Artikler, rapporter og annet (arktisk og marin biologi): Nye registreringer
Viser treff 1241-1260 av 1643
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Trophic niche similarity among sea trout Salmo trutta in Central Norway investigated using different time-integrated trophic tracers
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-21)From 2011 to 2013, anadromous brown trout Salmo trutta (213−730 mm, total body length, LT) were collected during or shortly after their marine feeding migration at 7 different localities in central Norway. The mean volume of stomach content (%) of marine fish prey eaten by S. trutta captured in marine waters varied from 34 to 89%. There was a high prevalence (67−100%) for parasite groups potentially ... -
Spatial patterns of spring meroplankton along environmental gradients in a sub-Arctic fjord
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-02)The spatial patterns in abundance and composition of benthic invertebrate larvae (meroplankton), the correlation between these patterns and environmental variables (temperature, salinity and chl a) and the relative abundance of meroplankton in the mesozooplankton community were investigated in the sub-Arctic Porsangerfjord, Norway (70° N). Zooplankton samples and CTD-profiles were collected at ... -
Spatial variability of CO2 uptake in polygonal tundra: Assessing low-frequency disturbances in eddy covariance flux estimates
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-29)The large spatial variability in Arctic tundra complicates the representative assessment of CO<sub>2</sub> budgets. Accurate measurements of these heterogeneous landscapes are, however, essential to understanding their vulnerability to climate change. We surveyed a polygonal tundra lowland on Svalbard with an unmanned aerial vehicle (UAV) that mapped ice-wedge morphology to complement eddy ... -
Variability and quasi-decadal changes in the methane budget over the period 2000-2012
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-20)Following the recent Global Carbon Project (GCP) synthesis of the decadal methane (CH<sub>4</sub> budget over 2000– 2012 (Saunois et al., 2016), we analyse here the same dataset with a focus on quasi-decadal and inter-annual variability in CH<sub>4</sub> emissions. The GCP dataset integrates results from topdown studies (exploiting atmospheric observations within an atmospheric inverse-modelling ... -
Salvage logging of mountain birch after geometrid outbreaks: Ecological context determines management outcomes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-01)Outbreaks of pest insects occasionally cause mortality of entire forest stands. Salvage logging of affected stands is the most common management response to such events. Logging may aid stand recovery by increasing the production and establishment of saplings, or stimulating the production of basal sprouts in sprouting tree species. However, the outcome of logging may depend on the ecological ... -
Ontogenetic dynamics of infection with Diphyllobothrium spp. cestodes in sympatric Arctic charr Salvelinus alpinus (L.) and brown trout Salmo trutta L.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-23)The trophic niches of Arctic charr and brown trout differ when the species occur in sympatry . Their trophically transmitted parasit es are expected to reflect these differences. Here , we investigate how the infections of Diphyllobothrium dendriticum and Diphyllobothrium ditremum differ between charr and trout. These tapeworms use copepods ... -
Correction: Anderson, H.B. et al. Using Ordinary Digital Cameras in Place of Near-Infrared Sensors to Derive Vegetation Indices for Phenology Studies of High Arctic Vegetation. Remote Sens. 2016, 8, 847
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-28)After the publication of the research paper by Anderson et al. [ 1 ], a reanalysis of the data showed that mistakes had been introduced in the calculation of the greenness indices and the filtering for outliers prior to the statistical analysis. The calculation of the 2G_RBi and Channel G% indices were the most affected, while the filtering of the data for outliers had inadvertently removed too ... -
Consistent isotopic differences between Schistocephalus spp. parasites and their stickleback hosts
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-23)Parasite−host systems show markedly variable patterns in isotopic fractionation: parasites can be either depleted or enriched in 15N and 13C as compared to their hosts. However, it remains unknown whether isotopic fractionation patterns are similar in comparable parasite−host systems from markedly different ecosystems. Results of this study show that large-sized Schistocephalus spp. endoparasites ... -
Hidden in the darkness of the Polar night: A first glimpse into winter migration of the Svalbard rock ptarmigan
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-06-05)Among many unknown aspects of the Svalbard rock ptarmigan’s biology is whether the birds migrate seasonally within the Svalbard archipelago. Visual observations in spring and fall have indicated that they could perform long-range migration, a behaviour that would allow them to track seasonal shifts in suitable feeding areas. However, the movement patterns and habitat use of the Svalbard rock ... -
Behavioural Responses of Moulting Barnacle Geese to Experimental Helicopter Noise and a Predator
