Viser treff 681-700 av 1636

    • Sea trout Salmo trutta in the subarctic: home-bound but large variation in migratory behaviour between and within populations 

      Strøm, John Fredrik; Jensen, Jenny L. A.; Nikolopoulos, Anna; Nordli, Eivind; Bjørn, Pål Arne; Bøhn, Thomas (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-28)
      Anadromous brown trout (sea trout), Salmo trutta, is currently in decline throughout its range, largely due to anthropogenic stressors in freshwater and marine habitats. Acoustic telmetry was utilized to study the marine migration of sea trout post-smolts from three populations in a relatively pristine subarctic fjord system. While at sea, the sea trout spent a substantial part of their time close ...
    • Multiple configurations and fluctuating trophic control in the Barents Sea food-web 

      Sivel, Elliot; Planque, Benjamin; Lindstrøm, Ulf; Yoccoz, Nigel G. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-09)
      The Barents Sea is a subarctic shelf sea which has experienced major changes during the past decades. From ecological time-series, three different food-web configurations, reflecting successive shifts of dominance of pelagic fish, demersal fish, and zooplankton, as well as varying trophic control have been identified in the last decades. This covers a relatively short time-period as available ...
    • Transmission across the water-air interface: resolving the impact of multiple interactions at the sea surface 

      Mckee, David; Piskozub, Jacek (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-07)
      A series of Monte Carlo and HydroLight radiative transfer simulations are used to demonstrate that the traditional form of the Fresnel transmission across the water-air interface is accurate. This contradicts assertions to the contrary in a recent paper [Opt. Express 25, 27086 (2017) [CrossRef] ] that suggested that the impact of multiple surface interactions had previously been ignored and that ...
    • Analysis of composition, morphology, and biosynthesis of cuticular wax in wild type bilberry (Vaccinium myrtillus L.) and its glossy mutant 

      Trivedi, Priyanka; Nguyen, Nga; Klavins, Linards; Kviesis, Jorens; Heinonen, Esa; Remes, Janne; Jokipii-Lukkari, Soile; Klavins, Maris; Karppinen, Katja; Jaakola, Laura; Häggman, Hely (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-09)
      In this study, cuticular wax load, its chemical composition, and biosynthesis, was studied during development of wild type (WT) bilberry fruit and its natural glossy type (GT) mutant. GT fruit cuticular wax load was comparable with WT fruits. In both, the proportion of triterpenoids decreased during fruit development concomitant with increasing proportions of total aliphatic compounds. In GT fruit, ...
    • Seasonal Variability in the Zooplankton Community Structure in a Sub-Arctic Fjord as Revealed by Morphological and Molecular Approaches 

      Coguiec, Estelle; Ershova, Elizaveta; Daase, Malin; Vonnahme, Tobias R.; Wangensteen, Owen S.; Gradinger, Rolf; Præbel, Kim; Berge, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-04)
      Phyto- and zooplankton in Arctic and sub-Arctic seas show very strong seasonal changes in diversity and biomass. Here we document the seasonal variability in the mesozooplankton community structure in a sub-Arctic fjord in Northern Norway based on monthly sampling between November 2018 and February 2020. We combined traditional morphological zooplankton identification with DNA metabarcoding of a 313 ...
    • All-sky camera system providing high temporal resolution annual time series of irradiance in the arctic 

      Johnsen, Geir; Zolich, Artur; Grant, Stephen; Bjorgum, Rune; Cohen, Jonathan H.; Mckee, David; Kopec, Tomasz Piotr; Vogedes, Daniel Ludwig; Berge, Jorgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-23)
      The ArcLight observatory provides hourly continuous time series of light regime data (intensity, spectral composition, and photoperiod) from the Arctic, Svalbard at 79° N. Until now, no complete annual time series of biologically relevant light has been provided from the high Arctic due to insufficient sensitivity of commercial light sensors during the Polar Night. We describe a camera system providing ...
    • Pelagic organisms avoid white, blue, and red artificial light from scientific instruments 

      Geoffroy, Maxime; Langbehn, Tom; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault; Fisher, Jonathan A. D.; Daase, Malin; Mckee, David; Cohen, Jonathan H.; Berge, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-22)
      In situ observations of pelagic fish and zooplankton with optical instruments usually rely on external light sources. However, artificial light may attract or repulse marine organisms, which results in biased measurements. It is often assumed that most pelagic organisms do not perceive the red part of the visible spectrum and that red light can be used for underwater optical measurements of biological ...
    • Hiding in plain sight - Euplokamis dunlapae (Ctenophora) in Norwegian waters 

      Majaneva, Sanna; Ringvold, Halldis; Johansen, Ellie; Østensen, Mari-Ann; Hosia, Aino Laila Johanna (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-17)
      Cydippid ctenophores of genus Euplokamis have been rarely reported from the north-east Atlantic in the scientific literature. The conspicuous lack of previous records is likely attributable to methodological constraints detrimental to sampling ctenophores, including the use of plankton nets and preservation of samples as well as poor identification literature and a lack of taxonomic expertise on ...
    • Two hundred years of zooplankton vertical migration research 

