Institutt for arktisk og marin biologi: Recent submissions
Now showing items 941-960 of 2049
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Simultaneous Oxidation of Atmospheric Methane, Carbon Monoxide and Hydrogen for Bacterial Growth
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-12)The second largest sink for atmospheric methane (CH<sub>4</sub>) is atmospheric methane oxidizing-bacteria (atmMOB). How atmMOB are able to sustain life on the low CH<sub>4</sub> concentrations in air is unknown. Here, we show that during growth, with air as its only source for energy and carbon, the recently isolated atmospheric methane-oxidizer <i>Methylocapsa gorgona</i> MG08 (USCα) oxidizes three ... -
Protist taxonomic and functional diversity in soil, freshwater and marine ecosystems
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-19)Protists dominate eukaryotic diversity and play key functional roles in all ecosystems, particularly by catalyzing carbon and nutrient cycling. To date, however, a comparative analysis of their taxonomic and functional diversity that compares the major ecosystems on Earth (soil, freshwater and marine systems) is missing. Here, we present a comparison of protist diversity based on standardized high ... -
Digestive tract morphology and enzyme activities of juvenile diploid and triploid Atlantic salmon (Salmo salar) fed fishmealbased diets with or without fish protein hydrolysates
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-11)Triploid, sterile Atlantic salmon (Salmo salar) could make a contribution to the development of the farming industry, but uncertainties about the performance and welfare of triploids have limited their adoption by farmers. In this study, we compared the ontogeny of digestive tract morphology and enzyme activities (pepsin, trypsin, chymotrypsin, alkaline phosphatase and aminopeptidase) of diploid ... -
Examining the accuracy of trackways for predicting gait selection and speed of locomotion
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-27)Using Froude numbers (<i>Fr</i>) and relative stride length (stride length: hip height), trackways have been widely used to determine the speed and gait of an animal. This approach, however, is limited by the ability to estimate hip height accurately and by the lack of information related to the substrate properties when the tracks were made, in particular for extinct fauna. By studying the Svalbard ... -
Reduced immune responsiveness contributes to winter energy conservation in an Arctic bird
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-27)Animals in seasonal environments must prudently manage energy expenditure to survive the winter. This may be achieved through reductions in the allocation of energy for various purposes (e.g. thermoregulation, locomotion, etc.). We studied whether such trade-offs also include suppression of the innate immune response, by subjecting captive male Svalbard ptarmigan (<i>Lagopus muta hyperborea</i>) to ... -
The neglected season: Warmer autumns counteract harsher winters and promote population growth in Arctic reindeer
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-24)Arctic ungulates are experiencing the most rapid climate warming on Earth. While concerns have been raised that more frequent icing events may cause die‐offs, and earlier springs may generate a trophic mismatch in phenology, the effects of warming autumns have been largely neglected. We used 25 years of individual‐based data from a growing population of wild Svalbard reindeer, to test how warmer ... -
Circadian clock mechanism driving mammalian photoperiodism
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-27)The annual photoperiod cycle provides the critical environmental cue synchronizing rhythms of life in seasonal habitats. In 1936, Bünning proposed a circadian-based coincidence timer for photoperiodic synchronization in plants. Formal studies support the universality of this so-called coincidence timer, but we lack understanding of the mechanisms involved. Here we show in mammals that long photoperiods ... -
Meiofauna as a valuable bioindicator of climate change in the polar regions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-14)Establishing robust estimates of polar marine biodiversity is important for interpreting future changes in the Arctic; however, despite a recent increase in scientific expeditions, this region remains relatively underexplored. Particularly overlooked in biodiversity assessments are small species, such as protists, fungi, and many small invertebrates that are collectively known as meiofauna. These ... -
Morphology, Transcriptomics and In Vitro Model of Skin from Polar Cod (Boreogadus Saida) and Atlantic Cod (Gadus Morhua)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-04)Fish skin is a multifunctional barrier tissue with high regeneration capacity that interacts with the surrounding environment and provides protection. Functional importance, high complexity and activity make skin an attractive tissue for studying the effects of environmental challenges and chemical stressors in fish. The aim of this work was to characterize skin from polar cod (<i>Boreogadus saida</i>) ... -
Resource‐driven colonization by cod in a high Arctic food web
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-23)<ol> <li>Climate change is commonly associated with many species redistributions and the influence of other factors may be marginalized, especially in the rapidly warming Arctic.</li> <li>The Barents Sea, a high latitude large marine ecosystem in the Northeast Atlantic has experienced above‐average temperatures since the mid‐2000s with divergent bottom temperature trends at subregional ... -
