Wenche Eikrem

Utvalgte publikasjoner:

• Jouenne, F, Eikrem W, Le Gall F, Marie D, Johnsen G, Vaulot D. 2010. Prasinoderma singularis sp. nov. (Prasinophyceae, Chlorophyta), a solitary coccoid prasinophyte from the South-East Pacific Ocean. Accepted. Protist
• Johnsen TM, Eikrem W, Olseng CD, Tollefsen K-E, Bjerknes V. 2010. Prymnesium parvum: The Norwegian Experience. Journal of the American Water Resource Association 32: 795-820.
• Worden AZ, Lee J-H, Mock T, Rouzé P, Simmons M. P, Aerts A. L, Allen A. E. Cuvelier M. L, Derelle E, Everett M. V, Foulon E, Grimwood J, Gundlach H, Henrissat B, Napoli C, McDonald S. M, Parker M. S, Rombauts S, Salamov A, Von Dassow P, Badger J.H, Coutinho P.M, Demir E, Dubchak I, Gentemann C, Eikrem W, Gready JE, John U, Lanier W, Lindquist E.A, Lucas S, Mayer KFX, Moreau H, Not F, Otillar R, Panaud O, Pangilinan J, Paulsen I, Piegu B, Poliakov A, Robbens S, Schmutz J, Toulza E, Wyss T, Zelensky A, Zhou A, Armbrust E.V, Bhattacharya D, Goodenough U.V, Van de Peer Y. and Grigoriev I.V . 2009. Green Evolution and Dynamic Adaptations Revealed by Genomes of the Marine Picoeukaryote Micromonas. Science. 324: 268-272.
• Seoane S, Eikrem W, Pienaar R and Edvardsen B. 2009. Chrysochromulina palpebralis sp. nov. (Prymnesiophyceae): a haptophyte, possessing two alternative morphologies. Phycologia 48: 165–176
• Seoane S, Eikrem W and Orive E. 2008. Haptophytes of the Nervión River estuary. Botanica Marina. 52: 47-59.
• Vaulot D, Eikrem W, Viprey M, Moreau H. 2008. The diversity of small eukaryotic phytoplankton(<3 µm) in marine ecosystems. FEMS microbiology review. 32:795-820.
• Silva PC, Throndsen J, Eikrem W. 2007. Revisiting the nomenclature of haptophytes. Phycologia 46: 471–475.
• Edvardsen B, Eikrem W, Johnsen G, Naustvoll L, Riisberg I, Shalchian-Tabrizi, K, Throndsen J. 2007Verrucophora farcimen gen. et sp. nov. (Dictyochophyceae, Hetrokontophyta), a bloom forming ichthyotoxic flagellate isolated from Skagerrak. Journal of Phycology 43: 1054-1070.
• Jakobsen KS, Shalchian-Tabrizi K, Klaveness D, Minge M, Vaulot D, Eikrem W, Le Gall, F. Romari K, Throndsen J, Botnen A, Massana R, Thomsen, H.A. 2007. Telonemia, a new protist phylum with affinity to chromist lineages. Proceedings of the Royal Society B: Biological Sciences.
• Not F, Massana R, Latasa M, Colson MD, Eikrem W, Pedros-Alio C, Vaulot D, Simon N. 2005. Late summer community composition and abundance of photosynthetic picoeukaryotes in Norwegian and Barents seas. Limnology & Oceanography 50: 1677-1686.
• Eikrem W., Romari K., Le Gall F., Latasa M., Throndsen J. & Vaulot D. Florenciella parvula gen. and sp. nov. (Dictyochophyceae, Heterokontophyta) a small flagellate isolated from the English Channel. Phycologia. 43:658-668.
• Guillou L, Eikrem W, Chrétiennot-Dinet M-J, Le Gall F, Massana R, Romari K, Pedrós-Alió C. & Vaulot D. Diversity of picoplanktonic Prasinophyceae assessed by direct SSU rDNA sequencing of environmental sequences and novel isolates retrieved from oceanic and coastal marine ecosystems. Protist. 155: 193-214
• Eikrem W, Edvardsen B, Green J, Medlin L.K. 1999.Phylogeny of the genera Prymnesium and Chrysochromulina inferred from 18 ribosomal DNA sequenses compared with available morphological and ultrastructural data, pp. 24. Manuscript in Wenche Eikrem dr. scient thesis, University of Oslo.
• Edvardsen B, Eikrem W, Green J, Moon-van der Staay Y, Andersen RA, Medlin LK. 2000. Phylogenetic reconstructions of the Haptophyta inferred from 18S ribosomal RNA sequences and available morphological data. Phycologia 39:19-35.
• Eikrem W. & Edvardsen B. 1999. Chrysochromulina fragiaria sp. nov. Describtion of a new haptophyte flagellate from Norwegian waters. Phycologia: 38:149-155.
• Eikrem W, Throndsen J. 1999. Chrysochromulina rotalis sp. nov. Describtion of a new haptophyte flagellate from Norwegian waters. Sarsia 84: 445-449.
• Eikrem W, Throndsen J. 1998. Morphology and some ultrastructural details of Chrysochromulina leadbeateri Estep et al. (Prymnesiophyceae, Haptophyta) from Northern Norway. Phycologia 37: 292-299.
• Eikrem W, Moestrup Ø. 1998. Structural analysis of the flagellar apparatus and the scaly periplast of Chrysochromulina scutellum sp. nov. (Prymnesiopyceae, Haptophyta) from the Skagerrak and the Baltic. Phycologia: Volume 37: 132-153.
• Eikrem W. Chrysochromulina throndsenii sp. nov. (Prymnesiophyceae) a new haptophyte flagellate from Norwegian coastal waters. 1996. Phycologia 35: 377-380.
• Egeland E.S, Johnsen G, Eikrem W, Throndsen J, Liaaen-Jensen S. 1995. The pigments of Bathycoccus prasinos (Prasinophyceae): methodological and chemosystematic implication. Journal of Phycology 3: 554-561.
• Larsen A, Eikrem W, Paasche E. 1993. Growth and toxicity of Prymnesium patelliferum (Prymnesiophyceae) isolated from Norwegian Waters. Canadian Journal of Botany 71: 1357-1362.
• Eikrem W,Throndsen J.1993. Toxic prymnesiophytes identified from Norwegian coastal waters. Toxic Phytoplankton Blooms in the Sea. Proceedings of the Fifth International Conference on Toxic Marine Phytoplankton, Newport, Rhode Island, U.S.A., 28 October - 1 November 1991, T. J.Smayda and Y.Shimizu, eds. Elsevier Science Publishers, Amsterdam (952 pp.): 687-692.
• Eikrem W, Throndsen, J. 1991. Chrysochromulina leadbeateri og andre Chrysochromulina arters biologi. I: Oppblomstringen av Chrysochromulina leadbeateri i Vestfjorden, mai-juni 1991 (Red. Francisco Rey). Fisken og Havet. 1991: (3)63-71.
• Eikrem W, Throndsen J. 1991. Identification of phytoplankton species by scale morphology: TEM an indispensible tool. Micron and Microscopica Acta 22: 37-38.
• Edvardsen B, Eikrem W, Paasche E. 1990. A possible alternate state in the life cycle of Chrysochromulina polylepis Manton & Parke (Prymnesiophyceae) Nova Hedwigia 100: 91-99.
• Eikrem W, Throndsen J. 1990. The ultrastructure of Bathycoccus gen. nov. and B. prasinos sp. nov., a non-motile picoplanktonic alga (Chlorophyta, Prasinophyceae) from the Mediterranean and Atlantic. Phycologia 29: 344-350.

 
Bøker

• Throndsen J, Eikrem W. 2010. Mikroorganismer i sand. 120 pp. Almater Forlag, Oslo
• Throndsen J, Eikrem W. 2000. Marine planktonalger i farger. 120 pp. Almater Forlag, Oslo.
   

• Briddon, Charlotte L.; Nicoară, Maria; Hegedüs, Adriana; Niculea, Adina; Bellerby, Richard & Eikrem, Wenche [Vis alle 9 forfattere av denne artikkelen] (2023). Acclimation to various temperature and pCO2 levels does not impact the competitive ability of two strains of Skeletonema marinoi in natural communities. Frontiers in Marine Science. ISSN 2296-7745. 10. doi: 10.3389/fmars.2023.1197570. Fulltekst i vitenarkiv Vis sammendrag

  Understanding the long-term response of key marine phytoplankton species to ongoing global changes is pivotal in determining how oceanic community composition will respond over the coming decades. To better understand the impact of ocean acidification and warming, we acclimated two strains of Skeletonema marinoi isolated from natural communities to three pCO2 (400 μatm, 600 μatm and 1000 μatm) for 8 months and five temperature conditions (7°C, 10°C, 13°C, 16°C and 19°C) for 11 months. These strains were then tested in natural microbial communities, exposed to three pCO2 treatments (400 μatm, 600 μatm and 1000 μatm). DNA metabarcoding of the 16S and 18S gene for prokaryotes and eukaryotes respectively was used to show differences in abundance and diversity between the three CO2 treatments. We found there were no significant differences in acclimated S. marinoi concentrations between the three pCO2 treatments, most likely due to the high variability these strains experience in their natural environment. There were significant compositional differences between the pCO2 treatments for prokaryotes suggesting that indirect changes to phytoplankton-bacteria interactions could be a possible driver of bacterial community composition. Yet, there were no differences for eukaryotic community composition, with all treatments dominated by diatoms (but not the acclimated S. marinoi) resulting in similar biodiversity. Furthermore, strain-specific differences in community composition suggests interactions between prokaryotic and eukaryotic taxa could play a role in determining future community composition.

• Lundsør, Elisabeth; Lømsland, Evy Rigmor; Johnsen, Torbjørn Martin; Engesmo, Anette; King, Andrew Luke & Staalstrøm, Andre [Vis alle 11 forfattere av denne artikkelen] (2022). Marine phytoplankton community data and corresponding environmental properties from eastern Norway, 1896–2020. Scientific Data. ISSN 2052-4463. 9. doi: 10.1038/s41597-022-01869-3. Fulltekst i vitenarkiv
• Lundsør, Elisabeth; Eikrem, Wenche; Stige, Leif Christian; Engesmo, Anette; Gran-Stadniczeñko, Sandra & Edvardsen, Bente (2022). Changes in phytoplankton community structure over a century in relation to environmental factors. Journal of Plankton Research. ISSN 0142-7873. 44(6), s. 854–871. doi: 10.1093/plankt/fbac055. Fulltekst i vitenarkiv Vis sammendrag

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

• John, Uwe; Supraha, Luka; Gran-Stadniczeñko, Sandra; Bunse, Carina; Cembella, Allan & Eikrem, Wenche [Vis alle 13 forfattere av denne artikkelen] (2022). Spatial and biological oceanographic insights into the massive fish-killing bloom of the haptophyte Chrysochromulina leadbeateri in northern Norway. Harmful Algae. ISSN 1568-9883. 118. doi: 10.1016/j.hal.2022.102287. Fulltekst i vitenarkiv Vis sammendrag

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

• Barcytė, Dovilė; Eikrem, Wenche; Engesmo, Anette; Seoane, Sergio; Wohlmann, Jens & Horák, Aleš [Vis alle 8 forfattere av denne artikkelen] (2021). Olisthodiscus represents a new class of Ochrophyta . Journal of Phycology. ISSN 0022-3646. 57(4), s. 1094–1118. doi: 10.1111/jpy.13155. Fulltekst i vitenarkiv Vis sammendrag

  The phylogenetic diversity of Ochrophyta, a diverse and ecologically important radiation of algae, is still incompletely understood even at the level of the principal lineages. One taxon that has eluded simple classification is the marine flagellate genus Olisthodiscus. We investigated Olisthodiscus luteus K-0444 and documented its morphological and genetic differences from the NIES-15 strain, which we described as Olisthodiscus tomasii sp. nov. Phylogenetic analyses of combined 18S and 28S rRNA sequences confirmed that Olisthodiscus constitutes a separate, deep, ochrophyte lineage, but its position could not be resolved. To overcome this problem, we sequenced the plastid genome of O. luteus K-0444 and used the new data in multigene phylogenetic analyses, which suggested that Olisthodiscus is a sister lineage of the class Pinguiophyceae within a broader clade additionally including Chrysophyceae, Synchromophyceae, and Eustigmatophyceae. Surprisingly, the Olisthodiscus plastid genome contained three genes, ycf80, cysT, and cysW, inherited from the rhodophyte ancestor of the ochrophyte plastid yet lost from all other ochrophyte groups studied so far. Combined with nuclear genes for CysA and Sbp proteins, Olisthodiscus is the only known ochrophyte possessing a plastidial sulfate transporter SulT. In addition, the finding of a cemA gene in the Olisthodiscus plastid genome and an updated phylogenetic analysis ruled out the previously proposed hypothesis invoking horizontal cemA transfer from a green algal plastid into Synurales. Altogether, Olisthodiscus clearly represents a novel phylogenetically distinct ochrophyte lineage, which we have proposed as a new class, Olisthodiscophyceae.