      Bandara, Kanchana; Varpe, Øystein; Wijewardene, Lishani; Tverberg, Vigdis; Eiane, Ketil (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-04)
      Vertical migration is a geographically and taxonomically widespread behaviour among zooplankton that spans across diel and seasonal timescales. The shorter-term diel vertical migration (DVM) has a periodicity of up to 1 day and was first described by the French naturalist Georges Cuvier in 1817. In 1888, the German marine biologist Carl Chun described the longer-term seasonal vertical migration ...
    • A distributed time-lapse camera network to track vegetation phenology with high temporal detail and at varying scales 

      Parmentier, Frans-Jan W.; Nilsen, Lennart; Tømmervik, Hans; Cooper, Elisabeth J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-29)
      Near-surface remote sensing techniques are essential monitoring tools to provide spatial and temporal resolutions beyond the capabilities of orbital methods. This high level of detail is especially helpful to monitor specific plant communities and to accurately time the phenological stages of vegetation – which satellites can miss by days or weeks in frequently clouded areas such as the Arctic. In ...
    • Fat storage influences fasting endurance more than body size in an ungulate 

      Trondrud, Liv Monica; Pigeon, Gabriel; Król, Elżbieta; Albon, Steve; Evans, Alina; Arnold, Walter; Hambly, Catherine; Irvine, R. Justin; Ropstad, Erik; Stien, Audun; Veiberg, Vebjørn; Speakman, John R.; Loe, Leif Egil (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-26)
      <ol> <li>The fasting endurance hypothesis (FEH) predicts strong selection for large body size in mammals living in environments where food supply is interrupted over prolonged periods of time. The Arctic is a highly seasonal and food restricted environment, but contrary to predictions from the FEH, empirical evidence shows that Arctic mammals are often smaller than their temperate conspecifics. ...
    • Distribution of rorquals and Atlantic cod in relation to their prey in the Norwegian high Arctic 

      Solvang, Hiroko K.; Haug, Tore; Knutsen, Tor; Gjøsæter, Harald; Bogstad, Bjarte; Hartvedt, Siri; Øien, Nils; Lindstrøm, Ulf (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-14)
      Recent warming in the Barents Sea has led to changes in the spatial distribution of both zooplankton and fish, with boreal communities expanding northwards. A similar northward expansion has been observed in several rorqual species that migrate into northern waters to take advantage of high summer productivity, hence feeding opportunities. Based on ecosystem surveys conducted during August–September ...
    • The Future of DNA Barcoding: Reflections from Early Career Researchers 

      Grant, Danielle M.; Brodnicke, Ole Bjørn; Evankow, Ann; Ferreira, André O.; Fontes, João T.; Hansen, Aslak Kappel; Jensen, Mads Reinholdt; Kalaycı, Tuğba Ergül; Leeper, Alexandra Eve Joyce; Patil, Shalaka Kiran; Prati, Sebastian; Reunamo, Anna; Roberts, Aradhana J; Shigdel, Rajesh; Tyukosova, Valentina; Bendiksby, Mika; Blaalid, Rakel; Costa, Filipe O.; Hollingsworth, Peter M.; Stur, Elisabeth; Ekrem, Torbjørn (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-09)
      Over the last two decades, the use of DNA barcodes has transformed our ability to identify and assess life on our planet. Both strengths and weaknesses of the method have been exemplified through thousands of peer-reviewed scientific articles. Given the novel sequencing approaches, currently capable of generating millions of reads at low cost, we reflect on the questions: What will the future bring ...
    • Determinants of heart rate in Svalbard reindeer reveal mechanisms of seasonal energy management 

      Trondrud, Liv Monica; Pigeon, Gabriel; Albon, Steve; Arnold, Walter; Evans, Alina; Irvine, R. Justin; Król, Elżbieta; Ropstad, Erik; Stien, Audun; Veiberg, Vebjørn; Speakman, John R.; Loe, Leif Egil (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-28)
      Seasonal energetic challenges may constrain an animal's ability to respond to changing individual and environmental conditions. Here, we investigated variation in heart rate, a well-established proxy for metabolic rate, in Svalbard reindeer (Rangifer tarandus platyrhynchus), a species with strong seasonal changes in foraging and metabolic activity. In 19 adult females, we recorded heart rate, ...
    • Experimental warming differentially affects vegetative and reproductive phenology of tundra plants 

