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norskArtikler, rapporter og annet (arktisk og marin biologi): Recent submissions
Now showing items 1501-1520 of 1637
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A range-wide synthesis and timeline for phylogeographic events in the red fox (Vulpes vulpes)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Many boreo-temperate mammals have a Pleistocene fossil record throughout Eurasia and North America, but only few have a contemporary distribution that spans this large area. Examples of Holarctic-distributed carnivores are the brown bear, grey wolf, and red fox, all three ecological generalists with large dispersal capacity and a high adaptive flexibility. While the two former have been examined ... -
Ecological speciation in postglacial European whitefish: rapid adaptive radiations into the littoral, pelagic, and profundal lake habitats
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Understanding how a monophyletic lineage of a species diverges into several adaptive forms has received increased attention in recent years, but the underlying mechanisms in this process are still under debate. Postglacial fishes are excellent model organisms for exploring this process, especially the initial stages of ecological speciation, as postglacial lakes represent replicated discrete ... -
What Do the IUCN Categories Really Protect? A Case Study of the Alpine Regions in Spain.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Protected area (PA) coverage is used as an indicator of biodiversity protection worldwide. The effectiveness of using PAs as indicators has been questioned due to the diversity of categories encompassed by such designations, especially in PAs established for purposes other than biodiversity protection. Although international standards have been developed by the International Union for Conservation ... -
The World's Northernmost Harbour Seal Population - How Many Are There?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)This study presents the first abundance estimate for the world’s northernmost harbour seal (Phoca vitulina) population, which resides in Svalbard, Norway, based on three digital stereoscopic photographic surveys conducted in 2009 and 2010. The counts from these high resolution 3D images were combined with a novel method for estimating correction factors for animals that were in the water at the ... -
New production regulates export stoichiometry in the ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)The proportion in which carbon and growth-limiting nutrients are exported from the oceans’ productive surface layer to the deep sea is a crucial parameter in models of the biological carbon pump. Based on .400 vertical flux observations of particulate organic carbon (POC) and nitrogen (PON) from the European Arctic Ocean we show the common assumption of constant C:N stoichiometry not to be met. ... -
Arctic Small Rodents Have Diverse Diets and Flexible Food Selection
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)The ecology of small rodent food selection is poorly understood, as mammalian herbivore food selection theory has mainly been developed by studying ungulates. Especially, the effect of food availability on food selection in natural habitats where a range of food items are available is unknown. We studied diets and selectivity of grey-sided voles (Myodes rufocanus) and tundra voles (Microtus oeconomus), ... -
Contrasting Population and Life History Responses of a Young Morph-Pair of European Whitefish to the Invasion of a Specialised Coregonid Competitor, Vendace
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Invasions of non-native species represent a global problem of great scientific interest. Here we study in detail the response in population and life history characteristics of closely related native species, with divergent habitat preferences, that are impacted by an invading species over a sufficient time period to allow a new stable state to become established. A time series of 20 years starting ... -
Bacterial diversity of aMasi, a South African fermented milk product, determined by clone library and denaturing gradient gel electrophoresis analysis
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)In the present study, we investigated the bacterial diversity of aMasi, a traditional South African fermented milk product, by 16S rRNA clone library and Denaturing Gradient Gel Electrophoresis (DGGE) analysis. Two hundred and eighty two clones from clone library were isolated and identified from aMasi, prepared from the milk of four cows from one herd in the EkuPindiseni Community, North West of ... -
Homing behaviour of Atlantic salmon (Salmo salar) during final phase of marine migration and river entry
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Little is known about Atlantic salmon behaviour during the last phase of the marine homing migration and subsequent river entry. In this study, 56 adult Atlantic salmon in the Alta Fjord in northern Norway were equipped with acoustic transmitters. Salmon generally followed the coastline, but their horizontal distribution was also affected by wind-induced spreading of river water across the fjord. ... -
Biovolume spectrum theories applied: spatial patterns of trophic levels within a mesozooplankton community at the polar front
(Journal article; Tidsskriftartikkel; Peer reviewed, 2010)Three-dimensional data on the mesoscale distribution of hydrography and mesozooplankton were collected at the Polar Front, northwestern Barents Sea, in spring 2008 (29 April 15 May) using a combination of multinet and towed instrument platform equipped with Laser Optical Plankton Counter, fluorometer and CTD. Trophic levels (TLS) within the zooplankton community (whole community and size-separated) ... -
Fjellrev i Finnmark” - Rapport for perioden 2008-2012.
