Artikler, rapporter og annet (arktisk og marin biologi): Nye registreringer
Viser treff 1381-1400 av 1643
-
Time-series benthic community composition and biomass and associated environmental characteristics in the Chukchi Sea during the RUSALCA 2004–2012 program
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09)Benthic macrofaunal and epifaunal composition and biomass and associated environmental drivers were evaluated for time-series stations occupied during three cruises of the RUSALCA (Russian-American Long-term Census of the Arctic) program undertaken in August 2004, September 2009, and September 2012. We focus on the benthic communities collected at repeat stations in the southern Chukchi Sea and ... -
Seasonal, oceanographic and atmospheric drivers of diving behaviour in a temperate seal species living in the high arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-21)The harbour seal (Phoca vitulina) population in Svalbard marks the northernmost limit of the species’ range. This small population experiences environmental extremes in sea and air temperatures, sea ice cover and also in light regime for this normally temperate species. This study deployed Conductivity Temperature Depth Satellite Relay Data Loggers (CTDSRDLs) on 30 adult and juvenile harbour ... -
Predation on early life stages is decisive for year-class strength in the Barents Sea capelin (Mallotus villosus) stock
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-11)Year-class strength of Barents Sea capelin has been monitored closely since the early 1970s and during this ∼45 years period three short periods of almost total recruitment failure leading to three stock collapses have been observed. These events triggered much attention since there was a large commercial fishery for capelin, but also because of observed ecosystem effects attributed to the first of ... -
In the dark: a review of ecosystem processes during the Arctic polar night
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-28)Several recent lines of evidence indicate that the polar night is key to understanding Arctic marine ecosystems. First, the polar night is not a period void of biological activity even though primary production is close to zero, but is rather characterized by a number of processes and interactions yet to be fully understood, including unanticipated high levels of feeding and reproduction in a ... -
Food Web Topology in High Mountain Lakes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-16)Although diversity and limnology of alpine lake systems are well studied, their food web structure and properties have rarely been addressed. Here, the topological food webs of three high mountain lakes in Central Spain were examined. We first addressed the pelagic networks of the lakes, and then we explored how food web topology changed when benthic biota was included to establish complete trophic ... -
Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-03)The light regime is an ecologically important factor in pelagic habitats, influencing a range of biological processes. However, the availability and importance of light to these processes in high Arctic zooplankton communities during periods of 'complete' darkness (polar night) are poorly studied. Here we characterized the ambient light regime throughout the diel cycle during the high Arctic ... -
Metabolic and molecular analysis of white mutant Vaccinium berries show down-regulation of MYBPA1-type R2R3 MYB regulatory factor
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-14)Main conclusion MYBPA1-type R2R3 MYB transcription factor shows down-regulation in white mutant berries of Vaccinium uliginosum deficient in anthocyanins but not proanthocyanidins suggesting a role in the regulation of anthocyanin biosynthesis. <p>Berries of the genus Vaccinium are among the best natural sources of flavonoids. In this study, the expression of structural and regulatory flavonoid ... -
Brucella pinnipedialis in hooded seal (Cystophora cristata) primary epithelial cells
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-25)Background: Marine Brucella spp. have been isolated from numerous pinniped and cetacean species, but pathological findings in association with infection with Brucella pinnipedialis in pinnipeds have been sparse. The capacity of brucellae to survive and replicate within host macrophages underlies their important ability to produce chronic infections, but previous work has shown that B. pinnipedialis ... -
A critical review of the Mediterranean sea turtle rescue network: a web looking for a weaver
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-16)A key issue in conservation biology is recognizing and bridging the gap between scientific results and specific action. We examine sea turtles—charismatic yet endangered flagship species—in the Mediterranean, a sea with historically high levels of exploitation and 22 coastal nations. We take sea turtle rescue facilities as a visible measure for implemented conservation action. Our study yielded ... -
Where do the treeless tundra areas of northern highlands fit in the global biome system: toward an ecologically natural subdivision of the tundra biome
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-15)According to some treatises, arctic and alpine sub-biomes are ecologically similar, whereas others find them highly dissimilar. Most peculiarly, large areas of northern tundra highlands fall outside of the two recent subdivisions of the tundra biome. We seek an ecologically natural resolution to this long-standing and far-reaching problem. We studied broad-scale patterns in climate and ... -