• Karlson, Bengt; Andersen, Per; Arneborg, Lars; Cembella, Allan; Eikrem, Wenche & John, Uwe [Vis alle 17 forfattere av denne artikkelen] (2021). Harmful algal blooms and their effects in coastal seas of Northern Europe. Harmful Algae. ISSN 1568-9883. 102. doi: 10.1016/j.hal.2021.101989. Fulltekst i vitenarkiv Vis sammendrag

  Harmful algal blooms (HAB) are recurrent phenomena in northern Europe along the coasts of the Baltic Sea, Kattegat-Skagerrak, eastern North Sea, Norwegian Sea and the Barents Sea. These HABs have caused occasional massive losses for the aquaculture industry and have chronically affected socioeconomic interests in several ways. This status review gives an overview of historical HAB events and summarises reports to the Harmful Algae Event Database from 1986 to the end of year 2019 and observations made in long term monitoring programmes of potentially harmful phytoplankton and of phycotoxins in bivalve shellfish. Major HAB taxa causing fish mortalities in the region include blooms of the prymnesiophyte Chrysochromulina leadbeateri in northern Norway in 1991 and 2019, resulting in huge economic losses for fish farmers. A bloom of the prymesiophyte Prymnesium polylepis (syn. Chrysochromulina polylepis) in the Kattegat-Skagerrak in 1988 was ecosystem disruptive. Blooms of the prymnesiophyte Phaeocystis spp. have caused accumulations of foam on beaches in the southwestern North Sea and Wadden Sea coasts and shellfish mortality has been linked to their occurrence. Mortality of shellfish linked to HAB events has been observed in estuarine waters associated with influx of water from the southern North Sea. The first bloom of the dictyochophyte genus Pseudochattonella was observed in 1998, and since then such blooms have been observed in high cell densities in spring causing fish mortalities some years. Dinoflagellates, primarily Dinophysis spp., intermittently yield concentrations of Diarrhetic Shellfish Toxins (DST) in blue mussels, Mytilus edulis, above regulatory limits along the coasts of Norway, Denmark and the Swedish west coast. On average, DST levels in shellfish have decreased along the Swedish and Norwegian Skagerrak coasts since approximately 2006, coinciding with a decrease in the cell abundance of D. acuta. Among dinoflagellates, Alexandrium species are the major source of Paralytic Shellfish Toxins (PST) in the region. PST concentrations above regulatory levels were rare in the Skagerrak-Kattegat during the three decadal review period, but frequent and often abundant findings of Alexandrium resting cysts in surface sediments indicate a high potential risk for blooms. PST levels often above regulatory limits along the west coast of Norway are associated with A. catenella (ribotype Group 1) as the main toxin producer. Other Alexandrium species, such as A. ostenfeldii and A. minutum, are capable of producing PST among some populations but are usually not associated with PSP events in the region. The cell abundance of A. pseudogonyaulax, a producer of the ichthyotoxin goniodomin (GD), has increased in the Skagerrak-Kattegat since 2010, and may constitute an emerging threat. The dinoflagellate Azadinium spp. have been unequivocally linked to the presence of azaspiracid toxins (AZT) responsible for Azaspiracid Shellfish Poisoning (AZP) in northern Europe. These toxins were detected in bivalve shellfish at concentrations above regulatory limits for the first time in Norway in blue mussels in 2005 and in Sweden in blue mussels and oysters (Ostrea edulis and Crassostrea gigas) in 2018. Certain members of the diatom genus Pseudo-nitzschia produce the neurotoxin domoic acid and analogs known as Amnesic Shellfish Toxins (AST). Blooms of Pseudo-nitzschia were common in the North Sea and the Skagerrak-Kattegat, but levels of AST in bivalve shellfish were rarely above regulatory limits during the review period. Summer cyanobacteria blooms in the Baltic Sea are a concern mainly for tourism by causing massive fouling of bathing water and beaches. Some of the cyanobacteria produce toxins, e.g. Nodularia spumigena, producer of nodularin, which may be a human health problem and cause occasional dog mortalities. Coastal and shelf sea regions in northern Europe provide a key supply of seafood, socioeconomic well-being and ecosystem services. I

• Chambouvet, Aurélie; Monier, Adam; Maguire, Finlay; Itoiz, Sarah; del Campo, Javier & Elies, Philippe [Vis alle 9 forfattere av denne artikkelen] (2019). Intracellular Infection of Diverse Diatoms by an Evolutionary Distinct Relative of the Fungi. Current Biology. ISSN 0960-9822. 29(23), s. 4093–4101.e4. doi: 10.1016/j.cub.2019.09.074. Fulltekst i vitenarkiv
• Yau, Sheree; Lopes dos Santos, Adriana; Eikrem, Wenche; Gérikas Ribeiro, Catherine; Gourvil, Priscillia & Balzano, Sergio [Vis alle 9 forfattere av denne artikkelen] (2019). Mantoniella beaufortii and Mantoniella baffinensis sp. nov. (Mamiellales, Mamiellophyceae), two new green algal species from the high arctic. Journal of Phycology. ISSN 0022-3646. 56(1), s. 37–51. doi: 10.1111/jpy.12932. Fulltekst i vitenarkiv
• Gran-Stadniczenko, Sandra; Egge, Elianne; Hostyeva, Vladyslava; Logares, Ramiro; Eikrem, Wenche & Edvardsen, Bente (2019). Protist Diversity and Seasonal Dynamics in Skagerrak Plankton Communities as Revealed by Metabarcoding and Microscopy. Journal of Eukaryotic Microbiology. ISSN 1066-5234. 66(3), s. 494–513. doi: 10.1111/jeu.12700. Fulltekst i vitenarkiv
• Piredda, Roberta; Claverie, Jean-Michel; Decelle, Johan; de Vargas, Colomban; Dunthorn, Micah & Edvardsen, Bente [Vis alle 19 forfattere av denne artikkelen] (2018). Diatom diversity through HTS-metabarcoding in coastal European seas. Scientific Reports. ISSN 2045-2322. 8(1), s. 1–12. doi: 10.1038/s41598-018-36345-9. Fulltekst i vitenarkiv Vis sammendrag

  Diatoms constitute a diverse lineage of unicellular organisms abundant and ecologically important in aquatic ecosystems. Compared to other protists, their biology and taxonomy are well-studied, offering the opportunity to combine traditional approaches and new technologies. We examined a dataset of diatom 18S rRNA- and rDNA- (V4 region) reads from different plankton size-fractions and sediments from six European coastal marine sites, with the aim of identifying peculiarities and commonalities with respect to the whole protistan community. Almost all metabarcodes (99.6%) were assigned to known genera (121) and species (236), the most abundant of which were those already known from classic studies and coincided with those seen in light microscopy. rDNA and rRNA showed comparable patterns for the dominant taxa, but rRNA revealed a much higher diversity particularly in the sediment communities. Peculiar to diatoms is a tight bentho-pelagic coupling, with many benthic or planktonic species colonizing both water column and sediments and the dominance of planktonic species in both habitats. Overall metabarcoding results reflected the marked specificity of diatoms compared to other protistan groups in terms of morphological and ecological characteristics, at the same time confirming their great potential in the description of protist communities.

• Engesmo, Anette; Strand, David; Gran-Stadniczeñko, Sandra ; Edvardsen, Bente; Medlin, Linda K. & Eikrem, Wenche (2018). Development of a qPCR assay to detect and quantify ichthyotoxic flagellates along the Norwegian coast, and the first Norwegian record of Fibrocapsa japonica (Raphidophyceae). Harmful Algae. ISSN 1568-9883. 75, s. 105–117. doi: 10.1016/j.hal.2018.04.007. Fulltekst i vitenarkiv Vis sammendrag

  Blooms of ichthyotoxic microalgae pose a great challenge to the aquaculture industry world-wide, and there is a need for fast and specific methods for their detection and quantification in monitoring programs. In this study, quantitative real-time PCR (qPCR) assays for the detection and enumeration of three ichthyotoxic flagellates: the dinoflagellate Karenia mikimotoi (Miyake & Kominami ex Oda) Hansen & Moestrup and the two raphidophytes Heterosigma akashiwo (Hada) Hada ex Hara & Chihara and Fibrocapsa japonica Toriumi & Takano were developed. Further, a previously published qPCR assay for the dinoflagellate Karlodinium veneficum (Ballantine) Larsen was used. Monthly samples collected for three years (Aug 2009–Jun 2012) in outer Oslofjorden, Norway were analysed, and the results compared with light microscopy cell counts. The results indicate a higher sensitivity and a lower detection limit (down to 1 cell L−1) for both qPCR assays. Qualitative and semi-quantitative results were further compared with those obtained by environmental 454 high throughput sequencing (HTS, metabarcoding) and scanning electron microscopy (SEM) examination from the same samplings. All four species were detected by qPCR and HTS and/or SEM in outer Oslofjorden (Aug 2009–Jun 2012); Karlodinium veneficum was present year-round, whereas Karenia mikimotoi, Heterosigma akashiwo and Fibrocapsa japonica appeared mainly during the autumn in all three years. This is the first observation of Fibrocapsa japonica in Norwegian coastal waters. This species has previously been recorded off the Swedish west coast and German Bight, which may suggest a northward dispersal.

• Lopes Dos Santos, Adriana; Pollina, Thibaut; Gourvil, Priscillia; Corre, Erwan; Marie, Dominique & Garrido, Jose Luis [Vis alle 10 forfattere av denne artikkelen] (2017). Chloropicophyceae, a new class of picophytoplanktonic prasinophytes. Scientific Reports. ISSN 2045-2322. 7, s. 1–20. doi: 10.1038/s41598-017-12412-5. Fulltekst i vitenarkiv
• Forster, Dominik; Dunthorn, Micah; Mahé, Frédéric; Dolan, John R.; Audic, Stéphane & Bass, David [Vis alle 35 forfattere av denne artikkelen] (2016). Benthic protists: The under-charted majority. FEMS Microbiology Ecology. ISSN 0168-6496. 92(8), s. 1–11. doi: 10.1093/femsec/fiw120.
• Banguera-Hinestroza, E; Eikrem, W; Mansour, H; Solberg, I; Cúrdia, J & Holtermann, K [Vis alle 8 forfattere av denne artikkelen] (2016). Seasonality and toxin production of Pyrodinium bahamense in a Red Sea lagoon. Harmful Algae. ISSN 1568-9883. 55, s. 163–171. doi: 10.1016/j.hal.2016.03.002.
• Engesmo, Anette; Eikrem, Wenche; Seoane, Sergio; Smith, Kirsty; Edvardsen, Bente & Hofgaard, Antje [Vis alle 7 forfattere av denne artikkelen] (2016). New insights into the morphology and phylogeny of Heterosigma akashiwo (Raphidophyceae), with the description of Heterosigma minor sp. nov. Phycologia. ISSN 0031-8884. 55(3), s. 279–294. doi: 10.2216/15-115.1.
• Egge, Elianne Sirnæs; Johannessen, Torill Vik; Andersen, Tom; Eikrem, Wenche; Bittner, Lucie & Larsen, Aud [Vis alle 8 forfattere av denne artikkelen] (2015). Seasonal diversity and dynamics of haptophytes in the Skagerrak, Norway, explored by high-throughput sequencing. Molecular Ecology. ISSN 0962-1083. 24(12), s. 3026–3042. doi: 10.1111/mec.13160. Fulltekst i vitenarkiv
• Johannessen, Torill Vik; Bratbak, Gunnar; Larsen, Aud; Ogata, Hirotaka; Egge, Elianne Sirnæs & Edvardsen, Bente [Vis alle 8 forfattere av denne artikkelen] (2015). Characterisation of three novel giant viruses reveals huge diversity among viruses infecting Prymnesiales (Haptophyta). Virology. ISSN 0042-6822. 476, s. 180–188. doi: 10.1016/j.virol.2014.12.014.
• Egge, Elianne Sirnæs; Eikrem, Wenche & Edvardsen, Bente (2015). Deep-branching novel lineages and high diversity of haptophytes in the Skagerrak (Norway) uncovered by 454 pyrosequencing. Journal of Eukaryotic Microbiology. ISSN 1066-5234. 62(1), s. 121–140. doi: 10.1111/jeu.12157. Vis sammendrag

  Microalgae in the division Haptophyta may be difficult to identify to species by microscopy because they are small and fragile. Here, we used high-throughput sequencing to explore the diversity of haptophytes in outer Oslofjorden, Skagerrak, and supplemented this with electron microscopy. Nano- and picoplanktonic subsurface samples were collected monthly for 2 yr, and the haptophytes were targeted by amplification of RNA/cDNA with Haptophyta-specific 18S ribosomal DNA V4 primers. Pyrosequencing revealed higher species richness of haptophytes than previously observed in the Skagerrak by microscopy. From ca. 400,000 reads we obtained 156 haptophyte operational taxonomic units (OTUs) after rigorous filtering and 99.5% clustering. The majority (84%) of the OTUs matched environmental sequences not linked to a morphological species, most of which were affiliated with the order Prymnesiales. Phylogenetic analyses including Oslofjorden OTUs and available cultured and environmental haptophyte sequences showed that several of the OTUs matched sequences forming deep-branching lineages, potentially representing novel haptophyte classes. Pyrosequencing also retrieved cultured species not previously reported by microscopy in the Skagerrak. Electron microscopy revealed species not yet genetically characterised and some potentially novel taxa. This study contributes to linking genotype to phenotype within this ubiquitous and ecologically important protist group, and reveals great, unknown diversity.

