Viser treff 261-280 av 5171

    • Understanding the effect of design parameters on the filtration efficiency of trawls intended for commercial harvesting of zooplankton 

      Grimaldo, Eduardo; Herrmann, Bent; Kostak, Enis Noyan; Brinkhof, Jesse Vallevik (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-01)
      A major challenge for the aquaculture sector is access to sustainable and cost-effective raw materials for feed. Copepods (Calanus spp.) have potential to meet this need for large volumes of marine raw materials to enable sustainable growth of aquaculture production worldwide. However, the lack of an energy- and catch-efficient trawl technology has limited the development of this fishery in the ...
    • Impacts of Vegetation and Temperature Changes on Carbon Cycling Microbial Communities in Arctic Wetlands 

      Bender, Kathrin Marina (Doctoral thesis; Doktorgradsavhandling, 2023-11-20)
      Climate change causes disturbances to soil environments. Such disturbances include shifts in vegetation composition and rising temperatures, which can impact the microbial communities involved in soil carbon cycling. In this thesis, my emphasis was centered on two main aspects: the effects of vegetation changes, caused by herbivory, and the effects of temperature changes on the soil organic matter ...
    • Large-scale seabird community structure along oceanographic gradients in the Scotia Sea and northern Antarctic Peninsula 

      Ollus, Victoria Marja Sofia; Biuw, Martin; Lowther, Andrew; Fauchald, Per; John Elling Deehr, Johannessen; Martín López, Lucía Martina; Gkikopoulou, Kalliopi C.; Oosthuizen, W. Chris; Lindstrøm, Ulf Ove (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-18)
      Introduction: The Scotia Sea and Antarctic Peninsula are warming rapidly and changes in species distribution are expected. In predicting habitat shifts and considering appropriate management strategies for marine predators, a community-level understanding of how these predators are distributed is desirable. Acquiring such data, particularly in remote areas, is often problematic given the cost ...
    • Long-term responses of Icelandic Arctic foxes to changes in marine and terrestrial ecosystems 

      Berthelot, Fanny Marie Lou; Unnsteinsdóttir, Ester R.; Ellgutter, Jennifer Alejandrina Carbonell; Ehrich, Susanna Dorothee (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-04)
      The long-term dynamics of predator populations may be driven by fluctuations in resource availability and reflect ecosystem changes such as those induced by climate change. The Icelandic Arctic fox (Vulpes lagopus) population has known major fluctuations in size since the 1950s. Using stable isotopes analysis of bone collagen over a long-time series (1979– 2018), we aimed at identifying the main ...
    • Acclimation of circadian rhythms in woodland strawberries (Fragaria vesca L.) to Arctic and mid-latitude photoperiods 

      Faehn, Corine Alexis; Reichelt, Michael; Mithöfer, Axel; Hytönen, Timo; Mølmann, Jørgen Alexander Barosen; Jaakola, Laura Elina (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-10)
      Background Though many abiotic factors are constantly changing, the photoperiod is a predictable factor that enables plants to time many physiological responses. This timing is regulated by the circadian clock, yet little is known about how the clock adapts to the differences in photoperiod between mid-latitudes and high latitudes. The primary objective of this study was to compare how clock gene ...
    • Enzymatic Hydrolysis of Orange-Footed Sea Cucumber (Cucumaria frondosa)—Effect of Different Enzymes on Protein Yield and Bioactivity 

      Vu, Dat Trong; Falch, Eva; Elvevoll, Edel Oddny; Jensen, Ida-Johanne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-07)
      While sea cucumber is a food delicacy in Asia, these food resources are less exploited in Europe. The aim of this study was to determine the chemical composition and potential food applications of the less exploited orange-footed sea cucumber (Cucumaria frondosa). In particular, the antioxidative capacity and free amino acids associated with the umami flavor released by enzymatic hydrolyses by ...
    • The application of unmanned aerial vehicle (UAV) surveys and GIS to the analysis and monitoring of recreational trail conditions 

      Tomczyk, Aleksandra M.; Ewertowski, Marek W.; Creany, Noah; Murguzur, Francisco Javier Ancin; Monz, Christopher (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-04)
      Recreational trails are a vital element of protected natural areas (PNAs) infrastructure, which enables visitors to travel through and engage in various activities such as hiking, biking, horse riding. Degradation of trails adversely affects the natural environment as well as the safety and comfort of visitors. As the role of many PNAs is to protect the natural environment and to provide recreational ...
    • Are offshore platforms a good candidate to restore functional diversity of reef fish communities in the Arabian Gulf? 

