffering caused to animals occurring in the wild and their nests, lairs and burrows shall be avoided. Likewise, unnecessary pursuing of wildlife shall be avoided.” Furthermore, in accordance with international legislation and agreements, the Wildlife Act (Section 9) states that the hunting season should not be set to the nesting and breeding season for the species in question. The Norwegian Environment Agency (NEA) asked VKM to (1) assess risk and risk-reducing measures on biodiversity and animal welfare when conducting spring hunting of ducks. The terms of reference were additionally clarified by the NEA to include assessments of the risks associated with hunting quotas of up to 150, 300, and 500 male individuals, on the populations of mallard (Anas platyrhynchos), tufted duck (Aythya fuligula), velvet scoter (Melanitta fusca), common scoter (Melanitta nigra), long-tailed duck (Clangula hyemalis), and red-breasted merganser (Mergus serrator). VKM was furthermore asked to (2) point out risk-reducing measures in scenarios with hunting bags corresponding to the mentioned quotas of all the six species. Method VKM appointed a project group to answer the request from NEA and assess the risks to biodiversity and animal welfare posed by spring hunting for adult male ducks. The project group narrowed down the scope of the biodiversity risk assessment to encompass risks for local populations of six target species: mallard, tufted duck, velvet scoter, common scoter, long-tailed duck, and red-breasted merganser, and non-target migratory waterbirds. Negative impacts on biodiversity was defined as negative effects on population viability. The VKM project group gathered data from publications retrieved from literature searches and reports from Kautokeino municipality to the Finnmark Estate (Finnmarkseiendommen), which were made available to the group by the Norwegian Environment Agency. Hunting statistics were acquired from Statistics Norway (Statistisk sentralbyrå; SSB). During the assessment, several critical knowledge gaps and uncertainties were identified. The main obstacle for assessment of the impact of spring hunting on viability of local populations in Kautokeino, is the lack of data on relevant population sizes and demographic rates for the six target species. The available population estimates are partly based on almost 30-year-old bird counts. In addition, knowledge about spatial and temporal distributions of each species, combined with local or remote-sensed data on ice breakup, is needed to estimate the proportion of the population being effectively hunted in early spring when ducks are congregating on available ice-free waters. Such knowledge, combined with information about where, when, how and by how many hunters the hunting is performed, is also critical for sound assessments of risk to biodiversity and harm to bird welfare. Improved data on hunting bags (reliable, spatially explicit, and detailed) and frequency of wounding and crippling is also needed to provide accurate assessments. The project group performed modelling of harvest scenarios for a range of conditions (e.g., number of birds harvested, reduced breeding success caused by indirect effects of disturbance, environmental stochasticity, and spatial variation in habitat) to assess how sensitive the populations are to different parameters and model assumptions. ..............................

• Formenti, Giulio; Theissinger, Kathrin; Fernandes, Carlos; Bista, Iliana; Bombarely, Aureliano & Bleidorn, Christoph [Show all 59 contributors for this article] (2022). The era of reference genomes in conservation genomics. Trends in Ecology & Evolution. ISSN 0169-5347. 37(3), p. 197–202. doi: 10.1016/j.tree.2021.11.008. Full text in Research Archive Show summary

  Progress in genome sequencing now enables the large-scale generation of reference genomes. Various international initiatives aim to generate reference genomes representing global biodiversity. These genomes provide unique insights into genomic diversity and architecture, thereby enabling comprehensive analyses of population and functional genomics, and are expected to revolutionize conservation genomics.

• Berg, Paul R.; Jorde, Per E.; Glover, Kevin A.; Dahle, Geir; Taggart, John B. & Korsbrekke, Knut [Show all 12 contributors for this article] (2021). Genetic structuring in Atlantic haddock contrasts with current management regimes. ICES Journal of Marine Science. ISSN 1054-3139. 78(1), p. 1–13. doi: 10.1093/icesjms/fsaa204. Full text in Research Archive Show summary

  The advent of novel genetic methods has made it possible to investigate population structure and connectivity in mobile marine fish species: knowledge of which is essential to ensure a sustainable fishery. Haddock (Melanogrammus aeglefinus) is a highly exploited marine teleost distributed along the coast and continental shelf on both sides of the North Atlantic Ocean. However, little is known about its population structure. Here, we present the first study using single-nucleotide polymorphism (SNP) markers to assess the genetic population structure of haddock at multiple geographic scales, from the trans-Atlantic to the local (fjord) level. Genotyping 138 SNP loci in 1329 individuals from 19 locations across the North Atlantic revealed three main genetic clusters, consisting of a Northwest Atlantic cluster, a Northeast Arctic cluster, and a Northeast Atlantic cluster. We also observed a genetically distinct fjord population and a pattern of isolation by distance in the Northeast Atlantic. Our results contrast with the current management regime for this species in the Northeast Atlantic, as we found structure within some management areas. The study adds to the growing recognition of population structuring in marine organisms in general, and fishes in particular, and is of clear relevance for the management of haddock in the Northeast Atlantic.

• Deininger, Anne; Martin, Angela Helen; Pardo, Juan; Berg, Paul Ragnar; Bhardwaj, Jyotirmoy & Catarino, Diana Sofia de Oliveira [Show all 15 contributors for this article] (2021). Coastal Research Seen Through an Early Career Lens—A Perspective on Barriers to Interdisciplinarity in Norway. Frontiers in Marine Science. 8. doi: 10.3389/fmars.2021.634999. Full text in Research Archive Show summary

  The value of interdisciplinarity for solving complex coastal problems is widely recognized. Many early career researchers (ECRs) therefore actively seek this type of collaboration through choice or necessity, for professional development or project funding. However, establishing and conducting interdisciplinary research collaborations as an ECR has many challenges. Here, we identify these challenges through the lens of ECRs working in different disciplines on a common ecosystem, the Norwegian Skagerrak coast. The most densely populated coastline in Norway, the Skagerrak coast, is experiencing a multitude of anthropogenic stressors including fishing, aquaculture, eutrophication, climate change, land runoff, development, and invasive species. The Skagerrak coastline has also been the focus of environmental science research for decades, much of which aims to inform management of these stressors. The region provides a fantastic opportunity for interdisciplinary collaboration, both within and beyond the environmental sciences. This perspective article identifies the barriers ECRs in Norway face in establishing interdisciplinary and collaborative research to inform management of coastal ecosystems, along with their root causes. We believe our discussion will be of broad interest to all research institutions who employ or educate ECRs (in Norway and worldwide), and to those who develop funding mechanisms for ECRs and interdisciplinary research.

• Langangen, Øystein; Färber, Leonie Anette; Stige, Leif Christian; Diekert, Florian Klaus; Barth, Julia Maria Isis & Matschiner, Michael [Show all 11 contributors for this article] (2018). Ticket to spawn: Combining economic and genetic data to evaluate the effect of climate and demographic structure on spawning distribution in Atlantic cod. Global Change Biology. ISSN 1354-1013. 25(1), p. 134–143. doi: 10.1111/gcb.14474. Full text in Research Archive Show summary

  Climate warming and harvesting affect the dynamics of species across the globe through a multitude of mechanisms, including distribution changes. In fish, migrations to and distribution on spawning grounds are likely influenced by both climate warming and harvesting. The Northeast Arctic (NEA) cod (Gadus morhua) performs seasonal migrations from its feeding grounds in the Barents Sea to spawning grounds along the Norwegian coast. The distribution of cod between the spawning grounds has historically changed at decadal scales, mainly due to variable use of the northern and southern margins of the spawning area. Based on historical landing records, two major hypotheses have been put forward to explain these changes: climate and harvesting. Climate could affect the distribution through, for example, spatial habitat shifts. Harvesting could affect the distribution through impacting the demographic structure. If demographic structure is important, theory predicts increasing spawner size with migration distance. Here, we evaluate these hypotheses with modern data from a period (2000–2016) of increasing temperature and recovering stock structure. We first analyze economic data from the Norwegian fisheries to investigate geographical differences in size of spawning fish among spawning grounds, as well as interannual differences in mean latitude of spawning in relation to changes in temperature and demographic parameters. Second, we analyze genetically determined fish sampled at the spawning grounds to unambiguously separate between migratory NEA cod and potentially smaller sized coastal cod of local origin. Our results indicate smaller spawners farther away from the feeding grounds, hence not supporting the hypothesis that harvesting is a main driver for the contemporary spawning ground distribution. We find a positive correlation between annual mean spawning latitude and temperature. In conclusion, based on contemporary data, there is more support for climate compared to harvesting in shaping spawning ground distribution in this major fish stock in the North Atlantic Ocean.

