Institutt for arktisk og marin biologi: Recent submissions
Now showing items 1301-1320 of 2050
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Detecting changes in the Arctic Ecosystem – Long-Term Benthos Monitoring network for detecting changes in the Arctic benthic ecosystem (LTM-Benthos) 2017-2020
(Research report; Forskningsrapport, 2018)<i>Introduction</i>: Main purpose of this group is data exploration. For example, megafaunal community characterization, modeling of variables that influence these communities (environment, stressors, etc.). Scaling of data matters: Depending on the objectives, required resolution of the data and analyses will vary, e.g. for managing trawl closures, fine-scale analyses are required; for understanding ... -
Ocean migration of pop-up satellite archival tagged Atlantic salmon from the Miramichi River in Canada
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-13)The ocean migration of 16 post-spawned adult Atlantic salmon [Salmo salar L.] from the Miramichi River, Canada, tagged concurrently with pop-up satellite archival tags and acoustic transmitters was reconstructed using a Hidden Markov Model. Individuals exclusively utilized areas within the Gulf of St Lawrence and the Labrador Sea, and showed little overlap with known distributions of European stocks. ... -
Anti-angiogenic VEGFAxxxb transcripts are not expressed in the medio-basal hypothalamus of the seasonal sheep
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-10)This study investigated Vegfa expression in the pars tuberalis (PT) of the pituitary and medio-basal hypothalamus (MBH) of sheep, across seasons and reproductive states. It has recently been proposed that season impacts alternative splicing of Vegfa mRNA in the PT, which shifts the balance between angiogenic VEGFAxxx and anti-angiogenic VEGFAxxxb isoforms (with xxx the number of amino acids of the ... -
Practical solutions for bottlenecks in ecosystem services mapping
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-03)<i>Background:</i> Ecosystem services (ES) mapping is becoming mainstream in many sustainability assessments, but its impact on real world decision-making is still limited. Robustness, enduser relevance and transparency have been identified as key attributes needed for effective ES mapping. However, these requirements are not always met due to multiple challenges, referred to here as ... -
Antimicrobial resistance in wildlife – potential for dissemination: Opinion of the Panel on Microbial Ecology of the Norwegian Scientific Committee for Food and Environment
(Research report; Forskningsrapport, 2018-03-16)<p>Antimicrobial resistance (AMR) is recognised as one of the greatest public health concerns of our time. The development of AMR occurs in nature as a defence by microbes against naturally occurring antimicrobials. However, the selective pressure, generated by the use of antimicrobial agents in human and veterinary medicine, livestock and plant production as well as aquaculture practices, is the ... -
Influence of photoperiod on central appetite regulation in captive Svalbard rock ptarmigan (Lagopus muta hyperborea)
(Master thesis; Mastergradsoppgave, 2018-08-09)The Svalbard rock ptarmigan displays a seasonal change of body mass as a selectively beneficial adaptation for survival in the high Arctic. This physiological change is sensitive to photoperiod (daylight duration in a 24h cycle) but little is known of the mechanism through which changes in photoperiod affects body mass in this species. We exposed winer adapted Sv. rock ptarmigan to a simulated ... -
Corvids response to fluctuating abundance of resources in tundra ecosystems
(Master thesis; Mastergradsoppgave, 2018-05-15)Aim Despite the numerous studies on corvids’ behaviour, their dynamics in different ecosystems is unknown. Ravens and hooded crows are opportunistic generalists acting as both predators and scavengers. Ravens are probably the most specialized scavengers on ungulate carcasses and both species are known as efficient hunters of small rodents. Small rodents are a key species in the tundra as they represent ... -
Initial Community Convergence on Plant Defense Syndromes Explains Community Responses to Herbivore Exclosures
(Master thesis; Mastergradsoppgave, 2017-11-15)General trade-offs in species’ energy use are highlighted here by mapping proposed defense syndromes, using trade-offs found between: constitutive phenolic compounds, silica and a high nutrient low defense region found between regional con-specifics. Differences in species composition between two catchments can be explained by proposed syndrome trade-offs seeking energy use optimums in differing ... -
Can novel pest outbreaks drive ecosystem transitions in northern-boreal birch forest?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-04)<p>1.The boreal biome exhibits distinct alternative ecosystem states with high and low levels of tree cover. Insect outbreaks facilitated by climate warming could potentially drive transitions from high to low tree cover states. We investigated whether two key premises for such outbreak‐induced transitions – critical thresholds (tipping points) and positive feedbacks that could maintain alternative ... -
Climate Events Synchronize the Dynamics of a Resident Vertebrate Community in the High Arctic
(Peer reviewed; Research report; Forskningsrapport, 2013-01-18)Recently accumulated evidence has documented a climate impact on the demography and dynamics of single species, yet the impact at the community level is poorly understood. Here, we show that in Svalbard in the high Arctic, extreme weather events synchronize population fluctuations across an entire community of resident vertebrate herbivores and cause lagged correlations with the secondary consumer, ... -