      Riera, Rodrigo; Torquato, Felipe; Range, Pedro; Ben-Hamadou, Radhouan; Møller, Peter Daniel Rask; Tuset, Víctor M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-04)
      Human-made structures are ubiquitous in the marine realm. Complex structures such as oil and gas platforms may constitute a suitable habitat for species in areas where natural reefs have been highly degraded by coastal development. We here explore the suitability of fish assemblages associated to offshore platforms as surrogates for depleted fish stocks from coastal areas. Taxonomic and functional ...
    • Small rodent population cycles and plants – after 70 years, where do we go? 

      Soininen, Eeva M; Neby, Magne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-12)
      Small rodent population cycles characterise northern ecosystems, and the cause of these cycles has been a long-lasting central topic in ecology, with trophic interactions currently considered the most plausible cause. While some researchers have rejected plant–herbivore interactions as a cause of rodent cycles, others have continued to research their potential roles. Here, we present an overview ...
    • Associations between serum taurine concentrations in mothers and neonates and the children's anthropometrics and early neurodevelopment: Results from the Seychelles Child Development Study, Nutrition Cohort 2 

      Beggan, Laura A.; Mulhern, Maria S.; Mæhre, Hanne; McSorley, Emeir M.; Yeates, Alison J.; Zavez, Alexis; Thurston, Sally W.; Shamlaye, Conrad; van Wijngaarden, Edwin; Davidson, Philip W.; Myers, Gary J.; Strain, J.J.; Elvevoll, Edel Oddny (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-25)
      Background: High concentrations of taurine are present in the developing human brain and maternal breast milk. Taurine is thought to influence fetal growth and brain development based on experimental rodent studies. As fish is an important dietary source of taurine, we investigated associations between taurine concentrations and child outcomes in a high fish consuming population.<p> <p>Objective: ...
    • Informed investors, screening, and sorting on the London capital market, 1891-1913 

      Fjesme, Sturla Lyngnes; Hannah, Leslie; Moore, Lyndon (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-02)
      Thousands of prospectuses offered shares to British investors at the turn of the twentieth century. We find evidence that there were informed investors who participated in the market at this time. Firms that attracted additional investor demand were more likely to be listed on the London Stock Exchange, survive longer, and achieve better long-run equity returns. We find that the exchange screened ...
    • Interactive effects of ocean acidification and temperature on oxygen uptake rates in Calanus hyperboreus nauplii 

      Espinel Velasco, Nadjejda; Gawinski, Christine; Kohlbach, Doreen; Pitusi, Vanessa; Graeve, Martin; Hop, Haakon (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-26)
      The Arctic region is undergoing rapid and significant changes, characterized by high rates of acidification and warming. These transformations prompt critical questions about the resilience of marine communities in the face of environmental change. In the Arctic, marine zooplankton and in particular calanoid copepods play a vital role in the food web. Changes in environmental conditions could ...
    • Role of grandparents in risky health behavior transmission: A study on smoking behavior in Norway 

      Sari, Emre; Moilanen, Mikko Antti; Lindeboom, Maarten (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-22)
      Exploring the role of grandparents in the intergenerational transmission of risky health behaviors, specifically smoking, this study aims to examine the differential influence of maternal and paternal grandparents on their grandchildren's smoking behavior in adulthood. Utilizing the Tromsø Study's unique three-generational dataset from Tromsø, Norway, we employ a control function approach. The ...
    • Evaluation of meso- and microplastic ingestion by the northern fulmar through a non-lethal sampling method 

