Viser treff 21-40 av 1950

    • Parasite communities in pink salmon (Oncorhynchus gorbuscha) along their invasion gradient in Norway – a cause for concern? 

      Gjestvang, August (Master thesis; Mastergradsoppgave, 2024-08-09)
      Globally, non-indigenous species (NIS) are increasing in both number and distribution. Sometimes NIS are intentionally introduced to provide food or financial gain. If NIS are moved to a new environment without their competitors, predators and parasites they may gain an advantage over native species. This is explained by the enemy release hypothesis, which also includes parasites, as NIS might lose ...
    • Necropsy findings, meat control pathology and causes of loss in semi-domesticated reindeer (Rangifer tarandus tarandus) in northern Norway 

      Mørk, Torill; Eira, Henrik Isaksen; Rødven, Rolf; Nymo, Ingebjørg Helena; Blomstrand, Berit Marie; Guttormsen, Sandra; Olsen, Line; Davidson, Rebecca K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-04)
      Background Reindeer herding in Norway is based on traditional Sámi pastoralism with the animals free ranging throughout the year. The animals move over large areas in varying terrain and often in challenging weather conditions. Winter crises, such as difficult grazing conditions caused by icing or large amounts of snow, are survival bottlenecks for reindeer. Calves are especially vulnerable, and ...
    • Seasonal acoustic presence of marine mammals at the South Orkney Islands, Scotia Sea 

      Åsvestad, Linn; Ahonen, Heidi; Menze, Sebastian; Lowther, Andrew; Lindstrøm, Ulf Ove; Krafft, Bjørn Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-03)
      Increased knowledge about marine mammal seasonal distribution and species assemblage from the South Orkney Islands waters is needed for the development of management regulations of the commercial fishery for Antarctic krill (Euphausia superba) in this region. Passive acoustic monitoring (PAM) data were collected during the autumn and winter seasons in two consecutive years (2016, 2017), which ...
    • A versatile, semi-automated image analysis workflow for time-lapse camera trap image classification 

      Celis, Gerardo; Ungar, Peter; Sokolov, Aleksandr; Soininen, Eeva M; Böhner, Hanna; Liu, Desheng; Gilg, Olivier; Fufachev, Ivan; Pokrovskaya, Olga; Ims, Rolf Anker; Zhou, Wenbo; Morris, Dan; Ehrich, Dorothee (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-26)
      Camera traps are a powerful, practical, and non-invasive method used widely to monitor animal communities and evaluate management actions. However, camera trap arrays can generate thousands to millions of images that require significant time and effort to review. Computer vision has emerged as a tool to accelerate this image review process. We propose a multi-step, semi-automated workflow which ...
    • Survey report (Part 2) from the joint Norwegian/Russian Ecosystem Survey in the Barents Sea and the adjacent waters August-October 2023 — Marine environment, Mesozooplankton, Commercial Demersal Fish, Fish Biodiversity, Commercial Shellfish, Benthic Invertebrate Community, Marine Mammals and Seabirds 

      Prozorkevich, Dmitri; Eriksen, Elena; Karlson, Stine; Trofimov, Aleksander; Ingvaldsen, Randi Brunvær; Grøsvik, Bjørn Einar; Prokhorova, Tatiana; Klepikovskiy, Roman; Bagøien, Espen; Johannesen, Edda; Bogstad, Bjarte; Wiedmann, Magnus Aune; Krivosheya, Pavel; Prokopchuk, Irina; Windsland, Kristin; Russkikh, Alexey; Wienerroither, Rupert; Filin, Anatoly; Zimmermann, Fabian; Hjelset, Ann Merete; Danielsen, Hanna Ellerine Helle; Bakanev, sergei; Stesko, Aleksei; Jørgensen, Lis Lindal; Blinova, Daria; Boehm, Frederike; Øien, Nils Inge; Strelkova, Natalia; Kudrayashova, Alexander; Fauchald, Per; Ollus, Victoria Marja Sofia; Ford, Jonathan; Elton, Gary (Research report; Forskningsrapport, 2024)
      The aim of the joint Norwegian/Russian ecosystem survey in the Barents Sea and adjacent waters, August-October (BESS) is to monitor the status and changes of in the Barents Sea ecosystem. The survey has since 2004 been conducted annually in the autumn, as a collaboration between the IMR in Norway and the Polar Branch of VNIRO (PINRO) in Russia. The general survey plan, tasks, and sailings routes are ...
    • Effects of resource availability and interspecific interactions on Arctic and red foxes' winter use of ungulate carrion in the Fennoscandian low-Arctic tundra 

