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norskArtikler, rapporter og annet (arktisk og marin biologi): Recent submissions
Now showing items 81-100 of 1521
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Radiolaria and Phaeodaria (siliceous Rhizaria) in south-western and northern Norwegian fjords during late summer 2016: dominant species and biomass in shallow-water assemblages
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-21)To determine the present-day community composition of siliceous Rhizaria (Radiolaria and Phaeodaria) in Norwegian fjords, plankton tows were conducted in south-western and northern Norwegian fjords in September 2016. The mean total abundance of radiolarians was 306 m<sup>–3</sup> in the Sognefjord complex, which was the southern research site, and, in the north, 945 m<sup>–3</sup> in Malangen and ... -
A long-established invasive species alters the functioning of benthic biofilms in lakes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-21)Invasive species often transform environmental conditions, exclude native species and alter ecosystem functioning, including key ecosystem processes underpinning nutrient and energy cycles. However, such impacts have been most documented during periods of invasive species dominance; their influences on functioning at lower relative abundances and after long-term establishment are less well-known.<p> <p>We ... -
Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack-Recent insights on these historically overlooked features
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-07)The rapid melt of snow and sea ice during the Arctic summer provides a significant source of low-salinity meltwater to the surface ocean on the local scale. The accumulation of this meltwater on, under, and around sea ice floes can result in relatively thin meltwater layers in the upper ocean. Due to the small-scale nature of these upper-ocean features, typically on the order of 1 m thick or less, ... -
Seasonal dynamics of sea-ice protist and meiofauna in the northwestern Barents Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-27)The rapid decline of Arctic sea ice makes understanding sympagic (ice-associated) biology a particularly urgent task. Here we studied the poorly known seasonality of sea-ice protist and meiofauna community composition, abundance and biomass in the bottom 30 cm of sea ice in relation to ice properties and ice drift trajectories in the northwestern Barents Sea. We expected low abundances during the ... -
Do DOM quality and origin affect the uptake and accumulation of lipid-soluble contaminants in coastal filter feeders? An experimental simulation of teflubenzuron exposure to blue mussels
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-25)The increased export of terrestrial dissolved organic matter (terrDOM) to coastal marine ecosystems may affect local filter feeders and the local food web via the altered uptake of organic material and associated contaminants. To compare terrDOM to marine DOM (marDOM) as contaminant vectors to coastal biota, we exposed blue mussels (Mytilus sp.) to the different DOM types in combination with ... -
Evolutionary history and seascape genomics of Harbour porpoises (Phocoena phocoena) across environmental gradients in the North Atlantic and adjacent waters
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-08)The Harbour porpoise (Phocoena phocoena) is a highly mobile cetacean species primarily occurring in coastal and shelf waters across the Northern hemisphere. It inhabits heterogeneous seascapes broadly varying in salinity and temperature. Here, we produced 74 whole genomes at intermediate coverage to study Harbour porpoise's evolutionary history and investigate the role of local adaptation in the ... -
Linking extreme seasonality and gene expression in Arctic marine protists
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-05)At high latitudes, strong seasonal differences in light availability affect marine organisms and regulate the timing of ecosystem processes. Marine protists are key players in Arctic aquatic ecosystems, yet little is known about their ecological roles over yearly cycles. This is especially true for the dark polar night period, which up until recently was assumed to be devoid of biological activity. ... -
Macrofauna and meiofauna food-web structure from Arctic fjords to deep Arctic Ocean during spring: A stable isotope approach
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-13)The knowledge on benthic trophic relations is particularly important for understanding the functioning of still pristine and less studied Arctic Ocean ecosystems. This study examines the benthic food-web structure in the European sector of the Arctic Ocean and assesses if and how it differs along depth gradients in the marginal seaice zone during spring. Samples of the sediment organic matter were ... -
Remote Operation of Marine Robotic Systems and Next-Generation Multi-Purpose Control Rooms
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-08)Since 2017, NTNU’s Applied Underwater Robotics Laboratory has been developing an infrastructure for remote marine/subsea operations in Trondheim Fjord. The infrastructure, named the OceanLab subsea node, allows remote experimentation for three groups of assets: seabed infrastructure, surface or subsea vehicles/robots, and assets at remote experimentation sites. To achieve this task, a shoreside ... -
Long-term herbivore removal experiments reveal how geese and reindeer shape vegetation and ecosystem CO2-fluxes in high-Arctic tundra
