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norskMastergradsoppgaver i biologi: Recent submissions
Now showing items 21-40 of 389
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Growth responses of seedlings along encroachment gradients of the allelopathic plant Empetrum nigrum
(Master thesis; Mastergradsoppgave, 2024-05-14)Empetrum nigrum is a native evergreen shrub distributed in alpine and circumpolar areas that is currently encroaching into new habitats. This is an allelopathic plant that releases secondary metabolites, which has a negative impact on seed germination and seedling growth. The species has been recorded to expand in altitude and latitude parallel to a warmer climate and is encroaching into new habitats. ... -
Spatial segregation by sympatrically breeding Antarctic and Snow Petrels.
(Master thesis; Mastergradsoppgave, 2024-05-14)Sympatrically breeding species may face intense competition for resources, which can lead to various forms of segregation to mitigate competitive pressures. Segregation of space or habitats is one possible strategy, particularly when species share similar diets and foraging behaviors. This study examines the differences in space and habitat use between Antarctic and Snow Petrels (Thalassoica ... -
Motivations and Effects of Volunteer Divers Restoring Norwegian Kelp Forests
(Master thesis; Mastergradsoppgave, 2024-05-14)Kelp forests are in decline worldwide due to increasing anthropogenic pressures. Along the coastline of Northern Norway, spanning 15,000 kilometers, sea urchins have transformed the seabed from biodiverse kelp forests into barren grounds dominated by sea urchins. To address this issue, the initiative The Guardians of the Kelp engages volunteer divers in Northern Norway in monthly clearing events to ... -
Arctic Shrub Expansion: Implications for Stream Benthic Invertebrate Community Structure & Function
(Master thesis; Mastergradsoppgave, 2024-05-15)The Arctic is rapidly warming and this increase in temperature has been found to drive range expansion of tall shrubs in the Arctic tundra ecosystems. Although the consequences of shrub expansion have been studied in the terrestrial tundra, effects on tundra stream ecosystems remain understudied. Riparian tall shrubs, such as willows, can provide stream ecosystems with leaf litter and shade, enhancing ... -
Maturation patterns and genetic diversity of the spinytail skate Bathyraja spinicauda
(Master thesis; Mastergradsoppgave, 2024-05-14)With the expansion of fisheries into deeper waters and climate change, it is increasingly important to determine the status of the species affected by these changes. One of these species is the spinytail skate Bathyraja spinicauda, an understudied skate species with vulnerable life history traits such as slow maturation and a low number of offspring. To address the lack of basic knowledge about the ... -
Lost and Found: Reassessing Ringed Seal Abundance in a Key Fjord System in Svalbard After a 20-Year Hiatus
(Master thesis; Mastergradsoppgave, 2024-05-15)Ringed seals (Pusa hispida) in Svalbard, Norway, are thought to be declining due to the impacts of climate change in the region, particularly due to a significant reduction in the extent of landfast sea ice that they rely on for breeding. The only available survey of ringed seals in Svalbard took place in 2002, so is now over twenty years old. Here, we address this data gap by conducting UAV aerial ... -
Temporal variation in marine mammal species assemblage at South Orkney Islands revealed through passive acoustic data from 2016 and 2017
(Master thesis; Mastergradsoppgave, 2022-06-02)Passive Acoustic Monitoring (PAM) is a non-invasive method providing high- resolution information about marine mammal acoustic presence. Multi-species PAM studies can increase our understanding of temporal changes in species diversity and assemblage and is especially useful in remote areas such as the Southern Ocean. This study was based on 16 months of acoustic data spanning two austral autumns and ... -
From Trash to Treasure: The use of Lumpfish (Cyclopterus lumpus) as feed for Red King Crab (Paralithodes camtschaticus)
(Master thesis; Mastergradsoppgave, 2023-05-15)This thesis explores the potential of using farmed lumpfish (Cyclopterus lumpus), discarded from Atlantic salmon (Salmo salar L.) aquaculture industry, as a sustainable feed for juvenile red king crabs (Paralithodes camtschaticus). The red king crab has successfully established a self-sustaining population in the Barents Sea. With the red king crab being a large generalist predator, its impact on ... -
Ingestion of Tyre Crumb Rubber and Uptake of Associated Contaminants in Marine Invertebrates (Pandalus borealis) and Fish (Cyclopterus lumpus) – An Experimental Exposure Study
(Master thesis; Mastergradsoppgave, 2022-05-15)Crumb rubber (CR) produced from end of life vehicle tires is widely used on artificial sports fields and to create urban artificial surfaces. It is also used as a surrogate for tyre wear particles in experimental studies simulating the behaviour and effects of car tyre particles in the environment. It is known to contain a wide range of organic chemicals and metals, some of which are only just being ... -
Aggregative response in white-tailed eagles- an initial study of the terrestrial implications of invasive Pacific pink salmons (Oncorhynchus gorbuscha) in northern Norway.