• Barth, Julia Maria Isis; Berg, Paul Ragnar; Jonsson, Per R; Bonanomi, Sara; Corell, Hanna & Hemmer-Hansen, Jakob [Show all 16 contributors for this article] (2017). Genome architecture enables local adaptation of Atlantic cod despite high connectivity. Molecular Ecology. ISSN 0962-1083. 26(17), p. 4452–4466. doi: 10.1111/mec.14207. Full text in Research Archive Show summary

  Adaptation to local conditions is a fundamental process in evolution; however, mechanisms maintaining local adaptation despite high gene flow are still poorly understood. Marine ecosystems provide a wide array of diverse habitats that frequently promote ecological adaptation even in species characterized by strong levels of gene flow. As one example, populations of the marine fish Atlantic cod (Gadus morhua) are highly connected due to immense dispersal capabilities but nevertheless show local adaptation in several key traits. By combining population genomic analyses based on 12K single nucleotide polymorphisms with larval dispersal patterns inferred using a biophysical ocean model, we show that Atlantic cod individuals residing in sheltered estuarine habitats of Scandinavian fjords mainly belong to offshore oceanic populations with considerable connectivity between these diverse ecosystems. Nevertheless, we also find evidence for discrete fjord populations that are genetically differentiated from offshore populations, indicative of local adaptation, the degree of which appears to be influenced by connectivity. Analyses of the genomic architecture reveal a significant overrepresentation of a large ~5 Mb chromosomal rearrangement in fjord cod, previously proposed to comprise genes critical for the survival at low salinities. This suggests that despite considerable connectivity with offshore populations, local adaptation to fjord environments may be enabled by suppression of recombination in the rearranged region. Our study provides new insights into the potential of local adaptation in high gene flow species within fine geographical scales and highlights the importance of genome architecture in analyses of ecological adaptation.

• Berg, Paul Ragnar; Star, Bastiaan; Pampoulie, Christophe; Bradbury, Ian R.; Bentzen, Paul & Hutchings, Jeffrey [Show all 8 contributors for this article] (2017). Trans-oceanic genomic divergence of Atlantic cod ecotypes is associated with large inversions. Heredity. ISSN 0018-067X. 119, p. 418–428. doi: 10.1038/hdy.2017.54. Full text in Research Archive Show summary

  Chromosomal rearrangements such as inversions can play a crucial role in maintaining polymorphism underlying complex traits and contribute to the process of speciation. In Atlantic cod (Gadus morhua), inversions of several megabases have been identified that dominate genomic differentiation between migratory and nonmigratory ecotypes in the Northeast Atlantic. Here, we show that the same genomic regions display elevated divergence and contribute to ecotype divergence in the Northwest Atlantic as well. The occurrence of these inversions on both sides of the Atlantic Ocean reveals a common evolutionary origin, predating the >100 000-year-old trans-Atlantic separation of Atlantic cod. The long-term persistence of these inversions indicates that they are maintained by selection, possibly facilitated by coevolution of genes underlying complex traits. Our data suggest that migratory behaviour is derived from more stationary, ancestral ecotypes. Overall, we identify several large genomic regions—each containing hundreds of genes—likely involved in the maintenance of genomic divergence in Atlantic cod on both sides of the Atlantic Ocean.

• Sodeland, Marte; Jorde, Per Erik; Lien, Sigbjørn; Jentoft, Sissel; Berg, Paul Ragnar & Grove, Harald [Show all 10 contributors for this article] (2016). "Islands of divergence" in the Atlantic cod genome represent polymorphic chromosomal rearrangements. Genome Biology and Evolution (GBE). 8(4), p. 1012–1022. doi: 10.1093/gbe/evw057. Full text in Research Archive Show summary

  In several species genetic differentiation across environmental gradients or between geographically separate populations has been reported to center at “genomic islands of divergence,” resulting in heterogeneous differentiation patterns across genomes. Here, genomic regions of elevated divergence were observed on three chromosomes of the highly mobile fish Atlantic cod (Gadus morhua) within geographically fine-scaled coastal areas. The “genomic islands” extended at least 5, 9.5, and 13 megabases on linkage groups 2, 7, and 12, respectively, and coincided with large blocks of linkage disequilibrium. For each of these three chromosomes, pairs of segregating, highly divergent alleles were identified, with little or no gene exchange between them. These patterns of recombination and divergence mirror genomic signatures previously described for large polymorphic inversions, which have been shown to repress recombination across extensive chromosomal segments. The lack of genetic exchange permits divergence between noninverted and inverted chromosomes in spite of gene flow. For the rearrangements on linkage groups 2 and 12, allelic frequency shifts between coastal and oceanic environments suggest a role in ecological adaptation, in agreement with recently reported associations between molecular variation within these genomic regions and temperature, oxygen, and salinity levels. Elevated genetic differentiation in these genomic regions has previously been described on both sides of the Atlantic Ocean, and we therefore suggest that these polymorphisms are involved in adaptive divergence across the species distributional range.

• Berg, Paul Ragnar; Star, Bastiaan; Pampoulie, Christophe; Sodeland, Marte; Barth, Julia Maria Isis & Knutsen, Halvor [Show all 8 contributors for this article] (2016). Three chromosomal rearrangements promote genomic divergence between migratory and stationary ecotypes of Atlantic cod. Scientific Reports. 6, p. 1–12. doi: 10.1038/srep23246. Full text in Research Archive Show summary

  Identification of genome-wide patterns of divergence provides insight on how genomes are influenced by selection and can reveal the potential for local adaptation in spatially structured populations. In Atlantic cod – historically a major marine resource – Northeast-Arctic- and Norwegian coastal cod are recognized by fundamental differences in migratory and non-migratory behavior, respectively. However, the genomic architecture underlying such behavioral ecotypes is unclear. Here, we have analyzed more than 8.000 polymorphic SNPs distributed throughout all 23 linkage groups and show that loci putatively under selection are localized within three distinct genomic regions, each of several megabases long, covering approximately 4% of the Atlantic cod genome. These regions likely represent genomic inversions. The frequency of these distinct regions differ markedly between the ecotypes, spawning in the vicinity of each other, which contrasts with the low level of divergence in the rest of the genome. The observed patterns strongly suggest that these chromosomal rearrangements are instrumental in local adaptation and separation of Atlantic cod populations, leaving footprints of large genomic regions under selection. Our findings demonstrate the power of using genomic information in further understanding the population dynamics and defining management units in one of the world’s most economically important marine resources.