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016)The response of animals to anthropogenic noise can be aggravated by lack of familiarity with its auditory pattern and also by nervousness characteristic of particular phases of their life cycle. Both conditions apply in the Arctic where human activity is highly localised and field operations, being largely restricted to summer, coincide with the period when animals produce and nurse offspring and, ... -
On the use of the HUGIN 1000 HUS Autonomous Underwater Vehicle for high resolution zooplankton measurements
(Journal article; Tidsskriftartikkel; Peer reviewed, 2010)This paper evaluates and tests the HUGIN 1000 HUS AUV as a carrier platform for the Laser Optical Plankton Counter (LOPC). The LOPC was mounted outside on top of the carrier platform, and the tests confirm that this concept did not create turbulence and zooplankton avoidance. A negligible velocity difference between the flow passing through the sampling tube and the AUV speed was detected. The ... -
Vicariance, dispersal, and hybridization in a naturally fragmented system: the afro-alpine endemics Carex monostachya and C. runssoroensis (Cyperaceae)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-08)The naturally fragmented habitat on the tallest African mountains provides a good model system to study vicariance, dispersal, and hybridization. Many mountains are separated by lowland that likely was unsuitable for high-alpine plants even during cold climatic periods. <br> We explore the relative importance of these processes using two endemic sister species: the widespread Ethiopian/eastern East ... -
Velferdskriterier i reindriften
(Research report; Forskningsrapport, 2017-06-07)Formålet med prosjektet var å identifisere ulike faktorer som kunne påvirke velferd hos tamrein, og som kunne implementeres i produksjonssystemene, på beite, i gjerdet, på slakteriet, gjennom produktmerking og fremtidige kvalitetssikringssystemer. I den senere tid har det vært et økt fokus på dyrehelse og -velferd i reindrifta. Det har for eksempel vært et fokus på lave slaktevekter, spesielt i ... -
Scientific opinion on chronic wasting disease (CWD) in cervids
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-18)In April and May of 2016, Norway confirmed two cases of chronic wasting disease (CWD) in a wild reindeer and a wild moose, respectively. In the light of this emerging issue, the European Commission requested EFSA to recommend surveillance activities and, if necessary, additional animal health risk-based measures to prevent the introduction of the disease and the spread into/within the EU, specifically ... -
Tresatt impediment og livsløpstrær av osp på hogstflater. Effektive tiltak for artsmangfoldet i norsk skog?
(Research report; Forskningsrapport, 2005-07)Skogbruket legger ned betydelige ressurser i form av arbeid og kapital for å ta hensyn til biologisk mangfold. Det er av stor betydning for skogbrukets økonomi og konkurranseevne at disse ressursene benyttes slik at man får best mulig bevaring av biologisk mangfold per krone. Rapporten omhandler to ulike delprosjekter som har vært gjennomført i forbindelse med Forskningsrådets prosjekt ... -
Konflikter mellom ærfugl og blåskjelldyrking
(Research report; Forskningsrapport, 2006-01)Oppdrett av blåskjell har i de senere år økt sterkt i omfang i Norge, men kunnskapen om de økologiske konsekvensene av virksomheten er meget begrenset. Et betydelig problem som har oppstått i denne forbindelse er predasjon fra fugl, og da særlig ærfugl. Dette har klare negative konsekvenser for lønnsomheten, samt representerer et kunstig habitat og mulige negative påvirkninger for fugl. Bedre ... -
Vertical fluxes of nitrate in the seasonal nitracline of the Atlantic sector of the Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-07-31)<p>This study compiles colocated oceanic observations of high-resolution vertical profiles of nitrate concentration and turbulent microstructure around the Svalbard shelf slope, covering both the permanently ice-free Fram Strait and the pack ice north of Svalbard. The authors present an overview over the seasonal evolution of the distribution of nitrate and its relation to upper ocean stratification. ... -
Røye som langtidsvert og smittereservoar for Gyrodactylus salaris i Skibotnelva i Troms
(Research report; Forskningsrapport, 2005-03)Skibotnelva i Troms var lenge det eneste vassdraget i våre to nordligste fylker med infeksjon av fiskeparasitten Gyrodactylus salaris. Parasitten ble første gang påvist i 1979, og to rotenonbehandlinger i den lakseførende delen (i 1988 og 1995) har vært mislykkede. Di-rektoratet for naturforvaltning vurderer bygging av langtidssperre som et av flere aktuelle utryddingstiltak i Skibotnelva. Imidlertid ... -
Harmonizing circumpolar monitoring of Arctic fox: benefits, opportunities, challenges and recommendations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-16)The biodiversity working group of the Arctic Council has developed pan-Arctic biodiversity monitoring plans to improve our ability to detect, understand and report on long-term change in Arctic biodiversity. The Arctic fox (Vulpes lagopus) was identified as a target of future monitoring because of its circumpolar distribution, ecological importance and reliance on Arctic ecosystems. We provide ... -
Impacts of Early Life Stress on the Methylome and Transcriptome of Atlantic Salmon
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-10)Exposure to environmental stressors during early-life stages can change the rate and timing of various developmental processes. Epigenetic marks affecting transcriptional regulation can be altered by such environmental stimuli. To assess how stress might affect the methylome and transcriptome in salmon, fish were treated using cold-shock and air-exposure from the eye-stage until start-feeding. ...