Doktorgradsavhandlinger (BFE-fak): Recent submissions

Now showing items 161-180 of 277

    • Ecology of a tropical bay and the social aspects of small-scale fisheries: Implications for management 

      Andrade Rodriguez, Hector Antonio (Doctoral thesis; Doktorgradsavhandling, 2015-09-02)

    • Spatial and temporal patterns of foraging of harbour seals (Phoca vitulina) in Porsangerfjord: from behavioural interpretation to resource selection. 

      Ramasco, Virginie (Doctoral thesis; Doktorgradsavhandling, 2015-09-24)
      The coastal cod stock of the Porsangerfjord has drastically declined in the 80’s and never fully recovered since. A population of harbour seals, known to be resident in the fjord all year round, has been hypothesised to act as predator-pit for cod in the area, affecting its lack of recovery. In order to understand the role of these seals in this local marine ecosystem, their foraging behaviour ...

    • Bioprospecting of Arctic marine organisms Employing bioassay-, chemistry-, and metabolomics-guided isolation 

      Olsen, Elisabeth Klungerbo (Doctoral thesis; Doktorgradsavhandling, 2015-09-25)
      The marine environment inhabits a large diversity of organisms that produce natural products as a strategy for survival. Many marine natural products are found to display different bioactivities and some of them have reached the market as drugs or dietary supplements. Comprehending the great potential of bioactive marine natural products motivates for the continuing bioprospecting of organisms from ...

    • "Bioactivity profile of barettin - With special focus on anti-inflammatory, antioxidant and anticoagulant activities" 

      Lind, Karianne Fredenfeldt (Doctoral thesis; Doktorgradsavhandling, 2015-04-17)
      The diversity of the marine species inhabiting the oceans makes them highly interesting as potential sources of bioactive molecules for various applications. The extreme environment in the Barents Sea, in terms of temperature and light availability, have forced its organisms to adapt to their surroundings by developing unique biomolecules, and Arctic marine organisms are therefore an excellent ...

    • Nest predation in birds of conservation concern. Case studies of monitoring and management. 

      Stien, Jennifer (Doctoral thesis; Doktorgradsavhandling, 2015-06-12)
      In this thesis I have used a variety of study methods at different spatial and temporal scales to explore population processes and management of 2 bird species of conservation concern, common eider and Slavonian grebe, focusing particularly on the role of nest predation in declining populations. I have demonstrated the role of proximate and ultimate causes of nest loss in eider at 2 declining colonies ...

    • Replacement of fishmeal with alternative proteins in diets for Atlantic salmon (Salmo salar L.): A study on the microbiota, morphology and function of the intestine 

      Hartviksen, Mali Anja Bjerkhaug (Doctoral thesis; Doktorgradsavhandling, 2015-06-16)
      The research presented in this thesis aims to gain knowledge on the impact of a variety of alternative feed ingredients for which there is an increasing use for in Atlantic salmon feed. In focus were effects on the community population and metabolism of intestinal microbiota, its ability to compete with pathogens, gut physiology and health as well as fish performance and feed utilization. The results ...

    • Antecedents and consequences of word of mouth - Consumer evaluation context, individualism, personality and defense of companies 

      Wien, Anders Hauge (Doctoral thesis; Doktorgradsavhandling, 2015-06-03)
      People often share word of mouth (WOM) with their friends, family, and colleagues, and they increasingly also share WOM with strangers through various Internet channels. Since WOM has been found to have an important impact on consumer behavior, businesses worldwide are eager to understand the intricacies of the phenomenon. In particular, businesses are interested in understanding how positive WOM ...

    • Atlantic salmon type I interferons - induction and antiviral activity 

      Svingerud, Tina (Doctoral thesis; Doktorgradsavhandling, 2013-03-22)

    • Bivalves as indicators of environmental perturbations related to climate and ocean acidification 

      Vihtakari, Mikko (Doctoral thesis; Doktorgradsavhandling, 2015-03-13)
      The aims of this thesis were to increase knowledge on 1) susceptibility of bivalves to environmental perturbations and 2) usage of bivalve shells as sub-annual environmental proxy archives. These objectives were addressed using two experimental settings: 1) an ocean acidification (OA) experiment on bivalve gametes and early larval stages, and 2) year-long bivalve deployments on oceanographic moorings ...

    • Buyer-seller relationships across cultures: Conceptual, empirical and methodological issues 

      Voldnes, Gøril (Doctoral thesis; Doktorgradsavhandling, 2015-01-22)
      The aim of this dissertation was to examine the factors important in achieving success in cross-cultural business relationships, in this case between Russian buyers and Norwegian sellers of seafood. Emphasis was placed on exploring how cultural differences influence factors important in relationship satisfaction, how to attain the various factors, and how cultural differences are managed by buyers ...

    • Infectious pancreatic necrosis virus (IPNV) - Persistent infections, virulence and antiviral defence 

      Julin, Kjersti (Doctoral thesis; Doktorgradsavhandling, 2015-02-06)
      Infeksiøs pankreas nekrose (IPN) er en fiskesykdom som rammer mange fiskeslag over store deler av verden. Det har store økonomiske konsekvenser for norsk lakseoppdrettsnæring. Infeksiøs pankreas nekrose var først kjent som en sykdom i yngel, men i de siste 10 til 20 årene har det vært et like stort problem i post-smolt. Antall utbrudd varierer fra år til år, der 2009 ble registrert som et år med ...