• Duffield, Christopher James; Edvardsen, Bente; Eikrem, Wenche & Alve, Elisabeth (2014). Effects of different potential food sources on upper-bathyal benthic foraminifera: an experiment with propagules. Journal of Foraminiferal Research. ISSN 0096-1191. 44(4), s. 416–433. doi: 10.2113/gsjfr.44.4.416.
• Stüken, Anke ; Dittami, Simon; Eikrem, Wenche; McNamee, Sara; Campbell, Katrina & Jakobsen, Kjetill Sigurd [Vis alle 7 forfattere av denne artikkelen] (2013). Novel hydrolysis-probe based qPCR assay to detect saxitoxin transcripts of dinoflagellates in environmental samples. Harmful Algae. ISSN 1568-9883. 28, s. 108–117. doi: 10.1016/j.hal.2013.06.003.
• Dittami, Simon; Hostyeva, Vladyslava; Egge, Elianne Sirnæs; Kegel, Jessica U.; Eikrem, Wenche & Edvardsen, Bente (2013). Seasonal dynamics of harmful algae in outer Oslofjorden monitored by microarray, qPCR, and microscopy. Environmental Science and Pollution Research. ISSN 0944-1344. 20(10), s. 6719–6732. doi: 10.1007/s11356-012-1392-0.
• Yabuki, Akinori; Eikrem, Wenche; Takishita, Kiyotaka & Patterson, David J. (2013). Fine Structure of Telonema subtilis Griessmann, 1913: A Flagellate with a Unique Cytoskeletal Structure Among Eukaryotes. Protist. ISSN 1434-4610. 164(4), s. 556–569. doi: 10.1016/j.protis.2013.04.004.
• McCoy, Gary; Raine, Robin; Medlin, Linda K.; Chen, Jixin; Kooistra, Wiebe & Barra, Luciana [Vis alle 21 forfattere av denne artikkelen] (2012). Field testing for toxic algae with a microarray: initial results from the MIDTAL project. I Pagou, Kalliopi & Hallegraeff, Gustaaf (Red.), Proceedings of the 14th International Conference on Harmful Algae. International Society for the Study of Harmful Algae and Intergovernmental Oceanographic Commission of UNESCO. Unesco. ISSN 978-87-990827-3-5. s. 209–211. Fulltekst i vitenarkiv
• Hostyeva, Vladyslava; Eikrem, Wenche; Edvardsen, Bente & Hasle, Grethe Rytter (2012). Annual cycle of Pseudo-nitzschia species in Outer Oslofjorden, Norway. I Pagou, Kalliopi & Hallegraeff, Gustaaf (Red.), Proceedings of the 14th International Conference on Harmful Algae. International Society for the Study of Harmful Algae and Intergovernmental Oceanographic Commission of UNESCO. Unesco. ISSN 978-87-990827-3-5. s. 81–83. Fulltekst i vitenarkiv
• Ota, Shuhei; Eikrem, Wenche & Edvardsen, Bente (2012). Ultrastructure and Molecular Phylogeny of Thaumatomonads (Cercozoa) with Emphasis on Thaumatomastix salina from Oslofjorden, Norway. Protist. ISSN 1434-4610. 163(4), s. 560–573. doi: 10.1016/j.protis.2011.10.007. Vis sammendrag

  A culture of Thaumatomastix was isolated from a sediment sample collected in Oslofjorden and established as a monospecific strain (UIO286). Based on this culture, light and transmission electron microscopy and phylogenetic analyses were carried out. Thaumatomastix species are confined within the order Thaumatomonadida of the class Imbricatea and phylum Cercozoa. They are heterotrophic and their cell bodies are covered with silica scales. Observations of thin sections as well as whole mounts indicate that the morphology and ultrastructure of UIO286 is identical to T. salina, which was initially described from salt pools in Denmark. Detailed examination revealed some new features such as the presence of pseudopodia and silica deposition vesicles producing spine scales. The phylogeny presented here includes ribosomal DNA sequences from both imbricatean cultures and environmental samples. The 18S rDNA phylogenetic tree suggests that (i) Thaumatomastix is paraphyletic within the Thaumatomonadida clade, (ii) there is no close affinity between T. salina and other cultured and sequenced strains, but it is closely related to a sequence obtained from environmental DNA; we propose the present strain to serve as a reference culture of Thaumatomastix species and T. salina. Further, we discuss the distribution, habitats, and evolution of scale formation among euglyphids and thaumatomonads.

• Lømsland, Evy Rigmor; Johnsen, Torbjørn Martin & Eikrem, Wenche (2012). Observations on Chattonella globosa in Norwegian coastal waters. Are Chattonella globosa and Dictyocha fibula one species? I Pagou, Kalliopi & Hallegraeff, Gustaaf (Red.), Proceedings of the 14th International Conference on Harmful Algae. International Society for the Study of Harmful Algae and Intergovernmental Oceanographic Commission of UNESCO. Unesco. ISSN 978-87-990827-3-5. Vis sammendrag

  Chattonella globosa Y. Hara & Chihara was observed for the first time in Norway in September 2007 where it appeared in eastern Skagerrak and later on at the west coast of Norway, presumably transported there by the Norwegian Coastal Current. The highest density of 15,000 cells/L was observed in inner Oslofjorden at low light conditions in November 2007. It reoccurred in September 2008 in Skagerrak and became the dominant autumn bloom species at our monitoring station in southern Norway (Arendal st.2, E08.8167, N58.3833 (EUREF89-WGS84)), where it constituted 54% of the total algal carbon. As in the previous year, C. globosa spread to the west coast reaching densities of 53,000 cells/L in early November co-occurring with Pseudochattonella sp. and Heterosigma akashiwo. During this bloom 100 tons of caged salmon died. A special observation was made during this blooming event, where cells of C. globosa were observed containing Dictyocha fibula-like skeletons in different stages of development. This observation was confirmed for at least 11 different localities along the west coast. Our findings suggest that C. globosa and D. fibula are related and may be stages in a common life cycle.

• Edvardsen, Bente; Eikrem, Wenche; Throndsen, Jahn; Sáez, Alberto; Probert, Ian & Medlin, Linda K. (2011). Ribosomal DNA phylogenies and a morphological revision provide the basis for a revised taxonomy of Prymnesiales (Haptophyta). European journal of phycology. ISSN 0967-0262. 46(3), s. 202–228. doi: 10.1080/09670262.2011.594095. Vis sammendrag

  Nucleotide sequences of the nuclear-encoded small subunit (18S rDNA) and partial large subunit (28S rDNA) ribosomal DNA were determined in 30 different species of the haptophyte genera Prymnesium, Chrysocampanula, Chrysochromulina, Imantonia and Platychrysis, all belonging to the order Prymnesiales. Phylogenies based on these and other available haptophyte 18S, 28S and plastid 16S rDNA sequences were reconstructed, and compared with available morphological and ultrastructural data. The rDNA phylogenies indicate that the genus Chrysochromulina is paraphyletic and is divided into two major clades. This is supported by ultrastructural and morphological data. There is a major split between Chrysochromulina species with a saddle-shaped cell form (clade B2) and the remaining species in the genus (clade B1). Clade B2 includes the type species C. parva and taxa belonging to this clade thus retain the name Chrysochromulina. The non-saddle-shaped Chrysochromulina species analysed are closely related to Hyalolithus, Prymnesium and Platychrysis species. Imantonia species are sister taxa to these species within clade B1. An amendment to the classification of the order Prymnesiales and the genera Prymnesium, Platychrysis and Chrysochromulina is proposed with one new and one emended family (Chrysochromulinaceae and Prymnesiaceae, respectively), two new genera (Haptolina and Pseudohaptolina), and one new species (Pseudohaptolina arctica). We suggest a revision of the taxonomy of the Prymnesiales that is in accordance with available molecular evidence and supported by morphological data.

• Orr, Russell; Stüken, Anke ; Rundberget, Thomas; Eikrem, Wenche & Jakobsen, Kjetill Sigurd (2011). Improved phylogenetic resolution of toxic and non-toxic Alexandrium strains using a concatenated rDNA approach. Harmful Algae. ISSN 1568-9883. 10(6), s. 676–688. doi: 10.1016/j.hal.2011.05.003.
• Jouenne, Fabien; Eikrem, Wenche; Le Gall, F; Marie, Dominique; Johnsen, Geir & Vaulot, Daniel (2011). Prasinoderma singularis sp. nov. (Prasinophyceae, Chlorophyta), a Solitary Coccoid Prasinophyte from the South-East Pacific Ocean. Protist. ISSN 1434-4610. 162(1), s. 70–84. doi: 10.1016/j.protis.2010.04.005.
• Johnsen, Torbjørn Martin; Eikrem, Wenche; Olseng, Christine Daae; Tollefsen, Knut-Erik & Bjerknes, Vilhelm Otto (2010). PRYMNESIUM PARVUM: THE NORWEGIAN EXPERIENCE. Journal of the American Water Resources Association. ISSN 1093-474X. 46(1), s. 6–13. doi: 10.1111/j.1752-1688.2009.00386.x.
• Seoane, Sergio; Eikrem, Wenche; Arluzea, Jon & Orive, Emma (2009). Haptophytes of the Nervion River estuary, northern Spain. Botanica Marina. ISSN 0006-8055. 52(1), s. 47–59. doi: 10.1515/BOT.2009.027.