      Lacombe, Simon; Ims, Rolf Anker; Yoccoz, Nigel Gilles; Kleiven, Eivind Flittie; Antunes Lopes Da Silva Nicolau, Pedro Guilherme; Ehrich, Dorothee (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-01)
      In the Arctic tundra, predators face recurrent periods of food scarcity and often turn to ungulate carcasses as an alternative food source. As important and localized resource patches, carrion promotes co-occurrence of different individuals, and its use by predators is likely to be affected by interspecific competition. We studied how interspecific competition and resource availability impact ...
    • Secondary production at the Barents Sea polar front in summer: contribution of different size classes of mesozooplankton 

      Gawinski, Christine; Basedow, Sünnje Linnéa; Sundfjord, Arild; Svensen, Camilla (Journal article; Tidsskriftartikkel, 2024-05-02)
      The Barents Sea polar front is characterized by high primary production following the retreat of the ice edge during spring. However, secondary production estimates of mesozooplankton across the front are scarce, despite being essential for understanding energy flow through the food web. We investigated mesozooplankton community composition and production across the Barents Sea polar front (75°-78°N) ...
    • Phytoplankton bloom distribution and succession driven by sea-ice melt in the Kong Håkon VII Hav 

      Lenss, Megan; Moreau, Sebastien; Hattermann, Tore; Wiktor, Josef; Różańska, Marta; Claeys, Philippe; Brion, Natacha; Chierici, Melissa; Fransson, Agneta; Campbell, Karley Lynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-02)
      The existence of ice-edge phytoplankton blooms in the Southern Ocean is well described, yet direct observations of the mechanisms of phytoplankton bloom development following seasonal sea-ice melt remain scarce. This study constrains such responses using biological and biogeochemical datasets collected along a coastal-to-offshore transect that bisects the receding sea-ice zone in the Kong Håkon VII ...
    • Impact of aggregate-colonizing copepods on the biological carbon pump in a high-latitude fjord 

      Svensen, Camilla; Iversen, Morten; Norrbin, Maria Fredrika; Möller, Klas Ove; Wiedmann, Ingrid; Skardhamar, Jofrid; Barth-Jensen, Coralie Marie Christine; Kwasniewski, Slawomir; Ormanczyk, Mateusz; Dąbrowska, Anna Maria; Koski, Marja (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-29)
      Zooplankton consumption of sinking aggregates affects the quality and quantity of organic carbon exported to the deep ocean. Increasing laboratory evidence shows that small particle-associated copepods impact the flux attenuation by feeding on sinking particles, but this has not been quantified in situ. We investigated the impact of an abundant particle-colonizing copepod, Microsetella norvegica, ...
    • Machine learning applied to species occurrence and interactions: the missing link in biodiversity assessment and modelling of Antarctic plankton distribution 

      Grillo, Marco; Schiaparelli, Stefano; Durazzano, Tiziana; Guglielmo, Letterio; Granata, Antonia; Huettmann, Falk (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-25)
      Background Plankton is the essential ecological category that occupies the lower levels of aquatic trophic networks, representing a good indicator of environmental change. However, most studies deal with distribution of single species or taxa and do not take into account the complex of biological interactions of the real world that rule the ecological processes.<p> <p>Results This study focused ...
    • Seasonality in phytoplankton communities and production in three Arctic fjords across a climate gradient 

      Chitkara, Cheshtaa; Juul-Pedersen, Thomas; Krawczyk, Diana; Søreide, Janne; Vader, Anna; Gradinger, Rolf Rudolf; HS Winding, Mie; Vonnahme, Tobias R (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-28)
      Phytoplankton communities and production in Arctic fjords undergo strong seasonal variations. Phytoplankton blooms are periods with high primary production, leading to elevated algal biomass fueling higher trophic levels. Blooms are typically driven bottom-up by light and nutrient availability but may also be top-down controlled by grazing. While phytoplankton spring blooms are common across all ...
    • Tracking gonadal development in fish: An in vivo MRI study on polar cod, Boreogadus saida (Lepechin, 1774) 