• Pampoulie, Christophe; Skírnisdóttir, Sigurlaug; Star, Bastiaan; Jentoft, Sissel; Jonsdottir, Ingibjörg G. & Hjorleifsson, Einar [Show all 13 contributors for this article] (2015). Rhodopsin Gene Polymorphism Associated with Divergent Light Environments in Atlantic Cod. Behavior Genetics. ISSN 0001-8244. 45(2), p. 236–244. doi: 10.1007/s10519-014-9701-7. Full text in Research Archive
• Berg, Paul Ragnar; Jentoft, Sissel; Star, Bastiaan; Ring, Kristoffer Hofaker; Knutsen, Halvor & Lien, Sigbjørn [Show all 8 contributors for this article] (2015). Adaptation to low salinity promotes genomic divergence in Atlantic Cod (Gadus morhua L.). Genome Biology and Evolution (GBE). 7(6), p. 1644–1663. doi: 10.1093/gbe/evv093. Full text in Research Archive Show summary

  How genomic selection enables species to adapt to divergent environments is a fundamental question in ecology and evolution. We investigated the genomic signatures of local adaptation in Atlantic cod (Gadus morhua L.) along a natural salinity gradient, ranging from 35‰ in the North Sea to 7‰ within the Baltic Sea. By utilizing a 12 K SNPchip, we simultaneously assessed neutral and adaptive genetic divergence across the Atlantic cod genome. Combining outlier analyses with a landscape genomic approach, we identified a set of directionally selected loci that are strongly correlated with habitat differences in salinity, oxygen, and temperature. Our results show that discrete regions within the Atlantic cod genome are subject to directional selection and associated with adaptation to the local environmental conditions in the Baltic- and the North Sea, indicating divergence hitchhiking and the presence of genomic islands of divergence. We report a suite of outlier single nucleotide polymorphisms within or closely located to genes associated with osmoregulation, as well as genes known to play important roles in the hydration and development of oocytes. These genes are likely to have key functions within a general osmoregulatory framework and are important for the survival of eggs and larvae, contributing to the buildup of reproductive isolation between the low-salinity adapted Baltic cod and the adjacent cod populations. Hence, our data suggest that adaptive responses to the environmental conditions in the Baltic Sea may contribute to a strong and effective reproductive barrier, and that Baltic cod can be viewed as an example of ongoing speciation.

• Bradbury, Ian R.; Bowman, Sharen; Borza, Tudor; Snelgrove, Paul V. R.; Hutchings, Jeffrey A. & Berg, Paul Ragnar [Show all 11 contributors for this article] (2014). Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in Atlantic cod. PLOS ONE. 9(9). doi: 10.1371/journal.pone.0106380. Full text in Research Archive Show summary

  Hybrid zones provide unprecedented opportunity for the study of the evolution of reproductive isolation, and the extent of hybridization across individuals and genomes can illuminate the degree of isolation. We examine patterns of interchromosomal linkage disequilibrium (ILD) and the presence of hybridization in Atlantic cod, Gadus morhua, in previously identified hybrid zones in the North Atlantic. Here, previously identified clinal loci were mapped to the cod genome with most (∼70%) occurring in or associated with (<5 kb) coding regions representing a diverse array of possible functions and pathways. Despite the observation that clinal loci were distributed across three linkage groups, elevated ILD was observed among all groups of clinal loci and strongest in comparisons involving a region of low recombination along linkage group 7. Evidence of ILD supports a hypothesis of divergence hitchhiking transitioning to genome hitchhiking consistent with reproductive isolation. This hypothesis is supported by Bayesian characterization of hybrid classes present and we find evidence of common F1 hybrids in several regions consistent with frequent interbreeding, yet little evidence of F2 or backcrossed individuals. This work suggests that significant barriers to hybridization and introgression exist among these co-occurring groups of cod either through strong selection against hybrid individuals, or genetic incompatibility and intrinsic barriers to hybridization. In either case, the presence of strong clinal trends, and little gene flow despite extensive hybridization supports a hypothesis of reproductive isolation and cryptic speciation in Atlantic cod. Further work is required to test the degree and nature of reproductive isolation in this species.

• Westengen, Ola Tveitereid; Ring, Kristoffer Hofaker; Berg, Paul Ragnar & Brysting, Anne Krag (2014). Modern maize varieties going local in the semi-arid zone in Tanzania. BMC Evolutionary Biology. 14(1), p. 1–12. doi: 10.1186/1471-2148-14-1. Full text in Research Archive Show summary

  Background: Maize is the most produced crop in Sub-Saharan Africa, but yields are low and climate change is projected to further constrain smallholder production. The current efforts to breed and disseminate new high yielding and climate ready maize varieties are implemented through the formal seed system; the chain of public and private sector activities and institutions that produce and release certified seeds. These efforts are taking place in contexts currently dominated by informal seed systems; local and informal seed management and exchange channels with a long history of adapting crops to local conditions. We here present a case study of the genetic effects of both formal and informal seed management from the semi-arid zone in Tanzania. Results: Two open pollinated varieties (OPVs), Staha and TMV1, first released by the formal seed system in the 1980s are cultivated on two-thirds of the maize fields among the surveyed households. Farmer-recycling of improved varieties and seed selection are common on-farm seed management practices. Drought tolerance and high yield are the most important characteristics reported as reason for cultivating the current varieties as well as the most important criteria for farmers’ seed selection. Bayesian cluster analysis, PCA and FST analyses based on 131 SNPs clearly distinguish between the two OPVs, and despite considerable heterogeneity between and within seed lots, there is insignificant differentiation between breeder’s seeds and commercial seeds in both OPVs. Genetic separation increases as the formal system varieties enter the informal system and both hybridization with unrelated varieties and directional selection probably play a role in the differentiation. Using a Bayesian association approach we identify three loci putatively under selection in the informal seed system. Conclusions: SOur results suggest that the formal seed system in the study area distributes seed lots that are true to type. We suggest that hybridization and directional selection differentiate farmer recycled seed lots from the original varieties and potentially lead to beneficial creolization. Access to drought tolerant OPVs in combination with farmer seed selection is likely to enhance seed system security and farmers’ adaptive capacity in the face of climate change.

• Andersen, Øivind; Rosa, Maria; Yadav, Prakash; Pirolli, Davide; Fernandes, Jorge & Berg, Paul Ragnar [Show all 8 contributors for this article] (2014). The conserved Phe GH5 of importance for hemoglobin intersubunit contact is mutated in gadoid fish. BMC Evolutionary Biology. 14. doi: 10.1186/1471-2148-14-54. Full text in Research Archive Show summary

  Background Functionality of the tetrameric hemoglobin molecule seems to be determined by a few amino acids located in key positions. Oxygen binding encompasses structural changes at the interfaces between the α1β2 and α2β1 dimers, but also subunit interactions are important for the oxygen binding affinity and stability. The latter packing contacts include the conserved Arg B12 interacting with Phe GH5, which is replaced by Leu and Tyr in the αA and αD chains, respectively, of birds and reptiles. Results Searching all known hemoglobins from a variety of gnathostome species (jawed vertebrates) revealed the almost invariant Arg B12 coded by the AGG triplet positioned at an exon-intron boundary. Rare substitutions of Arg B12 in the gnathostome β globins were found in pig, tree shrew and scaled reptiles. Phe GH5 is also highly conserved in the β globins, except for the Leu replacement in the β1 globin of five marine gadoid species, gilthead seabream and the Comoran coelacanth, while Cys and Ile were found in burbot and yellow croaker, respectively. Atlantic cod β1 globin showed a Leu/Met polymorphism at position GH5 dominated by the Met variant in northwest-Atlantic populations that was rarely found in northeast-Atlantic cod. Site-specific analyses identified six consensus codons under positive selection, including 122β(GH5), indicating that the amino acid changes identified at this position may offer an adaptive advantage. In fact, computational mutation analysis showed that the replacement of Phe GH5 with Leu or Cys decreased the number of van der Waals contacts essentially in the deoxy form that probably causes a slight increase in the oxygen binding affinity. Conclusions The almost invariant Arg B12 and the AGG codon seem to be important for the packing contacts and pre-mRNA processing, respectively, but the rare mutations identified might be beneficial. The Leu122β1(GH5)Met and Met55β1(D6)Val polymorphisms in Atlantic cod hemoglobin modify the intradimer contacts B12-GH5 and H2-D6, while amino acid replacements at these positions in avian hemoglobin seem to be evolutionary adaptive in air-breathing vertebrates. The results support the theory that adaptive changes in hemoglobin functions are caused by a few substitutions at key positions.