Modification of sunlight radiation through colored photo-selective nets affects anthocyanin profile in Vaccinium spp. berries
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-19)<p>Objectives In recent years, the interest on the effects of the specific wavelengths of the light spectrum on growth and metabolism of plants has been increasing markedly. The present study covers the effect of modified sunlight conditions on the accumulation of anthocyanin pigments in two Vaccinium species: the European wild bilberry (V. myrtillus L.) and the cultivated highbush blueberry ... -
Own,but not foreign seminal fluid inhibits sperm activation in a vertebrate with external fertilization
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-03)Seminal fluids are known to have a variety of effects on rival sperm, but in externally fertilizing species it is still unclear what effects seminal fluid can induce under sperm competition. We recorded sperm activity from natural ejaculates (including own seminal fluid) of an external fertilizer, the Arctic charr (Salvelinus alpinus), after activation either in water (the natural medium for ... -
Detection of Transgenes in Local Maize Varieties of Small-Scale Farmers in Eastern Cape, South Africa
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-12-31)Small-scale subsistence farmers in South Africa have been introduced to genetically modified (GM) crops for more than a decade. Little is known about i) the extent of transgene introgression into locally recycled seed, ii) what short and longterm ecological and socioeconomic impacts such mixing of seeds might have, iii) how the farmers perceive GM crops, and iv) to what degree approval conditions ... -
The intensity of horizontal and vertical search in a diving forager the harbour seal
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-05-27)<p>Background: Free ranging foraging animals can vary their searching intensity in response to the profitability of the environment by modifying their movements. Marine diving animals forage in a three dimensional space and searching intensity can be varied in both the horizontal and vertical planes. Therefore understanding the relationship between the allocation of searching effort in these two ... -
Phylogenetic and genomic analysis of Methanomassiliicoccales in wetlands and animal intestinal tracts reveals clade-specific habitat preferences
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-27)Methanogenic Thermoplasmata of the novel order Methanomassiliicoccales were recently discovered in human and animal gastro-intestinal tracts (GITs). However, their distribution in other methanogenic environments has not been addressed systematically. Here, we surveyed Methanomassiliicoccales presence in wetland soils, a globally important source of methane emissions to the atmosphere, and in the ... -
Highly overlapping winter diet in two sympatric lemming species revealed by DNA metabarcoding
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-30)Sympatric species are expected to minimize competition by partitioning resources, especially when these are limited. Herbivores inhabiting the High Arctic in winter are a prime example of a situation where food availability is anticipated to be low, and thus reduced diet overlap is expected. We present here the first assessment of diet overlap of high arctic lemmings during winter based on DNA ... -
Restructuring of a zooplankton community by perturbation from a wind-forced coastal jet
(Journal article; Tidsskriftartikkel; Peer reviewed, 2010-09)The impact of transient wind events on an established zooplankton community was observed during a, field survey in a, coastal region off northern Norway in May 2002. A transient wind event induced a coastal jet/filament intrusion of warm, saline water into our survey area where a semi-permanent eddy was present. There was an abrupt change in zooplankton community structure within 4-7 days of the ... -
Tree thinking cannot taken for granted: challenges for teaching phylogenetics
(Journal article; Tidsskriftartikkel; Peer reviewed, 2008-02-05)Tree thinking is an integral part of modern evolutionary biology, and a necessary precondition for phylogenetics and comparative analyses. Tree thinking has during the 20th century largely replaced group thinking, developmental thinking and anthropocentricism in biology. Unfortunately, however, this does not imply that tree thinking can be taken for granted. The findings reported here indicate ... -
The role of a dominant predator in shaping biodiversity over space and time in a marine ecosystem
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-24)Exploitation of living marine resources has resulted in major changes to populations of targeted species and functional groups of large-bodied species in the ocean. However, the effects of overfishing and collapse of large top predators on the broad-scale biodiversity of oceanic ecosystems remain largely unexplored. Populations of the Atlantic cod (Gadus morhua) were overfished and several collapsed ... -
Takvatnprosjektet - Forskning og kultivering av en overbefolka røyeberstand
(Research report; Forskningsrapport, 2015)Overbefolka fiskebestander er et stort problem i mange av våre innsjøer. Det typiske kjennetegnet er en stor tetthet av gammel, småvokst og mager fisk, gjerne med en høy infeksjon av parasitter. Hardt uttynningsfiske har vært foreslått som et mulig botemiddel, men selv om det har vært gjort mange forsøk på å komme problemet til livs, er det få som har lyktes. Denne rapporten ...


English
norsk


















