Now showing items 1221-1240 of 2040

    • Trophic interactions and abiotic factors drive functional and phylogenetic structure of vertebrate herbivore communities across the Arctic tundra biome 

      Speed, James David Mervyn; Skjelbred, Ina Åsnes; Barrio, Isabel C.; Martin, Michael David; Berteaux, Dominique; Bueno, Guillermo; Christie, Katie; Forbes, Bruce C.; Forbey, Jennifer; Fortin, Daniel; Grytnes, John-Arvid; Hoset, Katrine Skamfer; Lecomte, Nicolas; Marteinsdottir, Bryndis; Mosbacher, Jesper Bruun; Pedersen, Åshild Ø.; Ravolainen, Virve; Rees, Eileen C.; Skarin, Anna; Sokolova, Natalya; Thornhill, Andrew H; Tombre, Ingunn; Soininen, Eeva M (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-29)
      Communities are assembled from species that evolve or colonise a given geographic region, and persist in the face of abiotic conditions and interactions with other species. The evolutionary and colonisation histories of communities are characterised by phylogenetic diversity, while functional diversity is indicative of abiotic and biotic conditions. The relationship between functional and phylogenetic ...
    • Stakeholders’ perceptions of protected area management following a nationwide community-based conservation reform 

      Engen, Sigrid; Fauchald, Per; Hausner, Vera Helene (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-24)
      People’s perceptions can point to reasons for conservation support or lack thereof. In this study, we surveyed the perceptions of conservation among local stakeholders who participated in protected area (PA) management following a reform towards community-based conservation in Norway. We analyzed the link between perceptions of threats to conservation values, prioritized management actions and ...
    • Secondary Folds Contribute Significantly to the Total Surface Area in the Olfactory Organ of Chondrichthyes 

      Ferrando, Sara; Amaroli, Andrea; Gallus, Lorenzo; Aicardi, S; Di Blasi, D; Christiansen, Jørgen Schou; Vacchi, Marino; Ghigliotti, Laura (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-12)
      The olfactory organ of Chondrichthyes is characterized by a central support with several lamellae covered by a sensory olfactory epithelium. Although secondary folds are present on the lamellae in all the chondrichthyan species analyzed to date, their shape and size have not been described. We here analyze the olfactory organ of 13 elasmobranch and 1 holocephalan species, describe the shape of ...
    • New Late Pleistocene species of Acharax from Arctic methane seeps off Svalbard 

      Hansen, Jesper; Ezat, Mohamed; Åström, Emmelie; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-01)
      We report, for the first time, the solemyid <i>Acharax svalbardensis</i> sp. nov., from deep-sea methane seep sites on the western Svalbard margin, 79°N. This species is rather small and so far the northernmost representative of its genus. It is identified based on the following combination of diagnostic characters: umbo 27–30% valve length from posterior margin; H/L ratio ∼0.35; broadly rounded to ...
    • Can multitrophic interactions and ocean warming influence large-scale kelp recovery? 

      Christie, Hartvig C; Gundersen, Hege; Rinde, Eli; Filbee-Dexter, Karen; Norderhaug, Kjell Magnus; Pedersen, Torstein; Bekkby, Trine; Gitmark, Janne Kim; Fagerli, Camilla With (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-14)
      Ongoing changes along the northeastern Atlantic coastline provide an opportunity to explore the influence of climate change and multitrophic interactions on the recovery of kelp. Here, vast areas of sea urchin‐dominated barren grounds have shifted back to kelp forests, in parallel with changes in sea temperature and predator abundances. We have compiled data from studies covering more than 1,500‐km ...
    • Long-term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects 

      Weidberg, Nicholas; Basedow, Sünnje Linnéa (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-08)
      Critical gaps in knowledge hinder our ability to infer spatiotemporal dynamics in pelagic ecosystems. In particular, environmental changes affecting key copepod species while overwintering in deep waters are still not well understood. Here, we analyzed an 11 yr time series (2000–2010) of winter (January/February) samplings in the Lofoten Basin to characterize the spatial distribution of <i>Calanus ...
    • Developmental and Environmental Regulation of Cuticular Wax Biosynthesis in Fleshy Fruits 