• Brazauskas, Gintaras; Xing, Yongzhong; Studer, Bruno; Schejbel, Britt; Frei, Ursula & Berg, Paul Ragnar [Show all 7 contributors for this article] (2013). Identification of genomic loci associated with crown rust resistance in perennial ryegrass (Lolium perenne L.)divergently selected populations. Plant Science. ISSN 0168-9452. 208, p. 34–41. doi: 10.1016/j.plantsci.2013.02.017. Full text in Research Archive
• Culling, Mark; Freamo, Heather; Patterson, Kristen; Berg, Paul Ragnar; Lien, Sigbjørn & Boulding, Elizabeth G. (2013). Signatures of Selection on Growth, Shape, Parr Marks, and SNPs Among Seven Canadian Atlantic Salmon (Salmo Salar) Populations. Open Evolution Journal. 7. doi: 10.2174/1874404401307010001. Full text in Research Archive
• Pedersen, Stephanie; Berg, Paul Ragnar; Culling, Mark; Danzmann, Roy G.; Glebe, Brian & Leadbeater, Steven [Show all 10 contributors for this article] (2013). Quantitative trait loci for precocious parr maturation, early smoltification, and adult maturation in double-backcrossed trans-Atlantic salmon (Salmo salar). Aquaculture. ISSN 0044-8486. 410-411, p. 164–171. doi: 10.1016/j.aquaculture.2013.06.039. Full text in Research Archive
• Kerty, Emilia; Heuser, Kjell; Indahl, Ulf Geir; Berg, Paul Ragnar; Nakken, Sigve & Lien, Sigbjørn [Show all 9 contributors for this article] (2013). Is the brain water channel aquaporin-4 a pathogenetic factor in idiopathic intracranial hypertension? Results from a combined clinical and genetic study in a Norwegian cohort. Acta Ophthalmologica. ISSN 1755-375X. 91(1), p. 88–91. doi: 10.1111/j.1755-3768.2011.02231.x. Full text in Research Archive
• Westengen, Ola Tveitereid; Berg, Paul Ragnar; Kent, Matthew Peter & Brysting, Anne Krag (2012). Spatial Structure and Climatic Adaptation in African Maize Revealed by Surveying SNP Diversity in Relation to Global Breeding and Landrace Panels. PLOS ONE. 7(10). doi: 10.1371/journal.pone.0047832. Full text in Research Archive Show summary

  Background: Climate change threatens maize productivity in sub-Saharan Africa. To ensure food security, access to locally adapted genetic resources and varieties is an important adaptation measure. Most of the maize grown in Africa is a genetic mix of varieties introduced at different historic times following the birth of the trans-Atlantic economy, and knowledge about geographic structure and local adaptations is limited. Methodology: A panel of 48 accessions of maize representing various introduction routes and sources of historic and recent germplasm introductions in Africa was genotyped with the MaizeSNP50 array. Spatial genetic structure and genetic relationships in the African panel were analysed separately and in the context of a panel of 265 inbred lines representing global breeding material (based on 26,900 SNPs) and a panel of 1127 landraces from the Americas (270 SNPs). Environmental association analysis was used to detect SNPs associated with three climatic variables based on the full 43,963 SNP dataset. Conclusions: The genetic structure is consistent between subsets of the data and the markers are well suited for resolving relationships and admixture among the accessions. The African accessions are structured in three clusters reflecting historical and current patterns of gene flow from the New World and within Africa. The Sahelian cluster reflects original introductions of Meso-American landraces via Europe and a modern introduction of temperate breeding material. The Western cluster reflects introduction of Coastal Brazilian landraces, as well as a Northeast-West spread of maize through Arabic trade routes across the continent. The Eastern cluster most strongly reflects gene flow from modern introduced tropical varieties. Controlling for population history in a linear model, we identify 79 SNPs associated with maximum temperature during the growing season. The associations located in genes of known importance for abiotic stress tolerance are interesting candidates for local adaptations.

• Egeland, Thore; Fonneløp, Ane Elida; Berg, Paul Ragnar; Kent, Matthew Peter & Lien, Sigbjørn (2012). Complex mixtures: A critical examination of a paper by Homer et al. Forensic Science International. ISSN 0379-0738. 6(1), p. 64–69. doi: 10.1016/j.fsigen.2011.02.003. Full text in Research Archive
• Vasemägi, Anti; Nilsson, Jan; McGinnity, Philip; Cross, Tom; O'Reilly, Patrick & Glebe, Brian [Show all 9 contributors for this article] (2012). Screen for Footprints of Selection during Domestication/Captive Breeding of Atlantic Salmon. Comparative and Functional Genomics. ISSN 1531-6912. 2012. doi: 10.1155/2012/628204. Full text in Research Archive
• Lehtonen, PK; Laaksonen, T; Artemyev, AV; Belskii, E; Berg, Paul Ragnar & Both, C [Show all 20 contributors for this article] (2012). Candidate genes for colour and vision exhibit signals of selection across the pied flycatcher (Ficedula hypoleuca) breeding range. Heredity. ISSN 0018-067X. 108(4), p. 431–440. doi: 10.1038/hdy.2011.93. Full text in Research Archive
• Freamo, Heather; O'Reilly, Patrick; Berg, Paul Ragnar; Lien, Sigbjørn & Boulding, Elizabeth G. (2011). Outlier SNPs show more genetic structure between two Bay of Fundy metapopulations of Atlantic salmon than do neutral SNPs. Molecular Ecology Resources. ISSN 1755-098X. 11, p. 254–267. doi: 10.1111/j.1755-0998.2010.02952.x. Full text in Research Archive
• Bourret, Vincent; O'Reilly, Patrick T.; Carr, Jonathan W.; Berg, Paul Ragnar & Bernatchez, Louis (2011). Temporal change in genetic integrity suggests loss of local adaptation in a wild Atlantic salmon (Salmo salar) population following introgression by farmed escapees. Heredity. ISSN 0018-067X. 106(3), p. 500–510. doi: 10.1038/hdy.2010.165. Full text in Research Archive
• Star, Bastiaan; Nederbragt, Alexander Johan; Jentoft, Sissel; Grimholt, Unni; Malmstrøm, Martin & Gregers, Tone Fredsvik [Show all 42 contributors for this article] (2011). The genome sequence of Atlantic cod reveals a unique immune system. Nature. ISSN 0028-0836. 477(7363), p. 207–210. doi: 10.1038/nature10342. Full text in Research Archive Show summary

  Atlantic cod (Gadus morhua) is a large, cold-adapted teleost that sustains long-standing commercial fisheries and incipient aquaculture. Here we present the genome sequence of Atlantic cod, showing evidence for complex thermal adaptations in its haemoglobin gene cluster and an unusual immune architecture compared to other sequenced vertebrates. The genome assembly was obtained exclusively by 454 sequencing of shotgun and paired-end libraries, and automated annotation identified 22,154 genes. The major histocompatibility complex (MHC) II is a conserved feature of the adaptive immune system of jawed vertebrates, but we show that Atlantic cod has lost the genes for MHC II, CD4 and invariant chain (Ii) that are essential for the function of this pathway. Nevertheless, Atlantic cod is not exceptionally susceptible to disease under natural conditions5. We find a highly expanded number of MHC I genes and a unique composition of its Toll-like receptor (TLR) families. This indicates how the Atlantic cod immune system has evolved compensatory mechanisms in both adaptive and innate immunity in the absence of MHC II. These observations affect fundamental assumptions about the evolution of the adaptive immune system and its components in vertebrates.