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-23)1. Given the current rates of climate change, with associated shifts in herbivore population densities, understanding the role of different herbivores in ecosystem functioning is critical for predicting ecosystem responses. Here, we examined how migratory geese and resident, non-migratory reindeer—two dominating yet functionally contrasting herbivores—control vegetation and ecosystem processes in ... -
Marine Micro- and Macroalgae in the Polar Night
(Chapter; Bokkapittel, 2020)Microalgae have unique adaptions including low metabolic activity, utilization of lipid storage, and resting stage formation to survive the Polar Night. Some species are mixotrophic or heterotrophic and do survive periods that are not favorable for photosynthetic (autotrophic) growth, such as the Polar Night. In addi- tion, the autotrophic and mixotrophic species seem to maintain the key components ... -
An unexpected bird in Honkai: Star Rail and China’s war on sparrows
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023)In April 2023, the gacha game Honkai: Star Rail was launched, published by miHoYo/HoYoverse, a Chinese company now very famous for its hit game Genshin Impact. The game is a space opera focusing on a group of interstellar adventurers that travels across the universe to eliminate dangerous artifacts known as Stellarons. The player builds their team with a variety of anime-style characters (23 in total ... -
The global epidemiology of Brucella infections in terrestrial wildlife: A meta-analysis
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-17)Brucellosis is a widespread zoonotic disease with serious consequences on human and animal health. <i>Brucella</i> infections were reported in many terrestrial wild animals, from subtropical and temperate regions to arctic regions. In many areas, the epidemiology of brucellosis in wildlife is closely associated with the occurrence of the disease in livestock. Some wild species may contribute to the ... -
Retention of ice-associated amphipods: possible consequences for an ice-free Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012-09-12)Recent studies predict that the Arctic Ocean will have ice-free summers within the next 30 years. This poses a significant challenge for the marine organisms associated with the Arctic sea ice, such as marine mammals and, not least, the iceassociated crustaceans generally considered to spend their entire life on the underside of the Arctic sea ice. Based upon unique samples collected within ... -
Sea-ice decline could keep zooplankton deeper for longer
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-28)As Arctic sea ice deteriorates, more light enters the ocean, causing largely unknown effects on the ecosystem. Using an autonomous biophysical observatory, we recorded zooplankton vertical distribution under Arctic sea ice from dusk to dawn of the polar night. Here we show that zooplankton ascend into the under-ice habitat during autumn twilight, following an isolume of 2.4 × 10<sup>−4</sup> ... -
The roles of brain lipids and polar metabolites in the hypoxia tolerance of deep-diving pinnipeds
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-14)Lipids make up more than half of the human brain's dry weight, yet the composition and function of the brain lipidome is not well characterized. Lipids not only provide the structural basis of cell membranes, but also take part in a wide variety of biochemical processes. In neurodegenerative diseases, lipids can facilitate neuroprotection and serve as diagnostic biomarkers. The study of organisms ... -
Herbivory and warming have opposing short-term effects on plant-community nutrient levels across high-Arctic tundra habitats
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-11)Environmental changes can rapidly alter standing biomass in tundra plant communities; yet, to what extent can they modify plant-community nutrient levels? Nutrient levels and their changes can affect biomass production, nutrient cycling rates and nutrient availability to herbivores. We examined how environmental perturbations alter Arctic plant-community leaf nutrient concentrations (percentage of ... -
Ecological Drivers of Mercury Bioaccumulation in Fish of a Subarctic Watercourse
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-02)Mercury (Hg) is a serious concern for aquatic ecosystems because it may biomagnify to harmful concentrations within food webs and consequently end up in humans that eat fish. However, the trophic transfer of mercury through the aquatic food web may be impacted by several factors related to network complexity and the ecology of the species present. The present study addresses the interplay between ... -
First analysis of an Arctic sea ice meiofauna food web based on abundance, biomass and stable isotope ratios
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-23)Particulate organic carbon (POC) produced in sea ice is often included in stable isotopic food web studies of polar seas as a single value of particulate organic matter (POM), i.e. ‘ice POM’. During 10 field trips to landfast ice off Alaska’s north coast, we examined the seasonal contribution of sea ice-associated meiofauna to total POM and the trophic structure within the sea ice using bulk carbon ... -
Relating polar bears killed, human presence, and ice conditions in Svalbard 1987–2019
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-28)Conflicts between humans and polar bears have been predicted to increase as polar bear prime habitat, sea ice, is decreasing. In Svalbard, a strict protection and control schemes have secured near complete records of bears killed and found dead since 1987. We analyzed the trend in the number of kills and related this to human visitation to the archipelago. We found a slight decrease in the number ...