(Research report; Forskningsrapport, 2013)Som et av to prosjekter i en stor nasjonal satsning for å redde den utrydningstruede fjellreven, ble «Fjellrev i Finnmark» startet opp våren 2004. Prosjektet har fra starten av hatt to hovedmålsettinger. 1)Å gjøre grunnleggende forskning på økosystembetingelser som begrenser fjellrevenbestandens nåværende utbredelse og bestandsvekst i Øst-Finnmark spesielt, og i sub- & lav-Arktis generelt, med ... -
How spatial variation in areal extent and configuration of labile vegetation states affect the riparian bird community in Arctic Tundra
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)The Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by large herbivores and growing human activity. Thickets of tall shrubs represent a conspicuous vegetation state in northern and temperate ecosystems, where it serves important ecological functions, including habitat for wildlife. Thickets are however labile, as tall shrubs respond ... -
Arctic Ecosystem Services : interviews from Norway, Russia, Alaska and Canada
(Conference object; Konferansebidrag, 2013) -
Snefjordvassdraget. Driftsplan
(Research report; Forskningsrapport, 2013) -
Invasion genetics of vendace (Coregonus albula (L.)) in the Inari-Pasvik watercourse: revealing the origin and expansion pattern of a rapid colonization event
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Species invasions can have wide-ranging biological and socio-economic effects and are generally unwanted by legislation. Identification of the source population as well as the ecology and genetics of both the invader population and the receiving community is of crucial importance. The rapid invasion of a small coregonid fish vendace (Coregonus albula) in a major northern European subarctic watercourse ... -
A shortcut method for sexing juvenile European sea bass, Dicentrarchus labrax L.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2005)The objective of this study was to develop a rapid and effective method of sexing juvenile sea bass with minimum labour and material.To this end, the gonad squash mount technique was applied along with macroscopic techniques for sexing a large number of experimental fish at the age of 215-275 days post fertilization (p.f.). At this age, 90% of the 3894 fish could be unambiguously sexed by ... -
Genetic investigation of swimbladder inflation anomalies in the European sea bass, Dicentrarchus labrax L.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2007)Although the aetiology of swimbladder inflation anomalies in important aquaculture species such as European sea bass D. labrax is not fully determined, culture conditions are commonly suggested as main contributory factors. Little information is available on whether swimbladder inflation has a genetic basis for its expression too. In this work, 24 full-sibling sea bass families from a 4 dams x 6 ... -
Haematological and physiological characteristics of diploid and triploid sea bass, Dicentrarchus labrax L.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2005)The purpose of this study was to determine whether diploid and triploid sea bass differed in terms of main haematological and physiological characteristics. Diploid and triploid fish were produced by sub-optimal pressure treatments and held in communal environments under standard rearing conditions. Total red blood cell count (RBCC), haemoglobin concentration (Hb), hematocrit (Hct), mean cell volume ... -
Body shape variation in meiotic gynogenetic and triploid sea bass, Dicentrarchus labrax
(Journal article; Tidsskriftartikkel; Peer reviewed, 2010)A method of geometric morphometrics was used to characterize body shape variation in meiotic gynogenetic and triploid sea bass in comparison with diploid controls. A total of 13 coordinate landmark data were recorded on the profile of 34-month-old control (n = 81), gynogenetic (n = 117) and triploid (n = 131) siblings generated from two females (A and B). Three main axes of morphometric variation ... -
Induction of tetraploid gynogenesis in the European sea bass, Dicentrarchus labrax L.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2003)A preliminary study on tetraploid gynogenetic induction in the European sea bass was performed by pressure-blocking the second polar body release and the first cleavage in eggs fertilized with ultraviolet-irradiated sperm. Fertilization of eggs with genetically inactivated sperm produced only haploid development that terminated around hatching. Pressure treatments (8.500 psi for 2 min) applied at 6 ...