      Vogt, Nicole; Wermter, Felizitas C.; Nahrgang-Berge, Jasmine Magali; Storch, Daniela; Bock, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-07)
      Magnetic resonance imaging (MRI) was applied to determine the sex of polar cod (Boreogadus saida Lepechin, 1774) (Actinopterygii: Gadidae) and to follow the gonadal development in individual animals over time. Individual unanaesthetised fish were transferred to a measurement chamber inside a preclinical 9.4 T MRI scanner and continuously perfused with aerated seawater. A screening procedure at ...
    • Response of the copepod community to interannual differences in sea-ice cover and water masses in the northern Barents Sea 

      Gawinski, Christine; Daase, Malin Hildegard Elisabeth; Primicerio, Raul; Amargant I Arumi, Marti; Müller, Oliver; Wold, Anette; Ormanzcyk, Mateusz; Kwasniewski, Slawomir; Svensen, Camilla (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-27)
      The reduction of Arctic summer sea ice due to climate change can lead to increased primary production in parts of the Barents Sea if sufficient nutrients are available. Changes in the timing and magnitude of primary production may have cascading consequences for the zooplankton community and ultimately for higher trophic levels. In Arctic food webs, both small and large copepods are commonly present, ...
    • Reading tea leaves worldwide: Decoupled drivers of initial litter decomposition mass-loss rate and stabilization 

      Sarneel, Judith M.; Hefting, Mariet M.; Sandén, Taru; van den Hoogen, Johan; Routh, Devin; Adhikari, Bhupendra S.; Alatalo, Juha M.; Aleksanyan, Alla; Althuizen, Inge; Alsafran, Mohammed H S A; Atkins, Jeff W.; Augusto, Laurent; Aurela, Mika; Azarov, Aleksej V.; Barrio, Isabel C.; Beier, Claus; Bejarano, María D; Benham, Sue E.; Berg, Björn; Bezler, Nadezhda V.; Björnsdóttir, Katrín; Bolinder, Martin A.; Carbognani, Michele; Cazzolla Gatti, Roberto; Chelli, Stefano; Chistotin, Maxim V.; Christiansen, Casper Tai; Courtois, Pascal; Crowther, Thomas W.; Dechoum, Michele S.; Djukic, Ika; Duddigan, Sarah; Egerton-Warburton, Louise M.; Fanin, Nicolas; Fantappiè, Maria; Fares, Silvano; Fernandes, Geraldo W.; Filippova, Nina V.; Fliessbach, Andreas; Fuentes, David; Godoy, Roberto; Grünwald, Thomas; Guzmán, Gema; Hawes, Joseph; He, Yue; Hero, Jean-Marc; Hess, Laura L.; Hogendoorn, Katja; Høye, Toke T.; Jans, Wilma W P; Jónsdóttir, Ingibjörg S; Keller, Sabina; Kepfer-Rojas, Sebastian; Kuz'menko, Natalya N.; Larsen, Klaus S.; Laudon, Hjalmar; Lembrechts, Jonas J.; Li, Junhui; Limousin, Jean-Marc; Lukin, Sergey M.; Marques, Renato; Marín, César; McDaniel, Marshall D.; Meek, Qi; Merzlaya, Genrietta E.; Michelsen, Anders; Montagnani, Leonardo; Mueller, Peter; Murugan, Rajasekaran; Myers-Smith, Isla H.; Nolte, Stefanie; Ochoa-Hueso, Raúl; Okafor, Bernard N.; Okorkov, Vladimir V.; Onipchenko, Vladimir G.; Orozco, María C; Parkhurst, Tina; Peres, Carlos A.; Petit Bon, Matteo; Petraglia, Alessandro; Pingel, Martin; Rebmann, Corinna; Scheffers, Brett R.; Schmidt, Inger; Scholes, Mary C.; Sheffer, Efrat; Shevtsova, Lyudmila K.; Smith, Stuart; Sofo, Adriano; Stevenson, Pablo R.; Strouhalová, Barbora; Sundsdal, Anders; Sühs, Rafael B.; Tamene, Gebretsadik; Thomas, Haydn J D; Tolunay, Duygu; Tomaselli, Marcello; Tresch, Simon; Tucker, Dominique L.; Ulyshen, Michael D.; Valdecantos, Alejandro; Vandvik, Vigdis; Vanguelova, Elena I.; Verheyen, Kris; Wang, Xuhui; Yahdjian, Laura; Yumashev, Xaris S.; Keuskamp, Joost A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-07)
      The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived ...
    • The increase of an allelopathic and unpalatable plant undermines reindeer pasture quality and current management in the Norwegian tundra 

