Fakultet for biovitenskap, fiskeri og økonomi: Recent submissions
Now showing items 1181-1200 of 5180
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Unexpected feeding behaviour inferred by DNA metabarcoding of Barents Sea skates
(Master thesis; Mastergradsoppgave, 2022-05-18)Feeding studies give an indication about the role and position of species within ecosystems and provide crucial knowledge for management. Traditional methods are based on morphological identification of prey. DNA metabarcoding is a promising tool that allow for identification of specific prey items, also when highly digested. A total of 63 stomachs from three skate species caught in the Barents Sea ... -
Neighbourhood watch among common eiders (Somateria mollissima) – Does group nesting reduce nest predation?
(Master thesis; Mastergradsoppgave, 2022-05-16)Colony nesting is thought to be an example of the selfish herd strategy, where aggregating behaviour may be an evolutionary adaptation to reduce the risk of predation. The common eider (Somateria mollissima) is a ground nesting sea bird susceptible to high nest predation rates through the nesting period. They often nest in groups, yet some also choose to nest solitarily. I examined whether group ... -
Phylogeny of Somniosus sleeper sharks: insights from newly sequenced mitochondrial genomes
(Master thesis; Mastergradsoppgave, 2022-05-16)Mitochondrial DNA (mtDNA) has been extensively used to explore phylogenetics since the its use became available. This science is considered useful in discerning relationships and evolutionary histories that are not possible with morphological studies alone. The sleeper sharks (genus: Somniosus) are a group of poorly understood, long-lived, iconic species whose taxonomic status within the genus have ... -
The fate of conventional and potentially degradable gillnets in a seawater-sediment system
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-20)Abandoned gillnets in the marine environment represent a global environmental risk due to the ghost fishing caused by the nets. Degradation of conventional nylon gillnets was compared to that of nets made of poly- butylene succinate co-adipate-co-terephthalate (PBSAT) that are designed to degrade more readily in the envi- ronment. Gillnet filaments were incubated in microcosms of natural seawater ... -
Can baleen whales be safely live-captured for studies of their physiology?
(Master thesis; Mastergradsoppgave, 2022-05-16)Studying baleen whales is challenging and complex, where observation of their habitat, sensory modalities, behavior and physiology, are infrequent and brief. The biochemical and biophysical contribution of mysticetes serve a vital role in maintaining a healthy marine ecosystem, but they are facing anthropogenic threats. Before giving any indications of how these threats affect the baleen whales, it ... -
Temporal trends in mercury concentrations in eggs of Tawny owl (Strix aluco) from Central Norway between 1986-2019: influence of dietary ecological parameters and climate variables
(Master thesis; Mastergradsoppgave, 2022-05-18)Mercury (Hg) is considered as a global threat which is emitted in the environment through natural sources or anthropogenic activities. Emissions of mercury decreased during the last decades because of the implementation of mitigation measures. However, with the ongoing climate change, ecosystems are directly (e.g., rising temperature) or indirectly impacted (i.e., altered ecosystem by e.g., invasive ... -
Circadian disruption by light and its effect on the immune function of the Atlantic salmon (Salmo salar)
(Master thesis; Mastergradsoppgave, 2022-05-16)The Atlantic salmon (Salmo salar) is an anadromous salmonid that begins its life cycle in freshwater streams then, develops, in a process known as smoltification, into a marine-adapted fish prior to its migration to the sea. Smoltification is a photoperiod regulated process which involves extensive change in the salmons’ physiology. In recent years smoltification procedures in aquaculture has been ... -
Environmental drivers of multi-species synchrony in seabird breeding success
(Master thesis; Mastergradsoppgave, 2022-05-16)Populations living close together in space are likely to experience more similar environmental fluctuations, and thus may display similar temporal changes in population parameters, in other words synchrony. Interspecific synchrony has implications for ecosystem stability, and highly synchronous populations and communities tend to have a higher risk of extinction. In this thesis, I used long-term ... -
“Public perceptions of pink salmon in Norway and willingness to pay for the current eradication management program”
(Master thesis; Mastergradsoppgave, 2022-05-13)Abstract Since 2017, Norway has experienced a large influx of Pacific pink salmon (Oncorhynchus gorbusha), and this species occurrence has created challenges for society, businesses, the environment, and policymakers. However, there is currently no consensus on whether pink salmon is a new resource or a pest in Norway. While some people perceive pink salmon as a food resource and a good recreational ... -
Infectious salmon anemia virus (ISAV) replication is transiently inhibited by Atlantic salmon type I interferon in cell culture
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-08-20)Infectious salmon anemia virus (ISAV) is a piscine orthomyxovirus, which causes multisystemic disease in farmed Atlantic salmon that may result in large losses. Previous work has suggested that ISAV is able to resist the antiviral state induced in cells by type I interferon (IFN). These studies were, however, mainly based on cytopathic effect (CPE) reduction assays. Here we have investigated the ... -
Indirect food web interactions mediated by rodent cycles: Relative roles of lemmings and voles
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-12-23)Production cycles in birds are proposed as prime cases of indirect interactions in food webs. They are thought to be driven by predators switching from rodents to bird nests in the crash phase of rodent population cycles. Although rodent cycles are geographically widespread and found in different rodent taxa, bird production cycles appear to be most profound in the high Arctic where lemmings ... -
Kan kornkrisen redde flere brød?
