Mastergradsoppgaver i biologi: Nye registreringer

Viser treff 261-280 av 380

    • Associations between herbivorous zooplankton, phytoplankton and hydrography in Porsangerfjord, northern Norway 

      Priou, Pierre (Master thesis; Mastergradsoppgave, 2015-08-15)
      During three cruises in April, May and November 2014 in Porsangerfjord, northern Norway, the role of hydrography and phytoplankton composition in shaping zooplankton vertical distribution was studied. Simultaneous collection of biological (phytoplankton and zooplankton distribution/abundance) and environmental data (temperature, salinity, density, Chlorophyll a) was sampled using a high-resolution ...

    • Arctic fox diet in Yamal peninsula 

      Cerezo Araujo, Maite (Master thesis; Mastergradsoppgave, 2015-05-15)
      Arctic fox in inland areas has been typically described as a species dependent on rodent populations, but being able to use alternative prey, therefore named an opportunistic specialist. Rodent populations in the low shrub tundra of southern Yamal peninsula exhibit at present low amplitude cycles. The hypothesis for this thesis is that the low abundance of small rodents is not enough to sustain ...

    • Movement ecology of the Qamanirjuaq caribou (Rangifer tarandus groenladicus) herd with focus on their wintering grounds 

      Fredlund, Matt (Master thesis; Mastergradsoppgave, 2015-05-15)
      With a rapidly changing climate in the arctic there is concern that specialized species, such as caribou (Rangifer tarandus), may not be able to adapt. Currently, the importance of climatic changes for North-American caribou herds is unclear. In an effort to reduce this knowledge gap I have analysed the movement behaviour of caribou in the Qamanirjuaq herd, in the central Canadian Arctic, in relation ...

    • Sesongvariasjoner i aktivitet og dybdebruk hos kystnær atlanterhavskveite (Hippoglossus hippoglossus) 

      Bygdnes, Eirik E. (Master thesis; Mastergradsoppgave, 2015-05-21)
      Atlanterhavskveite er en ettertraktet fisk både for sportsfiskere og kommersielt fiske på grunn av størrelse og verdi. Bestanden regnes som høy i Nord-Norge, men lav i Sør-Norge. Det fiskes betydelige kvanta av arten i nordlige deler av landet, til tross for at kunnskap om atferd og livshistorietrekk er mangelfull. Hovedmålet med denne oppgaven var derfor å undersøke dybde- og temperaturbruk, og ...

    • Behaviour and saltwater tolerance of European whitefish Coregonus lavaretus (L.) in an Arctic estuary 

      Fagard, Pierre (Master thesis; Mastergradsoppgave, 2015-05-27)
      Abstract European whitefish is well described and renowned for its polymorphism and faculty to occupy a wide range of freshwater habitats. This includes observations of individuals in some populations that utilize brackish estuarine habitats as feeding areas, although information on these populations is generally scarce. By use of acoustic tracking technology and physiological sampling, the ...

    • Migration and habitat use of sea trout post-smolts Salmo trutta in a Norwegian fjord system 

      Flaten, Anne Cathrine (Master thesis; Mastergradsoppgave, 2015-05-20)
      The migration and habitat use of sea trout post-smolts were investigated in a fjord system in Central Norway during the period from 30 April – 26 November 2014. The main aims were to investigate timing of sea entry and freshwater return, return rate, marine residence time, spatial use of the fjord system and migration distance. Fifty sea trout smolts were tagged with acoustic transmitters and tracked ...

    • 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 ...

    • Breeding success in relation to telomere length in a long-lived seabird, the Antarctic Petrel (Thalassoica antarctica) 

      Lopez-Sarasa, Inigo (Master thesis; Mastergradsoppgave, 2015-05-15)
      Integrating information about the physiology of individuals and their reproductive performance can be a key aspect in determining the relationships between environmental conditions and demographic parameters, and of the individual variability in these relationships. Telomeres are the protective caps of chromosomes found in eukaryotic cells. They generally shorten in relation to the stressors an ...

    • Depth use of adult Atlantic salmon during the first and last phase of the marine migration 

      Kjellman, Mari (Master thesis; Mastergradsoppgave, 2015-05-15)
      The Atlantic salmon has declined in numbers over the last decades. Given the species’ anadromous nature, management is a challenge, and information is lacking, especially from the marine migratory phase. Information about repeat spawners and their migratory behaviour may be of major importance in management questions, as these individuals have been found to contribute significantly to spawning ...

    • Sesongmessig vandringsmønster til sjørøye og sjøørret i to nordnorske elver - en sammenligning mellom to arter i to elver 

      Høyning, Kristoffer Porsvik (Master thesis; Mastergradsoppgave, 2014-11-20)
      Sjørøye og sjøørret er anadrome fisker som vandrer mellom ferskvann og sjøvann. Det meste av kunnskapen om vandringsadferden på disse fiskene er gjort på bestander som har tilgang til innsjøer i ferskvannssystemet, i tillegg til at studiene ofte er relativt kortvarige undersøkelser som ikke strekker seg over et helt år. Kunnskapen om anadrome elvelevende bestander er til forskjell mangelfull, spesielt ...

