Browsing Artikler, rapporter og annet (arktisk og marin biologi) by Title
Now showing items 797-816 of 1515
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Lifelong divergence of growth patterns in Arctic charr life history strategies: implications for sustainable fisheries in a changing climate
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-18)Arctic charr (<i>Salvelinus alpinus</i> Linnaeus, 1758) are phenotypically variable with multiple life history strategies including anadromous and freshwater resident individuals. The mechanism determining life history is believed to be set early in life. Anadromous individuals show greater seasonality in growth and feeding after the first seaward migration relative to resident conspecifics. We used ... -
Light and freshwater discharge drive the biogeochemistry and microbial ecology in a sub-Arctic fjord over the Polar night
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-30)The polar night has recently received increased attention as a surprisingly active biological season. Yet, polar night microbial ecology is a vastly understudied field. To identify the physical and biogeochemical parameters driving microbial activity over the dark season, we studied a sub-Arctic fjord system in northern Norway from autumn to early spring with detailed monthly sampling. We focused ... -
Light and freshwater discharge drive the biogeochemistry and microbial ecology in a sub-Arctic fjord over the Polar night
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-30)The polar night has recently received increased attention as a surprisingly active biological season. Yet, polar night microbial ecology is a vastly understudied field. To identify the physical and biogeochemical parameters driving microbial activity over the dark season, we studied a sub-Arctic fjord system in northern Norway from autumn to early spring with detailed monthly sampling. We focused ... -
Light and temperature effects on bioactivity in diatoms
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-05)Isolates of five pelagic North Atlantic marine diatoms (Bacillariophyceae): Attheya longicornis, Chaetoceros socialis, Chaetoceros furcellatus, Skeletonema marinoi and Porosira glacialis were cultivated in large photobioreactors at two light and two temperature regimes to test if this affected bioactivity. We screened for bioactivity in assays representing five different therapeutic areas: ... -
Light-controlled flavonoid biosynthesis in fruits
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-10-09) -
Limited predatory effects on infaunal macrobenthos community patterns in intertidal soft-bottom of Arctic coasts
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-24)Predation shapes marine benthic communities and affects prey species population dynamics in tropic and temperate coastal systems. However, information on its magnitude in systematically understudied Arctic coastal habitats is scarce. To test predation effects on the diversity and structure of Arctic benthic communities, we conducted caging experiments in which consumers were excluded from plots at ... -
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. ... -
Lipid content and fatty acid composition of Porosira glacialis and Attheya longicornis in response to carbon dioxide (CO2) aeration
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-18)In the current study two novel psychrophilic diatoms Porosira glacialis and Attheya longicornis were tested for suitability to CO2 mitigation coupled with production of the physiologically requisite omega± 3 fatty acids. This study is in line with the worldwide conducted research aimed at applying biorefinery concept to heavy polluting industries. Since the production of algal high value compounds, ... -
Lipid sac area as a proxy for individual lipid content of arctic calanoid copepods
(Journal article; Tidsskriftartikkel; Peer reviewed, 2010)We present an accurate, fast, simple and non-destructive photographic method to estimate wax ester and lipid content in single individuals of the calanoid copepod genus Calanus and test this method against gas-chromatographic lipid measurements. -
Lipid Status of the Two High Latitude Fish Species, Leptoclinus maculatus and Lumpenus fabricii
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)A comparative study of the lipid status (i.e., the total lipid and phospholipid concentrations and the percentage of fatty acids of the total lipids) of adult specimens of daubed shanny (Leptoclinus maculatus) from Svalbard waters (Isfjord) and slender eel blenny (Lumpenus fabricii) from the White Sea (Onega Bay and Tersky shore) was performed to study the metabolism and functions of lipids of these ... -
Local and regional determinants of colonisation-extinction dynamics of a riparian mainland-island root vole metapopulation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)The role of local habitat geometry (habitat area and isolation) in predicting species distribution has become an increasingly more important issue, because habitat loss and fragmentation cause species range contraction and extinction. However, it has also become clear that other factors, in particular regional factors (environmental stochasticity and regional population dynamics), should be taken ... -
Local land use associated with socio-economic development in six arctic regions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-04)The socioeconomic causes of land use change are complex. They are highly context dependent, but most often studied through case studies. Here, we use a quasi-experimental paired block design to investigate whether better access to wage income leads to more visible land use around 28 settlements in six regions of the circumpolar Arctic. We mapped visible land use on high-resolution satellite images ... -
Location of studies and evidence of effects of herbivory on Arctic vegetation: a systematic map
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-14)Herbivores modify the structure and function of tundra ecosystems. Understanding their impacts is necessary to assess the responses of these ecosystems to ongoing environmental changes. However, the effects of herbivores on plants and ecosystem structure and function vary across the Arctic. Strong spatial variation in herbivore effects implies that the results of individual studies on herbivory ... -
Long-distance particle transport to the central Ionian Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-14)Together with T –S properties, particle abundance in situ measurements are useful to discriminate water masses and derive circulation patterns. In the upper layers of the Ionian Sea, the fresher Atlantic Waters (AW) recently crossing the Sicily Channel meet the resident and saltier AW, which circulated cyclonically in the eastern basin and modified after evaporation and eventually cooling. In ... -
Long-distance plant dispersal to North Atlantic islands: colonization routes and founder effect
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-04-15)Long-distance dispersal (LDD) processes influence the founder effect on islands.We use genetic data for 25 Atlantic species and similarities among regional floras to analyse colonization, and test whether the genetic founder effect on five islands is associated with dispersal distance, island size and species traits. Most species colonized postglacially via multiple dispersal events from several ... -
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 ... -
Long-term ecological studies in northern lakes – challenges, experiences, and accomplishments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-15)We review three long‐term research programs performed over the last four decades on the ecology and management of oligotrophic lake systems with different fish communities at 69° N in Norway. Through whole‐lake perturbation experiments, intensive culling of stunted fish removed 35 tons (1984–1991) of Arctic charr <i>Salvelinus alpinus</i> in Takvatn (15 km<sup>2</sup>) and 153 tons (1981–1983, ... -
Long-term environmental monitoring for assessment of change: measurement inconsistencies over time and potential solutions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-30)The importance of long-term environmental monitoring and research for detecting and understanding changes in ecosystems and human impacts on natural systems is widely acknowledged. Over the last decades, a number of critical components for successful long-term monitoring have been identified. One basic component is quality assurance/quality control protocols to ensure consistency and comparability ... -
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 ... -
Long-term monitoring of exposure to toxic and essential metals and metalloids in the tawny owl (Strix aluco): Temporal trends and influence of spatial patterns
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-10)As a result of regulatory decisions, atmospheric deposition of most toxic metals and metalloids (MEs) has decreased in Europe over the past few decades. However, little is known about how this reduction translates into exposure at higher trophic levels in the terrestrial environment where temporal trends may be spatially heterogeneous due to local current or legacy sources of emissions (e.g., industry) ...