      Trivedi, Priyanka; Nguyen, Nga; Hykkerud, Anne Linn; Häggman, Hely; Martinussen, Inger; Jaakola, Laura; Karppinen, Katja (Journal article; Peer reviewed, 2019-04-19)
      The aerial parts of land plants are covered by a hydrophobic layer called cuticle that limits non-stomatal water loss and provides protection against external biotic and abiotic stresses. The cuticle is composed of polymer cutin and wax comprising a mixture of very-long-chain fatty acids and their derivatives, while also bioactive secondary metabolites such as triterpenoids are present. Fleshy ...
    • Pelagic Ecosystem Characteristics Across the Atlantic Water Boundary Current from Rijpfjorden, Svalbard, to the Arctic Ocean during Summer (2010-2014) 

      Hop, Haakon; Assmy, Philipp; Wold, Anette; Sundfjord, Arild; Daase, Malin; Duarte, Pedro; Kwasniewski, Slawomir; Gluchowska, Marta; Wiktor, Józef Maria; Tatarek, Agnieszka; Wiktor, Józef Maria Jr.; Kristiansen, Svein; Fransson, Agneta Ingrid; Chierici, Melissa; Vihtakari, Mikko (Journal article; Peer reviewed, 2019-04-09)
      The northern coast of Svalbard contains high-arctic fjords, such as Rijpfjorden (80°N 22°30′E). This area has experienced higher sea and air temperatures and less sea ice in recent years, and models predict increasing temperatures in this region. Part of the West Spitsbergen Current (WSC), which transports relatively warm Atlantic water along the continental slope west of Svalbard, bypasses these ...
    • Ocean predation and mortality of adult Atlantic salmon 

      Strøm, John Fredrik; Rikardsen, Audun Håvard; Campana, Steven E.; Righton, David; Carr, Jonathan; Aarestrup, Kim; Stokesbury, Michael J.W.; Gargan, Patrick; Javierre, Pablo Caballero; Thorstad, Eva Bonsak (Journal article; Peer reviewed, 2019-05-27)
      Predation and mortality are often difficult to estimate in the ocean, which hampers the management and conservation of marine fishes. We used data from pop-up satellite archival tags to investigate the ocean predation and mortality of adult Atlantic salmon (Salmo salar) released from 12 rivers flowing into the North Atlantic Ocean. Data from 156 tagged fish revealed 22 definite predation events (14%) ...
    • Characterization of the cecum microbiome from wild and captive rock ptarmigans indigenous to Arctic Norway 

      Salgado-Flores, Alejandro; Tveit, Alexander Tøsdal; Wright, A-D; Pope, Phillip; Sundset, Monica Alterskjær (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-11)
      Rock ptarmigans (<i>Lagopus muta</i>) are gallinaceous birds inhabiting arctic and sub-arctic environments. Their diet varies by season, including plants or plant parts of high nutritional value, but also toxic plant secondary metabolites (PSMs). Little is known about the microbes driving organic matter decomposition in the cecum of ptarmigans, especially the last steps leading to methanogenesis. ...
    • The nestling diet of Svalbard snow buntings identified by DNA metabarcoding 

      Stolz, Christian (Master thesis; Mastergradsoppgave, 2019-05-15)
      Tundra arthropods have considerable ecological importance as a food source for several bird species that are reproducing in the Arctic. The actual arthropod taxa comprising the chick diet are however rarely known, complicating assessments of ecological interactions. In this study, I identified the nestling diet of Svalbard snow bunting (Plectrophenax nivalis) for the first time. Faecal samples of ...
    • Thermal behaviour of edible crab Cancer pagurus Linnaeus, 1758 in coastal Norway 

      Bakke, Snorre; Siikavuopio, Sten Ivar; Christiansen, Jørgen Schou (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-26)
      Ocean warming drives latitudinal shifts in the distribution of ectotherm species. The rate and magnitude of such shifts are constrained by physiology and behavioural thermoregulation. Here, we investigated the thermal preference and lower critical temperature (CTmin) in female edible crab <i>Cancer pagurus</i>, a decapod crustacean with an ongoing northward dispersal along the Norwegian coast. The ...
    • Can waste re-cycling increase the sustainability of animal feeds? 

