Browsing Mastergradsoppgaver i biologi by Title

Now showing items 303-322 of 362

    • Size composition, reproductive investment, and fecundity of red king crab (Paralithodes camtschaticus) in Finnmark fjords, 1994-2022 

      Hjertaas, Haakon Winge (Master thesis; Mastergradsoppgave, 2023-05-15)
      The release of red king crab (Paralithodes camtschaticus) into the Barents Sea by Russian scientists in the 1960s had the goal of establishing a self-sustaining stock for the purpose of commercial harvest. The red king crab has been successfully established as a stock in Norwegian waters where it has become an important commercial resource in the eastern regions of Finnmark. The Norwegian red king ...

    • Snow depth effects on vegetation dynamics and development of near-remote sensing techniques in high-Arctic tundra 

      Jørgensen, Andreas (Master thesis; Mastergradsoppgave, 2022-05-16)
      Snow exerts key controls on many aspects of plant ecology in the Arctic, including community composition. With climate predictions forecasting dramatic changes in winter climate and snow cover in the Arctic in the near future, it is important to improve our understanding of snow effects on plant communities in these regions. This study used a snow depth manipulation experiment established in 2006 ...

    • Soft-bottom communities in Balsfjord. Stable over time of under change? 

      Henriksen, Nina Elisabeth (Master thesis; Mastergradsoppgave, 2015-12-15)
      The soft-bottom macrofauna (>1 mm) was investigated at three different locations in Balsfjord; Andersdal, Svartnes and Tennes. The Svartnes data was then merged with Eivind Ougs long-term series from 1977-1994. The data showed that there were large variation between the three different stations in number of taxa and individuals found. A total of 59 taxa and 1514 (0.7 m2) individuals were found. The ...

    • Sources of variation in macrobenthic biodiversity and the implications for monitoring programmes in the Barents Sea 

      Bersås, Nina Marie (Master thesis; Mastergradsoppgave, 2009-07-01)
      In this thesis, several sources of variation which affect macrobenthic biodiversity was examined, in addition to addressing the resulting implications for monitoring programmes in the Barents Sea. Marine benthic biodiversity patterns at the time of sampling were examined across a range of scales, pre-defined by the study design. The benthic distribution was examined in relation to characteristics ...

    • 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 ...

    • A spatial and temporal study of Pseudocalanus acuspes, P. minutus and P. moultoni in the Svalbard – Barents Sea region and their potential as environmental indicator species in a changing Arctic 

      Astad, Sine-Sara (Master thesis; Mastergradsoppgave, 2022-11-22)
      <p>Many species of small copepods are morphologically similar and thus often grouped together at genus level rather than studied as individual species. However, species within the same genus may differ quite a lot in life history strategies and traits. In this study, I used a species-specific polymerase chain reaction to explore the abundance, distribution and size range of <i>Pseudocalanus</i> ...

    • Spatial distribution of mammals in relation to spruce plantations in birch forests of northern Norway 

      Juell, Kristoffer Hovind (Master thesis; Mastergradsoppgave, 2007-11)
      Spruce plantations in coastal birch forests of northern Norway might affect the spatial activity of mammals in the landscape. To investigate this relationship, I censused tracks of mammals in the winter according to the Finnish wildlife triangle method and analysed these at three spatial scales; tree stand level, landscape level and regional level, the two first being related to spruce. The spatial ...

    • The spatial relationship between pelagic fish species in the Barents Sea 

      Haukeland, Vegard Bjartveit (Master thesis; Mastergradsoppgave, 2008-05-15)
      Capelin (Mallotus villosus) is a pelagic fish species with large interannual stock variations in the Barents Sea ecosystem. Together with polar cod (Boreogadus saida) and juvenile herring (Clupea harengus), it functions as an intermediate link that transfers energy from zooplankton to higher trophic levels. Capelin is a key prey and important as a food resource both to sea birds, sea mammals and ...

    • Spatio-temporal Diptera visitation to Silene acaulis flowers studied with time-lapse cameras in Svalbard and Greenland 

      Klausen, Line (Master thesis; Mastergradsoppgave, 2022-08-15)
      Flower visitation by flying arthropods has mainly been studied by direct human observation, which usually neglects seasonal development of flower abundance even though this is known to be important for visitor dynamics and match between trophic levels. In the present study, the arthropod visitor community focusing on Diptera was investigated on the cushion plant Silene acaulis (L.) Jacq. in relation ...