(Master thesis; Mastergradsoppgave, 2023-05-15)Abstract The spawning population of invasive Pacific pink salmon (Oncorhynchus gorbuscha) has only continued to increase in the river systems on the Varanger peninsula in Norway, causing concerns across institutional boundaries and management communities. So far, the Norwegian research efforts on Pacific pink salmon have been centred on consequential effects in marine- and freshwater ecosystems, ... -
Exposure of marine invertebrates to car tire rubber: Uptake of rubber particles and related organic chemicals
(Master thesis; Mastergradsoppgave, 2023-05-15)Car tire rubber particles (CTRPs) are a major source of microplastic pollution to the environment, originating from abrasion during driving or the use of crumb rubber granulates made of discarded tires. However, large knowledge gaps remain regarding the distribution and presence of CTRPs in marine environments and interaction with marine organisms. The aims of this thesis were to investigate the ... -
Isolation and Characterization of Bacteriophages from the Arctic
(Master thesis; Mastergradsoppgave, 2023-05-14)Bacteriophages are viruses that specifically infect bacteria. These obligate intracellular parasites are Earth's most copious, ubiquitous, and genetically diverse (unexplored) biological entities. Organisms in the Arctic environment constantly experience extreme conditions, therefore life in the Arctic evolved different specialized strategies and molecules to survive which offers huge opportunities ... -
Diel activity rhythms in wild songbirds in the Subarctic
(Master thesis; Mastergradsoppgave, 2024-02-15)The highly rhythmic environment caused by the rotation of the earth has driven the evolution of an intrinsic timekeeping mechanism in most organisms known as circadian clocks. As climate change drives the expansion of southern species into northern latitudes, their circadian clocks are challenged by the novel light conditions they encounter. In contrast to the clear day and night in southern latitudes, ... -
To keep or not to keep track of time in eternal sunshine? Diel activity patterns of Svalbard arthropods during polar day
(Master thesis; Mastergradsoppgave, 2024-02-16)Organisms on Earth are exposed to cyclic changes in environmental variables due to Earth’s rotation around it’s axis. As a response, many organisms adapt their behaviour in a rhythmic manner, which is often cued by 24h light-dark cycles. However, in the Arctic, traditional 24h light- dark cycle cues do not exist for long periods at the time. Arthropods play an important role in the high latitude ... -
Establishment of killer whale cell cultures and their responses to pollutant exposure
(Master thesis; Mastergradsoppgave, 2022-03-15)The cosmopolitan apex predator killer whale (Orcinus orca) is one of the species worldwide with the highest levels of persistent organic pollutants (POPs) in their tissues. The knowledge of how POPs may affect the species is limited, likely due to the ethical, legal, and practical challenges of researching toxicology on free-ranging marine mammals. The use of in vitro models has proved to be a ... -
Role of the lactate receptor HCAR1 as part of neural adaptations to hypoxia in hooded seals (Cystophora cristata)
(Master thesis; Mastergradsoppgave, 2023-11-15)To maintain normal neuronal function, the mammalian brain requires a constant supply of energy. The deep-diving hooded seal (<i>Cystophora cristata</i>) brain exhibits remarkable tolerance to extreme hypoxia, presumably involving a reduction in brain activity to lower energy demand. Thus, some neurons, circuits or even regions in the seal’s brain presumably display a neural protective shutdown ... -
Human responses to year-round lighting using Google Trends to investigate seasonality in activity patterns and libido
(Master thesis; Mastergradsoppgave, 2023-11-16)Seasonal rhythms in humans are fascinating but studying them is inherently challenging due to the need for data that covers multiple years. Due to the experimental obstacles, it remains debated whether humans exhibit seasonal fluctuations in aspects such as activity levels and libido. To approach these topics through indirect digital measures, this thesis used multi-year data from Google Trends ... -
Reindeer diseases associated with supplementary feeding in Norway and Sweden - A questionnaire-based survey
(Master thesis; Mastergradsoppgave, 2021-11-15)Climatic and anthropogenic factors are increasingly affecting reindeer husbandry in Norway and Sweden. The potential health risks associated with a warming climate, and the necessity to avoid starvation by providing supplementary feed to semi-domesticated reindeer, need to be explored and identified. A questionnaire-based survey among reindeer herders was conducted, containing questions about the ... -
Thermal properties of arctic fox fur and the effect of fur lice infestation.
(Master thesis; Mastergradsoppgave, 2023-11-15)In 2019, a new species of sucking louse was observed in arctic foxes (Vulpes lagopus) on Svalbard and Northern Canada. Abnormal patterns of fur loss, inconsistent with normal moult, were observed across the neck, shoulders and back, raising concerns as to how the animals would cope with damaged fur during the cold Arctic winter. This study investigates the impact of these lice on Svalbard arctic ... -
Impact of autopolyploidy on leaf structure and photosynthesis in Saxifraga oppositifolia L.
(Master thesis; Mastergradsoppgave, 2023-12-01)Polyploidization can be a rapid path to speciation and is considered an important evolutionary mechanism. Some predict that all plants have undergone a polyploidization event during their evolutionary history, and the frequency of polyploid species increases with latitude. The Arctic-Alpine Saxifraga oppositifolia, an autopolyploid, has two polyploids that have successfully established themselves ...