      Jobling, Malcolm (Journal article; Tidsskriftartikkel, 2019)
      An annual procution of over one billion tonnes, and an economic turnover in excess of $US400 billion; this is the animal feed industry. The vast majority of animal feed is given to terrestrial farm animals; those reared for meat, and those used to produce eggs and dairy products. Fish feeds make up about 5% of the total volume of animal feeds and have a 10% share of marked sales. <p> <p>It is ...
    • Chronobiology of voluntary food intake in reindeer (Rangifer tarandus tarandus) 

      Rescia, Leonardo (Master thesis; Mastergradsoppgave, 2018-11-15)
      In all organisms, biological rhythms arise from the interaction between endogenous clocks and a rhythmic environment. The timing of sunrise and sunset synchronize internal timing processes and inform the organism not only of the time of day, but also of the time of year. For animals living in polar regions biological timekeeping represents a challenge, given that the sun does not rise during the ...
    • The Marine Plastic Microbiome: Microbial Colonization of Polymer Surfaces in the Arctic Marine Environment 

      Stitzlein, Tarah Marie (Master thesis; Mastergradsoppgave, 2018-09-25)
      While the sources and fates of plastic pollution are receiving growing attention, major knowledge gaps exist. Among these, microbial degradation (aka biodegradation) of plastics remains poorly investigated. The process of biodegradation begins with the formation of biofilm on the polymer surface; our study aimed to investigate microbial colonization of polymer surfaces in the Arctic marine environment ...
    • Evaluating the use of biotic interactions in species distribution models 

      Ball, Jack Ethan (Master thesis; Mastergradsoppgave, 2018-08-15)
      Species distribution models are a key tool in predicting and projecting population changes in the past, present and future. In the past they have mostly focused on using abiotic interactions for their models. This may be inadequate however as biotic interactions play an important role in determining community composition. Climate change has created and will create many novel communities that have ...
    • No support for cryptic choice by ovarian fluid in an external fertilizer 

      Kleppe, April Snøfrid; Nordeide, Jarle Tryti; Rudolfsen, Geir; Figenschou, Lars; Larsen, Berner; Reiss, Katrin; Folstad, Ivar (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-22)
      Whether the ovarian fluid (OF) represents a selective environment influencing cryp‐tic female choice was tested using an external fertilizer experiencing intense sperm competition and large effects of OF on sperm swimming behavior—the Arctic charr (<i>Salvelinus alpinus</i>). We physically separated the OF from the eggs of reproductively active females and reintroduced either their ...
    • Causes and consequences of ontogenetic dietary shifts: a global synthesis using fish models 

      Sanchez-Hernandez, Javier; Nunn, Andy D; Adams, Colin Ean; Amundsen, Per-Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-24)
      Ontogenetic dietary shifts (ODSs), the changes in diet utilisation occurring over the life span of an individual consumer, are widespread in the animal kingdom. Understanding ODSs provides fundamental insights into the biological and ecological processes that function at the individual, population and community levels, and is critical for the development and testing of hypotheses around key concepts ...
    • Prevalence of brucellosis among patients attending Wau Hospital, South Sudan 

      Madut, Nuol Aywel; Nasinyama, George William; Muma, John Bwalya; Sube, Kenneth L L; Ocan, Moses; Muwonge, Adrian; Godfroid, Jacques; Jubara, Ambrose Samuel; Kankya, Clovice (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-27)
      Brucellosis is a zoonotic disease of public health importance; its prevalence varies globally. In low-income countries, brucellosis is an endemic and neglected disease affecting both animals and humans. This study was intended to establish brucellosis sero-prevalence among patients attending Wau hospital, South Sudan. Across sectional study, was done among randomly selected patients attending Wau ...
    • Getting ready for the winter: timing and determinants of molt in an alpine ungulate 

      Déry, F.; Hamel, Sandra; Cote, Steeve D. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-14)
      Because growth of new hairs entails energetic costs, individual condition and access to food should determine the timing of molt. Previous studies on the timing of molt in ungulates have mostly focused on the influence of age class and reproductive status, but the effects of body condition and environmental phenology have not been evaluated. Our goal was to assess how intrinsic traits and environmental ...