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• Fransson, Agneta; Bluhm, Bodil Annikki Ulla Barbro; Kohlbach, Doreen; Assmy, Philipp Kurt Wolf; Bratbak, Gunnar & Amargant, Marti [Vis alle 36 forfattere av denne artikkelen] (2024). Nansen vs. Amundsen Basin: Constrasting physico-chemical properties and biota composition to inform management.
• Eikrem, Wenche; Vader, Anna; Hofgaard, Antje & Edvardsen, Bente (2023). Phytoplankton in the Arctic Ocean - Species Composition and Biomass during the Nansen Legacy Arctic basin cruise, 24 Aug-26 Sep 202. Vis sammendrag

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

• Edvardsen, Bente & Eikrem, Wenche (2022). Haptophyte taxonomy.
• Eikrem, Wenche (2022). Haptophyte taxonomy.
• Gradinger, Rolf; Eikrem, Wenche; Amargant, Marti & Assmy, Philipp (2021). Will the future Arctic Ocean become greener?
• Lopes dos Santos, Adriana; Pollina, Thibaut; Gourvil, Priscillia; Corre, Erwan; Marie, Dominique & Garrido, José Luis [Vis alle 10 forfattere av denne artikkelen] (2020). Author Correction: Chloropicophyceae, a new class of picophytoplanktonic prasinophytes (Scientific Reports, (2017), 7, 1, (14019), 10.1038/s41598-017-12412-5). Scientific Reports. ISSN 2045-2322. 10(1). doi: 10.1038/s41598-020-63703-3.
• Edvardsen, Bente; Supraha, Luka; Gran-Stadniczeñko, Sandra; Eikrem, Wenche & John, Uwe (2020). An in-depth study of Chrysochromulina leadbeateri bloom in northern Norway during spring 2019. Vis sammendrag

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

• Gustad, Eli; Naustvoll, Lars Johan; Steinhovden, Kristine; Chauton, Matilde Skogen; Kleiven, Mona Ring & Valestrand, Louise [Vis alle 8 forfattere av denne artikkelen] (2018). Norwegian Monitoring Program for Harmful Algae.
• Eikrem, Wenche; Medlin, Linda K.; Henderiks, Jorijntje; Rokitta, Sebastian; Rost, Björn & Throndsen, Jahn [Vis alle 8 forfattere av denne artikkelen] (2017). Haptophyta. I Archibald, John M.; Simpson, Alastair G B & Slamovits, Claudio H (Red.), Handbook of the Protists. Springer Publishing Company. ISSN 978-3-319-28148-3. s. 1–61. doi: 10.1007/978-3-319-32669-6_38-1. Vis sammendrag

  Haptophyta are predominantly planktonic and phototrophic organisms that have their main distribution in marine environments worldwide. They are a major component of the microbial ecosystem, some form massive blooms and some are toxic. Haptophytes are significant players in the global carbonate cycle through photosynthesis and calcification. They are characterized by the haptonema, a third appendage used for attachment and food handling, two similar flagella, two golden-brown chloroplasts, and organic body scales that serve in species identification. Coccolithophores have calcified scales termed coccoliths. Phylogenetically Haptophyta form a well-defined group and are divided into two classes Pavlovophyceae and Coccolithophyceae (Prymnesiophyceae). Currently, about 330 species are described. Environmental DNA sequencing shows high haptophyte diversity in the marine pico- and nanoplankton, of which many likely represent novel species and lineages. Haptophyte diversity is believed to have peaked in the past and their presence is documented in the fossil record back to the Triassic, approximately 225 million years ago. Some biomolecules of haptophyte origin are extraordinarily resistant to decay and are thus used by geologists as sedimentary proxies of past climatic conditions.

• Edvardsen, Bente; Egge, Elianne Sirnæs; Stadniczenko, Sandra Gran; Johannessen, Torill Vik; Eikrem, Wenche & Sandaa, Ruth-Anne [Vis alle 10 forfattere av denne artikkelen] (2015). Diversity and seasonal dynamics of marine haptophytes and their viruses and the role of biotic interactions. Vis sammendrag

  Members of the phytoplankton division Haptophyta are a major component in marine pico- and nanoplankton communities. They often occur in bloom concentrations that may have a major impact on the global carbon balance, on climate forcing and sometimes cause fish-kills. Because haptophytes are tiny and difficult to identify in the microscope little is known about their seasonal dynamics and ecological role at the species level. Virus may terminate haptophyte blooms and, according to the “killing the winner” concept, possibly prevent blooms by keeping them under constant control. The aim of this study within the HAPTODIV project was to reveal the diversity and dynamics of marine haptophytes to species level and how this relates to abiotic factors and viruses. We assessed the haptophyte and Phycodnaviridae/ Mimiviridae (algal viruses) taxonomic composition, OTU richness and relative abundance over time by high-throughput amplicon sequencing (metabarcoding) of monthly samples over 2 years from the outer Oslofjorden, Skagerrak, Southern Norway. Metabarcoding revealed higher haptophyte diversity (156 OTUs estimating species) than previously observed in the area with electron and light microscopy (85 spp), and most (84%) of this diversity remains to be cultured and sequenced. Many may represent novel lineages at the class to genus level, or species new for science. More than half of the OTUs (93) were affiliated with the order Prymnesiales such as members of e.g. Chrysochromulina and Prymnesium. Haptophyte richness and community composition showed high temporal variation and significant yearly periodicity correlating with light and temperature, with highest richness in autumn (Sep-Nov) and lowest in the spring (Apr-May). Our results indicated, however, that the abiotic factors only accounted for about 30% of the variation, and suggest that biotic factors explain some of the residual variation. Also algal virus diversity was high and showed temporal variations with highest richness in Sept-Oct. Biotic interactions between haptophytes and algal viruses were assessed by co-occurrence analyses. We detected 56 haptophyte-virus pairs with significant co-occurrence, of 49 000 possible pairs. The distribution patterns of these pairs may shed light on the role of virus infection on phytoplankton community composition and dynamics. We suggest that this approach may be a first step to test the “killing-the-winner” concept on haptophyte diversity and distribution.

• Edvardsen, Bente; Stadniczenko, Sandra Gran; Eikrem, Wenche; Hostyeva, Vladyslava; Logares, Ramiro & Egge, Elianne Sirnæs (2014). Diversity and seasonal dynamics of small dinoflagellates in the Skagerrak, Norway revealed by 454 pyrosequencing and microscopy. Vis sammendrag

  Some dinoflagellates are small and difficult to identify under the light microscope and thus little is known about their seasonal dynamics at the species level. Here we combined high-throughput sequencing and microscopy to explore their diversity and seasonal dynamics, and relate this to environmental factors. We collected 21 monthly samples of nanoplankton (3-45 μm size fraction) from outer Oslofjorden, southern Norway over two years. The 18S V4 ribosomal DNA was amplified from RNA/cDNA and 454-pyrosequenced. The reads were cleaned, denoised and clustered to 99% in Qiime and assigned to taxon. From 46250 reads assigned to Dinoflagellata we detected 367 unique operational taxonomic units (OTUs) assessed to represent species or genera. The most OTU-rich orders were Gymnodiniales (32%), Syndiniales (22%), and Peridiniales (17%), followed by Dinophysiales (8%), Gonyaulacales (7%) and Suessiales (4%). Reads assigned to Gymnodiniales dominated in all samples except June and August 2010 when reads assigned to Suessiales dominated. We observed strong seasonal variation and significant yearly periodicity in dinoflagellate richness and species composition. OTU richness was highest in late autumn and lowest in winter-spring. Seasonal dynamics of potentially toxic taxa were examined. We also assess and discuss the ability to detect potentially toxic dinoflagellate species with 18S V4 high throughput sequencing and compare this with standard microscopical methods and electron microscopy. Potentially toxic species <45 μm observed under the microscope included e.g. Alexandrium pseudogonyaulax, A. ostenfeldii, Azadinium spinosum, Karenia mikimotoi, Karlodinium veneficum and Prorocentrum minimum.

• Edvardsen, Bente; Egge, Elianne Sirnæs; Johannessen, Torill Vik; Eikrem, Wenche; Sandaa, Ruth-Anne & Bittner, Lucie [Vis alle 10 forfattere av denne artikkelen] (2014). Diversity and seasonal dynamics of marine haptophytes and their viruses. Vis sammendrag

  Members of the division Haptophyta are phytoplankton and a major component in marine pico- and nanoplankton communities. They often occur in bloom concentrations that may have a major impact on the global carbon balance, on climate forcing and sometimes cause fish-kills. Because haptophytes are small and difficult to identify in the microscope little is known about their seasonal dynamics and ecological role at the species level. We have studied the diversity and seasonal dynamics of marine haptophytes and their viruses, and how species composition and diversity are related to environmental factors using 454 pyrosequencing, complemented with electron microscopy and flow cytometry. This study revealed higher species richness of haptophytes than previously observed in the area with electron and light microscopy. The majority of the OTUs matched genetically uncharacterised taxa, most of which were affiliated with the order Prymnesiales. Several of the OTUs matched sequences forming deep-branching lineages, potentially representing novel classes of haptophytes. Haptophyte richness and community composition exhibited high temporal variation and significant yearly periodicity, with highest richness in autumn and lowest in the spring. Some taxa, such as some bloom forming species were present all year round, whereas most coccolithophores only appeared from summer to early winter. Also the algal virus (Phycodnaviridae) diversity was high and showed seasonal variations. Our results indicated that the abiotic factors only accounted for about 30% of the variation, and suggests that biotic factors may explain some of the residual variation.

• Engesmo, Anette; Hostyeva, Vladyslava; Strand, David; Naustvoll, Lars Johan; Vrålstad, Trude & Edvardsen, Bente [Vis alle 7 forfattere av denne artikkelen] (2013). Assessing the abundance of the ichthyotoxic Karenia mikimotoi by quantitative PCR and microscopy. Vis sammendrag

  The dinoflagellate Karenia mikimotoi may form blooms causing fish kills in coastal waters of the North East Atlantic region, including Norway and Sweden. A K. mikimotoi specific quantitative PCR (qPCR) assay was developed, based on the use of SYBR Green 1. The abundance of Karenia was assessed in samples from Outer Oslofjorden (Station OF2) collected monthly from August 2011 to June 2012, and 10 stations in Skagerrak collected during a cruise in April/May 2012. According to the qPCR assay, Karenia was present in all samples at station OF2, with a peak in August and September and with very low numbers in February, March, April and May. Karenia was also identified by light microscopy of net hauls (20 μm mesh) in both August and September. Cell counts were performed on the same samples and Karenia was only recorded in September (180 000 cells L-1). At the stations of the 2012 April/May Skagerrak cruise the abundance of Karenia was either very low or below the detection limit of our qPCR assay and Karenia was not observed by microscopy in any of the corresponding cell counts or net hauls. These results demonstrate that the qPCR assay was more sensitive than traditional counting methods using light microscopy in the detection of Karenia. In addition to traditional microscopy based methods, qPCR assays can be a powerful tool in the identification and quantification of Karenia and other harmful algae and may prove especially useful if applied in early warning programs.

• Brubak, Sissel Irene; Eikrem, Wenche; Fredriksen, Stein & Edvardsen, Bente (2013). Algekultursamlingen ved Universitetet i Oslo. Vis sammendrag

  Algekultursamlingen ved Universitetet i Oslo ble startet på 1950-tallet ved avdeling for Marin botanikk til bruk i eksperimentelle og taksonomiske studier. Samlingen har gjennomgått stadige forandringer og vært preget av pågående forskningsprosjekter. I dag består samlingen av mer enn 200 stammer av eukaryote og prokaryote marine mikroalger innen algedivisjonene Haptophyta, Dinophyta, Chlorophyta, Ochrophyta, Cryptophyta, Cyanophyta, Euglenozoa og Chloraracniophyta. De fleste stammene er isolert fra norske kystfarvann og ved fortynningsserier eller kapillærisolering av ansatte ved instituttet. De dyrkes i ulike sjøvannsmedier med saltholdighet fra 10 til 40 PSU, i 7 klimarom med temperaturer fra 3 til 25 °C. Nåværende samling har blitt utviklet blandt annet for forskning relatert til alger innen divisjonen Haptophyta, og inkluderer 85 stammer av denne gruppen. Samlingen inneholder flere "type-kulturer" som representerer en ny art beskrevet av UiO-forskere, og flere toksiske stammer. Algekulturene er en sentral del av forskningen og undervisningen om mikroalgers taksonomi, fylogeni, økologi, fysiologi, kjemi, genomikk og evolusjon ved instituttet. Kulturer sendes også til andre forskere i inn- og utland. Algekultursamlingen er en verdifull ressurs som også kan utnyttes innen bioprospektering og bioteknologi.

• Edvardsen, Bente; Egge, Elianne Sirnæs & Eikrem, Wenche (2013). Morphology, phylogeny and diversity of haptophytes.
• Edvardsen, Bente; Egge, Elianne Sirnæs; Torill Vik, Johannessen; Sandaa, Ruth-Anne; Eikrem, Wenche & Larsen, Aud [Vis alle 12 forfattere av denne artikkelen] (2013). Diversity and dynamics of marine haptophytes and their viruses. Vis sammendrag

  Haptophytes are nano- and picoplanktonic microalgae and important primary producers in the sea. They often form blooms that may impact on global carbon balance and climate forcing, and at times cause fish kills. Viruses may terminate these blooms. Knowledge on haptophyte diversity, quantitative distribution and dynamics at species level is limited because they are small and fragile, and species identification usually requires electron microscopy or molecular methods. In the project HAPTODIV we have developed methods to explore the diversity and dynamics of haptophytes and their viruses, using 454-pyrosequencing, environmental clone libraries, DNA-sequencing of new isolates, pulsed field gel electrophoresis, quantitative PCR, flow cytometry and microscopy. Plankton samples and environmental data were collected monthly from the Oslofjorden and Raunefjorden for two years. A high diversity of haptophytes was revealed, and a majority of the sequences represent unknown or uncultured species. Several taxa are recorded for the first time in Norwegian and North European waters and some may represent new taxonomic lineages (orders and class). In Oslofjorden and Raunefjorden, some taxa are present at all times, such as bloom-formers in the genera Emiliania, Phaeocystis, Chrysochromulina and Prymnesium, whereas the calcifying coccolithophorids were found mainly in summer-autumn, the period with highest diversity and temperature. The diversity of virus infecting algae (Phycodnaviridae), including haptophyte specific viruses, differed over time and with locality and was highest in spring and lowest in winter. We have isolated and characterised four new haptophyte specific viruses that differ more in genome size, DNA sequence or infection cycle than previously shown. Genetic characterisation of viruses and their haptophyte hosts have revealed their diversity, and also improved our understanding of virus-host interactions and fundamental biological processes in the ocean.