    • Isolation and Characterisation of Bioactive Secondary Metabolites from Arctic, Marine Organisms 

      Hanssen, Kine Østnes (Doctoral thesis; Doktorgradsavhandling, 2014-12-09)
      The list of achievements in developing pharmaceuticals and other useful products originating from Nature is long, and it continues to extend. Marine bioprospecting alone has generated three novel drugs in the last four years. The continued success motivates further bioprospecting efforts in the search for utilisable products from natural sources. In this thesis, extracts of Arctic marine organisms ...

    • Cyclically outbreaking geometrid moths in sub-arctic mountain birch forest: the organization and impacts of their interactions with animal communities 

      Vindstad, Ole Petter Laksforsmo (Doctoral thesis; Doktorgradsavhandling, 2015-01-09)
      In sub-arctic mountain birch forest in northern Fennoscandia, the 2 geometrid moth species Epirrita autumnata (autumnal moth) and Operophtera brumata (winter moth) show high-amplitude population cycles with regular 10-year periodicity. During some population peaks, moth populations attain outbreak densities and cause region-wide defoliation and mortality of mountain birch. The severity and duration ...

    • Marine tourism fisheries - Challenges of governance and governability Northern Norway as a case study 

      Solstrand, Maria-Victoria (Doctoral thesis; Doktorgradsavhandling, 2014-12-17)
      The research focus for this dissertation is marine tourism fisheries – a sector rapidly growing in popularity in Northern Norway. Data from this research study suggest that the ecological impacts may be more significant than previously thought. As such, it is suggested that marine tourism fisheries be considered separately from recreational fishing, and alongside commercial-scale and small-scale ...

    • Calanus spp. in the Arctic ecosystem - a story on predation, distribution and methodology 

      Vogedes, Daniel Ludwig (Doctoral thesis; Doktorgradsavhandling, 2014-11-19)
      The calanoid copepods of the genus Calanus (C. finmarchicus, C. glacialis and C. hyperboreus) are key elements in the Arctic ecosystem. They link primary producers (ice algae, phytoplankton) and higher trophic levels through their ability to convert low energy carbohydrates and proteins to high energy wax esters. This energy is stored in a separate and conspicuous lipid sac. This ability to store ...

    • Chondrichthyan fishes in the Arctic Ocean and adjacent seas - do we know our species? 

      Lynghammar, Arve (Doctoral thesis; Doktorgradsavhandling, 2014-10-31)
      The basal prerequisite for managing species and understanding ecosystems is correct species and population identification. Without knowing the species, we cannot with accuracy detect changes in distribution or abundance due to climate change, fisheries, diseases or any other types of impact. This thesis gives the first complete overview of chondrichthyan fishes (sharks, skates, rays and chimaeras), ...

    • The invasive red king crab (Paralithodes camtschaticus): Mortality, individual growth and dispersal in Norwegian waters 

      Windsland, Kristin (Doctoral thesis; Doktorgradsavhandling, 2014-10-01)
      To improve local economy, the red king crab (Paralithodes camtschaticus) was introduced to the Barents Sea by Soviet scientists in the 1960s. Adapting well to the new environment, the growing population gradually invaded new areas along the coast of northern Norway. The red king crab has become a valuable marine resource but as an introduced species, it is also a potential threat to the ecosystem. ...

    • Why do Prices Change? An Analysis of Supply and Demand Shifts and Price Impacts in the Farmed Salmon Market 

      Brækkan, Eivind Hestvik (Doctoral thesis; Doktorgradsavhandling, 2014-09-01)
      Price changes in any market are essentially due to shifts in supply relative to demand. In a global market there can be several simultaneous supply and demand shifts in different geographical locations, all affecting prices to different extents. This dissertation focuses on procedures for measuring such shifts and their relative effects on prices by looking at the global market for farmed salmon ...

    • Studies of JAK/STAT signaling in Atlantic salmon 

      Sobhkhez, Mehrdad (Doctoral thesis; Doktorgradsavhandling, 2014-06-27)
      In mammals the JAK-STAT pathway plays a significant role in mediating the biological activities of both type I and type II IFN, where JAKs are receptor associated kinases and STATs the transcription factors they activate. At the start of this project the knowledge of the JAK-STAT pathway in fish in general was scarce and there were few reports describing the function of any JAK-STAT family member ...

    • Foraging, reproduction and survival of the zooplanktivorous seabird Little Auk (Alle alle) in the Arctic in relation to climatic and environmental variability 

      Hovinen, Johanna Emilia Heidi (Doctoral thesis; Doktorgradsavhandling, 2014-06-23)
      The ability of individuals to acquire and store energy for life-history traits such as reproduction and survival, is finite. This demands prioritizing some traits at the expense of other traits. Which traits to prioritize, depends on the life-history strategy of a species. ‘Slow’-living species, in contrast to ‘fast’-living species, mature late, produce small broods, have low extrinsic mortality and ...