Institutt for arktisk og marin biologi: Nye registreringer
Viser treff 1581-1600 av 2078
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AUV-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-09-28)An autonomous underwater vehicle (AUV) carrying 614 kHz RDI acoustic doppler current profilers (ADCPs) was deployed at four locations over the West Spitsbergen outer shelf in July 2010. The backscatter signal recorded by the ADCPs was extracted and analysed to investigate the vertical distribution and patchiness of pelagic organisms during midnight sun. At the northernmost locations (Norskebanken ... -
Genetic diversity and connectivity within Mytilus spp. in the subarctic and Arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-10-26)Climate changes in the Arctic are predicted to alter distributions of marine species. However, such changes are difficult to quantify because information on present species distribution and the genetic variation within species is lacking or poorly examined. Blue mussels, Mytilus spp., are ecosystem engineers in the coastal zone globally. To improve knowledge of distribution and genetic structure of ... -
Moonlight Drives Ocean-Scale Mass Vertical Migration of Zooplankton during the Arctic Winter
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-07)In extreme high-latitude marine environments that are without solar illumination in winter, light-mediated patterns of biological migration have historically been considered non-existent [1]. However, diel vertical migration (DVM) of zooplankton has been shown to occur even during the darkest part of the polar night, when illumination levels are exceptionally low [2, 3]. This paradox is, as ... -
Evaluation of distribution coefficients and concentration ratios of 90Sr and 137Cs in the Techa River and the Miass River
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016)Empirical data on the behavior of radionuclides in aquatic ecosystems are needed for radioecological modeling, which is commonly used for predicting transfer of radionuclides, estimating doses, and assessing possible adverse effects on species and communities. Preliminary studies of radioecological parameters including distribution coefficients and concentration ratios, for 90Sr and 137Cs were not ... -
In vivo exposure to northern diatoms arrests sea urchin embryonic development
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01)There are numerous reports indicating that marine diatoms may act harmful to early developmental stages of invertebrates. It is believed that the compounds responsible for these detrimental effects are oxylipins resulting from oxidized polyunsaturated fatty acids, and that they may function as grazing deterrents. Most studies reporting these effects have exposed test organisms to diatom extracts or ... -
High Arctic flowering phenology and plant-pollinator interactions in response to delayed snow melt and simulated warming
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-15)The projected alterations to climate in the High Arctic are likely to result in changes to the short growing season, particularly with varying predicted effects on winter snowfall, the timing of summer snowmelt and air temperatures. These changes are likely to affect the phenology of interacting species in a variety of ways, but few studies have investigated the effects of combined climate drivers ... -
Early life stages of an arctic keystone species (Boreogadus saida) show high sensitivity to a water-soluble fraction of crude oil
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-08-06)Increasing anthropogenic activities in the Arctic represent an enhanced threat for oil pollution in a marine environment that is already at risk from climate warming. In particular, this applies to species with free-living pelagic larvae that aggregate in surface waters and under the sea ice where hydrocarbons are likely to remain for extended periods of time due to low temperatures. We exposed the ... -
Monitoring and analyzing of circadian and ultradian locomotor activity based on Raspberry-Pi
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-09-15)A new device based on the Raspberry-Pi to monitor the locomotion of Arctic marine invertebrates and to analyze chronobiologic data has been made, tested and deployed. The device uses infrared sensors to monitor and record the locomotor activity of the animals, which is later analyzed. The software package consists of two separate scripts: the first designed to manage the acquisition and the evolution ... -
Where are they now? – A case study of the impact of international travel support for early career Arctic researchers
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-09)Supporting and training the next generation of researchers is crucial to continuous knowledge and leadership in Arctic research. An increasing number of Arctic organizations have developed initiatives to provide travel support for Early Career Researchers (ECRs) to participate in workshops, conferences and meetings and to network with internationally renowned scientific leaders. However, there has ... -
From individuals to population cycles: the role of extrinsic and intrinsic factors in rodent populations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-28)Rodent population cycles have fascinated scientists for a long time. Among various hypotheses, an interaction of an extrinsic factor (predation) with intrinsic factors (e.g., sociality and dispersal) was suggested to lead to the generation of population cycles. Here, we tested this hypothesis with an individual-based model fully parameterized with an exceptionally rich empirical database on vole ... -
