Viser treff 336-355 av 362

    • Threat or opportunity? Landscape genetics in a coal mining area 

      Skottvoll, Bente Sved (Master thesis; Mastergradsoppgave, 2013-05-15)
      Aknowledgment The area of Sveagruva have experienced several periods of coal mining. This study aim to evaluating changes in vegetation composition, species distributions and genetic structure using a combination of field and molecular analyses, to identify whether or not coal mining have effected plant life in Svea. Investigations on species and gene level were done on two Luzula species, L. ...
    • Time dependent temperature effects on methane production in Arctic peat soils 

      Grunnvåg, Jeanette Slettnes (Master thesis; Mastergradsoppgave, 2019-05-16)
      Peatlands constitute the largest natural reservoir of carbon on the planet making them key components in the global carbon balance. Peatlands are mostly found in the northern hemisphere under cold conditions. As the world is warming and arctic peatlands are becoming heavily influenced by increasing temperatures, an increased interest in the peat soil microbial systems have arisen. Methane, a potent ...
    • 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 ...
    • To keep or not to keep track of time in eternal sunshine? Diel activity patterns of Svalbard arthropods during polar day 

      Huntsaar, Maria (Master thesis; Mastergradsoppgave, 2024-02-16)
      Organisms on Earth are exposed to cyclic changes in environmental variables due to Earth’s rotation around it’s axis. As a response, many organisms adapt their behaviour in a rhythmic manner, which is often cued by 24h light-dark cycles. However, in the Arctic, traditional 24h light- dark cycle cues do not exist for long periods at the time. Arthropods play an important role in the high latitude ...
    • Toxicology of the Svalbard Atlantic Puffin 

      Underwood, Arin Kendall Povelite (Master thesis; Mastergradsoppgave, 2019-05-19)
      The Arctic is a sink for pollutants that accumulate there via long-range transport and biomagnification of persistent organic pollutant (POPs). The main objectives of this study were to identify the pollutants in the Svalbard Atlantic puffin and to compare their levels with southern puffin colonies and Svalbard seabird species to assess risk to the puffin. Svalbard Samples were analysed for contaminants ...
    • 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 ...
    • 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 ...
    • Uncovering the foraging strategies in two pelagic diving seabird species outside their breeding season using coupled feather stable isotopes and light-based geolocators 

      Nilssen, Kristina Emilie (Master thesis; Mastergradsoppgave, 2022-02-16)
      The critical endangered Common and Brünnich guillemot are exhibiting contrasting population trends in the Barents Sea region, where the Common guillemots are increasing, while Brünnich guillemots are declining. The non-breeding season is regarded as the main mortality period among seabirds, especially in winter, as climate conditions may be harsh and prey availability rather limited. The contrasting ...
    • Uncovering the secrets they keep – the role of parasites in food web ecology 

      Moore, Shannon Elizabeth (Master thesis; Mastergradsoppgave, 2022-06-01)
      Interactions involving parasites often account for large proportions of links within aquatic food webs, yet few studies integrate parasites into their food web analyses. This analysis compares three sets of highly resolved food webs that differ in taxa composition, space, and time for a subarctic lake system. Key topological food web metrics, including connectance, linkage density, and mean generality ...
    • Under-ice plankton abundance and lipid dynamics in a subarctic lake. 

      Kers, Erwin (Master thesis; Mastergradsoppgave, 2022-05-16)
      Shortening winters and changing ice and snow cover conditions are examples of the many shifts expected in subarctic lakes due to climate change. Well-documented changes in ice and snow cover conditions highlight the need to understand under-ice ecosystems and the consequences a changing climate brings to the freshwater biota. This study investigated the impact of under-ice environmental conditions ...
    • Unexpected feeding behaviour inferred by DNA metabarcoding of Barents Sea skates 

      Kleiven, Stian K. (Master thesis; Mastergradsoppgave, 2022-05-18)
      Feeding studies give an indication about the role and position of species within ecosystems and provide crucial knowledge for management. Traditional methods are based on morphological identification of prey. DNA metabarcoding is a promising tool that allow for identification of specific prey items, also when highly digested. A total of 63 stomachs from three skate species caught in the Barents Sea ...
    • Ungulate population monitoring in a tundra landscape: evaluating total counts and distance sampling accuracy 

