Mastergradsoppgaver i biologi: Recent submissions
Now showing items 121-140 of 391
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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 ... -
Evaluation and use of a monitoring method to estimate Atlantic salmon spawning run
(Master thesis; Mastergradsoppgave, 2021-06-16)ARIS sonar and Timespace video cameras were used to estimate spawning run and migration pattern of Atlantic salmon in Máskejohka, a tributary belonging to the River Tana. Máskejohka has not been monitored before and needs more detailed information about the stock size and its migration pattern, after several years with declining Atlantic salmon catch. Data for the first weeks of the migration period ... -
Distribution, reproductive ecology, and colouration of the Arctic skate Amblyraja hyperborea (Collett, 1879) in the North Atlantic Ocean
(Master thesis; Mastergradsoppgave, 2021-06-14)<i>Amblyraja hyperborea</i> is the cartilaginous fish with the widest distribution across the Arctic seas and shelves and yet, large parts of its biology remain unknown. In a changing climate where the ice cover in the polar regions is retreating and fisheries are expanding northward, studying poorly known species is more important than ever. To provide a more exhaustive understanding of this species, ... -
Monitoring anthropogenic activity in the Hardangervidda wild reindeer range. Possible applications of crowdsourced Strava-data in remote settings
(Master thesis; Mastergradsoppgave, 2021-05-31)Seen in light of the increasing interest of nature-based tourism and recreational outdoor activities in Norway the last decades (Haukeland, Grue & Veisten, 2010), spatiotemporal information on human activity in remote areas and knowledge about how this activity may affect wildlife and nature is a crucial part of a knowledge-based management (Gundersen et.al., 2011, p.14; Gundersen, Strand & Punsvik, ... -
Can spruce forest stands be adapted to climate-driven natural disturbances? The consequential effects of two key disturbance agents and their management in spruce dominated stands under climate change – A review
(Master thesis; Mastergradsoppgave, 2021-05-20)The purpose of the thesis is to support the initial stage of the Climate Smart Forestry Norway (CSFN) undertaken by a consortium between NMBU, NIBIO, LUKE (Finland), and Wageningen University & Research, which is a five-year project aimed to assess how Norway’s forests are best managed in order to adapt to climate change. As part of the CSFN project a framework for quantifying probability and effects ... -
Temporal changes of persistent organic pollutants in Arctic foxes (Vulpes lagopus) from Svalbard
(Master thesis; Mastergradsoppgave, 2021-05-18)Recent evidence shows that temporal changes of persistent organic pollutants (POPs) in Arctic ecosystems are not only due to emission patterns and regulations; environment-related changes in prey availability and long-range transport may also influence concentrations of these compounds in tissues of Arctic predators. Arctic foxes (Vulpes lagopus) in Svalbard, Norway, scavenge and hunt opportunistically ... -
Effect of simulated latitudinal variation in daylength conditions on oscillations of circadian gene expression in populations of woodland strawberry (Fragaria vesca L.) from Northern Norway and Italy
(Master thesis; Mastergradsoppgave, 2021-05-15)Almost all species on Earth possess circadian rhythms that align their physiological processes with suitable times of day and year based on predictable changes in the light cycle. While it is known that natural variations exist in photoperiodic responses regulated by the circadian clock, there are currently no studies assessing the effect of latitudinal variations in daylength on the properties of ... -
Ingestion and egestion of microplastic fibers in the green sea urchin Strongylocentrotus droebachiensis: An experimental exposure
(Master thesis; Mastergradsoppgave, 2021-05-18)Plastic is a major component of marine litter in the world’s oceans and therefore it is critical we develop a better understanding of the fate of plastic in the marine environment, and the potential impacts on biota. Microplastics are the most abundant size class (<5 mm) of plastic found in the marine environment and have the potential to interact with smaller marine organisms at lower trophic levels. ... -
Long-term fluctuations in an arctic fox (Vulpes lagopus) population: a matter of diet?
(Master thesis; Mastergradsoppgave, 2021-06-14)The long-term dynamics of predator populations may be driven by fluctuations in resource availability and reflect ecosystem changes in response to climate change. The Icelandic arctic fox population has known major fluctuations in size since the 1950s, starting with a decreasing period until late 1970s, followed by a six-fold increase until 2008 when the population dropped to half its size within ... -
Characterization of the circadian clock in Hooded Seals (Cystophora Cristata) and its interaction with mitochondrial metabolism A multi-tissue comparison and cell culture approach
(Master thesis; Mastergradsoppgave, 2021-06-02)Circadian rhythms regulate living organisms over a 24h period. From daily activity to cellular function. The polar regions are subject to different photoperiods across the year, which impact the environmental conditions on a seasonal and daily basis. Evidence of crosstalk between circadian core clock genes and hypoxia with genes involved the mitochondrial dynamics, as well as oxygen sensing, provide ... -
A new look at whale behavior: identifying multiple spatial movement patterns of Norwegian killer whales
(Master thesis; Mastergradsoppgave, 2021-05-25)Studying an animal’s movement patterns in both space and time can shed light on the strategies individuals use to optimize foraging and adapt to seasonal and environmental variation. Killer whales (Orcinus orca) are dynamic, apex predators inhabiting all the world’s oceans, predating and specializing on a wide variety of prey. Over the last decade, large numbers of Norwegian killer whales have been ... -
Can a piscicide treatment alter stream ecosystem functioning through trophic cascading effects on benthic invertebrates?
(Master thesis; Mastergradsoppgave, 2021-05-18)Processing of detritus is an important ecosystem function in freshwaters. In rivers and streams, the activity of shredding invertebrates play an important role in processing of coarse-particulate organic matter such as leaf litter. In stream food webs, fish may act as top predators and control activity of consumers such as shredders top down. This top-down effect may be of a directly consumptive nature, ... -
Rapid microbial responses to temperature changes in Arctic anoxic peat soil
(Master thesis; Mastergradsoppgave, 2021-05-18)Arctic peatlands act as important sources and sinks of carbon. Microbial decomposition takes place in these soils, producing the greenhouse gasses carbon dioxide and methane as end-products. A variety of aerobic and anaerobic microbial pathways are involved in the decomposition of organic material in peat soil. In anoxic soil layers, methane and carbon dioxide is often produced through syntropic ... -
Changes in Survival with Age in Three Populations of a Long-lived Seabird, the Atlantic Puffin Fratercula arctica
(Master thesis; Mastergradsoppgave, 2021-05-18)Actuarial senescence is the irreversible decline of survival with increasing age. This phenomenon varies widely between taxa and species along the slow-fast continuum. However, inter-populational senescence differences have been less investigated, especially in the avian order. Here, I compared senescence rate between three contrasting populations of the Atlantic puffin (Fratercula arctica), and ... -
Characterization of the biological clock in Svalbard ptarmigan (Lagopus muta hyperborea)
(Master thesis; Mastergradsoppgave, 2021-05-18)Svalbard ptarmigan (Lagopus muta hyperborea), permanent inhabitants of the High Arctic, lose daily behavioral rhythmicity during polar day and night, and rhythms in core body temperature (Tb) weaken after prolonged exposure to constant photic conditions. A weak circadian system has been suggested in Svalbard ptarmigan, however, the molecular clockwork in Svalbard ptarmigan has not been investigated ...