      Collins, Courtney G.; Elmendorf, Sarah C.; Hollister, Robert D.; Henry, Greg H. R.; Clark, Karin; Bjorkman, Anne D.; Myers-Smith, Isla H.; Prevéy, Janet S.; Ashton, Isabel W.; Assmann, Jakob J.; Alatalo, Juha M.; Carbognani, Michele; Chisholm, Chelsea L.; Cooper, Elisabeth J.; Forrester, Chiara; Jónsdóttir, Ingibjörg Svala; Klanderud, Kari; Kopp, Christopher W.; Livensperger, Carolyn; Mauritz, Marguerite; May, Jeremy L.; Molau, Ulf; Oberbauer, Steven F.; Ogburn, Emily; Panchen, Zoe A.; Petraglia, Alessandro; Post, Eric; Rixen, Christian; Rodenhizer, Heidi; Schuur, Edward A.G.; Semenchuk, Philipp; Smith, Jane G.; Steltzer, Heidi; Totland, Ørjan; Walker, Marilyn D.; Welker, Jeffrey M.; Suding, Katharine N. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-11)
      Rapid climate warming is altering Arctic and alpine tundra ecosystem structure and function, including shifts in plant phenology. While the advancement of green up and flowering are well-documented, it remains unclear whether all phenophases, particularly those later in the season, will shift in unison or respond divergently to warming. Here, we present the largest synthesis to our knowledge of ...
    • Combined effects of crude oil exposure and warming on eggs and larvae of an arctic forage fish 

      Giebichenstein, Julia; Teisrud, Ragnar; Laurent, Jennifer Malica; Frantzen, Marianne; Meador, James P.; Sørensen, Lisbet; Hansen, Bjørn Henrik; Reinardy, Helena C.; Laurel, Benjamin J.; Nahrgang, Jasmine (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-16)
      Climate change, along with environmental pollution, can act synergistically on an organism to amplify adverse effects of exposure. The Arctic is undergoing profound climatic change and an increase in human activity, resulting in a heightened risk of accidental oil spills. Embryos and larvae of polar cod (Boreogadus saida), a key Arctic forage fish species, were exposed to low levels of crude oil ...
    • Trace element concentration and stable isotope ratio analysis in blueberries and bilberries: A tool for quality and authenticity control 

      Klavins, Linards; Maaga, Inessa; Bertins, Maris; Hykkerud, Anne Linn; Karppinen, Katja; Bobinas, Česlovas; Nguyen, Nga; Salo, Heikki M.; Salminen, Henriikka; Stankevica, Karina; Klavins, Maris (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-09)
      Vaccinium genus berries—wild bilberries (Vaccinium myrtillus L.) and cultivated highbush blueberries (Vaccinium corymbosum L.)—are consumed worldwide, and their consumption has a trend of stable increase. Thus, considering their wide use in ethnomedicine, for juice and jam production, as functional food, as well as their use in preparations of extracts which have application potential in pharmaceutical ...
    • Future trajectories of change for an Arctic deep-sea ecosystem connected to coastal kelp forests 

      Vilas, Daniel; Coll, Marta; Pedersen, Torstein; Corrales, Xavier; Filbee-Dexter, Karen; Wernberg, Thomas (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-22)
      Environmental stressors related to climate change and other anthropogenic activities are impacting Arctic marine ecosystems at exceptional rates. Within this context, predicting future scenarios of deep-sea ecosystems and their consequences linked with the fate of coastal areas is a growing need and challenge. We used an existing food-web model developed to represent the outer basin of the Malangen ...
    • Northern Fennoscandia via the British Isles: evidence for a novel postglacial recolonization route by winter moth (Operophtera brumata) 

      Andersen, Jeremy C.; Havill, Nathan P.; Griffin, Brian P.; Jepsen, Jane U.; Hagen, Snorre B.; Klemola, Tero; Barrio, Isabel C.; Kjeldgaard, Sofie A.; Høye, Toke T.; Murlis, John; Baranchikov, Yuri N.; Selikhovkin, Andrey V.; Vindstad, Ole Petter Laksforsmo; Caccone, Adalgisa; Elkinton, J (Journal article; Tidsskriftartikkel; Peer reviewed, 2021)
      The frequency and severity of outbreaks by pestiferous insects is increasing globally, likely as a result of human-mediated introductions of non-native organisms. However, it is not always apparent whether an outbreak is the result of a recent introduction of an evolutionarily naïve population, or of recent disturbance acting on an existing population that arrived previously during natural range ...
    • Functional Pattern of Benthic Epifauna in the Chukchi Borderland, Arctic Deep Sea 

      Zhulay, Irina; Bluhm, Bodil; Renaud, Paul E.; Degen, Renate; Iken, Katrin (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-26)
      Assessment of Arctic deep-sea ecosystem functioning is currently an urgent task considering that ongoing sea-ice reduction opens opportunities for resource exploitation of yet understudied deep-sea regions. We used Biological Trait Analysis to evaluate ecosystem functioning and test if common paradigms for deep-sea fauna apply to benthic epifauna of the deep-sea Arctic Chukchi Borderland (CBL). We ...