Viser treff 1181-1200 av 2040

    • Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system 

      Klutsch, Cornelya; Maduna, Simo; Polikarpova, Natalia; Forfang, Kristin; Aspholm, Paul Eric; Nyman, Tommi; Eiken, Hans Geir; Amundsen, Per-Arne; Hagen, Snorre (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-29)
      Habitat discontinuity, anthropogenic disturbance, and overharvesting have led to population fragmentation and decline worldwide. Preservation of remaining natural genetic diversity is crucial to avoid continued genetic erosion. Brown trout (<i>Salmo trutta</i> L.) is an ideal model species for studying anthropogenic influences on genetic integrity, as it has experienced significant genetic alterations ...
    • A rapid preparation procedure for laser microdissection‑mediated harvest of plant tissues for gene expression analysis 

      Olsen, Stian; Krause, Kirsten (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-02)
      <p><i>Background - </i>Gene expression changes that govern essential biological processes can occur at the cell-specific level. To gain insight into such events, laser microdissection is applied to cut out specific cells or tissues from which RNA for gene expression analysis is isolated. However, the preparation of plant tissue sections for laser microdissection and subsequent RNA isolation usually ...
    • Incomplete degradation of lichen usnic acid and atranorin in Svalbard reindeer (Rangifer tarandus platyrhynchus) 

      Węgrzyn, Michał Hubert; Wietrzyk-Pełka, Paulina; Galanty, Agnieszka; Cykowska-Marzencka, Beata; Sundset, Monica Alterskjær (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-22)
      Previous studies of Eurasian tundra reindeer (<i>Rangifer tarandus tarandus</i>) in Norway indicate that their rumen microbiota play a key role in degrading lichen secondary metabolites. We investigated the presence of usnic acid and atranorin in faecal samples from Svalbard reindeer (<i>R. tarandus platyrhynchus</i>). Samples were collected in Bolterdalen valley together with vegetation samples ...
    • Seasonal and ontogenetic variation in the infection of intestinal parasites in Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) in a subarctic lake. 

      Prati, Sebastian (Master thesis; Mastergradsoppgave, 2019-05-14)
      The vast majority of studies in northern lake systems have been carried out on a short-term scale, principally during spring and summer and mostly focusing on a single parasite species. There are few winter studies of fish parasites in the subarctic area, and even less regarding seasonal variations in the sub-communities of intestinal parasites in Arctic charr (Salvelinus alpinus) and brown trout ...
    • Seasonal dynamics of the marine CO2 system in Adventfjorden, a West Spitsbergen fjord 

      Ericson, Ylva; Chierici, Melissa; Falck, Eva; Fransson, Agneta Ingrid; Jones, Elizabeth Marie; Kristiansen, Svein (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-11)
      Time series of the marine CO<sub>2</sub> system and related parameters at the IsA Station, by Adventfjorden, Svalbard, were investigated between March 2015 and November 2017. The physical and biogeochemical processes that govern changes in total alkalinity (TA), total dissolved inorganic carbon (DIC) and the saturation state of the calcium carbonate mineral aragonite (Ω<sub>Ar</sub>) were assessed ...
    • Drones as a tool to monitor human impacts and vegetation changes in parks and protected areas 

      Ancin-Murguzur, Francisco Javier; Munoz, Lorena; Monz, Christopher; Hausner, Vera H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-04)
      Increased visitation to protected areas could have adverse impacts on the conservation values in the protected areas, and therefore effective visitor monitoring methods are needed to meet the complex management challenges that arise. Collecting data on human impacts is highly time consuming, thus requiring more effective tools that allow for high-quality and long-term measurements. In this study, ...
    • Drones and marine mammals in Svalbard 

      Palomino Gonzalez, Albert (Master thesis; Mastergradsoppgave, 2019-07-15)
      The impact of Remote Piloted Aircraft Systems (RPAS, or drones) on marine mammals remains poorly documented despite their increasing use by hobbyists and scientists. In the High-Arctic Archipelago of Svalbard, where marine mammals are facing increasing pressure from the coupled effects of climate modification and an expanding tourism industry, the use of RPAS remains largely unregulated to date. In ...
    • A patch of Calanus finmarchicus in the Lofoten-Vesterålen Region. Characteristics and determining factors 

      Santana Hernández, Néstor (Master thesis; Mastergradsoppgave, 2019-05-16)
      Zooplankton patchiness has been documented in many shelf areas and is of vital importance for understanding predator-prey relationships in pelagic marine systems. By combining hydrographic, acoustic and net data collected in spring 2017, we present a detailed understanding of the extent of this phenomenon in the Lofoten-Vesterålen region. Such patches are of potential interest not only for zooplankton ...
    • Advection of Mesozooplankton Into the Northern Svalbard Shelf Region 