• Bekkby, Trine; Rinde, Eli; Olsen, Heidi; Bøe, Reidulv; Steen, Henning & Moy, Frithjof [Vis alle 9 forfattere av denne artikkelen] (2013). Predictive habitat modeling as a tool in the Norwegian seabed mapping program.
• Egge, Elianne Sirnæs; Eikrem, Wenche; Hostyeva, Vladyslava; Andersen, Tom; Bittner, Lucie & Johannesen, Torill [Vis alle 9 forfattere av denne artikkelen] (2012). Diversity and seasonal dynamics of haptophytes in outer Oslofjorden revealed by 454 pyrosequencing.
• Egge, Elianne Sirnæs; Eikrem, Wenche; Andersen, Tom & Edvardsen, Bente (2012). HAPTODIV-Diversity and dynamics of marine haptophytes.
• Egge, Elianne Sirnæs; Eikrem, Wenche; Hostyeva, Vladyslava; Andersen, Tom; Bittner, Lucie & Johannesen, Torill [Vis alle 9 forfattere av denne artikkelen] (2012). Diversity and seasonal dynamics of haptophytes in outer Oslofjorden revealed by 454 pyrosequencing.
• Edvardsen, Bente; Egge, Elianne Sirnæs; Bittner, Lucie; Eikrem, Wenche; Audic, Stéphane & Andersen, Tom [Vis alle 9 forfattere av denne artikkelen] (2012). Diversity and dynamics of marine haptophytes as revealed by 454 pyrosequencing. Vis sammendrag

  Haptophytes are microalgae and a major component of marine plankton communities. Our aim is to provide new knowledge on the diversity and distribution of haptophytes below the genus-level, and how this is affected by environmental factors. We have developed and tested methods for analysing diversity using 454-pyrosequencing, We designed haptophyte-specific rDNA primers and constructed haptophyte databases and phylogenies for taxonomic assignation. We sequenced an artificial haptophyte community and compared the diversity and relative abundances from DNA and RNA/cDNA using various rDNA primers, and different programs to 18 remove errors from sequence data. We applied 454-pyrosequencing to samples from six European coastal sites and seasonal samples from Oslofjorden, and combined this with electron microscopy. We propose a strategy to more accurately depict the haptophyte diversity using 454-pyrosequencing and present results using this strategy.

• Hostyeva, Vladyslava; Dittami, Simon; Skylstad, Viljar Alain; Eikrem, Wenche & Edvardsen, Bente (2012). Seasonal dynamics of harmful algae in the outer Oslofjord monitored using microarrays, qPCR, and microscopy.
• Egge, Elianne Sirnæs; Eikrem, Wenche; Hostyeva, Vladyslava; Andersen, Tom; Bittner, Lucie & Johannessen, Torill Vik [Vis alle 8 forfattere av denne artikkelen] (2012). Diversity and seasonal dynamics of haptophytes in outer Oslofjorden revealed by 454 pyrosequencing.
• Edvardsen, Bente & Eikrem, Wenche (2011). Species committee for microalgae in the Norwegian Artsdatabanken.
• Edvardsen, Bente & Eikrem, Wenche (2011). Fish-killing algal problems in Norway. Vis sammendrag

  The aquaculture industry in Norway produced 940 000 metric tons salmon and trout to a value of 22 billion NOK in 2009 and is the world’s largest producer of farmed salmon. Ichthyotoxic algae may however cause large economic losses for fish farmers in Norway. Harmful algal blooms has been a threat to fish farms in Norway ever since its early era in the early70-ies. In the period 1974-1991 the dinoflagellate Karenia mikimotoi (=Gyrodinium aureolum) formed blooms almost yearly that at times discolored the water brown and caused recurrent fish kills in fish farms along the Skagerrak coast. In 1988 the haptophyte Chrysochromulina polylepis formed the possibly most extensive and toxic bloom ever recorded, killing not only farmed fish but also feral fauna and flora in the Skagerrak and Kattegat off the coasts of Norway, Sweden and Denmark. While this bloom appeared to be a unique event, the related haptophyte Prymnesium parvum formed recurrent blooms in a brackish-water fjord system in Ryfylke, W Norway that caused fish kills in the period 1989-1995. The fish farms were then moved from the most affected fjord arms and when they started up again in 2006 Prymnesium parvum again formed ichthyotoxic blooms. The haptophyte Chrysochromulina leadbeateri similarly killed farmed fish during several years (1991, 2000, 2003, and 2010) in the Lofoten area in N Norway. During the last decade another algal group has caused problems for fish farmers in Norwegian waters, the dictyochophytes, represented by Pseudochattonella and recently Dictyocha species. Pseudochattonella was for the first time recorded in bloom concentrations in N European waters in 1998, and it has been speculated whether it may have been introduced from Asia by ballast water. In 2001, Pseudochattonella formed a massive ichthyotoxic bloom in the Skagerrak and Kattegat, this time in cold waters (2-6 °C). Cultures were isolated, examined and found to represent a new species, Pseudochattonella farcimen, differing in rDNA sequence, ultrastructure and growth preferences from the previously known P. verruculosa (=Chattonella verruculosa), first reported from Japan. Since then Pseudochattonella has been recorded in the Kattegat and Skagerrak yearly and some years in bloom concentrations (e.g. 2006, 2011). The most recent ichthyotoxic algal flagellate to be recorded in Norwegian waters is the silicoflagellate Dictyocha fibula. It may occur in a naked form without the typical silica-skeleton (speculated to be identical to ‘Chattonella globosa’), in bloom concentrations together with the skeleton-bearing form. Fish-kills have occurred since 2007 along the W and S coast of Norway in waters dominated by this species. All these ichthyotoxic species have several features in common. They are nanoplanktonic (size range approx. 5-30 µm in diameter) flagellates with yellow-brown plastids of a haptophyte origin. They usually form blooms after the diatom spring bloom in stratified waters. Some have been shown to be mixotrophic. The toxin structure, production and toxicity are not well understood. Despite ample studies to elucidate factors influencing toxin production and growth we do still not fully understand what triggers the toxicity and bloom formation. Functional genomics may contribute to fill some of these gaps.

• Edvardsen, Bente; Nersveen, Lars; Torgrimsby, Tonie Leonora; Engesmo, Anette; Egge, Elianne Sirnæs & Eikrem, Wenche (2011). Diversity and distribution of nano- and picoeukaryotes in the Southern Ocean as revealed by 454-pyrosequencing, clone libraries and microscopy. Vis sammendrag

  In this study we explored the diversity and distribution of planktonic nano- and picoeukaryotes in Antarctic waters by combining 454-pyrosequencing, clone libraries and electron microscopy. Water samples were collected and physico-chemical parameters measured during summer 2008 with the Norwegian R/V G.O. Sars in the Atlantic sector of the Southern Ocean, at stations along a transect (15°E) between 45-67o S. Ribosomal DNA of plankton in the size range 0.8-35µm was amplified with universal eukaryotic and haptophyte specific primers followed by pyro- and Sanger sequencing. Most rDNA sequences could not be assigned to a cultured and sequenced species (at ≥99,3% identity level) indicating that a large fraction of the plankton community remains to be genetically characterized. Electron microscopy revealed some of this diversity, but more cultured strains are needed as reference for a precise identification. The taxonomic groups represented with highest number of clones/reads were dinoflagellates, stramenopiles and haptophytes. The species composition was significantly different at the northernmost station compared to further south, suggesting that nano- and picoeukaryote species composition and distribution may serve as indicators of climate change in polar waters.

• Eikrem, Wenche; Jouenne, Fabien; Andersen, Robert A.; O'Kelly, Charles J.; LeGall, Florence & Vaulot, Daniel (2011). GREEN, COCCOID PICOPLANKTON FROM MESOTROPHIC OCEANIC AREAS: A NEW CLADE OF GREEN ALGAE. European journal of phycology. ISSN 0967-0262. 46, s. 158–159.
• Hostyeva, Vladyslava; Eikrem, Wenche & Edvardsen, Bente (2010). Annual cycle of Pseudo-nitzschia species in the outer Oslofjord, Norway. Vis sammendrag

  Monitoring of microalgae, including toxic species like Pseudo-nitzschia , is based on light microscopy; nevertheless precise identification of Pseudo-nitzschia at the species level requires verification by electron microscopy and/or molecular biological tools. Earlier investigations from Norwegian waters have shown a considerable variation in the species composition of the genus Pseudo-nitzschia, both geographically and seasonally. The genus contains more than 30 species and many of them are found in Norwegian waters (e.g. P. delicatissima, P. fraudulenta, P. granii, P. heimii, P. pungens, P. multiseries, P. calliantha. P. seriata and P. americana). Several species of Pseudo-nitzschia have been shown to be toxic, including P. seriata, P. callianta, P. delicatissima, P. multiseries and P. fraudulenta, which all may occur in Norwegian waters. Vertical net tows (0-20 m), quantitative water samples and hydrographical data have been collected monthly over one year, from June 2009 to June 2010, in the outer Oslofjord, southern Norway. The succession of Pseudo-nitzschia species have been recorded from acid cleaned samples viewed in the scanning electron microscope and transmission electron microscope. The abundance of Pseudo-nitzschia species has been determined and related to hydrographical conditions. The ability to produce domoic acid varies between species, thus a precise identification and knowledge about their geographical and seasonal occurrence at the species level is important to early warning systems serving the aquaculture industry.

• Nersveen, Lars; Eikrem, Wenche; Andersen, Tom & Edvardsen, Bente (2010). Diversity and distribution of nano- and picoplankton in Antarctic and Arctic waters. Vis sammendrag

  Information on the diversity, distribution and abundance of pico- (0.2-2 µm) and nano-plankton (2-20 µm), that cannot be identified to species level under the light microscope, is still limited. The aim of this study is to explore the pico- and nano-eukaryotic diversity and distribution in Antarctic and Arctic waters by advanced microscopy and molecular biological techniques, such as environmental clone libraries and 454-pyrosequencing. Another aim is to obtain new information on the influence of environmental factors on the plankton biodiversity and species composition in polar waters. Water samples and net hauls were collected and physical and chemical parameters measured during austral summer 2008 with the Norwegian R/V G.O. Sars in the Atlantic sector of the Southern Ocean, at stations along a N-S transect between 45-67o S at 15°E. During summer 2009, stations were sampled with the R/V Lance along an E-W transect from Spitsbergen into the Fram Strait. The Antarctic transect was conducted in open ocean, while the Arctic took place in a fjord, open ocean and along the ice edge. Water samples were size fractioned (>3, 45-3 and 3-0.6 µm) by filtration on board, for DNA isolation and analysis in the laboratory. Clone libraries are under construction and massive parallel tag sequencing will be tried to explore the diversity of planktonic pico- and nanoeukaryotes and their distribution along the transects. Light and scanning electron microscopy will be used as a comparison. We have a focus on the algal division Haptophyta, an important component of the pico- and nano-plankton community in the ocean. The study may give new information on plankton diversity and distribution in polar waters, as well as on differences in ecosystem functioning between the Southern Ocean and Arctic waters.

