Institutt for arktisk og marin biologi: Nye registreringer
Viser treff 1201-1220 av 2040
-
Development of diving capacity and behaviour in harp seal (Pagophilus groenlandicus) weanlings from the Greenland Sea Stock
(Master thesis; Mastergradsoppgave, 2019-05-15)This study represents one of the first studies that has explored the spatial and temporal differences in diving behaviour of weaned harp seal pups (Pagophilus groenlandicus) from the Greenland Sea stock. The study is also the first to map the weaned harp seal pups from the Greenland Sea population. In April 2017, newly weaned harp seal pups (n=26) from the Greenland Sea stock were tagged with satellite ... -
In Silico Screening for inhibitors against Apicoplast Phosphate Translocator from Toxoplama gondii
(Master thesis; Mastergradsoppgave, 2019-05-16)Apicomplexa parasites, including Toxoplasma gondii and Plasmodium falciparum, contain a secondary endosymbiosis-derived plastid like organ, called apicoplast, which is an anabolic hub. This apicoplast is fueled by phosphate translocator (APT), which transport phosphorylated sugar molecules in exchange of inorganic phosphate. Disruption of APT in T. gondii was found to be lethal for parasite. Beside ... -
Differences in chick feeding frequency between parental sex and morph combination in the Common guillemot Uria aalge
(Master thesis; Mastergradsoppgave, 2019-05-15)The Common guillemot (Uria aalge) is a monomorphic seabird who exhibits two colour morphs: a bridled and an unbridled. The aim of this study was to investigate which effect parental sex and morph had on the daily chick feeding frequency and during the chick-rearing period. To assess this, two fixed time-lapse cameras were used to document the chick feeding frequency for 27 Common guillemot families ... -
Ringed seal (Pusa hispida) diet on the west coast of Spitsbergen, Svalbard, Norway
(Master thesis; Mastergradsoppgave, 2019-05-15)The diet of 99 coastal-feeding ringed seals (Pusa hispida), collected in western Spitsbergen, Svalbard (Norway), was analysed via identification of hard-parts in the contents of their gastrointestinal tracts (GITs). The study animals where shot either in spring (n = 30; April-July) or autumn (n = 69; August-October) during four consecutive years (2014-2017). Thirty different prey types were identified ... -
Brain capillarization in diving mammals: a selection of staining and quantification methods
(Master thesis; Mastergradsoppgave, 2019-05-15)Diving species can cope with acute and repeated hypoxia through adaptations that are absent in non-diving animals. One of the greatest challenges to deal with during diving is the lowering of the arterial oxygen pressure (PaO2), which causes a decrease in the driving force for the oxygen diffusion from the capillaries to the cells. My hypothesis is that the marine mammalian brain shows improved brain ... -
Riverine and glacier influence on infaunal benthic communities in Isfjorden, Svalbard.
(Master thesis; Mastergradsoppgave, 2019-05-15)Fjords are the interface between land and ocean, and processes happening on land have implication for the coastal areas. In addition, differences in fjord characteristics, such as morphology, sedimentation and water circulation, can drive differences in fjord ecology, including benthic community composition (Syvitsky et al. 1986). Soft-bottom macro-fauna was collected in August 2018 using a Van-Veen ... -
Seasonality in mercury bioaccumulation in particulate organic matter and zooplankton in a river-influenced Arctic fjord (Adventfjord, Svalbard).
(Master thesis; Mastergradsoppgave, 2019-05-15)Methylmercury (MeHg) is of concern because it has the capacity to readily bioaccumulate and biomagnify along trophic levels until humans, exhibiting toxic effects such as neurotoxicity. Increased permafrost melt (that stores large amounts of carbon and mercury (Hg)) and river inputs, are expected to increase the exposure to Hg through uptake and transfer of contaminants through the food web. The ... -
Activity of XTHs during host plant infection by the parasitic plant Cuscuta.