    • Studie av bunnforhold og forekomst og tetthet av utvalgte fisk og pigghuder - Evaluering av undervannsfilming som metode 

      Wiesener, Jørgen (Master thesis; Mastergradsoppgave, 2015-02-15)
      Undervannsvideo er en metode for beregning av forekomst av marine dyr og kartlegging av bunnsubstrat og algedekke. Metoden har vært sammenlignet med andre metoder som dykking og bunntrål (Spencer et al. 2005). I dette studiet ble det gjort en evaluering av undervannsfilm som metode for undersøkelse av forekomst og tetthet av utvalgte fisk og pigghuder, og kartlegging av bunnforhold på grunt vann. ...

    • Lipid content, composition and dynamics in northern marine diatoms. An experimental study using different analytical methods 

      Svenning, Jon Brage (Master thesis; Mastergradsoppgave, 2014-11-20)
      In this study, the fluorophore Nile Red was used as a probe for lipid accumulation during nutrient stress in the diatom Coscinodiscus concinnus, and to quantify lipid concentration fluorometrically in 5 monocultures of northern diatoms. The results from the fluorometrical quantification were validated by solvent extraction and HPLC-MS analysis in Bergen. In addition, 17 monocultures of 7 species of ...

    • Annual population dynamics of the small harpacticoid copepod Microsetella norvegica in a high latitude fjord (Balsfjord, Northern Norway) 

      Antonsen, Maria Terese (Master thesis; Mastergradsoppgave, 2014-11-16)
      Annual population dynamics and vertical distribution of the small (< 0.6 mm) hapacticoid copepod, Microsetella norvegica, was investigated through monthly sampling at station Svartnes in Balsfjord, Northern Norway from May 2013 to June 2014. M. norvegica is a pelagic particle feeder, and distributed from temperate waters to sub-arctic fjords, but frequently underestimated because of its small size. ...

    • Space use by South Polar Skua during the breeding season at Svarthammaren, Antarctica 

      Swärd, Johan Nils (Master thesis; Mastergradsoppgave, 2014-11-17)
      South Polar Skua is a seabird feeding on both marine resources and on other seabirds’ egg and chicks. There are few studies investigating South Polar Skua space use during breeding season and how it is affected by sex or phenology. This study was carried out during the breeding season 2012-2013 at Svarthammaren in Dronning Maud Land (71° 53′ S, 05° 10′ E). 56 GPS loggers were used to track 48 ...

    • The summer diet of hooded (Cystophora cristata) and harp (Pagophilus groenlandicus) seals in the West Ice 

      Enoksen, Solveig (Master thesis; Mastergradsoppgave, 2014-08-15)
      The harp (Pagophilus groenlandicus) and hooded (Cystophora cristata) seals both inhabit the drift ice areas in the West Ice during certain times of the year, and the present study is part of the Institute of Marine Research’s management studies of these seals. Contents of gastrointestinal tracts from hooded and harp seals from June-July 2008 and 2010 and harp seal faeces samples were identified ...

    • "Can energy expenditure of free-ranging kittiwakes be estimated by body acceleration?" 

      Kristiansen, Martin (Master thesis; Mastergradsoppgave, 2014-08-15)
      Abstract The way energy is used and acquired are fundamental questions in animal biology and figure greatly into conservation of a species. Accurate estimates of energy expenditure are critical in understanding how successful animals are throughout their lifespan and in quantifying population energy budgets and their role and impact on an ecosystem. Two methods have been commonly used to estimate ...

    • Efflux of neurotransmitter from brain slices during O2 deprivation – comparing diving and non-diving species 

      Ragazzi, Lorenzo (Master thesis; Mastergradsoppgave, 2014-08-15)
      During hypoxic insult, neuronal tissue undergoes an excitotoxic cascade of events leading to cell death. This response involves loss of membrane potential and uncontrolled release of primarily excitatory neurotransmitters. I propose that this fatal cascade is significantly delayed or attenuated in diving species, which are adapted to repeated exposures to hypoxic conditions as a consequence of ...

    • Organohalogenated contaminants in nestlings of white-tailed eagles (Haliaeetus albicilla): Plasma concentrations and possible influences on biomarkers of health 

      Sletten, Silja (Master thesis; Mastergradsoppgave, 2014-09-15)
      Biomagnifying organohalogenated contaminants (OCHs) may have adverse effects on the health of birds, especially in marine avian top predators that accumulates high loads of such contaminants. Contaminants may impact the immune system by impairment of the humoral immunity and also influence the antioxidant enzyme activity. Moreover, developmental conditions may affect the shortening of telomeres, one ...

    • Spectral Analysis and image classification of the dwarf shrub Empetrum nigrum (L.) by means of remote sensing data. 

      Ibarrola, Edurne (Master thesis; Mastergradsoppgave, 2014-05-15)
      Empetrum nigrum dominates in alpine and northern part of Norway. It is an allelopathic species that can reduce both productivity and biodiversity in ecosystems. The study focuses on identifying and determining different cover of E. nigrum by means of remote sensing data within two regions of Northern Norway, Ifjord in Finnmark and Troms areas. Field data were collected within 50 study points and E. ...

    • 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 ...