• Lien, Sigbjørn; Gidskehaug, Lars Halvor; Moen, Thomas; Hayes, Ben J.; Berg, Paul Ragnar & Davidson, William S [Show all 8 contributors for this article] (2011). A dense SNP-based linkage map for Atlantic salmon (Salmo salar) reveals extended chromosome homeologies and striking differences in sex-specific recombination patterns. BMC Genomics. 12. doi: 10.1186/1471-2164-12-615. Full text in Research Archive
• Heuser, Kjell; Nagelhus, Erlend Arnulf; Taubøll, Erik; Indahl, Ulf Geir; Berg, Paul Ragnar & Lien, Sigbjørn [Show all 9 contributors for this article] (2010). Variants of the genes encoding AQP4 and Kir4.1 are associated with subgroups of patients with temporal lobe epilepsy. Epilepsy Research. ISSN 0920-1211. 88(1), p. 55–64. doi: 10.1016/j.eplepsyres.2009.09.023. Full text in Research Archive
• Sandve, Simen Rød; Rudi, Heidi; Dørum, Guro; Vigeland, Magnus Dehli; Berg, Paul Ragnar & Rognli, Odd Arne (2010). Genotyping Unknown Genomic Terrain in Complex Plant Genomes. In Huyghe, Christian (Eds.), Sustainable use of Genetic Diversity in Forage and Turf Breeding. Springer Science+Business Media B.V.. ISSN 9789048187058. p. 455–459. Full text in Research Archive
• Heuser, Kjell; Hoddevik, Eystein Hellstrøm; Taubøll, Erik; Gjerstad, Leif; Indahl, Ulf Geir & Kaczmarek, L [Show all 10 contributors for this article] (2010). Temporal Lobe Epilepsy and Matrix Metalloproteinase 9: A tempting relation but negative genetic association. Seizure. ISSN 1059-1311. 19(6), p. 335–338. doi: 10.1016/j.seizure.2010.05.003. Full text in Research Archive
• Solaas, Karianne; Legry, Vanessa; Retterstøl, Kjetil; Berg, Paul Ragnar; Holven, Kirsten Bjørklund & Ferrieres, Jean [Show all 21 contributors for this article] (2010). Suggestive evidence of associations between liver X receptor beta polymorphisms with type 2 diabetes mellitus and obesity in three cohort studies: HUNT2 (Norway), MONICA (France) and HELENA (Europe). BMC Medical Genetics. 11(144). doi: 10.1186/1471-2350-11-144. Full text in Research Archive Show summary

  Background The liver X receptors (LXR) α and β regulate lipid and carbohydrate homeostasis and inflammation. Lxrβ -/- mice are glucose intolerant and at the same time lean. We aimed to assess the associations between single nucleotide polymorphisms (SNPs) in LXRβ and risk of type 2 diabetes mellitus (T2DM), obesity and related traits in 3 separate cohort studies. Methods Twenty LXRβ SNPs were identified by sequencing and genotyped in the HUNT2 adult nested case-control study for T2DM (n = 835 cases/1986 controls). Five tag-SNPs (rs17373080, rs2695121, rs56151148, rs2303044 and rs3219281), covering 99.3% of the entire common genetic variability of the LXRβ gene were identified and genotyped in the French MONICA adult study (n = 2318) and the European adolescent HELENA cross-sectional study (n = 1144). In silico and in vitro functionality studies were performed. Results We identified suggestive or significant associations between rs17373080 and the risk of (i) T2DM in HUNT2 (OR = 0.82, p = 0.03), (ii) obesity in MONICA (OR = 1.26, p = 0.05) and (iii) overweight/obesity in HELENA (OR = 1.59, p = 0.002). An intron 4 SNP (rs28514894, a perfect proxy for rs17373080) could potentially create binding sites for hepatic nuclear factor 4 alpha (HNF4α) and nuclear factor 1 (NF1). The C allele of rs28514894 was associated with ~1.25-fold higher human LXRβ basal promoter activity in vitro. However, no differences between alleles in terms of DNA binding and reporter gene transactivation by HNF4α or NF1 were observed. Conclusions Our results suggest that rs17373080 in LXRβ is associated with T2DM and obesity, maybe via altered LXRβ expression.

• Sandve, Simen Rød; Rudi, Heidi; Dørum, Guro; Berg, Paul Ragnar & Rognli, Odd Arne (2010). High-throughput genotyping of unknown genomic terrain in complex plant genomes: lessons from a case study. Molecular breeding. ISSN 1380-3743. 26(4), p. 711–718. doi: 10.1007/s11032-010-9479-0. Full text in Research Archive
• Samulin-Erdem, Johanna Maria; Berg, Paul Ragnar; Sundvold, Hilde; Grindflek, Eli & Lien, Sigbjørn (2009). Expression of DLK1 splice variants during porcine adipocyte development in vitro and in vivo. Animal Genetics. ISSN 0268-9146. 40(2), p. 239–241. doi: 10.1111/j.1365-2052.2008.01812.x. Full text in Research Archive Show summary

  Delta-like 1 (DLK1) belongs to the epidermal growth factor-like transmembrane protein family and is involved in the regulation of adipogenesis. Several splice variants of DLK1 have been identified in various species, of which two have been previously identified in pig. Here, we present two novel porcine DLK1 splice variants DLK1A and DLK1C. The gene expression profile of these variants together with the previously described DLK1B and DLK1C2 variants was studied in adipose tissue depots of pigs and during adipocyte differentiation in vitro. The short DLK1C and DLK1C2 transcripts were most abundantly expressed and their expression was reduced during porcine adipogenesis.

• Moen, T; Hayes, B; Nilsen, Frank; Nilsen, Frank; Delghandi, Madjid & Fjalestad, KT [Show all 9 contributors for this article] (2008). Identification and characterisation of novel SNP markers in Atlantic cod: Evidence for directional selection. BMC Genetics. 9. doi: 10.1186/1471-2156-9-18. Full text in Research Archive Show summary

  Background The Atlantic cod (Gadus morhua) is a groundfish of great economic value in fisheries and an emerging species in aquaculture. Genetic markers are needed to identify wild stocks in order to ensure sustainable management, and for marker-assisted selection and pedigree determination in aquaculture. Here, we report on the development and evaluation of a large number of Single Nucleotide Polymorphism (SNP) markers from the alignment of Expressed Sequence Tag (EST) sequences in Atlantic cod. We also present basic population parameters of the SNPs in samples of North-East Arctic cod and Norwegian coastal cod obtained from three different localities, and test for SNPs that may have been targeted by natural selection. Results A total of 17,056 EST sequences were used to find 724 putative SNPs, from which 318 segregating SNPs were isolated. The SNPs were tested on Atlantic cod from four different sites, comprising both North-East Arctic cod (NEAC) and Norwegian coastal cod (NCC). The average heterozygosity of the SNPs was 0.25 and the average minor allele frequency was 0.18. FST values were highly variable, with the majority of SNPs displaying very little differentiation while others had FST values as high as 0.83. The FST values of 29 SNPs were found to be larger than expected under a strictly neutral model, suggesting that these loci are, or have been, influenced by natural selection. For the majority of these outlier SNPs, allele frequencies in a northern sample of NCC were intermediate between allele frequencies in a southern sample of NCC and a sample of NEAC, indicating a cline in allele frequencies similar to that found at the Pantophysin I locus. Conclusion The SNP markers presented here are powerful tools for future genetics work related to management and aquaculture. In particular, some SNPs exhibiting high levels of population divergence have potential to significantly enhance studies on the population structure of Atlantic cod.

• Nilsen, Heidi; Hayes, Ben J.; Berg, Paul Ragnar; Roseth, Arne; Sundsaasen, Kristil Kindem & Nilsen, K. [Show all 7 contributors for this article] (2008). Construction of a dense SNP map for bovine chromosome 6 to assist the assembly of the bovine genome sequence. Animal Genetics. ISSN 0268-9146. 39(2), p. 97–104. doi: 10.1111/j.1365-2052.2007.01686.x. Full text in Research Archive Show summary

  A linkage map was constructed for bovine chromosome 6 (BTA6), using 399 single nucleotide polymorphisms (SNPs) detected primarily from PCR-resequencing. The efficiency of SNP detection was highly dependent on the source of sequence information chosen for primer design (BAC-end sequences, introns or promoters). The SNPs were used to build a linkage map comprising 104 cM on BTA6. The SNP order in the linkage map corresponded very well with radiation hybrid (RH) maps available for BTA6 as well as with expected positions in the human comparative map, but diverged significantly from the current assembly of the bovine genome (Btau_3.1). When performing linkage analysis with the marker order suggested from the Btau_3.1 we observed an expansion of the genetic map from 104 cM to 137 cM, strongly suggesting a reordering of scaffolds in the current version of the bovine genome assembly. The extent of LD on BTA6 was evaluated by calculating the average r(2) for SNP pairs separated by given distances. The decline of LD was rapid with distance, such that r(2) was 0.1 at 100 kb. Our results indicate that linkage mapping will be a valuable source of information for correcting errors in the current bovine assembly. These errors were sufficiently frequent to be of concern for the accuracy of mapping QTL with panels of SNPs whose positions are based on the current assembly.

