Now showing items 141-160 of 391

    • The metabolism of lean and fat hooded seal pups (Cystophora cristata): how fat contributes to the total metabolic rate 

      Evertsen, Agnete Pedersen (Master thesis; Mastergradsoppgave, 2021-05-17)
      Hooded seal pups are highly adapted to their proximate environment from the moment they are born. They are born with a substantial blubber layer, and they gain 20+ kg of body mass during their short nursing-period (2-4 days). With the body mass gained during nursing mainly being a result of fat deposition, it made them an excellent model to use when studying the fat metabolism and its contribution ...
    • The behaviour of anadromous Arctic charr during their first marine migration 

      Nordli, Eivind (Master thesis; Mastergradsoppgave, 2021-05-17)
      Climate change-induced alterations of aquatic ecosystems, increased water temperature and human activity are substantial stressors to anadromous Arctic charr, and these are all expected to increase in the future. The knowledge of the marine behaviour of anadromous Arctic charr, especially post-smolts, is limited and few studies has described their residency at sea in detail. Therefore, more ...
    • Transcriptomic basis for differentiation of fjord and offshore Boreogadus saida (Polar cod) populations 

      Hill, Griffin (Master thesis; Mastergradsoppgave, 2021-05-16)
      Boreogadus saida (Polar cod) is a critical ecological linkage between planktonic primary production and megafaunal top consumers in the Arctic. Despite its critical ecology, the population structure, especially the relationship between fjord and oceanic groups inhabiting environments with different physical characteristics, is poorly described. Though the subject of several genetic studies, an ...
    • Vegetation-environment analysis of areas with peat accumulation and hummock formation in the context of NiN (Natur i Norge). A study from Laggu, Gamvik municipality, Troms and Finnmark county. 

      Plathe, Elin Karin (Master thesis; Mastergradsoppgave, 2021-05-18)
      A conspicuous type of heath and forest with peat accumulation and hummock formation in terrestrial systems has been investigated in Laggu, Gamvik municipality in northern Norway. The aim was to describe vegetational composition, soil depth and hummock distribution, and identify environmental factors that cause terrestrial peat accumulation. Vascular plants, bryophytes and lichens were registered ...
    • Changes in fat metabolism in the seasonal body mass cycle of captive Svalbard rock ptarmigan (Lagopus muta hyperborea) 

      Aspelund, Linn (Master thesis; Mastergradsoppgave, 2021-05-12)
      The Svalbard ptarmigan exhibits profound seasonal variations in body mass. The deposition of fat in the fall is an adaptation that allows the ptarmigan to survive periods of food shortages during the Arctic winter. In this study, previously unexplored molecular aspects of this well- established body mass cycle were investigated. Captive Svalbard ptarmigan fed ad libitum and kept under short photoperiod ...
    • Let it glow! Adapting a method to detect microplastics in snow and evaluate the potential for long-range transport 

      Stürzinger, Vegard (Master thesis; Mastergradsoppgave, 2020-05-31)
      Harmonization of methods in microplastics research is lacking; this is affecting the comparability of results and hindering reproducibility. Investigating microplastics in snow is a relatively new field of research, and it can be used to answer questions about long-range atmospheric transport of microplastics. In this thesis, snow sampling methods were combined with the dye, Nile Red, to develop a ...
    • Spring sea ice algal development in the sub-Arctic Ramfjorden, northern Norway 

      Persson, Emma (Master thesis; Mastergradsoppgave, 2020-05-29)
      The seasonal development of sea ice algae and bacteria was investigated in Ramfjorden, Norway, from February to April 2019 and compared to data from two Arctic fjords, Van Mijenfjorden and Billefjorden, sampled in April 2019. The sea ice in Ramfjorden was heavily freshwater influenced with bulk salinities ranging from 0.0 to 2.8, similar to those found in freshwater influenced Baltic Sea ice. The ...
    • Fecundity and egg size in anadromous brown trout Salmo trutta 

      Rinaldo, Adrian (Master thesis; Mastergradsoppgave, 2020-05-31)
      Historically, anadromous salmonids provided a necessary provisioning service for Norwegian coastal settlements that has transitioned into the socio-cultural service that they provide today. Over the past decades, human impact has caused anadromous salmonid populations to decline. A recent assessment found many Norwegian sea trout populations to be in poor condition. Reference point management has ...
    • Linking methane fluxes and oxidation rates to methane oxidizing bacteria in an Arctic terrestrial methane seep, Svalbard 

      Nagel, Franziska (Master thesis; Mastergradsoppgave, 2020-05-29)
      Global warming has especially detrimental effects on Arctic regions. One major issue is permafrost thaw and sub-permafrost methane escape via surface seeps. While the mitigation potential of methane-consuming bacteria on marine pingo-like methane seeps is well described, terrestrial methane seeps are still understudied. Recently, open system pingos have gained attention as terrestrial methane seeps. ...
    • Hibernation in European Hamsters (Cricetus crisetus): An assessment of brain permeability during torpor-arousal cycling 

      Markussen, Fredrik Andreas Fasth (Master thesis; Mastergradsoppgave, 2020-05-22)
      Hibernation is a physiological and behavioural adaptation that permits survival during seasonal periods of energy shortage via a combination of pre-hibernal energy storage and hibernal metabolic depression, i.e. torpor. The central mechanisms in the brain that control torpor expression and arousal from it has been under investigation since the dawn of hibernation research but remains unknown. Recent ...
    • Feeding ecology and interactions of invasive vendace and DR whitefish in the Pasvik watercourse 