Emergent rainy winter warm spells may promote boreal predator expansion into the arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-06-06)Climate change has been characterized as the most serious threat to Arctic biodiversity. In addition to gradual changes such as climate warming, extreme weather events, such as melting temperatures in winter and rain on snow, can have profound consequences for ecosystems. Rain-on-snow events lead to the formation of ice layers in the snow pack, which can restrict access to forage plants and cause ... -
Analyzing the proximity to cover in a landscape of fear: A new approach applied to fine-scale habitat use by rabbits facing feral cat predation on Kerguelen archipelago
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-07)Although proximity to cover has been routinely considered as an explanatory variable in studies investigating prey behavioral adjustments to predation pressure, the way it shapes risk perception still remains equivocal. This paradox arises from both the ambivalent nature of cover as potentially both obstructive and protective, making its impact on risk perception complex and context-dependent, and ... -
On Roald Amundsen’s scientific achievements
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-25)This paper describes the significant direct and indirect contributions to science made by the Norwegian polar explorer Roald Amundsen in the period 1897–1924. It documents that his expeditions through the North-west Passage (1903–06) with Gjøa, to the South Pole (1910–12) with Fram and through the North-east Passage (1918–1920) and the Chukchi and East Siberian seas (1921–25) with Maud yielded vast ... -
High Arctic plant phenology is determined by snowmelt patterns but duration of phenological periods is fixed: an example of periodicity
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-29)The duration of specific periods within a plant’s life cycle are critical for plant growth and performance. In the High Arctic, the start of many of these phenological periods is determined by snowmelt date, which may change in a changing climate. It has been suggested that the end of these periods during late-season are triggered by external cues, such as day length, light quality or temperature, ... -
Multiple metrics of diversity have different effects on temperate forest functioning over succession.
(Journal article; Tidsskriftartikkel, 2016-09-27)Biodiversity can be measured by taxonomic, phylogenetic, and functional diversity. How ecosystem functioning depends on these measures of diversity can vary from site to site and depends on successional stage. Here, we measured taxonomic, phylogenetic, and functional diversity, and examined their relationship with biomass in two successional stages of the broad-leaved Korean pine forest in northeastern ... -
Approaches for delaying sexual maturation in salmon and their possible ecological and ethical implications
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-07-21)The aquaculture industry is under pressure to satisfy global demand for marine foods. Atlantic salmon has been bred for more than 40 years, and substantial progress has been made within the culturing and breeding programs. The improved growth rate of Atlantic salmon has been accompanied by an earlier onset of maturation. Among the factors controlling maturation in salmon are photoperiod, temperature, ... -
Ørekyt i Namsenvassdraget. Utbredelse, spredningsrisiko og tiltak
(Research report; Forskningsrapport, 2006-04)Undersøkelser i Namsenvassdraget i 2005 viste at ørekyt forekommer i tette bestander i innsjøer og flyer øverst i vassdraget. I Otersjøen øverst i Sanddøla har ørekyt forekommet i solide bestander siden 1960-tallet. I Tunnsjøen og i Namsvatnet ble arten først registrert på 1990-tallet. Kartleggingen i 2005 viste at ørekyt hadde spredt seg fra Tunnsjøen til Tunnsjøflyan, men ikke videre ned ... -
When the brain goes diving: transcriptome analysis reveals a reduced aerobic energy metabolism and increased stress proteins in the seal brain
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-08-09)<b>Background: </b>During long dives, the brain of whales and seals experiences a reduced supply of oxygen (hypoxia). The brain neurons of the hooded seal (Cystophora cristata) are more tolerant towards low-oxygen conditions than those of mice, and also better survive other hypoxia-related stress conditions like a reduction in glucose supply and high concentrations of lactate. Little is known ... -
Methyl jasmonate: An alternative for improving the quality and health properties of fresh fruits
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-31)Methyl jasmonate (MeJA) is a plant growth regulator belonging to the jasmonate family. It plays an important role as a possible airborne signaling molecule mediating intra- and inter-plant communications and modulating plant defense responses, including antioxidant systems. Most assessments of this compound have dealt with post-harvest fruit applications, demonstrating induced plant resistance ... -
Carotenoid metabolism during bilberry (Vaccinium myrtillus L.) fruit development under different light conditions is regulated by biosynthesis and degradation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-04-21)<b>Background:</b> Carotenoids are important pigments and precursors for central signaling molecules associated in fruit development and ripening. Carotenoid metabolism has been studied especially in the climacteric tomato fruit but the content of carotenoids and the regulation of their metabolism have been shown to be highly variable between fruit species. Non-climacteric berries of the genus ...