Institutt for arktisk og marin biologi: Recent submissions
Now showing items 41-60 of 2012
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Circadian coupling of mitochondria in a deep-diving mammal
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-08)Regulation of mitochondrial oxidative phosphorylation is essential to match energy supply to changing cellular energy demands, and to cope with periods of hypoxia. Recent work implicates the circadian molecular clock in control of mitochondrial function and hypoxia sensing. Because diving mammals experience intermittent episodes of severe hypoxia, with diel patterning in dive depth and duration, ... -
Does long-term grazing cause cascading impacts on the soil microbiome in mountain birch forests?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-02-01)In subarctic mountain birch forests, reindeer grazing and moth outbreaks act as important biotic drivers of ecosystem functioning. We investigated how a long-term contrast in reindeer grazing regimes and short-term ungulate exclusion affected soil fungal and bacterial communities in mountain birch forests recovering from a recent moth outbreak. We separately described the impacts on microbial ... -
Descriptive analyses of knowledge, attitudes, and practices regarding rabies transmission and prevention in rural communities near wildlife reserves in Uganda: a One Health cross-sectional study
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-19)Background Despite urban (domestic dog) rabies cycles being the main target for rabies elimination by 2030, syl‑ vatic (wildlife) rabies cycles can act as rabies spillovers especially in settlements contiguous to wildlife reserves. Rural communities next to wildlife reserves are characterized by unique socio-demographic and cultural practices includ‑ ing bat consumption, hunting for bushmeat, and ... -
Shifting invertebrate distributions in the Barents Sea since pre-1900
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-23)Marine invertebrate habitats are experiencing warming, and oceanic carbon dioxide levels are on the rise. These changes result in shifts in species distributions. Monitoring and understanding these shifts provides vital information because each species plays a unique ecological role, and the human utilization of marine species is intrinsically linked to their geographic locations. Here, we ... -
c-fos induction in the choroid plexus, tanycytes and pars tuberalis is an early indicator of spontaneous arousal from torpor in a deep hibernator
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-23)Hibernation is an extreme state of seasonal energy conservation, reducing metabolic rate to as little as 1% of the active state. During the hibernation season, many species of hibernating mammals cycle repeatedly between the active (aroused) and hibernating (torpid) states (T–A cycling), using brown adipose tissue (BAT) to drive cyclical rewarming. The regulatory mechanisms controlling this process ... -
Hypothalamic tanycytes as mediators of maternally programmed seasonal plasticity
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-12)In mammals, maternal photoperiodic programming (MPP) provides a means whereby juvenile development can be matched to forthcoming seasonal environmental conditions.<sup>1–4</sup> This phenomenon is driven by in utero effects of maternal melatonin<sup>5–7</sup> on the production of thyrotropin (TSH) in the fetal pars tuberalis (PT) and consequent TSH receptor-mediated effects on tanycytes lining ... -
Biophysical characterization of summer Arctic sea-ice habitats using a remotely operated vehicle-mounted underwater hyperspectral imager
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-08)The impact of a rapidly shifting sea-ice cover on climate, ecosystem processes and biophysical habitat properties is not yet fully understood, particularly in the central Arctic Ocean, due to a lack of spatially representative observations. From June to July 2020 during the year-long Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC, leg 4) in the Transpolar Drift, we ... -
Parasitic dodder expresses an arsenal of secreted cellulases with multi-substrate specificity during host invasion
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-17)Cuscuta campestris is a common and problematic parasitic plant which relies on haustoria to connect to and siphon nutrients from host plants. Glycoside hydrolase family 9 (GH9) cellulases (EC 3.2.1.4) play critical roles in plant cell wall biosynthesis and disassembly, but their roles during Cuscuta host invasion remains underexplored. In this study, we identified 22 full-length GH9 cellulase ... -
Management strategy evaluation for northern shrimp in the Barents Sea (ICES subareas 1 and 2)
(Research report; Forskningsrapport, 2024-09-02)To establish a management plan for northern shrimp (Pandalus borealis) in the Barents Sea, the Norwegian-Russian Fisheries Commission requested in 2023 a proposal for a harvest control rule (HCR). Based on discussions with stakeholders, six different HCRs were defined and evaluated against three performance criteria: 1. precautionarity (less than 5% risk of falling below limit reference point for ... -
Zooplankton fecal pellet flux drives the biological carbon pump during the winter–spring transition in a high-Arctic system
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-24)Recent research highlighted significant marine biological activity during the Arctic winter, with poorly known implications for the biological carbon pump. We used moored instruments to (1) track the development of the pelagic food web of a high-Arctic marine ecosystem from winter to spring, and (2) assess the role of zooplanktonmediated processes in the sinking export of particulate organic carbon ... -