(Chronicle; Kronikk, 2022-03-27)Krig, nedbør og økte priser på olje, kunstgjødsel og papiremballasje fører til kornkrise som gjør at Ola og Kari Nordmann må betale mer for sitt daglige brød i tiden fremover. -
Response and resilience of the microbial methane filter to ecosystem changes in Arctic peatlands
(Doctoral thesis; Doktorgradsavhandling, 2022-06-30)<p>Climate change is a major concern in the Arctic region, as large amounts of organic carbon (C) are stored in permafrost soils and sediments. Increasing average temperatures have the potential to release that C and making it available to biologic activity. Carbon-rich, anoxic soils such as peatlands are inhabited by methanogenic archaea that can metabolize by-products of microbial C decomposition ... -
Towards a unifying pan-arctic perspective: A conceptual modelling toolkit
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-17)The Arctic Ocean is overwhelmingly forced by its lateral boundaries, and interacts with, the global system. For the development of nested conceptual models of the Arctic Ocean ecosystem we here choose the full pan-Arctic as our focal scale. Understanding the pan-Arctic scale, however, requires that we look at the underlying scales of its major components, by considering regionality, connectivity and ... -
Transcriptome analysis reveals a high aerobic capacity in the whale brain
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-30)The brain of diving mammals is repeatedly exposed to low oxygen conditions (hypoxia) that would have caused severe damage to most terrestrial mammals. Some whales may dive for > 2 h with their brain remaining active. Many of the physiological adaptations of whales to diving have been investigated, but little is known about the molecular mechanisms that enable their brain to survive sometimes ... -
Pelagic ecosystem dynamics between late autumn and the post spring bloom in a sub-Arctic fjord
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-13)Marine ecosystems, and particularly fjords, are experiencing an increasing level of human activity on a yearround basis, including the poorly studied winter period. To improve the knowledge base for environmentally sustainable management in all seasons, this study provides hydrographic and biological baseline data for the sub-Arctic fjord Kaldfjorden, Northern Norway (69.7 N, 18.7 E), between ... -
Thyroid hormone and seasonal rhythmicity
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-02-26)Living organisms show seasonality in a wide array of functions such as reproduction, fattening, hibernation, and migration. At temperate latitudes, changes in photoperiod maintain the alignment of annual rhythms with predictable changes in the environment.The appropriate physiological response to changing photoperiod in mammals requires retinal detection of light and pineal secretion of melatonin, ... -
Circuit-level analysis identifies target genes of sex steroids in ewe seasonal breeding
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-15)Thyroid hormone (TH) and estradiol (E2) direct seasonal switches in ovine reproductive physiology. In sheep, as in other mammals and birds, control of thyrotropin (TSH) production by the pars tuberalis (PT) links photoperiod responsiveness to seasonal breeding. PT-derived TSH governs opposite seasonal patterns of the TH deiodinases Dio2/Dio3 expression in tanycytes of the neighboring medio-basal ... -
What promotes motivation and learning in project management students?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-10)This article discusses what promotes motivation and learning in students of project management. It is based on a qualitative study with six students from different project groups at a higher education institution in Norway. The study shows that ownership of self-chosen projects and regular feedback from the supervisor lead to hard work, intrinsic motivation and learning in all phases of the project. ... -
En studie av sammenhengen mellom budsjett og aktivitet i spesialisthelsetjenesten
(Master thesis; Mastergradsoppgave, 2017-06-02)Bakgrunnen for denne avhandlingen bygger på utfordringene i helsesektoren, som tar en stadig økende andel av bruttonasjonalproduktet. Innen økonomistyring er det svært mange ulike faktorer som kan analyseres for å bidra til å belyse denne problematikken. Vår avhandling fokuserer på forholdet mellom det som blir ansett som det viktigste styringsverktøyet i offentlig sektor, budsjettet, opp mot ...