      Wassmann, Paul; Slagstad, Dag; Ellingsen, Ingrid H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-14)
      The northern Svalbard shelf region is part of the Atlantic advective contiguous domain along which nutrients, phyto- and mesozooplankton are advected with Atlantic Water from the Norwegian Sea along the Norwegian shelf break and into the Arctic Ocean. By applying the SINMOD model, we investigated how much mesozooplankton may be advected into the northern Svalbard shelf region. We also compared this ...
    • Tidewater glaciers and bedrock characteristics control the phytoplankton growth environment in a fjord in the arctic 

      Halbach, Laura; Vihtakari, Mikko; Duarte, Pedro; Everett, Alistair; Granskog, Mats; Hop, Haakon; Kauko, Hanna Maria; Kristiansen, Svein; Myhre, Per Inge; Pavlov, Alexey K.; Pramanik, Ankit; Tatarek, Agnieszka; Torsvik, Tomas; Wiktor, Józef Maria; Wold, Anette; Wulff, Angela; Steen, Harald; Assmy, Philipp (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-31)
      Meltwater discharge from tidewater glaciers impacts the adjacent marine environment. Due to the global warming, tidewater glaciers are retreating and will eventually terminate on land. Yet, the mechanisms through which meltwater runoff and subglacial discharge from tidewater glaciers influence marine primary production remain poorly understood, as data in close proximity to glacier fronts are scarce. ...
    • A glimpse into the biogeography, seasonality, and ecological functions of arctic marine Oomycota 

      Hassett, Brandon Thomas; Thines, Marco; Buaya, Anthony; Ploch, Sebastian; Gradinger, R. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-20)
      High-latitude environments are warming, leading to changes in biological diversity patterns of taxa. <i>Oomycota</i> are a group of fungal-like organisms that comprise a major clade of eukaryotic life and are parasites of fish, agricultural crops, and algae. The diversity, functionality, and distribution of these organisms are essentially unknown in the Arctic marine environment. Thus, it was our ...
    • A way forward with eco evo devo: an extended theory of resource polymorphism with postglacial fishes as model systems 

      Skulason, Skuli; Parsons, Kevin J; Svanback, Richard; Räsänen, Katja; Ferguson, Moira M; Adams, Colin Ean; Amundsen, Per-Arne; Bartels, Pia; Bean, Colin W.; Boughman, Janette W.; Englund, Göran; Gudbrandsson, Johannes; Hooker, Oliver E.; Hudson, Alan G; Kahilainen, Kimmo Kalevi; Knudsen, Rune; Kristjánsson, Bjarni Kr.; Leblanc, Camille A-L; Jonsson, Zophonias; Ohlund, Gunnar; Smith, Carl; Snorrason, Sigurdur S (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-19)
      A major goal of evolutionary science is to understand how biological diversity is generated and altered. Despite considerable advances, we still have limited insight into how phenotypic variation arises and is sorted by natural selection. Here we argue that an integrated view, which merges ecology, evolution and developmental biology (eco evo devo) on an equal footing, is needed to understand the ...
    • Zooplankton communities associated with new and regenerated primary production in the Atlantic inflow north of Svalbard 

      Svensen, Camilla; Halvorsen, Elisabeth; Vernet, Maria; Franzè, Gayantonia; Dmoch, Katarzyna; Lavrentyev, Peter J.; Kwasniewski, Slawomir (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-05)
      The Arctic Ocean is changing rapidly with respect to ice cover extent and volume, growth season duration and biological production. Zooplankton are important components in the arctic marine food web, and tightly coupled to the strong seasonality in primary production. In this study, we investigate zooplankton composition, including microzooplankton, copepod nauplii, as well as small and large copepod ...
    • DNA metabarcoding of deep-sea sediment communities using COI: community assessment, spatio-temporal patterns and comparison with the 18S rDNA marker 

      Atienza Casas, Sara (Master thesis; Mastergradsoppgave, 2019-06-15)
      The deep sea is the largest biome on Earth, albeit it is the least studied. Among the complex ecosystems and habitats that form the deep sea, submarine canyons and open slope systems are regarded to be potential hot-spots of biodiversity. The Mediterranean Sea hosts the 8.86% of the inventoried submarine canyons in the global ocean, like the Blanes Canyon, located in its Northwestern section. We ...
    • Cardiotoxic Effects from the Water-Soluble Fraction of Crude Oil on an Arctic Keystone Species – Polar Cod (Boreogadus saida) 

      Teisrud, Ragnar Nicolaysen (Master thesis; Mastergradsoppgave, 2019-05-23)
      The Arctic ecosystems and its species are under increased anthropogenic pressure from both climate change and industrial activities. Of special interest is pollution from petrogenic substances, and in particular accidental oil spills, that pose a risk to arctic marine organisms. An oil spill in the Arctic may see crude oil encapsulated into the sea ice and over time leaching to surface waters in the ...
    • Documenting lemming population change in the Arctic: Can we detect trends? 

