Now showing items 61-80 of 379

    • Morphological variation in the redfish (Sebastes spp.) complex in Norwegian waters 

      Bruvold, Ingrid Marie (Master thesis; Mastergradsoppgave, 2021-06-02)
      The golden redfish Sebastes norvegicus is a long-lived commercial species of redfish in the North Atlantic. Excessive harvest through decades has led to a decline in the mature population in Norwegian waters, which is currently considered to be severely depleted. Accumulating genetic evidence suggest a more complex structure within the Sebastes genus in the North Atlantic, which has recently formed ...
    • Inflammatory responses in lumpfish (Cyclopterus lumpus L.) vaccinated at different water temperatures with intraperitoneal injection 

      Knutsen, Ingrid Svihus (Master thesis; Mastergradsoppgave, 2021-05-18)
      The use of lumpfish (Cyclopterus lumpus L.) as cleaner fish in salmonid aquaculture for the biological control of sea lice infestation levels has increased in recent years. The species is relatively new to aquaculture and susceptible to various infectious agents. The health situation for lumpfish is currently considered poor, indicating the necessity for developing more efficient vaccines. Studying ...
    • Plastic occurrence in six different species of Arctic seabirds - Harmonizing methods and closing knowledge gaps on plastic occurrence and polymer identity 

      Benjaminsen, Stine Charlotte (Master thesis; Mastergradsoppgave, 2021-05-18)
      The once pristine Arctic is now facing negative alterations with a rapidly changing climate, increasing human activity, and plastic pollution. Seabirds are intrinsic to the marine ecosystems, and in recent years, plastic ingestion by seabirds has been of increasing concern because of the potential negative impact on individual and population levels. The aim of this study was to investigate the plastic ...
    • Snow depth effects on vegetation dynamics and development of near-remote sensing techniques in high-Arctic tundra 

      Jørgensen, Andreas (Master thesis; Mastergradsoppgave, 2022-05-16)
      Snow exerts key controls on many aspects of plant ecology in the Arctic, including community composition. With climate predictions forecasting dramatic changes in winter climate and snow cover in the Arctic in the near future, it is important to improve our understanding of snow effects on plant communities in these regions. This study used a snow depth manipulation experiment established in 2006 ...
    • Timing is everything: Within-plant flowering phenology impacts fruit production in the Arctic-Alpine cushion plant Silene acaulis (L.) Jacq. 

      Ween, Rebekka Eriksen (Master thesis; Mastergradsoppgave, 2022-05-16)
      Timing is everything for Arctic flowering plants. Early flowers might be destroyed by frost, while late flowers have less time and resources to mature fruit. With climate change, Arctic flowering phenology is shifting. Yet for many species, phenology studies only encompass the onset of flowering and lack baseline data on within-plant flowering times. I used the gynodioecious cushion plant Silene ...
    • Effect of simulated disturbance by geese on soil temperature and active layer thickness over one growing season 

      Holm, Hildur Søndergaard (Master thesis; Mastergradsoppgave, 2022-05-13)
      The Arctic is an area predicted to be strongly affected by climate change, and the extent of permafrost is expected to decrease. The insulating capacity of bryophytes is central in permafrost preservation. In High-Arctic Svalbard, disturbance by geese through grubbing may damage and remove parts of the bryophyte layer in moss tundra. The disruption is expected to lead to increased soil temperatures ...
    • Spatiotemporal distribution and co-occurrence of Arctic herbivores in spring 

      Grimsby, Anna Caroline (Master thesis; Mastergradsoppgave, 2022-04-19)
      Biotic interactions play an important role in the structure and dynamics of food-webs and may drive the spatial distribution of species. In the Arctic, spring snow-cover limits the availability of resources at a critical time for resident and migratory herbivores, which could lead to resource competition. This study takes a first step towards understanding the potential for competition between the ...
    • Lipids and diapause in Calanus spp. in a high-Arctic fjord: state-dependent strategies? Tracking lipids through the polar night 

      Bailey, Allison M. (Master thesis; Mastergradsoppgave, 2010-11-15)
      Calanus copepods C. finmarchicus, C. glacialis and C. hyperboreus are keystone species in the Arctic marine ecosystem, constituting 70-90% of the zooplankton biomass. In high latitudes, the growing season is short and unpredictable, and the winter long and unproductive. These species have adapted flexible life histories, lipid accumulation, and a state of deep-water diapause to survive. Winter ...
    • Metabolomic and genomic investigation of two North-Norwegian cyanobacterial isolates for bioprospecting of new compounds 

      Norum Kirkesæther, Ane (Master thesis; Mastergradsoppgave, 2022-02-15)
      Cyanobacteria are an excellent source of bioactive natural products that can be used in the development of new medicinal drugs. The cyanobacterial genus Nostoc have proven to be prolific producers of molecules with exciting bioactivities, including anti-bacterial, anti-fungal, and anti-cancerous. This feature combined with the Nostoc’s complex life cycle and sizeable genomes make them interesting ...
    • Historic changes in abundance, biomass and taxonomic composition of seaweed-associated fauna in Kongsfjorden, Svalbard 

      Niklass, Jessica (Master thesis; Mastergradsoppgave, 2022-11-15)
      The Arctic is warming rapidly. Atmospheric temperatures in the Barents Sea region are increasing 5 – 7 times faster than the global average. As a result, Arctic sea ice extent is declining by nearly 12% per decade during the summer months. The study site in Kongsfjorden, Svalbard, has been mostly ice free since 2006. These changes in the physical environment likely affect the ecology of coastal ...
    • Experimental evidence for species-specific adherence of nanoplastic particles in Arctic phytoplankton communities 