• Engesmo, Anette; Eikrem, Wenche; Lundholm, Nina & Edvardsen, Bente (2010). Fragilariopsis and Pseudo-nitzschia species (Bacillariophyceae) in the Antarctic and Arctic: distribution, morphology and genetic variation. Vis sammendrag

  The pennate diatom genera Pseudo-nitzschia and Fragilariopsis are common components of the phytoplankton community in Antarctic and Arctic waters and are important primary producers. Cryptic and pseudo-cryptic species of these genera occur, and electron microscopy and molecular methods are here required for a precise species identification. The aim of this study is to determine which species of Pseudo-nitzschia and Fragilariopsis that are present in different polar water masses, which species appear to be bipolar, and do strains from Antarctic and Arctic waters differ morphologically and genetically. The material from the Atlantic sector of the Southern Ocean was collected during a cruise with R/V G.O. Sars during summer 2008 along a N-S transect at 15°E between 45-67°S, while the material from the Arctic was collected along a E-W transect from Svalbard into Fram Strait summer 2009 with R/V Lance. Water samples, net hauls, and hydrographical data were collected and algal cultures started onboard on both cruises. More than 50 diatom strains from Antarctic and about 20 from Arctic waters have been established. Preserved and live algal material have been examined in the light and electron microscope, and 8 different Fragilariopsis species were observed from one Antarctic station. The cultured strains have been identified to species by electron microscopy (SEM and TEM) and analysed genetically, using coding (LSU) and non-coding (ITS) ribosomal DNA sequences as markers. Genetic examination of Fragilariopsis from the Antarctic shows that ITS, but not LSU rDNA can discriminate between closely related species. Our ITS rDNA sequence data suggests two genotypes in culture of the F. cylindrus and F. nana ‘species-complex’, differing from those previously reported. Our results will link morphology with genetic signature and geographic origin, and will give new knowledge on their genetic variability and distribution.

• Oug, Eivind; Christie, Hartvig C; Eikrem, Wenche; van der Meeren, Gro Ingleid; Nilssen, Kjell Tormod & Lorentsen, Svein-Håkon (2010). Kyst (bunn og pelagisk). I Nybø, Signe (Red.), Naturindeks for Norge 2010.. Direktoratet for naturforvaltning. ISSN 978-82-7072-419-2. s. 46–59. Vis sammendrag

  Formålet med å etablere en naturindeks for Norge er å få en oversikt over den samlede utviklingen til biologisk mangfold og avklare hvorvidt vi klarte å stanse tapet av biologisk mangfold innen utgangen av 2010. Arbeidet er det første forsøket på å etablere en helhetlig indeks for Norge, og deltakere fra mange forskningsdisipliner har bidratt i prosjektet. For å lage indeksen har man valgt ut en rekke indikatorer som samlet skal gi et representativt bilde av tilstanden til biologisk mangfold. Naturindeksen inkluderer indikatorer som reflekterer bestandsendringer hos arter, men også indirekte indikatorer (som for eksempel død ved). Det er totalt benyttet ca 309 indikatorer som dekker viktige aspekter ved biologisk mangfold. Data om indikatorene er samlet inn fra eksperter som har gitt estimater av indikator verdier på flere tidspunkter på grunnlag av ekspertvurderinger, overvåkingsdata eller bestandsmodeller. For å kunne sette sammen dataene til en indeks, har en referansetilstand blitt beregnet for hver indikator. Referansetilstanden reflekterer en økologisk bærekraftig tilstand for indikatoren, og indikatorverdiene viser eventuelle avvik fra denne tilstanden. Denne utredningen dokumenterer datagrunnlaget for hver enkelt indikator som inngår i datasettet. biologisk mangfold, tilstand, naturindeks, ferskvann, hav, kystvann, myr, åpent lavland, fjell, skog, biodiversity, condition, state, Nature Index, freshwater, sea, coastal waters, mire, semi-natural habitats, mountain, forest

• Orr, Russell; Stüken, Anke ; Rundberget, Thomas; Eikrem, Wenche & Jakobsen, Kjetill Sigurd (2010). Improved phylogenetic resolution of toxic and non-toxic Alexandrium strains using a concatenated rDNA approach.
• Orr, Russell; Stüken, Anke ; Rundberget, Thomas; Eikrem, Wenche & Jakobsen, Kjetill Sigurd (2010). Improved phylogenetic resolution of toxic and non-toxic Alexandrium strains using a concatenated rDNA approach.
• Eikrem, Wenche; Valestrand, Louise; Norli, Marit; Harvey, E. Therese & Saesin, Pipatthra (2024). Årsovervåking med FerryBox og satelllittdata – Indre Oslofjord 2023 – datarapport. Norsk institutt for vannforskning. ISSN 978-82-577-7709-8. Fulltekst i vitenarkiv
• Christensen, Guttorm; Mannvik, Hans Petter; Sperre, Kristine Hopland; Dahl-Hansen, Ida; Siwertsson, Anna & Aasen, Anne Tårånd [Vis alle 16 forfattere av denne artikkelen] (2023). ØKOKYST – delprogram Norskehavet Nord, Årsrapport 2022. Miljødirektoratet.
• Christensen, Guttorm; Larsen, Lars-Henrik; Siwertsson, Anna; Fredriksen, Rosalyn; Mannvik, Hans Petter & Sperre, Kristine Hopland [Vis alle 16 forfattere av denne artikkelen] (2023). Økokyst – delprogram Barentshavet, Årsrapport 2022. Miljødirektoratet.
• Dankel, Eli; Supraha, Luka; Edvardsen, Bente; Eikrem, Wenche & Saubrekka, Karoline (2023). Arktiske kalkflagellater: et morfologisk og molekylært dypdykk i det nordlige Barentshavet. Universitetet i Oslo. Vis sammendrag

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

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

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

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

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

• Trannum, Hilde C.; Bekkby, Trine; Borgersen, Gunhild; Crespo, Bibiana; Eikrem, Wenche & Fagerli, Camilla With [Vis alle 10 forfattere av denne artikkelen] (2023). Økokyst - DP Nordsjøen, Årsrapport 2022. Norsk institutt for vannforskning. ISSN 978-82-577-7635-0. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – Økokyst" har til hensikt å overvåke miljøtilstanden langs norskekysten i henhold til vannforskriften. Økokyst delprogram Nordsjøen dekker kyststrekningen fra Lista til Sognefjorden. 21 vannforekomster inngikk. Av disse fikk fem vannforekomster «moderat» tilstand, to «svært god» tilstand og de resterende fikk «god» tilstand. Det var hovedsakelig oksygen som trakk ned tilstanden, og i Jøsenfjorden også bløtbunnsfauna.

• Egge, Elianne; Deininger, Anne; Bekkby, Trine; Eikrem, Wenche; Mengeot, Caroline & Frigstad, Helene [Vis alle 12 forfattere av denne artikkelen] (2023). ØKOKYST – DP Norskehavet Sør, Årsrapport 2022. Norsk institutt for vannforskning. ISSN 978-82-577-7634-3. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – Økokyst" har til hensikt å overvåke miljøtilstanden langs norskekysten i henhold til vannforskriften. Økokyst delprogram Norskehavet Sør dekker kyststrekningen fra Ulsteinvik i sør til Helgeland i nord. Av de ni vannforekomstene som kunne klassifiseres i 2022 fikk én samlet «svært god» tilstand, sju «god» tilstand, mens én fikk «moderat» tilstand, der oksygenverdier i bunnvann trakk ned. De to ålegress-stasjonene var lokalisert i samme vannforekomst og fikk begge “god” tilstand. I tillegg til parameterne brukt til klassifisering ble klimaparameterne dyreplankton, lys og organisk materiale overvåket ved én stasjon i vannforekomst Steinsfjorden nær Ulsteinvik.

• Eikrem, Wenche; Valestrand, Louise; Harvey, E. Therese; Saesin, Pipatthra; Berezina, Anfisa & Tobiesen, August E.Dessen (2023). Årsovervåkning med FerryBox og satellittdata- Indre Oslofjord 2022 - Datarapport. Norsk institutt for vannforskning. ISSN 978-82-577-7595-7. Fulltekst i vitenarkiv Vis sammendrag

  Denne rapporten presenterer resultatene fra årsovervåkningen utført for Fagrådet for vann- og avløpsteknisk samarbeid i indre Oslofjord i 2022 med bruk av NIVAs FerryBox system for måling og prøveinnsamling og fjernmålingsdata fra Copernicus-satellittene Sentinel-2 og 3. Høyoppløselige sensor-data fra FerryBox med observasjoner hver andre dag illustrerer frekvensen og intensiteten til algeblomstringene i fjorden godt og at de kan ha en varighet på under 2 uker. Med månedlig prøvetagning kan man miste informasjon om flere oppblomstringer. De øvrige sensordataene viser utviklingen av andre miljøog klimavariabler. Satellittdata ga en god romslig dekning av fjorden og gjorde det mulig å følge utviklingen av klorofyll-a i tid og rom. Det var god overensstemmelse mellom in situ data og satellitt data, men satellitt data viste i perioder (april og oktober) høyere verdier. For mange stasjoner kunne antallet observasjoner fordobles og for andre med få eller ingen in situ observasjoner ga satellitt nye data. Samsvaret mellom satellittdata og in situ data var god.

• Walday, Mats Gunnar; Borgersen, Gunhild; Gitmark, Janne Kim; Engesmo, Anette; Fagerli, Camilla With & Staalstrøm, Andre [Vis alle 8 forfattere av denne artikkelen] (2023). Revisjon av kystvannsdelen av veileder 02:2018. Norsk institutt for vannforskning. ISSN 978-82-577-7592-6. Fulltekst i vitenarkiv Vis sammendrag

  NIVA har på oppdrag fra Miljødirektoratet utført oppgaver relatert til kystvannsdelen av veileder 02:2018 «Klassifisering av miljøtilstand i vann». Rapporten gir en beskrivelse av gjennomført arbeid og en rekke konkrete innspill til revisjon av veilederen. Innspillene omfatter anbefalinger for både støtteparametere og de biologiske kvalitetselementene planteplankton, makroalger og bløtbunn. Det gis også anbefalinger om behov for videre arbeid med veilederen.

• Dale, Trine; Eikrem, Wenche; Glåmseter, Øystein; Feest, Patricio; Cisterna, Fernanda & Refseth, Gro Harlaug [Vis alle 12 forfattere av denne artikkelen] (2023). Hvordan forebygge og håndtere episoder med skadelige alger og maneter i oppdrettsnæringen. Norsk institutt for vannforskning. ISSN 978-82-577-7579-7. Fulltekst i vitenarkiv Vis sammendrag

  Dette er hovedrapport for prosjektet «Hvordan forebygge og håndtere episoder med skadelige alger og maneter i oppdrettsnæringen» finansiert av Fiskeri og havbruksnæringens forskningsfinansiering. Hovedmålet i prosjektet har vært å sammenstille eksisterende kunnskap, erfaringer og teknologiske løsninger som er i bruk for å forebygge og håndtere episoder med skadelige alger og maneter og basert på dette utforme og formidle anbefalinger og om mulig beste praksis i ulike situasjoner. Det er utviklet en prototype av et verktøy som på en enkel og lettfattelig måte fremstiller anbefalinger og beste praksis samt kunnskapen som danner bakgrunn for disse.

• Fransson, Agneta; Bluhm, Bodil; Arumi, Marti A.; Assmann, Karen; Gravelle, Amalie M. & Bratrein, Marius [Vis alle 34 forfattere av denne artikkelen] (2022). The Nansen Legacy Report Series. No. 30 - Joint Cruise 2-2 2021: Cruise report. UiT Norges arktiske universitet. ISSN 2703-7525.
• Andersen, Jesper Harbo; Kallenbach, Emilie; Kjeldgaard, Mathias Brink; Knudsen, Steen Wilhelm; Eikrem, Wenche & Fagerli, Camilla With [Vis alle 21 forfattere av denne artikkelen] (2022). A baseline study of the occurrence of non-indigenous species in Danish harbours. Norsk institutt for vannforskning. ISSN 978-82-577-7505-6. Fulltekst i vitenarkiv Vis sammendrag

  We report the first ever nation-wide study of the occurrence of non-indigenous species in Danish harbours. The sampling was car-ried out using both conventional and biomolecular methods (eDNA). In total, 16 harbours were covered – Esbjerg and Aarhus, the two largest harbours in Denmark, with intensive sampling and 14 harbours with a reduced programme. 26 non-indigenous species were recorded using conventional sampling and 13 species were recorded using eDNA-based methods. Excluding overlapping rec-ords, we have recorded a total of 34 non-indigenous species in the 16 harbours studied. Based on the results, we conclude the following: 1) more non-indigenous species are found in the western parts of Denmark (North Sea region) then in the eastern parts (Baltic Sea), and 2) a few species previously unseen in Danish marine waters were recorded, i.e. the two bristle worms Eteone het-eropoda (fam. Phyllodocidae) and Streblospio benedicti (fam. Spionidae). Further, we provide a proof-of-concept regarding the overarching objectives of the MONIS 1-3 projects and the eDNA-based test systems developed. The results constitute a baseline for future studies in Danish ports and other hotspot areas.