      Ehrich, Dorothée; Schmidt, Niels M.; Gauthier, Gilles; Alisauskas, Ray; Angerbjörn, Anders; Clark, Karin; Ecke, Frauke; Eide, Nina E.; Framstad, Erik; Frandsen, Jay; Franke, Alastair; Gilg, Olivier; Giroux, Marie-Andrée; Henttonen, Heikki; Hörnfeldt, Birger; Ims, Rolf A.; Kataev, Gennadiy D.; Kharitonov, Sergey P.; Killengreen, Siw T.; Krebs, Charles J.; Lanctot, Richard B.; Lecomte, Nicolas; Menyushina, Irina E.; Morris, Douglas W.; Morrisson, Guy; Oksanen, Lauri; Oksanen, Tarja; Olofsson, Johan; Pokrovsky, Ivan G.; Yu, Igor; Reid, Donald; Roth, James D.; Saalfeld, Sarah T.; Samelius, Gustaf; Sittler, Benoit; Sleptsov, Sergey M.; Smith, Paul A.; Sokolov, Alekstandr A.; Sokolova, Natalya A.; Soloviev, Mikhail Y.; Solovyeva, Diana V. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-22)
      Lemmings are a key component of tundra food webs and changes in their dynamics can affect the whole ecosystem. We present a comprehensive overview of lemming monitoring and research activities, and assess recent trends in lemming abundance across the circumpolar Arctic. Since 2000, lemmings have been monitored at 49 sites of which 38 are still active. The sites were not evenly distributed ...
    • Comparison of eyfluke (Diplostomum spp.) infections of polymorphic whitefish (Coregonus lavaretus L.) populations in two sub-Arctic Norwegian lakes 

      Øie, Ida (Master thesis; Mastergradsoppgave, 2018-08-15)
      Abstract Parasites might be small, but they are very important elements in the ecosystems. Parasites may have a strong negative influence on their host, and some species might even manipulate their hosts. Parasites commonly have complex life cycles and may use multiple different hosts. This study has been conducted in two sub-arctic lakes in Northern Norway with polymorphic whitefish populations. ...
    • Alien plants, animals, fungi and algae in Norway: an inventory of neobiota 

      Sandvik, Hanno; Dolmen, Dag; Elven, Reidar; Falkenhaug, Tone; Forsgren, Elisabet; Hansen, Haakon; Hassel, Kristian; Husa, Vivian; Kjærstad, Gaute; Ødegaard, Frode; Pedersen, Hans Christian; Solheim, Halvor; Stokke, Bård Gunnar; Åsen, Per Arvid; Åström, Sandra Charlotte Helene; Brandrud, Tor Erik; Elven, Hallvard; Endrestøl, Anders; Finstad, Anders Gravbrøt; Fredriksen, Stein; Gammelmo, Øivind; Gjershaug, Jan Ove; Gulliksen, Bjørn; Hamnes, Inger Sofie; Hatteland, Bjørn Arild; Hegre, Hanne; Hesthagen, Trygve H.; Jelmert, Anders; Jensen, Thomas Correll; Johnsen, Stein Ivar; Karlsbakk, Egil; Magnusson, Christer; Nedreaas, Kjell Harald; Nordén, Björn; Oug, Eivind; Pedersen, Oddvar; Pedersen, Per Anker; Sjøtun, Kjersti; Skei, Jon Kristian; Solstad, Heidi; Sundheim, Leif; Swenson, Jon; Syvertsen, Per Ole; Talgø, Venche; Vandvik, Vigdis; Westergaard, Kristine Bakke; Wienerroither, Rupert; Ytrehus, Bjørnar; Hilmo, Olga; Henriksen, Snorre; Gederaas, Lisbeth (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-03)
      We present the results of an inventory and status assessment of alien species in Norway. The inventory covered all known multicellular neobiota, 2496 in total, 1039 of which were classified as naturalised. The latter constitute c. 3% of all species known to be stably reproducing in Norway. These figures are higher than expected from Norway’s latitude, which may be due a combination of ...
    • Decomposition in differing snow regimes in high Arctic Svalbard 

      Heavyside, Paige Kathryn (Master thesis; Mastergradsoppgave, 2019-05-29)
      Rapidly rising temperatures are having great effects on the high arctic ecosystem, historically characterized by long, cold winter periods, and cold dry summers. Due to the length of the winter season, arctic soils have been an important carbon sink, but may now be facing increased microbial activity due to increasing temperatures. Temperature, moisture, and litter quality play important roles in ...
    • Cardiotoxic Effects from the Water-Soluble Fraction of Crude Oil on an Arctic Keystone Species – Polar Cod (Boreogadus saida) 

      Teisrud, Ragnar Nicolaysen (Master thesis; Mastergradsoppgave, 2019-05-23)
      Abstract The Arctic ecosystems and its species are under increased anthropogenic pressure from both climate change and industrial activities. Of special interest is pollution from petrogenic substances, and in particular accidental oil spills, that pose a risk to arctic marine organisms. An oil spill in the Arctic may see crude oil encapsulated into the sea ice and over time leaching to surface ...