Assessing the responses of Sphagnum micro-eukaryotes to climate changes using high throughput sequencing
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-18)Current projections suggest that climate warming will be accompanied by more frequent and severe drought events. Peatlands store ca. one third of the world’s soil organic carbon. Warming and drought may cause peatlands to become carbon sources through stimulation of microbial activity increasing ecosystem respiration, with positive feedback effect on global warming. Micro-eukaryotes play a key role ... -
The Chloroplast Ribonucleoprotein CP33B Quantitatively Binds the psbA mRNA
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-17)Chloroplast RNAs are stabilized and processed by a multitude of nuclear-encoded RNA-binding proteins, often in response to external stimuli like light and temperature. A particularly interesting RNA-based regulation occurs with the <i>psbA</i> mRNA, which shows light-dependent translation. Recently, the chloroplast ribonucleoprotein CP33B was identified as a ligand of the <i>psbA</i> mRNA. We here ... -
Mercury in fish from a subarctic watercourse and its relation to trophic ecology
(Master thesis; Mastergradsoppgave, 2020-11-16)Mercury (Hg) contamination in aquatic ecosystems is a serious concern because it can bioaccumulate and biomagnify to harmful concentrations within a food web and consequently end up in humans that eat polluted fish. The Pasvik watercourse, located in the border area between Norway, Finland and Russia, is strongly affected by the emissions of heavy metals from nearby Russian metallurgic smelters. In ... -
Latitudinal Cline in Chromosome Numbers of Ice Cod A. glacialis (Gadidae) from Northeast Greenland
(Journal article; Tidsskriftartikkel, 2020-12-18)The ice cod <i>Arctogadus glacialis</i> (Peters, 1872) is one of the few fish species endemic to the Arctic. With a circumpolar distribution, the species is confined to the fjords and shelves of the Arctic seas. Biological information on <i>A. glacialis</i> is scarce, with genomic information restricted to microsatellites. Within the frame of the TUNU-Programme: Arctic Ocean Fishes—Diversity, ... -
Benthic scavenger community composition and carrion removal in Arctic and Subarctic fjords
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-05)In high latitude coastal regions, benthic scavenger communities are largely composed of invertebrates that play a key role in the cycling of organic matter. Factors including temperature and depth can structure Arctic and Subarctic fjord benthic communities, but the response of scavenging communities to these factors is poorly known. To address this, we compared scavenging fauna in eight fjords with ... -
Mitogenomics and the genetic differentiation of contemporary Balaena mysticetus (Cetacea) from Svalbard
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-12)Full mitochondrial genomes were assembled for 12 recently sampled animals from the Svalbard bowhead whale (Balaena mysticetus) stock via high-throughput sequencing data, facilitating analysis of the demographic history of the population for the first time. The Svalbard population has retained noticeable amounts of mitochondrial genome diversity despite extreme historical harvest levels. Haplotype ... -
Modelling the effect of mesh size and opening angle on size selection and capture pattern in a snow crab (Chionoecetes opilio) pot fishery
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-18)Size selection in commercial snow crab (Chionoecetes opilio) pot fisheries is important for reducing on-board sorting and unintended mortality of undersized individuals. In this paper, we tested whether snow crab of various sizes geometrically could pass through diamond meshes of different sizes and opening angles, to estimate a model for predicting the effect of mesh size and mesh opening angle on ... -
The tomato receptor CuRe1 senses a cell wall protein to identify Cuscuta as a pathogen
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-20)Parasitic plants of the genus Cuscuta penetrate shoots of host plants with haustoria and build a connection to the host vasculature to exhaust water, solutes and carbohydrates. Such infections usually stay unrecognized by the host and lead to harmful host plant damage. Here, we show a molecular mechanism of how plants can sense parasitic Cuscuta. We isolated an 11 kDa protein of the parasite cell ... -
Connecting the data landscape of long‐term ecological studies: The SPI‐Birds data hub
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-17)<ol> <li>The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long‐term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global ... -
A highly efficient protocol for transforming Cuscuta reflexa based on artificially induced infection sites
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-10)The parasitic plant genus <i>Cuscuta</i> is notoriously difficult to transform and to propagate or regenerate in vitro. With it being a substantial threat to many agroecosystems, techniques allowing functional analysis of gene products involved in host interaction and infection mechanisms are, however, in high demand. We set out to explore whether <i>Agrobacterium</i>‐mediated transformation of ...