• Deininger, Anne; Bekkby, Trine; Trannum, Hilde Cecilie; Borgersen, Gunhild; Eikrem, Wenche & Fagerli, Camilla With [Vis alle 12 forfattere av denne artikkelen] (2022). ØKOKYST – DP Norskehavet Sør, Årsrapport 2021. Norsk institutt for vannforskning. ISSN 978-82-577-7482-0. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – Økokyst" har til hensikt å overvåke miljøtilstanden langs norskekysten i henhold til vannforskriften. Økokyst delprogram Norskehavet Sør dekker kyststrekningen fra Ulsteinvik i sør til Helgeland i nord. Av de 11 vannforekomster som kunne klassifiseres, fikk 1 “svært god” tilstand, 7 «god» tilstand og 3 «moderat» tilstand. Tilstanden var minst “god” for makroalger, bløtbunnsfauna og planteplankton, mens det var støtteparameterne og ålegress som trakk ned tilstanden på stasjonene hvor samlet tilstand kun ble «moderat».

• Trannum, Hilde Cecilie; Bekkby, Trine; Borgersen, Gunhild; Deininger, Anne; Eikrem, Wenche & Fagerli, Camilla With [Vis alle 13 forfattere av denne artikkelen] (2022). Økokyst - DP Nordsjøen, Årsrapport 2021. Norsk institutt for vannforskning. ISSN 978-82-577-7481-3. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – Økokyst" har til hensikt å overvåke miljøtilstanden langs norskekysten i henhold til vannforskriften. Økokyst delprogram Nordsjøen dekker kyststrekningen fra Lista i sør til Sognefjorden i nord. Av de 19 vannforekomster som kunne klassifiseres, fikk 6 “svært god” tilstand, 10 «god» tilstand og 3 «moderat» tilstand. Tilstanden var minst “god” for makroalger, bløtbunnsfauna og planteplankton, mens det var støtteparameterne og ålegress som trakk ned tilstanden på stasjonene hvor samlet tilstand kun ble «moderat». Utover parameterne som kunne klassifiseres, ble dyreplankton, lys og andre “klimaparametere” overvåket på én stasjon i Sognefjorden. The monitoring program "Ecosystem Monitoring in Coastal Water - Økokyst" aims at monitoring the environmental status along the Norwegian coast according to vannforskriften (the Water Framework Directive). Subprogram Nordsjøen includes the coastline from Lista in south to Sognefjorden in north. Of the 19 water bodies that could be classified, 6 obtained «very good» state, 10 obtained “good” state and 3 “moderate” state. The state was at least “good” for macroalgae, soft bottom fauna and phytoplankton, while it was the supporting elements and sea grass which reduced the state for the stations where the overall state was only “moderate”. In addition to the parameters that could be classified, zooplankton, light and other “climate parameters” were monitored at one station in Sognefjorden.

• Fagerli, Camilla With; Trannum, Hilde Cecilie; Staalstrøm, Andre; Eikrem, Wenche; Deininger, Anne & Sørensen, Kai [Vis alle 7 forfattere av denne artikkelen] (2022). Økokyst – DP Skagerrak. Årsrapport 2020. Norsk institutt for vannforskning. ISSN 978-82-577-7486-8. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – Økokyst" har til hensikt å overvåke miljøtilstanden i utvalgte områder langs norskekysten i henhold til vannforskriften. Delprogram Skagerrak omfatter 14 vannforekomster lokalisert i Ytre Oslofjord og Grenlands- fjordene. Samlet tilstand i vannforekomstene varierte fra “dårlig” til “god” tilstand i 2020. Blant undersøkte biologiske kvalitetselementer, er det særlig makroalge-samfunnene som viser en negativ trend. Totalt fem av åtte makroalgestasjoner oppnår «moderat» tilstand i 2020.

• Fagerli, Camilla With; Trannum, Hilde Cecilie; Golmen, Lars Gunder; Eikrem, Wenche & Mengeot, Caroline (2021). Økokyst – DP Norskehavet Sør (II). Årsrapport 2020. Norsk institutt for vannforskning. ISSN 978-82-577-7366-3. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – ØKOKYST" har til hensikt å overvåke miljøtilstanden i utvalgte områder langs norskekysten i henhold til vannforskriften. Delprogram Norskehavet Sør II omfatter områdene Trondheimsfjorden/Fosen, Namsfjorden og Helgeland. Samlet klassifisering av vannforekomstene varierer fra «moderat» til «svært god» tilstand, hvorav fire vannforekomster viste «moderat» tilstand i 2020. Det er i hovedsak vannmassestasjonene og støtteparametere som trekker tilstanden ned.

• Trannum, Hilde Cecilie; Golmen, Lars Gunder; Eikrem, Wenche & Mengeot, Caroline (2021). Økokyst – DP Norskehavet Sør (I). Årsrapport 2020. . Norsk institutt for vannforskning. ISSN 978-82-577-7365-6. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – Økokyst" har til hensikt å overvåke miljøtilstanden langs norskekysten i henhold til vannforskriften. Delprogram Norskehavet Sør I omfatter områdene Ulsteinvik og Geirangerfjorden, hvor det i 2020 ble overvåket planteplankton og støtteparametere. Samlet tilstand ble «god» for vannforekomsten Herøyfjorden-Røyrasundet, men kun «moderat» for Steinsfjorden og Geirangerfjorden.

• Dale, Trine; Eikrem, Wenche; Fagerli, Camilla With; Kristiansen, Trond; Trannum, Hilde Cecilie & Valestrand, Louise (2021). ØKOKYST Delprogram Nordsjøen Nord, Årsrapport 2020. Norsk institutt for vannforskning. ISSN 978-82-577-7364-9. Fulltekst i vitenarkiv Vis sammendrag

  Økokyst-delprogram Nordsjøen Nord består av tolv vannforekomster hvorav åtte ble undersøkt i 2020. I områdene Aurlandsfjorden og Sognefjorden ble hele grunnprogrammet gjennomført, mens det i områdene Korsfjorden, Fusa/Bjørnafjorden og Hardangerfjorden kun var prøvetakning av vannmasser. Prøvetakningen inkluderte syv pelagiske stasjoner (hvorav en FerryBox stasjon), tre bløtbunnstasjoner og syv hardbunnstasjoner. Alle undersøkte vannforekomster tilfredsstiller kravet om minst «god» økologisk tilstand. Vannforekomstene Korsfjorden og Bjørnafjorden fikk samlet tilstand «svært god». Vannforekomstene Aurlandsfjorden, Sognefjorden, Sognesjøen, Maurangerfjorden, Samlafjorden og Nyhammarsundet fikk samlet tilstand «god».

• Walday, Mats Gunnar; Fagerli, Camilla With; Frigstad, Helene; Staalstrøm, Andre; Kaurin, Maria & Christensen, Guttorm [Vis alle 8 forfattere av denne artikkelen] (2020). Evaluering av ØKOKYST - stasjonsnett og klassegrenser. Norsk institutt for vannforskning. ISSN 978-82-577-7262-8. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – ØKOKYST" har til hensikt å overvåke miljøtilstanden i utvalgte områder langs norskekysten i henhold til vannforskriften. Miljødirektoratet har bedt NIVA gjennomgå resultatene fra alle delprogrammene i ØKOKYST for de ulike biologiske kvalitetselementene for å vurdere: 1. Tilsier resultatene så langt at vi har "truffet" på valg av trend- og referansestasjoner, eller burde noen stasjoner omdefineres (fra trend til referanse eller motsatt)? 2. Er det enkelte stasjoner som åpenbart bør flyttes for å dekke opp behovet for både trend og referansestasjoner? 3. Hvilke åpenbare mangler i stasjonsnettverket hindrer utarbeidingen av et komplett klassifiseringssystem for økologisk tilstand i kystvann? Vurderingen er gjort for hvert enkelt delprogram, og de foreslåtte endringer er sammenfattet i et eget kapittel i slutten av rapporten. I tillegg er det gitt en kort beskrivelse av området og miljøtilstanden for stasjonene i hvert enkelt delprogram. I det avsluttende kapittelet er det gjort noen generelle og overordnede betraktninger og gitt forslag for utforming og utførelse av ØKOKYST-programmene.

• Golmen, Lars Gunder; Eikrem, Wenche; Fagerli, Camilla With; Staalstrøm, Andre; Mengeot, Caroline & Frigstad, Helene (2020). ØKOKYST – DP Norskehavet Sør (II). Årsrapport 2019. Norsk institutt for vannforskning. ISSN 978-82-577-7240-6. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – ØKOKYST" har til hensikt å overvåke miljøtilstanden i utvalgte områder langs norskekysten i henhold til vannforskriften. Delprogram Norskehavet Sør II omfatter områdene Trondheimsfjorden/Fosen, Namsfjorden og Helgeland. Stasjon VR52 og VR31 viser «svært god» tilstand for planteplankton men støtteparametere trekker tilstanden ned til «god». Samlet økologisk tilstand vurderes dermed som «god» for alle stasjoner/ vannforekomster (7 totalt) som inngår i delprogrammet i 2019.

• Fagerli, Camilla With; Trannum, Hilde Cecilie; Staalstrøm, Andre; Eikrem, Wenche; Sørensen, Kai & Marty, Sabine [Vis alle 8 forfattere av denne artikkelen] (2020). ØKOKYST – DP Skagerrak. Årsrapport 2019. Norsk institutt for vannforskning. ISSN 978-82-577-7239-0. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – ØKOKYST" har til hensikt å overvåke miljøtilstanden i utvalgte områder langs norskekysten i henhold til vannforskriften. Delprogram Skagerrak omfatter 14 vannforekomster lokalisert i Ytre Oslofjord og Grenlandsfjordene. Samlet tilstand i vannforekomstene varierte fra “dårlig” til “god” tilstand i 2019. Undersøkelser over tid viser en særlig negativ trend for makroalger, hvor fem av totalt åtte undersøkte hardbunnstasjoner oppnår dårligere tilstand enn «god» for makroalger i 2019.

• Dale, Trine; Eikrem, Wenche; Ledang, Anna Birgitta; Kristiansen, Trond & Frigstad, Helene (2020). ØKOKYST Delprogram Nordsjøen Nord, Årsrapport 2019. Norsk institutt for vannforskning. ISSN 978-82-577-7238-3. Fulltekst i vitenarkiv Vis sammendrag

  I ØKOKYST-delprogram Nordsjøen Nord var det kun prøvetakning av vannmasser i 2019. Den samlede vurderingen av vannforekomstene baserer seg på undersøkelse av det biologiske kvalitetselementet planteplankton samt fysisk-kjemiske støtteparametere. Av de tolv vannforekomstene i delprogrammet, ble ni prøvetatt i 2019. Det var tilstrekkelig datagrunnlag til å foreta endelig tilstandsklassifisering i alle vannforekomstene. Vannforekomstene Sognesjøen, Korsfjorden og Fusa-Bjørnafjorden fikk samlet tilstand «Meget god». De øvrige vannforekomstene fikk alle samlet tilstand «God».

• Trannum, Hilde Cecilie; Fagerli, Camilla With; Golmen, Lars Gunder; Eikrem, Wenche; Frigstad, Helene & Staalstrøm, Andre (2020). ØKOKYST – DP Norskehavet Sør (I). Årsrapport 2019. Norsk institutt for vannforskning. ISSN 978-82-577-7235-2. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – ØKOKYST" har til hensikt å overvåke miljøtilstanden i utvalgte områder langs norskekysten i henhold til vannforskriften. Delprogram Norskehavet Sør I omfatter områdene Ulsteinvik og Geirangerfjorden. Alle de biologiske kvalitetselementene oppnådde minst “god” tilstand, men samlet tilstand ble “god” eller “moderat” i de undersøkte vannforekomstene.

• Norli, Marit; Valestrand, Louise & Eikrem, Wenche (2020). Årsovervåking med FerryBox - Indre Oslofjord 2018 - Datarapport. Norsk institutt for vannforskning. ISSN 978-82-577-7231-4. Fulltekst i vitenarkiv Vis sammendrag

  Her rapporteres resultatene fra 2018 for årsovervåkingen med FerryBox i Indre Oslofjord for 2018. Undersøkelsene omfatter fysiske, kjemiske og biologiske forhold målt med FerryBox om bord på MS Color Fantasy. Målingene omfatter sensormålinger mellom 59.7-59.9 °N i Vestfjorden, og vannprøvetakinger på stasjonen Dk1 tatt ved hjelp av en automatisk prøvetaker om bord på fartøyet. Året var preget av sesongmessige variasjoner i temperatur og saltholdighet, med en relativt lang periode med lav saltholdighet. Klorofyll a mengden i produksjonsperioden lå mellom <0,3 og 10,0 μg klorofyll a L-1 med en biomasse maksimum i mars.