• Hayes, Ben J.; Lien, Sigbjørn; Nilsen, Heidi; Olsen, Hanne Gro; Berg, Paul Ragnar & Maceachern, S. [Show all 8 contributors for this article] (2008). The origin of selection signatures on bovine chromosome 6. Animal Genetics. ISSN 0268-9146. 39(2), p. 105–111. doi: 10.1111/j.1365-2052.2007.01683.x. Full text in Research Archive Show summary

  The extent and pattern of linkage disequilibrium (LD) between closely spaced markers contain information about population history, including past population size and selection history. Selection signatures can be identified by comparing the LD surrounding a putative selected allele at a locus to the putative non-selected allele. In livestock populations, locations of selection signatures identified in this way should be correlated with QTL affecting production traits, as the populations have been under strong artificial selection for these traits. We used a dense SNP map of bovine chromosome 6 to characterize the pattern of LD on this chromosome in Norwegian Red cattle, a breed which has been strongly selected for milk production. The pattern of LD was generally consistent with strong selection in regions containing QTL affecting milk production traits, including a strong selection signature in a region containing a mutation known to affect milk production. The results demonstrate that in livestock populations, the origin of selection signatures will often be QTL for livestock production traits, and illustrate the value of selection signatures in uncovering new mutations with potential effects on quantitative traits.

• Boulding, EG; Culling, M; Glebe, B; Berg, Paul Ragnar; Lien, Sigbjørn & Moen, Thomas (2008). Conservation genomics of Atlantic salmon: SNPs associated with QTLs for adaptive traits in parr from four trans-Atlantic backcrosses. Heredity. ISSN 0018-067X. 101(4), p. 381–391. doi: 10.1038/hdy.2008.67. Full text in Research Archive Show summary

  European Atlantic salmon ( Salmo salar) differ in skin pigmentation and shape from the North American lineage of Atlantic salmon but the genetic basis of these differences are poorly understood. We created four large (N = 300) backcross families by crossing F1 hybrid male siblings to two females from the European and two from the North American aquacultural strains. We recorded 15 morphological landmarks and two skin pigmentation, three growth and three condition traits on parr. The backcross families were genotyped for at least 129 SNPs ( single nucleotide polymorphisms) within expressed sequence tags ( ESTs) spaced throughout the Atlantic salmon linkage map. The high polymorphism and low rates of crossover in our hybrid sires provided enough statistical power to detect 79 significant associations between SNP markers and quantitative traits after experiment-wide permutation analysis for all families within traits. Linkage group AS22 contained a quantitative trait loci (QTL) for parr mark number; its homolog AS24 contained a large QTL, which explained 26% of the phenotypic variance in parr mark contrast. We found 25 highly significant QTLs for body shape and fin position on seven different linkage groups, and 16 for growth and condition on six different linkage groups. QTL(s) for pectoral fin position, caudal peduncle position, late parr growth and condition index were associated with an SNP on linkage group AS1, which was linked to the sex-determining locus. Our work adds to the evidence that much of the variation in growth rate, shape and skin pigmentation observed among Atlantic salmon parr from different natal streams is genetic.

• Moen, Thomas; Hayes, Ben J.; Nilsen, Frank; Delghandi, M; Fjalestad, Kjersti T & Fevolden, Svein-Erik [Show all 8 contributors for this article] (2008). Identification and characterisation of novel SNP markers in Atlantic cod: Evidence for directional selection. BMC Genetics. 9, p. 9–9. Full text in Research Archive Show summary

  Conclusion: The SNP markers presented here are powerful tools for future genetics work related to management and aquaculture. In particular, some SNPs exhibiting high levels of population divergence have potential to significantly enhance studies on the population structure of Atlantic cod.

• Moen, Thomas; Hayes, Ben J.; Baranski, Matthew; Berg, Paul Ragnar; Kjøglum, Sissel & Koop, Ben F. [Show all 9 contributors for this article] (2008). A linkage map of the Atlantic salmon (Salmo salar) based on EST-derived SNP markers. BMC Genomics. 9. doi: 10.1186/1471-2164-9-223. Full text in Research Archive Show summary

  Conclusion: The linkage map presented here is an important resource for genetic, comparative, and physical mapping of the Atlantic salmon. The female map is likely to have a map coverage that is not far from complete, whereas the male map length is likely to be significantly shorter than the true map, due to suboptimal marker coverage in the apparently small physical regions where male crossovers occur. 'Useful LD' was found at inter-marker distances less than 5 cM.

• Hayes, Ben J.; Nilsen, Kjetil; Berg, Paul Ragnar; Grindflek, Eli & Lien, Sigbjørn (2007). SNP detection exploiting multiple sources of redundancy in large EST collections improves validation rates. Bioinformatics. ISSN 1367-4803. 23(13), p. 1692–1693. Full text in Research Archive Show summary

  Motivation: Single nucleotide polymorphism ( SNP) detection exploiting redundancy in expressed sequence tag ( EST) collections that arises from the presence of transcripts of the same gene from different individuals has been used to generate large collections of SNPs for many species. A second source of redundancy, namely that EST collections can contain multiple transcripts of the same gene from the same individual, can be exploited to distinguish true SNPs from sequencing error. In this article, we demonstrate with Atlantic salmon and pig EST collections that splitting the EST collection in two, detecting SNPs in both subsets, then accepting only cross-validated SNPs increases validation rates. Results: In the pig data set, 676 cross-validated putative SNPs were detected in a collection of 160 689 ESTs. When validating a subset of these by genotyping on MassARRAY 85.1% of SNPs were polymorphic in successful assays. In the salmon data set, 856 cross-validated putative SNPs were detected in a collection of 243 674 ESTs. Validation by genotyping showed that 81.0% of the cross-validated putative SNPs were polymorphic in successful assays.

• Martens, Harald; Kohler, Achim; Afseth, Nils Kristian; Wold, Jens-Petter; Hersleth, Margrethe & Berget, Ingunn [Show all 19 contributors for this article] (2007). High-throughput Measurements for Functional Genomics of Milk. Journal of Animal and Feed Sciences. ISSN 1230-1388. 16(1), p. 172–172. Full text in Research Archive Show summary

  Recent developments in analytical technology have simplified a detailed characterization of milk and milk-based samples. A range of powerful new instrumentation types have recently been installed at various institutes at Campus Ås (Norway). At the campus we have recently implemented efficient, multi-channel instrumentation for genomics, transcriptomics, proteomics, biospectroscopy, metabolomics and various quality assessments. The present paper gives an informal outline of various modern analytical tools for characterization of various milk and milk-based samples.

• Olsen, Hanne Gro; Nilsen, Heidi; Hayes, Ben J.; Berg, Paul Ragnar; Svendsen, Morten & Lien, Sigbjørn [Show all 7 contributors for this article] (2007). Genetic support for a quantitative trait nucleotide in the ABCG2 gene affecting milk composition of dairy cattle. BMC Genetics. 8(art. 32), p. 32–40. Full text in Research Archive Show summary

  Conclusion: Based on our results, OPN_3907 can be excluded as the polymorphism underlying the QTL. The results of this and other papers strongly suggest the [A/C] mutation in ABCG2_49 as the causal mutation, although the possibility that ABCG2_49 is only a marker in perfect LD with the true mutation can not be completely ruled out.