      Collard, France; Strøm, Hallvard; Fayet, Marie-Océane; Gudmundsson, Fannar Theyr; Herzke, Dorte; Hotvedt, Ådne; Løchen, Arja Katrina Lea Arnesen; Malherbe, Cédric; Eppe, Gauthier; Gabrielsen, Geir W. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-11)
      An increasing number of organisms from the polar regions are reported contaminated by plastic. Rarely a nonkilling sampling method is used. In this study we wanted to assess plastic levels using stomach flushing and evaluate the method suitability for further research and monitoring. The stomach of 22 fulmars from Bjørnøya, Svalbard, were flushed with water in the field. On return to the laboratory, ...
    • Copepods’ true colors: astaxanthin pigmentation as an indicator of fitness 

      Vilgrain, Laure; Maps, Frédéric; Basedow, Sünnje Linnéa; Trudnowska, Emilia; Madoui, Mohammed-Amin; Niehoff, Barbara; Ayata, Sakina‐Dorothée (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-08)
      Pigmentation is often overlooked in zooplankton, since these organisms are mostly colorless to fit the translucid water medium. However, one of the dominant zooplankton taxa in aquatic ecosystems—copepods—often show a bright red-orange or blue coloration owing to the accumulation of carotenoid pigments in some parts of their bodies. Even though there are many functional traits describing copepod’s ...
    • Over 20% of marine fishes shifting in the North and Barents Seas, but not in the Norwegian Sea 

      Gordo Vilaseca, Francesc; Pecuchet, Laurene Anne Marie; Coll, Marta; Reiss, Henning; Jueterbock, Alexander; Costello, Mark John (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-31)
      Climate warming generally induces poleward range expansions and equatorward range contractions of species’ environmental niches on a global scale. Here, we examined the direction and magnitude of species biomass centroid geographic shifts in relation to temperature and depth for 83 fish species in 9,522 standardised research trawls from the North Sea (1998–2020) to the Norwegian (2000–2020) and ...
    • Patterns and repeatability of multi-ecotype assemblages of sympatric salmonids 

      Blain, Stephanie A.; Schluter, Dolph; Adams, Colin E.; Amundsen, Per-Arne; Knudsen, Rune; Chavarie, Louise (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-04)
      Aim: High repeatability among assemblages of closely related but ecologically distinct ecotypes implies predictability in evolution and assembly of communities. The conditions under which ecotype assemblages form predictably, and the reasons, have been little investigated. Here, we test whether repeatability declines as the number of ecotypes builds.<p> <p>Location: Postglacial lakes with a ...
    • Water column distribution of zooplanktonic size classes derived from in-situ plankton profilers: Potential use to contextualize contaminant loads in plankton 

      Espinasse, Boris Dristan; Pagano, M.; Basedow, Sünnje Linnéa; Chevalier, C.; Malengros, D.; Carlotti, F. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-29)
      Pollution is one of the main anthropogenic threats to marine ecosystems. Studies analysing the accumulation and transfer of contaminants in planktonic food webs tend to rely on samples collected in discrete water bodies. Here, we assessed the representativeness of measurements at the chlorophyll-a maximum layer during the MERITEHIPPOCAMPE cruise for the entire water column by investigating the ...
    • Leveraging Return Prediction Approaches for Improved Value-at-Risk Estimation 

      Bagheri, Farid; Reforgiato Recupero, Diego; Sirnes, Espen (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-17)
      Value at risk is a statistic used to anticipate the largest possible losses over a specific time frame and within some level of confidence, usually 95% or 99%. For risk management and regulators, it offers a solution for trustworthy quantitative risk management tools. VaR has become the most widely used and accepted indicator of downside risk. Today, commercial banks and financial institutions ...
    • Long-term monitoring of exposure to toxic and essential metals and metalloids in the tawny owl (Strix aluco): Temporal trends and influence of spatial patterns 

      Devalloir, Quentin; Fritsch, Clementine; Bangjord, Georg; Bårdsen, Bård-Jørgen; Bourgeon, Sophie; Eulaers, Igor; Bustnes, Jan Ove (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-10)
      As a result of regulatory decisions, atmospheric deposition of most toxic metals and metalloids (MEs) has decreased in Europe over the past few decades. However, little is known about how this reduction translates into exposure at higher trophic levels in the terrestrial environment where temporal trends may be spatially heterogeneous due to local current or legacy sources of emissions (e.g., industry) ...