(Master thesis; Mastergradsoppgave, 2019-05-15)Parasitic plants including Cuscuta develop specialized structures called haustoria during infection. These specialized organs give the parasite the capacity of host attachment, invasion, vasculature connection and material transfer between the host and the parasite. Successful invasion allows organic substances, nutrients and water to flow into the parasite through the host phloem and xylem cells. ... -
Time dependent temperature effects on methane production in Arctic peat soils
(Master thesis; Mastergradsoppgave, 2019-05-16)Peatlands constitute the largest natural reservoir of carbon on the planet making them key components in the global carbon balance. Peatlands are mostly found in the northern hemisphere under cold conditions. As the world is warming and arctic peatlands are becoming heavily influenced by increasing temperatures, an increased interest in the peat soil microbial systems have arisen. Methane, a potent ... -
Toxicology of the Svalbard Atlantic Puffin
(Master thesis; Mastergradsoppgave, 2019-05-19)The Arctic is a sink for pollutants that accumulate there via long-range transport and biomagnification of persistent organic pollutant (POPs). The main objectives of this study were to identify the pollutants in the Svalbard Atlantic puffin and to compare their levels with southern puffin colonies and Svalbard seabird species to assess risk to the puffin. Svalbard Samples were analysed for contaminants ... -
Impacts of water level regulation on trophic niche and growth of Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) in Norwegian hydropower reservoirs
(Master thesis; Mastergradsoppgave, 2019-05-15)Hydropower is among the largest renewable energy sources globally. However, it can have drastic environmental and socio-economic impacts on dammed lakes (i.e., reservoirs) and rivers where water levels are regulated due to hydropower operations. Water level regulation in hydropower reservoirs is known to be a large environmental problem, leading to changes in the abiotic conditions, which subsequently ... -
Seasonal abundance and activity of sympagic meiofauna in Van Mijenfjorden, Svalbard
(Master thesis; Mastergradsoppgave, 2019-05-15)The importance of landfast ice as a nursery and breeding ground for Arctic marine invertebrates was studied in Van Mijenfjorden (77°N, 15/16°W), southwestern Svalbard from March to May 2017. The collection of first-year ice cores with stations along a depth gradient allowed the investigation of both temporal and spatial differences in sympagic meiofauna community composition and abundance. Furthermore, ... -
Zooplankton communities on the Northeast coast of Greenland. How can we explain vertical and regional distribution?
(Master thesis; Mastergradsoppgave, 2019-05-16)Most studies on zooplankton investigate the famous, and omnipresent, Calanoid copepods Calanus spp., because they are abundant, and constitute the major trophic link in marine ecosystems. Indeed, Northeast Greenland is located on the crossroad of Arctic and Atlantic waters which, potentially, can lead to a high biodiversity originating from different domains of marine life. However, there are very ... -
Perception and Appreciation of Plant Biodiversity, An assessment of human perception and appreciation of plant biodiversity using photography of artificial plant communities
(Master thesis; Mastergradsoppgave, 2017-07-31)Anthropogenically caused global biodiversity declines and other human drivers point to the possibility of local plant diversity changes. The well-studied effects of local plant diversity on ecosystem processes implicate consequences to human well-being in the form of altered ecosystem services (including cultural services). Public awareness (knowledge and correct perception) about these changes ... -
Greenland Shark (Somniosus microcephalus) stomach contents and stable isotope values reveal an ontogenetic dietary shift
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-04)Current knowledge on the feeding ecology of the Greenland shark (<i>Somniosus microcephalus</i>), a potential top predator in arctic marine ecosystems, is based on small sample sizes as well as narrow size ranges of sharks. Therefore, potential size-related feeding patterns remain poorly documented. Using stomach content data (<i>N</i> = 88) and stable isotope values of white muscle tissue (<i>N</i> ... -
Dead or Alive; or Does It Really Matter? Level of Congruency Between Trophic Modes in Total and Active Fungal Communities in High Arctic Soil
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-08)Describing dynamics of belowground organisms, such as fungi, can be challenging. Results of studies based on environmental DNA (eDNA) may be biased as the template does not discriminate between metabolically active cells and dead biomass. We analyzed ribosomal DNA (rDNA) and ribosomal RNA (rRNA) coextracted from 48 soil samples collected from a manipulated snow depth experiment in two distinct ... -
Efficient sampling for ecosystem service supply assessment at a landscape scale
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-19)Decision makers and stakeholders need high-quality data to manage ecosystem services (ES) efficiently. Landscape-level data on ES that are of sufficient quality to identify spatial tradeoffs, co-occurrence and hotspots of ES are costly to collect, and it is therefore important to increase the efficiency of sampling of primary data. We demonstrate how ES could be assessed more efficiently through ... -
Rodent population cycle as a determinant of gastrointestinal nematode abundance in a low-arctic population of the red fox
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-22)We analyzed an 11-year time series (2005–2015) of parasite abundance for three intestinal nematode species in the red fox (<i>Vulpes vulpes</i>) as a function of the multi-annual rodent population cycle in low-arctic Norway, while correcting for other potential covariates that could influence prevalence and abundance. Rodents are paratenic and facultative intermediate hosts for the two Ascarididae ... -
Contrasting associations between breeding coloration and parasitism of male Arctic charr relate to parasite species and life cycle stage
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-23)Conspicuous carotenoid ornamentation is considered a signal of individual “quality” and one of the most intensely studied traits found to co-vary with parasitism. Since it has been suggested that only “high quality” individuals have enough resources to express excessive sexual ornaments and resist parasites, current theory struggles to explain cases where the brightest individuals carry the most ... -
Arctic charr brain transcriptome strongly affected by summer seasonal growth but only subtly by feed deprivation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-27)<i>Background</i>: The Arctic charr (<i>Salvelinus alpinus</i>) has a highly seasonal feeding cycle that comprises long periods of voluntary fasting and a short but intense feeding period during summer. Therefore, the charr represents an interesting species for studying appetite-regulating mechanisms in fish. <p> <p><i>Results</i>: In this study, we compared the brain transcriptomes of fed and ...