Seasonal changes in background levels of deuterium and oxygen- 18 prove water drinking by harp seals, which affects the use of the doubly labelled water method
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-29)The aim of this study was to monitor seasonal changes in stable isotopes of pool freshwater and harp seal (Phoca groenlandica) body water, and to study whether these potential seasonal changes might bias results obtained using the doubly labelled water (DLW) method when measuring energy expenditure in animals with access to freshwater. Seasonal changes in the background levels of deuterium and ... -
Bacterial response to permafrost derived organic matter input in an Arctic fjord
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-06)The warming of the Arctic causes increased riverine discharge, coastal erosion, and the thawing of permafrost. Together, this is leading to an increased wash out of terrestrial dissolved organic matter (tDOM) into the coastal Arctic ecosystems. This tDOM may be anticipated to affect both carbon and nutrient flow in the microbial food web and microbial community composition, but there are few ... -
Abscisic acid regulates anthocyanin biosynthesis and gene expression associated with cell wall modification in ripening bilberry (vaccinium myrtillus l.) fruits
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-29)Ripening of non-climacteric bilberry (Vaccinium myrtillus L.) fruit is characterized by a high accumulation of health-beneficial anthocyanins. Plant hormone abscisic acid (ABA) and sucrose have been shown to be among the central signaling molecules coordinating non-climacteric fruit ripening and anthocyanin accumulation in some fruits such as strawberry. Our earlier studies have demonstrated an ... -
Transferability of biotic interactions: temporal consistency of arctic plant-rodent relationships is poor
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-17)Variability in biotic interaction strength is an integral part of food web functioning. However, the consequences of the spatial and temporal variability of biotic interactions are poorly known, in particular for predicting species abundance and distribution. The amplitude of rodent population cycles (i.e., peak-phase abundances) has been hypothesized to be determined by vegetation properties ... -
First record of a rare species, Polyasterias problematica (Prasinophyceae), in Balsfjord, northern Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-13)<i>Polyasterias problematica</i> is a poorly investigated prasinophyte species, practically known only from a few, primarily historical studies. Fragmentary information on the species indicates that <i>P. problematica</i> is mainly distributed in the euphotic zone of the Canadian and Russian Arctic, Atlantic Canada, the mid-Atlantic and some European seas. Here, we present the first record of this ... -
Hva forskerne egentlig gjør
(Chronicle; Kronikk, 2018-10-19)<p><i>Introduction</i>: Forskningsdagene ved UiT Norges arktiske universitet, åpen dag ved Framsenteret, ulike arrangement rundt UiTs 50 års jubileum og en UiT spesialforestilling på Hålogaland teater: Forskningen i Tromsø har vist seg seg fram denne høsten. Uansett hvor du går i Tromsø, så formidler forskere til deg at forskning er spennende og at det er kjempegøy å være forsker. Som forsker står ... -
Seroprevalence for Brucella spp. in Baltic ringed seals (Phoca hispida) and East Greenland harp (Pagophilus groenlandicus) and hooded (Cystophora cristata) seals
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-12)Zoonotic infections transmitted from marine mammals to humans in the Baltic and European Arctic are of unknown significance, despite given considerable potential for transmission due to local hunt. Here we present results of an initial screening for <i>Brucella</i> spp. in Arctic and Baltic seal species. Baltic ringed seals (<i>Pusa hispida</i>, n = 12) sampled in October 2015 and Greenland Sea harp ... -
Choose your poison – Space-use strategy influences pollutant exposure in Barents Sea polar bears
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-24)Variation in space-use is common within mammal populations. In polar bears, Ursus maritimus, some individuals follow the sea ice (offshore bears) whereas others remain nearshore yearlong (coastal bears). We studied pollutant exposure in relation to space-use patterns (offshore vs coastal) in adult female polar bears from the Barents Sea equipped with satellite collars (2000–2014, n = 152). First, ... -
Hyperbenthic food-web structure in an Arctic fjord
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-17)Current knowledge of the Arctic marine ecosystem is based primarily on studies performed during the polar day on the pelagic and benthic realms. Both the polar night and the hyperbenthic layer remain as substantial knowledge gaps in our understanding of the marine system at high latitudes. This study investigated the hyperbenthic food web in Kongsfjord, a high-latitude, ice-free fjord, in September ... -
Photoperiod revisited: is there a critical day length for triggering a complete parr–smolt transformation in Atlantic salmon Salmo salar?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-26)The present study investigated whether there is a critical length of photoperiod needed to stimulate a completed parr–smolt transformation (PST) in Atlantic salmon <i>Salmo salar</i>. In two experiments, <i>S. salar</i> parr of the Norwegian aquaculture strain held on continuous light were exposed to a short photoperiod (6 L:18D) followed by exposure to 8 L:16D, 12 L:12D, 16 L:8D, 20 L:4D and 24 ...