Now showing items 201-220 of 391

    • Ringed seal (Pusa hispida) diet on the west coast of Spitsbergen, Svalbard, Norway 

      Bengtsson, Olof Mikael (Master thesis; Mastergradsoppgave, 2019-05-15)
      The diet of 99 coastal-feeding ringed seals (Pusa hispida), collected in western Spitsbergen, Svalbard (Norway), was analysed via identification of hard-parts in the contents of their gastrointestinal tracts (GITs). The study animals where shot either in spring (n = 30; April-July) or autumn (n = 69; August-October) during four consecutive years (2014-2017). Thirty different prey types were identified ...
    • Brain capillarization in diving mammals: a selection of staining and quantification methods 

      Ciccone, Chiara (Master thesis; Mastergradsoppgave, 2019-05-15)
      Diving species can cope with acute and repeated hypoxia through adaptations that are absent in non-diving animals. One of the greatest challenges to deal with during diving is the lowering of the arterial oxygen pressure (PaO2), which causes a decrease in the driving force for the oxygen diffusion from the capillaries to the cells. My hypothesis is that the marine mammalian brain shows improved brain ...
    • Riverine and glacier influence on infaunal benthic communities in Isfjorden, Svalbard. 

      Ugelstad, Charlotte Pedersen (Master thesis; Mastergradsoppgave, 2019-05-15)
      Fjords are the interface between land and ocean, and processes happening on land have implication for the coastal areas. In addition, differences in fjord characteristics, such as morphology, sedimentation and water circulation, can drive differences in fjord ecology, including benthic community composition (Syvitsky et al. 1986). Soft-bottom macro-fauna was collected in August 2018 using a Van-Veen ...
    • Seasonality in mercury bioaccumulation in particulate organic matter and zooplankton in a river-influenced Arctic fjord (Adventfjord, Svalbard). 

      Carrasco, Nathalie (Master thesis; Mastergradsoppgave, 2019-05-15)
      Methylmercury (MeHg) is of concern because it has the capacity to readily bioaccumulate and biomagnify along trophic levels until humans, exhibiting toxic effects such as neurotoxicity. Increased permafrost melt (that stores large amounts of carbon and mercury (Hg)) and river inputs, are expected to increase the exposure to Hg through uptake and transfer of contaminants through the food web. The ...
    • Activity of XTHs during host plant infection by the parasitic plant Cuscuta. 

      Sarfowaa, Adwoa (Master thesis; Mastergradsoppgave, 2019-05-15)
      Parasitic plants including Cuscuta develop specialized structures called haustoria during infection. These specialized organs give the parasite the capacity of host attachment, invasion, vasculature connection and material transfer between the host and the parasite. Successful invasion allows organic substances, nutrients and water to flow into the parasite through the host phloem and xylem cells. ...
    • 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 ...
    • 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 ...
    • Impacts of water level regulation on trophic niche and growth of Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) in Norwegian hydropower reservoirs 

      Kytökorpi, Mikko Antero (Master thesis; Mastergradsoppgave, 2019-05-15)
      Hydropower is among the largest renewable energy sources globally. However, it can have drastic environmental and socio-economic impacts on dammed lakes (i.e., reservoirs) and rivers where water levels are regulated due to hydropower operations. Water level regulation in hydropower reservoirs is known to be a large environmental problem, leading to changes in the abiotic conditions, which subsequently ...
    • Seasonal abundance and activity of sympagic meiofauna in Van Mijenfjorden, Svalbard 

      Pitusi, Vanessa (Master thesis; Mastergradsoppgave, 2019-05-15)
      The importance of landfast ice as a nursery and breeding ground for Arctic marine invertebrates was studied in Van Mijenfjorden (77°N, 15/16°W), southwestern Svalbard from March to May 2017. The collection of first-year ice cores with stations along a depth gradient allowed the investigation of both temporal and spatial differences in sympagic meiofauna community composition and abundance. Furthermore, ...
    • Zooplankton communities on the Northeast coast of Greenland. How can we explain vertical and regional distribution? 

      Beroujon, Théo (Master thesis; Mastergradsoppgave, 2019-05-16)
      Most studies on zooplankton investigate the famous, and omnipresent, Calanoid copepods Calanus spp., because they are abundant, and constitute the major trophic link in marine ecosystems. Indeed, Northeast Greenland is located on the crossroad of Arctic and Atlantic waters which, potentially, can lead to a high biodiversity originating from different domains of marine life. However, there are very ...
    • Perception and Appreciation of Plant Biodiversity, An assessment of human perception and appreciation of plant biodiversity using photography of artificial plant communities 

      Breitschopf, Eva (Master thesis; Mastergradsoppgave, 2017-07-31)
      Anthropogenically caused global biodiversity declines and other human drivers point to the possibility of local plant diversity changes. The well-studied effects of local plant diversity on ecosystem processes implicate consequences to human well-being in the form of altered ecosystem services (including cultural services). Public awareness (knowledge and correct perception) about these changes ...
    • The nestling diet of Svalbard snow buntings identified by DNA metabarcoding 

