Viser treff 341-360 av 2040

    • Serological screening for tick-borne encephalitis virus in eight Norwegian herds of semi-domesticated reindeer 

      Lamsal, Alaka; Tryland, Morten; Paulsen, Katrine M.; Romano, Javier Sánchez; Nymo, Ingebjørg H.; Stiasny, Karin; Soleng, Arnulf; Vikse, Rose; Andreassen, Åshild Kristine (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-01)
      Tick-borne encephalitis virus (TBEV) is found in Ixodes ricinus ticks throughout the area where viable tick populations exist. In Norway, TBEV is found in I. ricinus from the south coast until Brønnøy municipality in Nordland County and the range of the vector is expanding due to changes in climate, vegetation, host animals and environmental conditions. TBEV might thus have the potential to establish ...
    • Does crypsis influence foraging patterns in a colour polymorphic Arctic fox population? 

      Pepels, Kos Jack Johan (Master thesis; Mastergradsoppgave, 2023-05-26)
      Seasonal coat colour moulting species moult to white winter fur for crypsis in snow-covered landscapes. Seasonal coat colour moulting occurs in birds and mammals; some are colour polymorphic; one of which is the arctic fox (Vulpes lagopus), having a blue and white colour morph. Camouflage, thermoregulation and physiology likely contributed to the evolution of this polymorphism. Climate change is ...
    • Gelatinous zooplankton diversity, distribution and seasonality in the northern Barents Sea and Arctic Ocean 

      Ciambelli, Angelo (Master thesis; Mastergradsoppgave, 2023-05-15)
      Gelatinous zooplankton, here referring to the phylum Cnidaria and Ctenophora and the class Appendicularia are important components of marine ecosystems due to their very diverse diets, life cycles and seasonal dynamics. In the Barents Sea, several studies reviewed the gelatinous zooplankton diversity, yet few studies documented the diversity and distribution patterns between the advected ...
    • Estimating secondary production and egg production of Calanus spp. at the Polar front 

      Granaas, Torkel (Master thesis; Mastergradsoppgave, 2023-05-15)
      Secondary production was estimated at the Polar Front in 2022 using optical sampling techniques to sample zooplankton, growth rates computed with semi-emprical equations and egg production of Calanus spp. was also estimated.
    • Food web-mediated interaction between marine mammals and fisheries in the Norwegian and Barents seas. 

      Bas, Lucas Johannes (Master thesis; Mastergradsoppgave, 2023-05-15)
      Ecological systems, such as marine ecosystems, are complex adaptive systems in which large scale system properties (e.g., trophic structure, energy flux patterns, etc.) emerge from interactions between ecosystem components or species. This makes them difficult to understand, predict, and model. The Norwegian and Barents Seas support multiple commercial fisheries, including those for herring, cod, ...
    • Effect of climate change and invasive species on Arctic marine food-webs 

      Yagüe Arranz, Sonia (Master thesis; Mastergradsoppgave, 2023-05-15)
      Climate warming induces poleward distributional shifts of boreal species in Arctic regions resulting in compositional changes with poorly understood consequences for Arctic food-webs. This thesis addresses the spatial variation in Barents Sea food-webs using previously compiled distributional data in polygons specified for the Nowegian and Barents Sea NoBa Atlantis model and a highly resolved Barents ...
    • The effect of endurance training on mitochondrial function in Siberian huskies and Alaskan huskies 

      Sælen-Helgesson, Silje (Master thesis; Mastergradsoppgave, 2023-05-15)
      Teams of Alaskan huskies and Siberian Huskies are used to pull sleds and compete in long-distance races such as Finnmarksløpet (1200 km) and the Iditarod (1600 km). That is an elite athlete performance, and their ability to conduct such extreme endurance challenges under arctic conditions is poorly understood. A previous study has shown that Alaskan huskies possibly have the highest values of ...
    • Microplastics Accumulation in Recirculating Aquaculture Systems (RAS) 

      Eidsvik, Erlend Vartdal (Master thesis; Mastergradsoppgave, 2023-05-14)
      It has in recent years been a shift in the land-based aquaculture production from flow through systems (FTS) to recirculating aquaculture systems (RAS). With emerging use of RAS, it is necessary with knowledge regarding potential issues, whereas one potentially increasing problem is accumulation of microplastics (MP) in the RAS water. The objects of this study were to determine MPs concentration in ...
    • Microbial responses to warming and seasonal temperature changes in sub-Arctic forest and grassland soils 

      Ahlers, Laureen Sarah (Master thesis; Mastergradsoppgave, 2023-05-15)
      Atmospheric carbon dioxide (CO2) levels and global temperatures have increased steadily over the past 100 years (IPCC, 2018). Greenhouse gases, such as CO2, and their emissions from soils play an important role in shaping future climate scenarios. Soil microorganisms are responsible for the turnover of soil organic matter and the release of CO2 to the atmosphere (Hartley et al., 2008), thereby ...
    • The Suprachiasmatic Nucleus of The Reindeer (Rangifer tarandus tarandus) and it’s Circadian Outputs 

      Holmen, Mariel Wictoria (Master thesis; Mastergradsoppgave, 2023-05-14)
      The Earth is in constant movement around the Sun – this has created environments with changing light throughout the day and year. Through evolution animals have adapted to this change in light and circadian and circannual rhythms have evolved to enhance fitness and survival. Animals living in the Arctic region have a different relationship to light changes as for several months a year the Sun ...
    • Biotic and abiotic drivers of barnacle recruitment along a sub-Arctic intertidal rocky shore 