• Sørensen, Kai; Eikrem, Wenche; Valestrand, Louise; Kristiansen, Trond & Norli, Marit (2020). Årsovervåking med FerryBox - Indre Oslofjord 2019 - Datarapport. Norsk institutt for vannforskning. ISSN 978-82-577-7232-1. Fulltekst i vitenarkiv Vis sammendrag

  Her rapporteres resultatene for årsovervåkingen med FerryBox i Indre Oslofjord for 2019. Undersøkelsene omfatter fysiske, kjemiske og biologiske forhold målt med FerryBox om bord på MS Color Fantasy. Målingene omfatter sensormålinger mellom 59.7-59.9 °N i Vestfjorden, og vannprøvetakinger på stasjonen Dk1 tatt ved hjelp av en automatisk prøvetaker om bord på fartøyet. Temperaturen i vannet var litt varmere på vinteren og kaldere om sommeren sammenliknet med 2018 og saltholdighet noe høyere. Næringssalter lå som normalt for fjorden med innholdet av oppløst organisk materiale litt lavere enn 2018. Klorofyll-a mengden i produksjonsperioden lå mellom 1 og 4 μg klorofyll-a L-1 med biomasse maksimum i april (våroppblomstringen) og juni. Utviklingen av planteplanktonsamfunnet, mengden av planteplankton og artsrikdommen var i 2019 innenfor det som regnes for normalt i Oslofjorden.

• Walday, Mats Gunnar; Borgersen, Gunhild; Beylich, Bjørnar; Eikrem, Wenche; Gitmark, Janne Kim & Naustvoll, Lars Johan [Vis alle 8 forfattere av denne artikkelen] (2019). Overvåking av Ytre Oslofjord i 2014-2018. 5-årsrapport. Norsk insitutt for vannforskning. ISSN 978-82-577-7158-4. Fulltekst i vitenarkiv Vis sammendrag

  Siden 2001 har tilstanden i Ytre Oslofjord blitt overvåket i regi av Fagrådet for Ytre Oslofjord. Undersøkelsene gir informasjon om forurensende tilførsler til fjordområdet og om miljøtilstanden på bunnen og i vannmassene. Hovedvekten er på beskrivelse av tilførsler og effekter av næringssalter. Overvåkingen har i perioden 2007-2018 vært utført som et samarbeid mellom NIVA og Havforskningsinstituttet. Denne rapporten oppsummerer og drøfter resultater fra overvåkingen i perioden 2014-2018, også i forhold til andre relevante undersøkelser og tidligere overvåking i de samme havområder. Sist i rapporten er det et det også et kapittel med spesialtema om vannsirkulasjonen i Drammensfjorden.

• Dale, Trine; Fagerli, Camilla With; Trannum, Hilde Cecilie; Eikrem, Wenche; Ledang, Anna Birgitta & Kristiansen, Trond (2019). ØKOKYST Delprogram Nordsjøen Nord, Årsrapport 2018. Norsk insitutt for vannforskning. ISSN 978-82-577-7120-1. Fulltekst i vitenarkiv Vis sammendrag

  I ØKOKYST-delprogram Nordsjøen Nord ble deler av grunnprogrammet gjennomført i 2018. Prøvetakningen inkluderte 8 pelagiske stasjoner, 6 hardbunnstasjoner og 5 bløtbunnstasjoner, hvorav 2 pelagiske, 2 hardbunns og 1 bløtbunnstasjon var tilleggsundersøkelser (opsjoner). En stasjon fra Ferrybox er også inkludert i 2018-programmet. Det inngår 12 vannforekomster i delprogram Nordsjøen Nord, og 11 av disse ble prøvetatt i 2018. Tilstanden varierte fra «Dårlig» til «Meget god» i 2018. Vannforekomsten Maurangsfjorden fikk tilstand «Dårlig», og redusert tilstand var knyttet til kvalitetselementet makroalger. Vannforekomsten Aurlandsfjorden fikk tilstand «Moderat». Her var redusert tilstand knyttet til kvalitetselementet klorofyll-a. 5 av vannforekomstene fikk «God» tilstand, mens de resterende 4 fikk tilstand «Meget god».

• Fagerli, Camilla With; Trannum, Hilde Cecilie; Staalstrøm, Andre; Eikrem, Wenche; Gitmark, Janne Kim & Marty, Sabine [Vis alle 7 forfattere av denne artikkelen] (2019). ØKOKYST – DP Skagerrak. Årsrapport 2018. Norsk insitutt for vannforskning. ISSN 978-82-577-7119-5. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – ØKOKYST" har til hensikt å overvåke miljøtilstanden i utvalgte områder langs norskekysten i henhold til vannforskriften. Delprogram Skagerrak omfattet i 2018 14 vannforekomster lokalisert i Ytre Oslofjord og Grenlandsfjordene. Samlet tilstand i vannforekomstene varierte fra «dårlig» til «god» tilstand i 2018.

• Trannum, Hilde Cecilie; Fagerli, Camilla With; Golmen, Lars Gunder; Eikrem, Wenche & Staalstrøm, Andre (2019). ØKOKYST – DP Norskehavet Sør (I). Årsrapport 2018. Norsk insitutt for vannforskning. ISSN 978-82-577-7118-8. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – ØKOKYST" har til hensikt å overvåke miljøtilstanden i utvalgte områder langs norskekysten i henhold til vannforskriften. Delprogram Norskehavet Sør I omfatter områdene Ulsteinvik og Geirangerfjorden. Alle de biologiske kvalitetselementene oppnådde minst “god” tilstand, men samlet tilstand ble «god» eller «moderat» fordi støtteparameterene trakk ned tilstanden.

• Eikrem, Wenche; Golmen, Lars Gunder; Fagerli, Camilla With; Kristiansen, Trond; Staalstrøm, Andre & Engesmo, Anette (2019). ØKOKYST – DP Norskehavet Sør (II). Årsrapport 2018. Norsk insitutt for vannforskning. ISSN 978-82-577-7116-4. Fulltekst i vitenarkiv Vis sammendrag

  Overvåkingsprogrammet "Økosystemovervåking i Kystvann – ØKOKYST" har til hensikt å overvåke miljøtilstanden i utvalgte områder langs norskekysten i henhold til vannforskriften. I 2018 omfattet delprogram Norskehavet Sør (II) totalt 7 stasjoner (inkl. 4 FerryBox-stasjoner) med prøvetaking av det biologiske kvalitetselementet planteplankton samt fysisk-kjemiske støtteparametere. Stasjonene er lokalisert i områdene Trondheimsfjorden/Fosen, Namsfjorden og Helgeland. Tilstanden til de syv vannforekomstene i undersøkelsesområdet varierte fra «moderat» til «svært god» tilstand i 2018.

• Norli, Marit & Eikrem, Wenche (2018). Årsovervåking med FerryBox - Indre Oslofjord 2017-Datarapport. Norsk institutt for vannforskning. ISSN 978-82-577-7001-3. Fulltekst i vitenarkiv Vis sammendrag

  Her rapporteres resultatene fra 2017 for årsovervåkingen med FerryBox i Indre Oslofjord for 2017. Undersøkelsene omfatter fysiske, kjemiske og biologiske forhold målt med FerryBox om bord på MS Color Fantasy. Målingene omfatter sensormålinger mellom 59.7-59.9 °N i Vestfjorden, og vannprøvetakinger på stasjonen Dk1 tatt ved hjelp av en automatisk prøvetaker om bord på fartøyet. Året var preget av sesongmessige variasjoner i temperatur og saltholdighet. Klorofyll a mengden i produksjonsperioden lå mellom 1 og 6.5 μg klorofyll a L-1 med en biomasse maksimum i mars målt som cellekarbon.

• Frigstad, Helene; Trannum, Hilde Cecilie; Andersen, Guri Sogn; Kristiansen, Trond; Norli, Marit & Gitmark, Janne Kim [Vis alle 9 forfattere av denne artikkelen] (2017). Klima-overblikk: Sammenstilling av klimarelevante resultater fra utvalgte overvåkingsprogram i kystsonen. Norsk institutt for vannforskning. ISSN 978-82-577-6949-9. Fulltekst i vitenarkiv Vis sammendrag

  Miljødirektoratet drifter Økosystemovervåking i kystvann (ØKOKYST), Elvetilførselsprogrammet, Havforsuringsprogrammet og finansierer delvis programmet Marin hardbunnsfauna langs kysten av Nord-Norge og Svalbard. NIVA gir i denne rapporten en kvalitativ oversikt over klimarelevante parametere i nevnte overvåkingsprogram. Rapporten sammenstiller klimarelevante resultater og gir råd og anbefalinger for å øke klimarelevansen innenfor rammen av hvert program og på tvers av programmene. I tillegg er det laget en oversikt over datatilgjengeligheten for de ulike overvåkingsprogrammene i Vannmiljø, og det blir diskutert kvantitative analyser til en opsjon.

• Andersen, Jesper Harbo; Brink, Mathias; Kallenbach, Emilie; Hesselsøe, Martin; Knudsen, Steen W. & Støttrup, Josianne G. [Vis alle 10 forfattere av denne artikkelen] (2017). Sampling protocol for monitoring of non-indigenous species in selected Danish harbours. Norsk institutt for vannforskning. ISSN 978-82-577-6910-9. Fulltekst i vitenarkiv Vis sammendrag

  The sampling protocol is a product of the MONIS 4 project, or in full “Monitoring of non-indigenous species in selected Danish harbours”. Sampling will take place using a broad range of methods, both conventional sampling methods and sampling of water and subsequent analyses of DNA remains of a total of 20 species on the Danish non-indigenous target species list. Groups of organisms covered by this study include: (1) phytoplankton, (2) zooplankton, (3) softbottom com- munities (infauna and epifauna), (4) hardbottom communities (both flora and fauna), as well as (5) fish. The results of this comprehensive sampling effort in 16 Danish harbours is planned to be reported by Summer 2018. Data will after publication of the report be submitted to relevant data repositories.

• Bekkby, Trine; Kile, Maia Røst; Brkljacic, Marijana Stenrud; Tveiten, Lise Ann; Eikrem, Wenche & Brænden, Roar (2017). Kartlegging av ålegrasenger (Zostera marina) etter ny metodikk i Innherred samkommune. Norsk institutt for vannforskning. ISSN 978-82-577-6868-3. Fulltekst i vitenarkiv Vis sammendrag

  Det er viktig at forvaltere og planleggere har god oversikt og kunnskap om områder som er viktige for biologisk mangfold. Innherred samkommune ønsket derfor en oppdatert status for kjente ålegrasenger og kartlegging av mulige enger som tidligere ikke har vært registrert. Ålegrasengene ble kartlagt 11-14. juli 2016. Feltkartleggingen foregikk med vannkikkert i de grunnere områdene og undervannskamera fra båt i de dypere områdene. Feltkartleggingen, avgrensing og verdisetting ble utført etter omforent metode, utarbeidet i Nasjonalt program for kartlegging av biologisk mangfold – kyst. Av de 27 registrerte ålegrasengene var det to A-områder (nasjonal verdi), ett B-område (regional verdi) og 24 C-områder (lokal verdi). Totalt areal for alle ålegrasengene var 581 742 m2. Den største engen var 202 395 m2 (Eidsbotn sørvest), og den minste kun 740 m2(Falstadbukta midt). Dypeste observerte punkt med ålegras varierte fra 0,3 m til 3,1 m. Dersom man sammenligner ålegrasengene slik de ble kartlagt nå (2016) med avgrensingen som ble gjort i 2009/2010 er det en del endringer, noen enger har blitt mindre, andre har blitt fragmentert. Nedre voksegrense har ikke endret seg siden 2009/2010. Det har heller ikke andelen av punktene med middels tett og tett ålegras.

• Bekkby, Trine & Eikrem, Wenche (2012). Økosystemtjenester i Nordsjøen - regulerende og støttende økosystemtjenester diskutert gjennom tre naturtyper. Klima- og forurensningsdirektoratet.

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