• Hayes, Ben J.; Lærdahl, Jon K; Lien, Sigbjørn; Moen, Thomas; Berg, Paul Ragnar & Hindar, Kjetil [Show all 10 contributors for this article] (2007). An extensive resource of single nucleotide polymorphism markers associated with Atlantic salmon (Salmo salar) expressed sequences. Aquaculture. ISSN 0044-8486. 265(1-4), p. 82–90. doi: 10.1016/j.meatsci.2007.03.018. Full text in Research Archive Show summary

  As well as being one of the most important aquaculture species, Atlantic salmon (Salmo salar) have been proposed as a model organism for studying the consequences of genome duplication, given the recent tetraploidization event in the salmonoid common ancestor. Availability of large nuntbers of single nucleotide polymorphisms (SNPs) for Atlantic salmon would be extremely useful for both mapping of genes affecting quantitative traits, as well as a tool to establish the extent and location of duplication in the salmon genome. Here we describe the discovery of 2507 putative SNPs from the alignment of Atlantic salmon expressed sequence tags (ESTs). Eighty-six of the SNPs were chosen for validation in a panel of,55 salmon from locations across their range. Seventy four percent of these SNPs were polymorphic in this panel. Twelve of the validated SNPs showed extreme heterozygous excess, and partial genome duplication is proposed as a possible explanation for this result. Flanking SNP sequences are available from the authors, and the annotations of the SNP containing sequences are publicly available at http://www.salmongenome.no/data/ annotation/SNPproj. (c) 2007 Elsevier B.V. All rights reserved.

• Hayes, Ben J.; Hagesæther, Nina; Ådnøy, Tormod; Pellerud, Grunde; Berg, Paul Ragnar & Lien, Sigbjørn (2006). Effects on production traits of haplotypes among casein genes in Norwegian goats and evidence for a site of preferential recombination. Genetics. ISSN 0016-6731. 174(September), p. 455–464. Full text in Research Archive Show summary

  In goat milk the most abundant proteins are the casein genes, CSN1S1, CSN2, CSN1S2, and CSN3. Mutations have been identified within these genes affecting the level of gene expression, and effects on milk production traits have been reported. The aim of this study was to detect polymorphisms (SNPs) in the casein genes of Norwegian goats, resolve haplotype structures within the loci, and assess the effect of these haplotypes on milk production traits. Four hundred thirty-six Norwegian bucks were genotyped for 39 polymorphic sites across the four loci. The numbers of unique haplotypes present in each locus were 10, 6, 4, and 8 for CSN1S1, CSN2, CSNIS2, and CSN3, respectively. The effects of the CSN1S1 haplotypes on protein percentage and fat kilograms were significant, as were the effects of CSN3 haplotypes on fat percentage and protein percentage. A deletion in exon 12 of CSN1S1, unique to the Norwegian goat population, explained the effects of CSN1S1 haplotypes on fat kilograms, but not protein percentage. Investigation of linkage disequilibrium between all possible pairs of SNPs revealed higher levels of linkage disequilbrium for SNP pairs within casein loci than for SNP pairs between casein loci, likely reflecting low levels of intragenic recombination. Further, there was evidence for a site of preferential recombination between CSN2 and CSNIS2. The value of the haplotypes for haplotype-assisted selection (HAS) is discussed.

• Olsen, Hanne Gro; Lien, Sigbjørn; Gautier, Mathieu; Nilsen, Heidi; Roseth, Arne & Berg, Paul Ragnar [Show all 9 contributors for this article] (2005). Mapping of a milk production quantitative trait locus to a 420-kb region on bovine chromosome 6. Genetics. ISSN 0016-6731. 169(1), p. 275–283. Full text in Research Archive Show summary

  A QTL affecting milk production traits was previously mapped to an interval of 7.5 cM on chromosome 6 in Norwegian dairy cattle. This article aimed to refine this position by increasing the map density in the region by a set of single-nucleotide polymorphisms and analyzing the data with a combined linkage and linkage disequilibrium approach. Through a series of single- and multitrait and single- and multipoint analyses, the QTL was positioned to an interval surrounded by the genes ABCG2 and LAP3. As no recombinations were detected in this interval, physical mapping was required for further refining. By using radiation hybrid mapping as well as BAC clones, the bovine and human comparative maps in the region are resolved, and the QTL is mapped within a distance of 420 kb.

• Berg, Paul Ragnar & Mork, Jarle (2004). Tissue enzyme loci for routine genotyping in Norway pout (Trisopterus esmarkii Nilsson, 1855): electrophoresis conditions, tissue manifestations, allele designations and basic population genetic parameters. Sarsia. ISSN 0036-4827. 89(6), p. 411–422. doi: 10.1080/00364820410002668. Full text in Research Archive
• Berg, Paul Ragnar (2003). Isolation and characterization of microsatellite loci from two inbreeding bark beetle species (Coccotrypes). Molecular Ecology Notes. ISSN 1471-8278. 3(2), p. 270–273. doi: 10.1046/j.1471-8286.2003.00423.x. Full text in Research Archive Show summary

  We developed 14 microsatellite markers in Coccotrypes carpophagus and 14 in C. dactyli- perda. These loci will be used for studying genetic structure and the level of inbreeding in populations in the Canary Islands and Madeira. As a result of long-term inbreeding, genetic variability is relatively low in these bark beetle species. We found one to five alleles per locus in 29 C. carpophagus and 41 C. dactyliperda from various localities. Eleven of the markers developed for C. carpophagus amplified in C. dactyliperda and seven of the mark- ers developed for C. dactyliperda amplified in C. carpophagus.

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• Sura, Appalanaidu; Panda, Uma Sankar; Ramakrishnan, Sivasankar; Munnoor, Kumaraswami; Vijay, Akhilesh & Puente, Santiago de la [Show all 10 contributors for this article] (2025). Potential sources of impacts linked to ciliate epibiont occurrence on the macrobenthic invertebrates in the Coringa Mangrove Ecosystem: Preliminary documentation. Environmental Science and Pollution Research. ISSN 0944-1344. doi: 10.1007/s11356-025-36748-y. Full text in Research Archive
• Chen, Wenting & Berg, Paul Ragnar (2024). Developing the ocean accounts, focusing on ocean assets, flow to the economy, and flows to the environment compilation. Full text in Research Archive
• Stenseth, Nils Christian; Jentoft, Sissel; Haugen, Thrond Oddvar; Bekkby, Trine; Walday, Mats Gunnar & Berg, Paul Ragnar [Show all 11 contributors for this article] (2024). Økosystemet i Oslofjorden kollapser – vi trenger tiltak. Khrono.no. ISSN 1894-8995. Full text in Research Archive
• Berg, Paul Ragnar (2023). Relevante kompetanser og mulig bidrag fra NIVA. Full text in Research Archive
• Berg, Paul Ragnar; Gundersen, Hege; Hancke, Kasper; Sander, Gunnar; Skjellum, Solrun Figenschau & Wathne, Cecilie Linn (2021). Oppfølgingsmøte om blå skog. Full text in Research Archive
• Barth, Julia Maria Isis; Star, Bastiaan; Matschiner, Michael; Berg, Paul Ragnar; Jakobsen, Kjetill Sigurd & Jentoft, Sissel (2016). Ancient genomic variation separates Atlantic cod ecotypes; implications for management. Full text in Research Archive
• Star, Bastiaan; Jentoft, Sissel; Matschiner, Michael; Nederbragt, Alexander Johan; Kjesbu, Olav Sigurd & Berg, Paul Ragnar [Show all 12 contributors for this article] (2015). Does historic DNA provide genomic evidence for recent selection in Atlantic cod? Full text in Research Archive
• Berg, Paul Ragnar; Jentoft, Sissel; Star, Bastiaan; Ring, Kristoffer Hofaker; Knutsen, Halvor & Lien, Sigbjørn [Show all 8 contributors for this article] (2014). Adaptation to low salinity promotes genomic divergence in Atlantic cod (Gadus morhua L.). Full text in Research Archive
• Matschiner, Michael; Star, Bastiaan; Berg, Paul Ragnar; Tørresen, Ole Kristian; Nederbragt, Alexander Johan & Hansen, Marianne Helén Selander [Show all 11 contributors for this article] (2014). Population differentiation and local adaptation in Atlantic cod. Full text in Research Archive
• Barth, Julia Maria Isis; Berg, Paul Ragnar; Star, Bastiaan; Bonanomi, Sara; Hemmer-Hansen, Jakob & Knutsen, Halvor [Show all 8 contributors for this article] (2014). A genomic perspective on cod connectivity in the Skagerrak/Kattegat. Full text in Research Archive
• Berg, Paul Ragnar (2013). Population genomics in Atlantic cod - Baltic vs. North Sea. Full text in Research Archive
• Berg, Paul Ragnar (2012). Ecological genomics of Atlantic cod (Gadus morhua) - adaptive responses to changing selection regimes. Full text in Research Archive
• Nederbragt, Alexander Johan; Tørresen, Ole Kristian; Khelik, Ksenia; Lagesen, Karin; Rounge, Trine Ballestad & Star, Bastiaan [Show all 13 contributors for this article] (2012). Challenges and Opportunities for Improving the Atlantic Cod Genome Assembly and Annotation. Full text in Research Archive
• Berg, Paul Ragnar (2012). Populasjonsgenomikk på torsk - et verktøy for identifisering av viktige genomiske regioner for oppdrettsnæringen. Full text in Research Archive
• Star, Bastiaan; Nederbragt, Alexander Johan; Jentoft, Sissel; Grimholt, Unni; Malmstrøm, Martin & Gregers, Tone Fredsvik [Show all 18 contributors for this article] (2011). The genome of Atlantic cod reveals a unique immune system. Full text in Research Archive
• Kent, Matthew Peter; Hayes, Ben J.; Qin, Xiang; Berg, Paul Ragnar; Gibbs, Richard A. & Lien, Sigbjørn (2009). Development Of 16.5K SNP-Chip For Atlantic Salmon. Full text in Research Archive Show summary