      Høstmark, Malin Solheim (Master thesis; Mastergradsoppgave, 2021-02-15)
      Introductions and invasions of species outside their natural range can have devastating effects on the native species and be a major driver of biodiversity change. When the zooplanktivorous vendace invaded the Pasvik watercourse in the 1990s, it quickly took over the ecological role of the native DR whitefish. In the upper part of the watercourse, DR whitefish was displaced from the pelagic habitat ...
    • Gastrointestinal nematodes in Icelandic reindeer (Rangifer tarandus tarandus) 

      Dembereldagva, Selengemurun (Master thesis; Mastergradsoppgave, 2021-01-18)
      Reindeer (<i>Rangifer tarandus</i>) are host to gastrointestinal-tract nematodes (GINs) throughout the world. Some populations of reindeer exist in almost complete isolation from others, and this can have a key influence on the species and infection rates of GINs. An example of an isolated reindeer population occurs in Iceland. In this study, I have investigated the prevalence of GINs in Icelandic ...
    • Fibroblast in vitro stimulation with TGFβ1 and bFGF; αSMA expression and S100A4 immunohistochemistry staining in oral cancer 

      Alexopoulou, Eirini (Master thesis; Mastergradsoppgave, 2020-12-16)
      Oral squamous cell carcinoma (OSCC) is an aggressive cancer associated with high mortality rates. The objective of this master project was to test the following hypotheses: (1) transforming growth factor β1 (TGFβ1) activates fibroblasts in vitro and basic fibroblast growth factor (bFGF) deactivates them while both increase fibroblast proliferation in cancer associated fibroblasts (CAFs); (2) the ...
    • Within-Season Trends in Abundance and Distribution of Humpback Whales (Megaptera novaeangliae) in the Antarctic Peninsula Region 

      Johannessen, John Elling Deehr (Master thesis; Mastergradsoppgave, 2020-12-15)
      Fine-scale knowledge of cetacean abundance and distribution throughout the Antarctic Peninsula (AP) is lacking yet essential for effective ecosystem-based fisheries management (EBFM). We investigated an important area both for migratory humpback whales (Megaptera novaeangliae) and Antarctic krill (Euphausia superba) fisheries to assess potential spatio-temporal interactions, for use in adaptive EBFM ...
    • The effect of climate change on the fish community in Lille Rostavatn, northern Norway 

      Dalbak, Katrine (Master thesis; Mastergradsoppgave, 2020-12-21)
      Over the last 20 years there has been a large change in the fish community structure in Lille Rostavatn, northern Norway. The relative contribution of the cold-water adapted fish species, Arctic charr (<i>Salvelinus alpinus</i>) and burbot (<i>Lota lota</i>), has distinctly decreased whereas the more temperate-adapted fish species, grayling (<i>Thymallus thymallus</i>) and brown trout (<i>Salmo ...
    • Hydrocarbon biodegradation potential in environmental bacterial metagenome 

      Caro Pascual, Alicia (Master thesis; Mastergradsoppgave, 2020-12-15)
      Hydrocarbon pollution in marine environments present an acute problem which is aggravated by cold temperatures. This is especially relevant in important environmental and economic northern regions such as the Barents Sea. The Barents Sea region has become the focus of oil industries from Russia and Norway, incrementing the risk of hydrocarbon pollution. Bioremediation is a cost-effective and ...
    • Variation in epiphytic vegetation in spruce plantations and adjacent native birch forests in North Norway 

      Nilsen, Kjersti Wannebo (Master thesis; Mastergradsoppgave, 2007-05)
      Epiphytic vegetation can contribute to increased knowledge on how planting of spruce in areas where spruce does not occur naturally in the landscape can affect the environment. In the current study, 31 spruce plantations in Troms and Vesterålen in North Norway were investigated, with emphasis on species abundance of macrolichens on tree trunks and branches. The main assumption was that planting of ...
    • Mercury in fish from a subarctic watercourse and its relation to trophic ecology 

      Henriksson, Matilda (Master thesis; Mastergradsoppgave, 2020-11-16)
      Mercury (Hg) contamination in aquatic ecosystems is a serious concern because it can bioaccumulate and biomagnify to harmful concentrations within a food web and consequently end up in humans that eat polluted fish. The Pasvik watercourse, located in the border area between Norway, Finland and Russia, is strongly affected by the emissions of heavy metals from nearby Russian metallurgic smelters. In ...
    • Foraging behaviour of humpback whales (Megaptera novaeangliae): Automatic detection of feeding lunges from two-dimensional data 

      Pedersen, Maren Andrea (Master thesis; Mastergradsoppgave, 2020-09-10)
      Rorqual whales (Family Balaenopteridae) forage almost exclusively by performing so-called feeding lunges. It is difficult to study rorqual foraging behaviour through direct observation because most of the lunges are carried out deep in the water column. The introduction of high-resolution digital tags recording three-dimensional (3D) acceleration has allowed for the collection of complex movement ...
    • The influence of herring (Clupea harengus) biomass and distribution on killer whale (Orcinus orca) movements on the Norwegian shelf 

      Vogel, Emma F. (Master thesis; Mastergradsoppgave, 2020-06-01)
      Killer whales (Orcinus orca) have a cosmopolitan distribution with a broad diet ranging from fish to marine mammals. Regional populations show local prey specialization and their movements are tightly linked to those of their prey. Norwegian killer whales are known to feed extensively on Norwegian spring spawning (NSS) herring (Clupea harengus). Over the last decade, killer whales have begun to ...