Environmental drivers of food webs in charr and trout-dominated cold-water lakes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-15)Cold-water lakes situated in high latitudes and altitudes have pivotal socio-ecological importance both globally and locally. However, they are increasingly threatened by multiple anthropogenic stressors, such as climate change, hydropower and invasive species. The development of efficient management strategies is therefore urgently needed and requires a comprehensive understanding of the factors ... -
Calibration verification of an underwater hyperspectral imaging push broom instrument to measure light in absolute units and field demonstration
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-09-16)The push broom design of an underwater hyperspectral imaging (UHI) instrument makes it possible to measure angle-resolved spectral radiance L(λ)in a plane. We describe the characterization of a commercial UHI instrument (UHI-4, Ecotone AS, Norway) and the spectral, geometric, and radiometric calibration transfer for measuring L(λ) in absolute units [µW cm<sup>−2</sup> nm<sup>−1</sup> sr<sup>−1</sup> ]. ... -
Ecosystem risk from human use of ocean space and resources: a case study from the Norwegian coast
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-30)Coastal and adjacent shelf waters are generally highly productive ecosystems harboring important ecological processes and exposed to a range of anthropogenic pressures from land-based and marine sectors. Ensuring that the cumulative pressures from human activities do not cause unacceptable, permanent harm to the ecosystem is challenging but crucial for sustainable management of these regions. ... -
Genomic architecture and population structure of Boreogadus saida from Canadian waters
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-20)The polar cod, Boreogadus saida, is an abundant and ubiquitous forage fish and a crucial link in Arctic marine trophic dynamics. Our objective was to unravel layers of genomic structure in B. saida from Canadian waters, specifically screening for potential hybridization with the Arctic cod, Arctogadus glacialis, large chromosomal inversions, and sex-linked regions, prior to interpreting population ... -
Mixing, Water Transformation, and Melting Close to a Tidewater Glacier
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-15)Marine-terminating glacier fjords play a central role in the transport of oceanic heat toward ice sheets, regulating their melt. Mixing processes near glacial termini are key to this circulation but remain poorly understood. We present new summer measurements of circulation and mixing near a marine-terminating glacier with active sub-glacial discharge. 65% of the fjord's vertical overturning circulation ... -
Feathers as integrated archives of environmental stress: Direct and indirect effects of metal exposure and dietary ecology on physiological stress in a terrestrial raptor
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-09-18)Metal pollution is a global environmental issue with adverse biological effects on wildlife. Long-term studies that span declines in metal emissions due to regulation, resulting in varying levels of environmental contamination, are therefore well-suited to investigate effects of toxic metals, while also facilitating robust analysis by incorporating fluctuating environmental conditions and food ... -
The nasal cavity of the bearded seal: An effective and robust organ for retaining body heat and water
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-09-10)We report the effects of varying physiological and other properties on the heat and water exchange in the maxilloturbinate structure (MT) of the bearded seal (Erignathus barbatus or Eb) in realistic environments, using a computational fluid dynamics (CFD) model. We find that the water retention in percent is very high (about 90 %) and relatively unaffected by either cold (−30 ◦C) or warm (10 ◦C) ... -
Seasonal food intake and energy balance: Neuronal and non-neuronal control mechanisms
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-22)Animals inhabiting temperate and high latitudes undergo drastic seasonal changes in energy storage, facilitated by changes in food intake and body mass. Those seasonal changes in the animal’s biology are not mere consequences of environmental energy availability but are anticipatory responses to the energetic requirements of the upcoming season and are actively timed by tracking the annual ... -
High uptake of sympagic organic matter by benthos on an Arctic outflow shelf
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-07)On Arctic shelves, benthic food-webs are tightly linked to overlying primary production. In the seasonal ice zone, sympagic (ice-associated) primary production can be a major source of carbon for the benthos on productive inflow shelves. However, the role of sympagic organic matter is less well-understood in food webs of heavily ice-covered, less- productive outflow shelves, such as the northeast ... -
Characterization of cellulases from softening fruit for enzymatic depolymerization of cellulose
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-14)Cellulose is a major renewable resource for a wide variety of sustainable industrial products. However, for its utilization, finding new efficient enzymes for plant cell wall depolymerization is crucial. In addition to microbial sources, cellulases also exist in plants, however, are less studied. Fleshy fruit ripening includes enzymatic cell wall hydrolysis, leading to tissue softening. Therefore, ...