      Prieto Del Campo, Marta (Master thesis; Mastergradsoppgave, 2023-05-15)
      Most marine ecological research in the Arctic has focused on open water ecosystems, while coastal ecosystems are systematically under-studied. However, Arctic near-shore ecosystems are highly stressed environments and play a major role in biogeochemical cycling (e.g., nutrient input from thawing permafrost). Furthermore, the Arctic region has extreme environmental conditions which are expected ...
    • Circannual rhythms in Arctic charr (Salvelinus alpinus) 

      Pelko, Magdalena Maria (Master thesis; Mastergradsoppgave, 2023-05-15)
      The Arctic charr (Salvelinus alpinus) is a true arctic species and is considered to be the northernmost freshwater fish. Since this species is being known for its great variability in size, phenotype, colour, ecology and history, some of them are landlocked (which stay in freshwater all their life) and others are anadromous (they undertake summer migrations to sea and then they come back to ...
    • Changes in the distribution of marine invertebrates in a warming Barents Sea over the last century 

      Calvet, Nathalie (Master thesis; Mastergradsoppgave, 2023-05-14)
      The Barents Sea is a shelf sea in the European Arctic and is influenced by the North Atlantic Current and the Arctic Ocean. The North Atlantic Current is composed of warmer, saline waters compared to the cold, fresher waters from the Arctic Ocean. Over the last century, the Barents Sea mean temperature has increased by 1.5°C above a depth of 60m and by 0.5-0.8°C below 60m. This warming is ...
    • Developing a mitigation hierarchy framework to conserve wetland biodiversity under pressure from development 

      Dahle, Mathias Leines (Master thesis; Mastergradsoppgave, 2023-05-16)
      Wetlands are severely affected by human development. About 50 % of their original global extent has been lost, their populations of plants and animals have declined faster than for any other ecosystem, and 25 % of wetland-dependent species are threatened. As the main reason for these declines is habitat loss, often caused by infrastructure development, it is critical to develop conservation strategies ...
    • Beyond Catching Fish: Exploring the role of Relational Values in Mobilizing Community-based Management Efforts in a north Norwegian lake 

      Mæland, Kjerstin Andrea (Master thesis; Mastergradsoppgave, 2023-05-15)
      All over the world, local communities are actively engaging in the management and monitoring of natural resources. The underlying driver of most community-driven efforts goes beyond the direct utilization of natural resources to entail a deeper relation to the place or ecosystem they are managing. Relational values have been suggested as a potential driver of such initiatives, but empirical research ...
    • 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 ...
    • High seasonal overlap in habitat suitability in a nonmigratory High Arctic ungulate 

      Pedersen, Åshild Ønvik; Soininen, Eeva M; Hansen, Brage Bremset; Le Moullec, Mathilde; Loe, Leif Egil; Paulsen, I.M.G.; Eischeid, Isabell; Karlsen, Stein Rune; Ropstad, Erik; Stien, Audun; Tarroux, Arnaud; Tømmervik, Hans; Ravolainen, Virve (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-26)
      Understanding drivers of space use and habitat selection is essential for management and conservation, especially under rapid environmental change. Here, we develop summer and winter habitat suitability models for the endemic wild Svalbard reindeer (Rangifer tarandus platyrhynchus). The High Arctic Svalbard tundra is currently subject to the fastest temperature increases on Earth, and reindeer ...
    • Northern expansion is not compensating for southern declines in North American boreal forests 

      Rotbarth, Ronny; Van Nes, Egbert H.; Scheffer, Marten; Jepsen, Jane Uhd; Vindstad, Ole Petter Laksforsmo; Xu, Chi; Holmgren, Milena (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-08)
      Climate change is expected to shift the boreal biome northward through expansion at the northern and contraction at the southern boundary respectively. However, biome-scale evidence of such a shift is rare. Here, we used remotely-sensed tree cover data to quantify temporal changes across theNorth American boreal biome from 2000 to . 2019. We reveal a strong northsouth asymmetry in tree cover change, ...
    • Increased importance of cool-water fish at high latitudes emerges from individual-level responses to warming 

      Smalås, Aslak; Primicerio, Raul; Kahilainen, Kimmo K.; Terentjev, Petr; Kashulin, Nikolay; Zubova, Elena; Amundsen, Per-Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-06)
      High latitude ecosystems are experiencing the most rapid warming on earth, expected to trigger a diverse array of ecological responses. Climate warming affects the ecophysiology of fish, and fish close to the cold end of their thermal distribution are expected to increase somatic growth from increased temperatures and a prolonged growth season, which in turn affects maturation schedules, reproduction, ...
    • Estimating the cumulative impact and zone of influence of anthropogenic features on biodiversity 

      Niebuhr, Bernardo Brandão; Van Moorter, Bram; Stien, Audun; Tveraa, Torkild; Strand, Olav; Langeland, Knut; Sandstrom, Per; Alam, Moudud; Skarin, Anna; Panzacchi, Manuela (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-02)
      1. The concept of cumulative impacts is widespread in policy documents, regu-lations and ecological studies, but quantification methods are still evolving. Infrastructure development usually takes place in landscapes with preexist-ing anthropogenic features. Typically, their impact is determined by computing the distance to the nearest feature only, thus ignoring the potential cumulative impacts of ...