      Miettinen, Anna (Master thesis; Mastergradsoppgave, 2022-11-15)
      Plastic debris are ubiquitous, and the Arctic is no exception. Despite the relatively low population number around the Arctic, abundances of microplastic litter are like those of the most polluted subtropical areas. Micro- and nanoplastics have been found in Arctic fauna, but due to constraints in methodology, measurements of nanoplastics in sea water have not been carried out yet. Micro- and ...
    • A spatial and temporal study of Pseudocalanus acuspes, P. minutus and P. moultoni in the Svalbard – Barents Sea region and their potential as environmental indicator species in a changing Arctic 

      Astad, Sine-Sara (Master thesis; Mastergradsoppgave, 2022-11-22)
      <p>Many species of small copepods are morphologically similar and thus often grouped together at genus level rather than studied as individual species. However, species within the same genus may differ quite a lot in life history strategies and traits. In this study, I used a species-specific polymerase chain reaction to explore the abundance, distribution and size range of <i>Pseudocalanus</i> ...
    • Drivers of behavioural transition in foraging adult female southern elephant seals (Mirounga leonina) tracked from Bouvetøya 

      Hannén, Rebecca (Master thesis; Mastergradsoppgave, 2022-10-18)
      Southern elephant seals are abundant top trophic predators with a circumpolar distribution in the Southern Ocean. They spend up to 80% of their life at sea on long-ranging migrations to remote foraging grounds. During breeding and moulting they haulout on subantarctic islands. During these migrations they dive continuously to great depth, encountering various environmental conditions. They ...
    • Spatio-temporal Diptera visitation to Silene acaulis flowers studied with time-lapse cameras in Svalbard and Greenland 

      Klausen, Line (Master thesis; Mastergradsoppgave, 2022-08-15)
      Flower visitation by flying arthropods has mainly been studied by direct human observation, which usually neglects seasonal development of flower abundance even though this is known to be important for visitor dynamics and match between trophic levels. In the present study, the arthropod visitor community focusing on Diptera was investigated on the cushion plant Silene acaulis (L.) Jacq. in relation ...
    • Cetacean presence on the northern Mid Atlantic Ridge revealed through passive acoustic monitoring 

      Dunning, Katherine; Ahonen, Heidi; Menze, Sebastian (Master thesis; Mastergradsoppgave, 2022-09-16)
      Cetaceans are known to utilise the Mid-Atlantic Ridge, a key topographical feature in the Atlantic Ocean, for migratory and feeding purposes. Passive acoustic monitoring was used over a one-year period (2007/2008) to identify cetacean vocalisations that occurred on a location near the Charlie Gibbs Fracture Zone. Using species-specific vocalisations that have previously been documented in the North ...
    • Application of an underwater hyperspectral imager (UHI) for the study of sea ice algae 

      Osanen, Janina (Master thesis; Mastergradsoppgave, 2022-08-22)
      Sea ice provides an important habitat for sea ice algae, the main primary producers in sea ice covered ocean areas. In order to reliably estimate sea ice algal distribution and production, it is important to develop remote sensing methods that can provide these estimates with minimal coring. Underwater hyperspectral imagers (UHI) can capture fine-scale variability in the transmitted spectral profile ...
    • Progression in humpback whale song structure and complexity on a subarctic feeding ground in Northern Norway 

      Martin, Saskia C. (Master thesis; Mastergradsoppgave, 2021-08-16)
      Male humpback whales (Megaptera novaeangliae) sing structurally complex songs traditionally associated with low latitude breeding grounds. This vocal behaviour is increasingly reported outside these areas. All singers in a given population sing the same version of a song that is constantly evolving with modifications on different levels within the song structure. This study provides the first detailed ...
    • Turbid Arctic Coastal Waters: Potential Hotspots for Primary Productivity. Riverine Influence on Microbial Productivity in high Arctic Fjords 

      Andersen, Sebastian D.J. (Master thesis; Mastergradsoppgave, 2022-05-16)
      The coastal domain of the Arctic is in rapid change with shifts in discharge phenology and catchment characteristics. Riverine discharge shapes hydrography, under water light climate, and nutrient dynamics during the brief melt season. Nutrients transported from catchment to coast can stimulate primary productivity, yet light attenuation caused by high surface turbidity is considered a limiting ...
    • Genetic diversity and differentiation of velvet belly lanternshark (Etmopterus spinax) in the Northeast Atlantic 

      Walther, Iselin C. W. (Master thesis; Mastergradsoppgave, 2022-06-15)
      Deep-sea sharks are little resilient to targeted harvesting and bycatch fisheries due to their life history strategy characterized by slow growth, late sexual maturity, low fecundity, and few offspring. The Northeast Atlantic component of Etmopterus spinax is an example of a species where substantial population changes in terms of abundances have occurred due to intensive fisheries induced mortality. ...
    • Fear towards the four large carnivores in Norway; a geospatial survey from 2010 and 2019 

      Sponberg, Vilde Bech (Master thesis; Mastergradsoppgave, 2022-06-05)
      Abstract Through the last centuries it has become high disturbances and interventions in natural areas, which has forced wildlife to interact with humans. This has led to human-wildlife conflicts (HWC), where animals have become a threat to peoples’ safety or livelihood. These conflicts have often ended with species becoming endangered or extinct globally, including Norway. There are small populations ...