      Tuomi, Maria Wilhelmina; Utsi, Tove Hilde Ågnes; Yoccoz, Nigel Gilles; Armstrong, Claire W.; Gonzalez, Victoria; Hagen, Snorre; Jonsdottir, Inga-Svala; Pugnaire, Francisco I.; Shea, Katriona; Wardle, David A.; Zielosko, Sophia Theresa; Braathen, Kari Anne (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-03)
      Ongoing Arctic greening can increase productivity and reindeer pasture quality in the tundra. However, greening may also entail proliferation of unpalatable species, with consequences for pastoral socialecological systems. Here we show extensive greening across 20 reindeer districts in Norway between 2003 and 2020, which has reduced pasture diversity. The allelopathic, evergreen dwarf-shrub crowberry ...
    • Interactions between 0-group Saithe (Pollachius virens) and 0-group Cod (Gadhus morhua) in shallow nursery areas 

      Mørch, Octavia (Per-Aksel) Wistnes (Master thesis; Mastergradsoppgave, 2024-05-14)
      In this study diet width and overlap between 0-group saithe (Pollachius virens) and 0-group cod (Gadhus morhua) was studied. Along with studying if habitat characteristics, length of the fish (cod and saithe), fjord distance, predator specie (cod or saithe) had an impact on the diet composition of the sampled fishes. A diet comparison between my diet findings and findings in earlier studies. The ...
    • Co‑creating coastal sustainability goals and indicators 

      Engen, Sigrid; Hausner, Vera Helene; Mikkelsen, Eirik Inge; Gundersen, Hege; Christie, Hartvig C; Falk-Andersson, Jannike; Halpern, Benjamin S.; Fauchald, Per (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-24)
      Indicators can be powerful tools to measure progress towards achieving societal goals, and many indicators have been developed for sustainability goals nationally and internationally. When indicators are developed solely through top-down approaches without engaging local knowledge, they often fall short of capturing local perceptions and concerns relevant to decision-making. The aim of this project ...
    • Seasonal changes of intertidal benthic microalgae photoacclimation during the summer to mid-winter transition period on Tromsøya 

      Reast, Emily (Master thesis; Mastergradsoppgave, 2024-05-15)
      The microphytobenthos (MPB), defined as the microscopic photosynthesizers inhabiting sediments in marine and estuarine environments, are a vital component to intertidal ecosystems. They contribute greatly to ecosystem services in many ways and are responsible for a high amount of primary productivity in their environments. Microphytobenthic abundance and community structure studies have been increasing ...
    • Phylogeography and gut content of Priapulus caudatus in Norway 

      Hansen, Maren Christine (Master thesis; Mastergradsoppgave, 2024-05-15)
      Priapulus caudatus is a marine worm in the phylum Priapulida, commonly known as penis worms. Since it was discovered, P. caudatus has had many names that are now considered synonyms. Fossils of Priapulida from the Cambrian period are found all over the world, and extant species show that there have been little changes in their morphology since the Palaeozoic. P. caudatus are found in clay/muddy ...
    • Ageing and growth of the Arctic brittle star Ophiopleura borealis (Echinodermata: Ophiuroidea) from the Barents Sea and North East Greenland 

      Dinevik, Hanna (Master thesis; Mastergradsoppgave, 2024-05-15)
      Species inhabiting cold-water environments exhibit typically slower growth and a longer lifespan than warm-water species, implying a slowed ability to recover from natural and anthropogenic disturbances. Longevity estimates for species inhabiting the Arctic region are sparse, despite the ongoing changes and disturbances in the region. Brittle stars (Ophiuroidea) often dominate Arctic shelf ...