      Le Moullec, Mathilde (Master thesis; Mastergradsoppgave, 2014-05-19)
      Researchers and managers are constantly working towards decreasing monitoring uncertainties in order to improve inferences in population ecology. The solitary and sedentary Svalbard reindeer (Rangifer tarandus platyrhynchus) inhabit a high-Arctic tundra landscape highly suitable to compare accuracy (precision and bias) of population monitoring methods in the wild. The flexible Bayesian state-space ...
    • Use of bubble flotation to improve copepod fisheries: laboratory studies on the physical and behavioural interactions of Calanus finmarchicus and air bubbles 

      Jeuthe, Henrik (Master thesis; Mastergradsoppgave, 2008-11-15)
      The current study presents a novel approach to zooplankton harvest in the ocean, where copepods are lifted through the water column and concentrate them at the ocean surface. There they are harvested with a surface skimmer or shallow trawl. The method can potentially reduce fuel costs and unwanted by-catch compared to a conventional plankton trawl. The optimal bubble size for attachment to Calanus ...
    • Using food web structure based on stable nitrogen and carbon isotopes to investigate pelagic-benthic coupling in different areas of the Barents Sea 

      Tillman, Ann Mikaela (Master thesis; Mastergradsoppgave, 2017-11-15)
      Pelagic-benthic coupling is generally assumed to be tighter on Arctic shelves than in lower latitudes, due to for example pronounced seasonal cycles of sunlight and primary production and a potential mismatch between the bloom and its pelagic consumers. Pelagic-benthic coupling is also often stronger in shallower areas compared to deeper areas, due to the shorter distance between the productive, ...
    • The utility of in vitro Precision-Cut Liver Slices to investigate toxicity pathways of contaminants in polar cod (Boreogadus saida) 

      Aranguren Abadia, Libe (Master thesis; Mastergradsoppgave, 2015-06-12)
      The development of in vitro methodologies has contributed significantly in elucidating mechanisms of xenobiotic toxicity in aquatic organisms. The present study aimed to develop the in vitro methodology Precision-Cut Liver Slices (PCLS) and to investigate the effects of model compounds (WY-14,643 [WY] and benzo(a)pyrene [BaP]) and two mixtures of 2- and 3-4-ring polycyclic aromatic hydrocarbons ...
    • Validating the Tritiated Water Method in Adult Harp Seal 

      Sørli, Bernhard Jakob Salen (Master thesis; Mastergradsoppgave, 2022-05-16)
      As one of the top predators in the northeast Atlantic, and most numerous, the harp seal (Pagophilus groenlandicus), has a significant role in the higher trophic levels in the ecosystem. Their condition can be an indicator of changes in prey availability, competition with other species or even climate. It can also be a useful tool in predicting the pup production and breeding success. The ...
    • Variation in abundance, diet, otolith zone patterns and black spot disease (Cryptocotyle lingua) of 0-group coastal cod (Gadus morhua L.) in northern Norway 

      Sandneseng, Elida (Master thesis; Mastergradsoppgave, 2006-12-11)
      Knowledge of the early life-history and habitat requirements of coastal cod is very sparse. Young of the year cod juveniles from three different locations in northern Norway were collected monthly from August to November 2005 using beach seine. Diet analyses based on stomach contents showed that 0-group cod mainly ate copepods, gammarids, polychaetes, mysids, shrimps and isopods. The three ...
    • Variation in egg size, fecundity and size structure in female red king crab (Paralithodes camtschaticus, Tilesius 1815) from Varangerfjorden over time. 

      Høyning, Rasmus Kristoffer (Master thesis; Mastergradsoppgave, 2018-05-14)
      The introduced red king crab (Paralithodes camtschaticus) has successfully established in Norwegian waters since its release to the Barents Sea in the 1960’s. It has become an important commercial resource contributing to the local coastal society in the eastern region of Finnmark. The fishery consists of one quota regulated area east of 26° (North Cape) and an open fishery west of 26°E. During the ...
    • 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 ...
    • 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 ...