Mastergradsoppgaver i biologi: Nye registreringer
Viser treff 141-160 av 425
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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 ... -
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 ... -
Pathogen exposure surveillance in Southern Ocean pinnipeds
(Master thesis; Mastergradsoppgave, 2019-05-15)An increased pressure of human activities that can introduce new infectious agents and therefore alter host-pathogen interactions, resulting in epizootics and biodiversity loss, challenges the Southern Ocean. Health status information and the potential effect of disease outbreaks in the Southern Ocean fauna is scare and evaluating the susceptibility to new infectious agents is decisive for its ... -
Changes in environment cause dietary shifts in the Svalbard Arctic fox: A stable isotope study
(Master thesis; Mastergradsoppgave, 2022-02-15)In this thesis, shift in diet of Arctic foxes on Svalbard over a long time frame was analyzed. The Svalbard Arctic fox is a generalist who links the terrestrial and marine ecosystems. The objectives were 1) investigate whether there are spatial and temporal trends in Arctic fox diet on Svalbard, 2) determine how important the changes in the environmental variables are for dietary shifts of the Arctic ... -
Uncovering the foraging strategies in two pelagic diving seabird species outside their breeding season using coupled feather stable isotopes and light-based geolocators
(Master thesis; Mastergradsoppgave, 2022-02-16)The critical endangered Common and Brünnich guillemot are exhibiting contrasting population trends in the Barents Sea region, where the Common guillemots are increasing, while Brünnich guillemots are declining. The non-breeding season is regarded as the main mortality period among seabirds, especially in winter, as climate conditions may be harsh and prey availability rather limited. The contrasting ... -
Plant-Soil Feedback: Alpine Grassland Plants in Home and Away soil
(Master thesis; Mastergradsoppgave, 2021-12-16)For the grassland, plant soil feedback (PSF) has been the focus of much recent research to understand plant species dynamics. Experimental methods are very important in the plant soil feedback (PSF) analysis, and it has been observed that various PSF experimental approaches yield in different feedback values. More field type experiments are required to understand the role of PSFs in plant communities ... -
Interactions between white-tailed eagle Haliaeetus albicilla, seabirds and tourism; how the breeding success of the endangered black-legged kittiwake Rissa tridactyla is affected
(Master thesis; Mastergradsoppgave, 2021-12-17)In many seabird colonies along the coast of Norway, the increased population of white-tailed eagle Haliaeetus albicilla and the growing industry of birdwatching tourism are causing a dilemma for management decisions. Thus, this study aimed to examine the indirect effect of white-tailed eagles and tourists on the breeding success of the endangered seabird species, black legged kittiwake Rissa tridactyla ... -
Shifts in bacterial biodiversity along an environmental gradient in high-Arctic tundra
(Master thesis; Mastergradsoppgave, 2019-11-18)Arctic soil microbiomes may have to face drastic climate changes in the coming century. Currently, the arctic tundra act as a carbon sink due to slow decomposition rates of soil organic carbon, which partly owes to low temperatures and poor water drainage. However, with elevated temperatures, large, latent carbon pools stored in arctic permafrost are exposed to mineralization by the active layer ... -
Developmental effects of embryonic exposure to a water-soluble fraction of crude oil on early life stages of capelin (Mallotus villosus)
(Master thesis; Mastergradsoppgave, 2020-05-15)The rise in offshore oil and gas operations, maritime shipping and tourism in northern latitudes enhance the risk of petroleum pollution and anthropogenic impacts of oil-related compounds on sub-Arctic and Arctic organisms. In particular, there is a need to investigate the potential adverse effects of petroleum to the early life stages of capelin (<i>Mallotus villosus</i>), an important forage and ... -
Contrasting body burdens of organohalogenated contaminants in two Arctic glaucous gull Larus hyperboreus populations in relation to their dietary ecology
(Master thesis; Mastergradsoppgave, 2021-06-12)This study compared body burdens of organohalogenated contaminants (OHCs) between glaucous gull populations from Bjørnøya and Kongsfjorden, Svalbard and if OHC levels was influenced by their dietary ecology and biological variables (body condition index and sex). To do so, blood from 112 adult glaucous gulls were sampled during the breeding seasons of 2015 until 2019 in Bjørnøya and Kongsfjorden. ... -
Seabird guild composition and distribution relative to biophysical cues throughout the Antarctic Peninsula and Scotia Sea
(Master thesis; Mastergradsoppgave, 2021-08-16)Seabird distributions reflect physical and biological features of the marine environment and their variability on different spatial and temporal scales. Different species assemblages are associated with specific oceanic habitats and concentrations of birds typically occur in areas of high biological productivity. Here I explore seabird distributions and habitat use relative to biophysical cues of ... -
Feeding ecology of harbor seals (Phoca vitulina) in the outer Oslofjord quantified by DNA metabarcoding of scat soft-matrix and morphological analysis of hard prey remains
(Master thesis; Mastergradsoppgave, 2021-08-15)The feeding ecology of harbor seals in the outer Oslofjord was investigated during late summer and autumn of 2019 using DNA metabarcoding and morphological hard-parts identification. To evaluate potential competition between seals and fisheries, the annual consumption of fish by harbor seals was estimated and compared to the fisheries landings in the outer Oslofjord. Fish species from 16 and 18 ... -
Novel methanotrophic community assemblages in a terrestrial methane seep in Svalbard
(Master thesis; Mastergradsoppgave, 2020-08-14)Recent studies have concluded that groundwater driven methane escape through open system pingos is an important greenhouse gas source in the vulnerable high Arctic. In wetlands and marine sediments, large quantities of methane are consumed by methane oxidizing bacteria (MOB) and ANaerobic MEthanotrophic (ANME) archaea, preventing its release to the atmosphere. The methanotrophic capacity of open ... -
Metabolomic and metagenomic study of Lake Baikal diseased sponges
(Master thesis; Mastergradsoppgave, 2020-08-15)Widespread mortality and disease are recognized as growing problems in benthic marine coral and sponge communities across the globe and despite being extensively studied, in most cases the etiology of disease remains unknown. Since 2011, sponge communities in freshwater Lake Baikal, Siberia, Russia have been affected by an unknown agent of disease, which has been causing an array of physical disease ... -
The effect of coloured LED light treatments on the biosynthesis of flavonoids in woodland strawberry (Fragaria vesca L.) originating from different latitudes
(Master thesis; Mastergradsoppgave, 2019-07-31)Flavonoids are a group of phenolic compounds produced in plants. They have many biological functions in plants and also beneficial bioactivities in human’s health. Light quality is one of the major environmental factors regulating the accumulation of flavonoids in plants. Understanding plants accumulation of secondary metabolites in response to light qualities is important in order to optimize plants ... -
Growth and Maturation of a Subarctic Fish Community Under a Changing Climate
(Master thesis; Mastergradsoppgave, 2021-06-15)Increasing water temperatures from novel climate change may alter freshwater fish life history strategies, especially those of fish populations in northern latitudes. Fish species life history strategies are reflected by their environments and increasing water temperature may alter the most favorable strategies considering growth and reproductive patterns. In this study, life history traits of a ...