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norskMastergradsoppgaver i biologi: Nye registreringer
Viser treff 281-300 av 391
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Sesongmessig vandringsmønster til sjørøye og sjøørret i to nordnorske elver - en sammenligning mellom to arter i to elver
(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
(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
(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)
(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
(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
(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?"
(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
(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
(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.
(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
(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 ... -
Can ground nesting birds escape predation by breeding in less productive habitats? A large-scale artificial nest study from Finnmark, Northern Norway
(Master thesis; Mastergradsoppgave, 2014-05)Predation is known to be one of the most important causes of nest failure in ground nesting birds, and many populations are experiencing a decline in breeding success worldwide. Predator abundance are expected to be highest closer to productive areas (i.e. Ecosystem exploitation hypothesis), and vary according to the availability of other prey (i.e. Alternative prey hypothesis). I hypothesized that ... -
Sampling site and potential errors in estimating total body water and water turnover rate in fasting hooded seals (Cystophora cristata)
(Master thesis; Mastergradsoppgave, 2014-05-15)The purpose of this project is to study in detail the water balance and methodological aspects of the use of the tritiated water method of hooded seals (Cystophora cristata). Following 24 hours of fasting, 5 sub-adult hooded seals aged 1.5 years were injected intravenously with a bolus dose of tritiated water through a catheter inserted into the extradural intravertebral vein (EDV) at the level of ... -
Parallelism in parasite infections in two populations of polymorphic Arctic charr (Salvelinus alpinus L.) in northern Norway
(Master thesis; Mastergradsoppgave, 2014-05-15)The composition and structure of a component community can vary widely across host populations of the same host species. Revealing the causes and consequences of geographical variation in parasite community composition is of great importance in order to determine parasites role in an ecosystem. Divergence in parasite infections among sympatric polymorphic Arctic charr is commonly associated with ... -
Recovery potential of Arctic wetland tundra on Svalbard. Long-term impacts of grazing by barnacle geese (Branta leucopsis) within the context of climate change
(Master thesis; Mastergradsoppgave, 2014-05-19)The substantial increase of the migratory Svalbard population of Barnacle geese Branta leucopsis during the past 50 years has been attributed to a warming climate, changes in agricultural land use, and conservation measures. The geese are likely to continue to forage and reproduce in Arctic wetlands in increasing numbers. This project revisited the experimental plots from an earlier experiment ... -
Langtidsstudie av næringsøkologi og vekst hos storørret i Pasvikvassdraget - en sammenligning mellom utsatt og vill ørret
(Master thesis; Mastergradsoppgave, 2014-05-15)Kraftutbyggingen i Pasvikvassdraget startet i 1964 og det finnes syv kraftverk i vassdraget. Storørretbestanden gikk kraftig tilbake som følge av kraftutbyggingen og i 1979 ble det startet et utsettingsprogram av ørret i elva for å kompensere for reduksjonen i størrelsen av den naturlige populasjonen. I dag settes det årlig ut 5000 ørret større enn 25 cm. Dette langtidsstudiet omhandler diett og ... -
Seasonal abundance of parasitic Marine Alveolate Group II (MALV II) in an Arctic fjord, Svalbard
(Master thesis; Mastergradsoppgave, 2014-05)During the last decade, knowledge has been building of the parasitic dinoflagellate group Marine Alveolate Group II (MALV II, within Syndiniales). While environmental cloning and sequencing approaches have indicated a high abundance of MALV II throughout the world’s oceans, relatively little is known about their seasonality and the significance of their role in the marine ecosystem. No studies to ... -
Autumn senescence response to a changing climate: effects of snow-depth on High Arctic plants
(Master thesis; Mastergradsoppgave, 2014-05-15)Temperature and precipitation in the Arctic are projected to increase over the next century with a changing climate. Understanding how tundra plants respond to this change is still unclear. Little is known about autumn senescence in the Arctic and with a short growing season, timing is critical. If a plant senesces too early, it compromises photosynthetic activity and growth. If a plant senesces ... -
Samfunnsstruktur og tetthet av bunndyr i littoralsonen av en oligotrof, subarktisk innsjø - variasjoner gjennom dyp og sesong
(Master thesis; Mastergradsoppgave, 2014-05-15)Bentiske makroinvertebrater i littoralsonen av innsjøer utgjør en stor del av innsjøers økosystem, og samfunnsstrukturen av disse dyrene kan være med å påvirke hele økosystemet. Forskjellige arter av bunndyr har forskjellige livssykluser og tilpasninger til habitatene de lever i og det er rimelig å forvente at sammensetningen av arter endrer seg med forskjellige dyp og bunnsubstrat, og også over ... -
Long-term population dynamics of Diphyllobothrium ditremum and D. dendriticum (Cestoda: Pseudophyllidea) in their salmonid hosts following a fish removal experiment
(Master thesis; Mastergradsoppgave, 2014-02-15)Parasite-host interactions are important in understanding ecosystem processes, for instance by using trophically transmitted parasites as indicators of host ecology. Parasite infections are expected to correlate with host density, habitat choice and feeding behaviour. The importance of long-term data and perturbation experiments has been emphasized for advancing our knowledge of the parasite-host ...
