Artikler, rapporter og annet (arktisk og marin biologi): Nye registreringer
Viser treff 81-100 av 1643
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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, ... -
Melatonin and Seasonal Synchrony in Mammals
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-12)In mammals, seasonal opportunities and challenges are anticipated through programmed changes in physiology and behavior. Appropriate anticipatory timing depends on synchronization to the external solar year, achieved through the use of day length (photoperiod) as a synchronizing signal. In mammals, nocturnal production of melatonin by the pineal gland is the key hormonal mediator of photoperiodic ... -
Exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in Norway and beyond
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-15)This study investigates effects of subtle methodological choices on the estimation and biological interpretation of age, growth and reproductive parameters for harbour porpoises. The core analyses are based on a focal Norwegian data set built on samples from 134 harbour porpoises caught incidentally in gillnet fisheries along the Norwegian coast during autumn 2016 and spring 2017. Two contrasting ... -
Targeting methanotrophs and isolation of a novel psychrophilic Methylobacter species from a terrestrial Arctic alkaline methane seep in Lagoon Pingo, Central Spitsbergen (78° N)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-22)The microbial diversity associated with terrestrial groundwater seepage through permafrost soils is tightly coupled to the geochemistry of these fluids. Terrestrial alkaline methane seeps from Lagoon Pingo, Central Spitsbergen (78°N) in Norway, with methane-saturated and oxygen-limited groundwater discharge providing a potential habitat for methanotrophy. Here, we report on the microbial community’s ... -
Physiological basis for atmospheric methane oxidation and methanotrophic growth on air
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-16)Atmospheric methane oxidizing bacteria (atmMOB) constitute the sole bio-logical sink for atmospheric methane. Still, the physiological basis allowing atmMOB to grow on air is not well understood. Here we assess the ability and strategies of seven methanotrophic species to grow with air as sole energy, carbon, and nitrogen source. Four species, including three outside the canonical atmMOB group USCα, ... -
Essential omega-3 fatty acids are depleted in sea ice and pelagic algae of the Central Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-19)Microalgae are the main source of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), essential for the healthy development of most marine and terrestrial fauna including humans. Inverse correlations of algal EPA and DHA proportions (% of total fatty acids) with temperature have led to suggestions of a warming-induced decline in the global production of these biomolecules ... -
Overview of the MOSAiC expedition: Ecosystem
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-21)The international and interdisciplinary sea-ice drift expedition “The Multidisciplinary drifting Observatory for the Study of Arctic Climate” (MOSAiC) was conducted from October 2019 to September 2020. The aim of MOSAiC was to study the interconnected physical, chemical, and biological characteristics and processes from the atmosphere to the deep sea of the central Arctic system. The ecosystem team ... -
Governance for Earth system tipping points – A research agenda
(Journal article; Tidsskriftartikkel, 2024-06-12)Tipping points in the Earth system could be passed within the Paris Agreement's temperature goal range (1.5°C–2°C). Tipping processes are a feature of complex Earth system dynamics that present major governance challenges not addressed by existing global governance institutions. The common governance toolkit is a poor match for dealing with tipping processes, especially non-linear change, and radical ... -
Efficacy, persistence and residue levels of fungicides for Botrytis control in wild blueberry
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-02-17)Botrytis blossom blight disease is one of the major challenges to wild blueberry production with annual losses frequently exceeding 20%. In this study, the effect of different fungicide treatments on Botrytis blight development and yield, as well as the mobility and persistence of these fungicides within flower tissues, and fruit of wild blueberries were evaluated under field conditions. This ... -
Bacterioplankton taxa compete for iron along the early spring–summer transition in the Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-18)Microbial assemblages under the sea ice of the Dease Strait, Canadian Arctic, were sequenced for metagenomes of a small size fraction (0.2–3 μm). The community from early March was typical for this season, with Alpha- and Gammaproteobacteria as the dominant taxa, followed by Thaumarchaeota and Bacteroidetes. Toward summer, Bacteroidetes, and particularly the genus Polaribacter, became increasingly ... -
Mapping Potential Timing of Ice Algal Blooms From Satellite
(Journal article; Tidsskriftartikkel, 2024-04-17)As Arctic sea ice and its overlying snow cover thin, more light penetrates into the ice and upper ocean, shifting the phenology of algal growth within the bottom of sea ice, with cascading impacts on higher trophic levels of the Arctic marine ecosystem. While field data or autonomous observatories provide direct measurements of the coupled sea ice-algal system, they are limited in space and time. ...