      Stolz, Christian (Master thesis; Mastergradsoppgave, 2019-05-15)
      Tundra arthropods have considerable ecological importance as a food source for several bird species that are reproducing in the Arctic. The actual arthropod taxa comprising the chick diet are however rarely known, complicating assessments of ecological interactions. In this study, I identified the nestling diet of Svalbard snow bunting (Plectrophenax nivalis) for the first time. Faecal samples of ...
    • Chronobiology of voluntary food intake in reindeer (Rangifer tarandus tarandus) 

      Rescia, Leonardo (Master thesis; Mastergradsoppgave, 2018-11-15)
      In all organisms, biological rhythms arise from the interaction between endogenous clocks and a rhythmic environment. The timing of sunrise and sunset synchronize internal timing processes and inform the organism not only of the time of day, but also of the time of year. For animals living in polar regions biological timekeeping represents a challenge, given that the sun does not rise during the ...
    • The Marine Plastic Microbiome: Microbial Colonization of Polymer Surfaces in the Arctic Marine Environment 

      Stitzlein, Tarah Marie (Master thesis; Mastergradsoppgave, 2018-09-25)
      While the sources and fates of plastic pollution are receiving growing attention, major knowledge gaps exist. Among these, microbial degradation (aka biodegradation) of plastics remains poorly investigated. The process of biodegradation begins with the formation of biofilm on the polymer surface; our study aimed to investigate microbial colonization of polymer surfaces in the Arctic marine environment ...
    • Evaluating the use of biotic interactions in species distribution models 

      Ball, Jack Ethan (Master thesis; Mastergradsoppgave, 2018-08-15)
      Species distribution models are a key tool in predicting and projecting population changes in the past, present and future. In the past they have mostly focused on using abiotic interactions for their models. This may be inadequate however as biotic interactions play an important role in determining community composition. Climate change has created and will create many novel communities that have ...
    • Influence of photoperiod on central appetite regulation in captive Svalbard rock ptarmigan (Lagopus muta hyperborea) 

      Melum, Vebjørn Jacobsen (Master thesis; Mastergradsoppgave, 2018-08-09)
      The Svalbard rock ptarmigan displays a seasonal change of body mass as a selectively beneficial adaptation for survival in the high Arctic. This physiological change is sensitive to photoperiod (daylight duration in a 24h cycle) but little is known of the mechanism through which changes in photoperiod affects body mass in this species. We exposed winer adapted Sv. rock ptarmigan to a simulated ...
    • Corvids response to fluctuating abundance of resources in tundra ecosystems 

      Kebir, Zina Asnah (Master thesis; Mastergradsoppgave, 2018-05-15)
      Aim Despite the numerous studies on corvids’ behaviour, their dynamics in different ecosystems is unknown. Ravens and hooded crows are opportunistic generalists acting as both predators and scavengers. Ravens are probably the most specialized scavengers on ungulate carcasses and both species are known as efficient hunters of small rodents. Small rodents are a key species in the tundra as they represent ...
    • Initial Community Convergence on Plant Defense Syndromes Explains Community Responses to Herbivore Exclosures 

      Robinson, Jacob (Master thesis; Mastergradsoppgave, 2017-11-15)
      General trade-offs in species’ energy use are highlighted here by mapping proposed defense syndromes, using trade-offs found between: constitutive phenolic compounds, silica and a high nutrient low defense region found between regional con-specifics. Differences in species composition between two catchments can be explained by proposed syndrome trade-offs seeking energy use optimums in differing ...
    • Temporal trends of persistent organic pollutants in Svalbard polar bears (Ursus maritimus) in relation to climate-associated changes in feeding habits 

      Lippold, Anna (Master thesis; Mastergradsoppgave, 2018-05-15)
      Persistent organic pollutants (POPs) reach the Arctic ecosystems from lower latitudes mostly via air and ocean currents. They biomagnify through Arctic food webs and reach considerably high concentrations in top predators such as polar bears (Ursus maritimus). Although many of these compounds have been banned or restricted for decades, concentrations of polychlorinated byphenyls (PCBs), organochlorine ...
    • Epibenthic community structure in Northeast Greenland and the Kitikmeot Sea in the Canadian Arctic Archipelago 

      Fredriksen, Rosalyn (Master thesis; Mastergradsoppgave, 2018-05-15)
      Climate warming in the Arctic results in increased human use of Arctic shelf regions through oil and gas development and increased shipping. Such pressures necessitate the closing of knowledge gaps in poorly studied areas, here two areas located at outflow shelves in the Arctic, to record the current status of epibenthic marine ecosystems. This study characterizes epibenthic community structure, ...