  Description of the development of Cigenes Atlantic Salmon genotyping array.

• Sandve, Simen Rød; Rudi, Heidi; Dørum, Guro; Vigeland, Magnus D.; Berg, Paul Ragnar & Rognli, Odd Arne (2009). Genotyping unknown genomic terrain in complex plant genomes. Full text in Research Archive
• Sandve, Simen Rød; Rudi, Heidi; Berg, Paul Ragnar; Fosnes, Kjetil & Rognli, Odd Arne (2009). Genotyping unknown genomic terrain in complex plant genomes. Full text in Research Archive
• Heuser, Kjell; Nagelhus, Erlend A.; Taubøll, Erik; Indahl, Ulf; Berg, Paul Ragnar & Nakken, S [Show all 9 contributors for this article] (2008). DO PATIENTS WITH TEMPORAL LOBE EPILEPSY AND CHILDHOOD FEBRILE SEIZURES CONSTITUTE A GENETIC SUBGROUP? RESULTS FROM AN ASSOCIATION STUDY OF AQUAPORIN-4 AND POTASSIUM CHANNEL GENES. Epilepsia. ISSN 0013-9580. p. 344–344. Full text in Research Archive
• Biong, M; Edvardsen, H; Dragseth, V; Berg, PR; Berg, P & Gram, Inger Torhild [Show all 10 contributors for this article] (2008). Genetic markers for the prediction of breast density and breast cancer risk. European Journal of Cancer. ISSN 0959-8049. 6, p. 200–200. Full text in Research Archive
• Gjuvsland, Arne Bjørke; Sundsaasen, Kristil Kindem; Karoliussen, Silje; Berg, Paul Ragnar; Lien, Sigbjørn & Plahte, Erik [Show all 8 contributors for this article] (2008). Allele action patterns connect genetic dominance with gene regulatory architecture. Full text in Research Archive
• Roseth, Arne; Berg, Paul Ragnar; Sundsaasen, Kristil Kindem & Lien, Sigbjørn (2006). CIGENE - a core facility for detection, typing and interpretation of SNPs. Full text in Research Archive
• Moen, Thomas; Berg, Paul Ragnar; Hayes, Ben J.; Lien, Sigbjørn; Omholt, Stig W. & Våge, Dag Inge (2005). Atlantic salmon research within Centre of Integrative Genetics (CIGENE). Full text in Research Archive
• Våge, Dag Inge; Berg, Paul Ragnar; Hayes, Ben J.; Høyheim, Bjørn; Lien, Sigbjørn & Moen, Thomas [Show all 8 contributors for this article] (2005). CIGENEs rolle i genomforskningen på laks. Full text in Research Archive
• Zimonja, Monika; Berget, Ingunn; Martens, Harald; Berg, Paul Ragnar & Lien, Sigbjørn (2005). Chemometrics in MALDI-TOF mass spectrometry: More accurate and economical SNP genotyping. Full text in Research Archive Show summary

  CIGENE uses matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) for genotyping of single nucleotide polymorphisms (SNP) (Figure 1). This methodology is expensive, but the cost per sample is highly reduced if a large number of SNPs can be analyzed simultaneously. The accuracy of the available software is too poor for analyzing experiments with a large number of SNPs. We therefore aim at developing a MATLAB toolbox where a chemometric approach for preprocessing the MALDI-TOF spectra and estimate the SNP genotype is taken.

• Berg, Paul Ragnar; Roseth, Arne; Sundsaasen, Kristil Kindem; Lien, Sigbjørn & Omholt, Stig W. (2004). CIGENE-Centre for Integrative Genetics. Full text in Research Archive
• Andrews, Adam Jon; Pardo, Juan; Bjorbækmo, Marit Frederikke Markussen & Berg, Paul Ragnar (2025). The potential of offshore wind farms to spread marine alien species. Norsk institutt for vannforskning (NIVA). ISSN 9788257778491. Full text in Research Archive Show summary

  Alien species are organisms introduced to new areas through human activities that have been associated with artificial structures in coastal zones. Offshore wind farms (OWFs), rapidly expanding across marine environments, provide novel artificial surfaces that may facilitate the establishment and spread of alien species in regions lacking natural habitats. In the southern North Sea, offshore energy structures already support such species, with similar patterns observed globally. Despite international and national policies calling for better understanding of alien marine species, their pathways, and early detection systems, Norway lacks an understanding of how OWFs will impact the spread of alien marine species. The impact of OWFs on alien species spread remains understudied globally. This study synthesizes current knowledge and explores three mechanisms by which OWFs may promote alien species dispersal to Norway: (1) acting as stepping-stones for regional and international spread, (2) enabling hitchhiking on vessels and structures between offshore and inshore areas, and (3) creating refuges for alien species due to fishing restrictions within OWFs. We highlight relevant alien taxa for each and identify knowledge gaps, aiming to support biodiversity protection efforts and meet national and commercial obligations.

• Mariussen, MS; Strøm, V; Valseth, ÅA; Vennemo, K; Bjorbækmo, Marit & Chen, Wenting [Show all 16 contributors for this article] (2023). Mariussen MS, Strøm V, Valseth ÅA, Vennemo K, Bjorbækmo MFM, Chen W, Furuseth IS, Bekkby T, Berg PR, Saesin P, Staalstrøm A, Walday MG, Kaste Ø, Ruus A, Hess-Erga O-K, Langaas S. Mulighetskartlegging for kystbaserte næringer i Viken – Indre Oslofjord og Drammensfjorden. Vista Analyse Report 2023/11. ISBN 978-82-8126-623-0. https://www.vista-analyse.no/site/assets/files/7886/va-rapport_2023- 11_mulighetskartlegging_for_kystbaserte_naeringer_i_viken.pdf. Vista Analyse . Full text in Research Archive
• Rueness, Eli Knispel; Berg, Paul Ragnar; Gulla, Snorre; Halvorsen, Kim Aleksander Tallaksen; Järnegren, Johanna & Malmstrøm, Martin [Show all 19 contributors for this article] (2019). Assessment of the risk to Norwegian biodiversity from import of wrasses and other cleaner fish for use in aquaculture. Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment. Norwegian Scientific Committee for Food and Environment (VKM). ISSN 9788282593304. Full text in Research Archive

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