    • Spatio-temporal dynamics in breeding occurrence of passerine birds in subarctic birch forest 

      Bjørkås, Ragnhild (Master thesis; Mastergradsoppgave, 2017-05-15)
      The three box-nesting passerine bird species pied flycatcher, great tit and common redstart breed at their distributional limit in Troms, Northern Norway. Access to food and favourable weather conditions is expected to be of importance for the birds´ breeding population dynamics. In the same area, geometrid moth larvae experience cyclic population outbreaks at approx. 10 year intervals, constituting ...

    • Spatiotemporal distribution and co-occurrence of Arctic herbivores in spring 

      Grimsby, Anna Caroline (Master thesis; Mastergradsoppgave, 2022-04-19)
      Biotic interactions play an important role in the structure and dynamics of food-webs and may drive the spatial distribution of species. In the Arctic, spring snow-cover limits the availability of resources at a critical time for resident and migratory herbivores, which could lead to resource competition. This study takes a first step towards understanding the potential for competition between the ...

    • Spawning behavior of Arctic charr (Salvelinus alpinus): spawning synchrony, vibrational communication and mate guarding. 

      Brattli, Magnus Beyer (Master thesis; Mastergradsoppgave, 2017-05-15)
      A mismatch between male and female gamete release can result in reduced or failed fertilization in external fertilizers, sperm competition and reduced paternity. Here, I video monitored spawning behavior of free living Arctic charr (Salvelinus alpinus), and analyzed details of their reproductive biology. In total, 157 spawnings were recorded. Females clearly preferred spawning with the dominant male, ...

    • Species validity of five common northern/Arctic spring bloom diatoms: a combined morphological and molecular study 

      Uradnikova, Martina (Master thesis; Mastergradsoppgave, 2020-02-15)
      Relevant taxonomical morphological characters of five common spring bloom centric diatoms, preliminary identified as Attheya longicornis Crawford & Gardner, Chaetoceros furcellatus Yendo, Porosira glacialis Jørgensen, Coscinodiscus sp. and Skeletonema marinoi Sarno & Zingone were observed and described using light and scanning electron microscope. Further, samples of cultured diatoms were sent to ...

    • 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. ...

    • Spring sea ice algal development in the sub-Arctic Ramfjorden, northern Norway 

      Persson, Emma (Master thesis; Mastergradsoppgave, 2020-05-29)
      The seasonal development of sea ice algae and bacteria was investigated in Ramfjorden, Norway, from February to April 2019 and compared to data from two Arctic fjords, Van Mijenfjorden and Billefjorden, sampled in April 2019. The sea ice in Ramfjorden was heavily freshwater influenced with bulk salinities ranging from 0.0 to 2.8, similar to those found in freshwater influenced Baltic Sea ice. The ...

    • Stability of space use in Svalbard coastal female polar bears: Intra-individual variability and influence of kinship 

      Brun, Clément (Master thesis; Mastergradsoppgave, 2020-06-01)
      Philopatry influences the distribution of animals and can lead to the formation of kinship-based population structures when relatedness among individuals is tightly linked to their proximity. Two different polar bear ecotypes exist in the Barents Sea sub-population: “coastal” bears and “offshore” bears. Coastal bears remain year-round within the Svalbard archipelago whereas offshore bears follow the ...

    • Strategies for timing of nest departure in the common guillemot Uria aalge 

      Johansen, Malin Kjellstadli (Master thesis; Mastergradsoppgave, 2017-05-15)
      Duration of parental care in avian species varies widely, from altricial to precocial species. The seabird family Alcidae is unique among birds in the variation of mass and age at nest departure. The common guillemot Uria aalge exhibits an intermediate nest departure, where chicks leave the nest flightless and only at a quarter of adult body size. The aim of this study was to examine factors controlling ...

    • Structure and dynamics of the Barents Sea Polar Front near the Great Bank and associated plankton distribution in August 2007 

      Våge, Selina (Master thesis; Mastergradsoppgave, 2010-03-30)
      The Polar Front separating Atlantic Water (AW) and Arctic Water (ArW) is one of the most dominant mesoscale features in the Barents Sea and a highly productive region. Here, the results of sub-mesoscale variability in physical and biological fields associated with the Barents Sea Polar Front (BSPF) at the Great Bank are reported from a high-resolution survey in August 2007. A nearly synoptic data ...

    • The structure of nasal conchae in Svalbard rock ptarmigan (Lagopus muta hyperborea) with comparisons to three other Galliform birds 

      Westvik, Marie Aas (Master thesis; Mastergradsoppgave, 2022-05-27)
      Birds are endothermic homeotherms that regulate internal metabolic heat production to keep a stable body core temperature. Lung ventilation, which is required to obtain oxygen for metabolism, is potentially a large source for heat and water loss. In a polar habitat with low year-round temperatures and scarcity of food in the winter, conservation of heat and water is crucial for survival of the ...

    • 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. ...