Blar i tittel Mastergradsoppgaver i biologi
Viser treff 318-337 av 360
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Structure and dynamics of the Barents Sea Polar Front near the Great Bank and associated plankton distribution in August 2007
(Master thesis; Mastergradsoppgave, 2010-03-30)The Polar Front separating Atlantic Water (AW) and Arctic Water (ArW) is one of the most dominant mesoscale features in the Barents Sea and a highly productive region. Here, the results of sub-mesoscale variability in physical and biological fields associated with the Barents Sea Polar Front (BSPF) at the Great Bank are reported from a high-resolution survey in August 2007. A nearly synoptic data ... -
The structure of nasal conchae in Svalbard rock ptarmigan (Lagopus muta hyperborea) with comparisons to three other Galliform birds
(Master thesis; Mastergradsoppgave, 2022-05-27)Birds are endothermic homeotherms that regulate internal metabolic heat production to keep a stable body core temperature. Lung ventilation, which is required to obtain oxygen for metabolism, is potentially a large source for heat and water loss. In a polar habitat with low year-round temperatures and scarcity of food in the winter, conservation of heat and water is crucial for survival of the ... -
Studie av bunnforhold og forekomst og tetthet av utvalgte fisk og pigghuder - Evaluering av undervannsfilming som metode
(Master thesis; Mastergradsoppgave, 2015-02-15)Undervannsvideo er en metode for beregning av forekomst av marine dyr og kartlegging av bunnsubstrat og algedekke. Metoden har vært sammenlignet med andre metoder som dykking og bunntrål (Spencer et al. 2005). I dette studiet ble det gjort en evaluering av undervannsfilm som metode for undersøkelse av forekomst og tetthet av utvalgte fisk og pigghuder, og kartlegging av bunnforhold på grunt vann. ... -
The substrate specificities and physiological function of the Toxoplasma gondii apicoplast phosphate translocator
(Master thesis; Mastergradsoppgave, 2009-05-15)The apicomplexan parasites including the causative agents of malaria (Plasmodium spp.) and toxoplasmosis (Toxoplasma gondii) are running the risk of developing resistance to existing drugs. Members of the phylum Apicomplexa harbour a relict plastid, the apicoplast, which show homology to the chloroplasts of plants and algae. The apicoplast appears to be indispensable to the parasites, and due to its ... -
The summer diet of hooded (Cystophora cristata) and harp (Pagophilus groenlandicus) seals in the West Ice
(Master thesis; Mastergradsoppgave, 2014-08-15)The harp (Pagophilus groenlandicus) and hooded (Cystophora cristata) seals both inhabit the drift ice areas in the West Ice during certain times of the year, and the present study is part of the Institute of Marine Research’s management studies of these seals. Contents of gastrointestinal tracts from hooded and harp seals from June-July 2008 and 2010 and harp seal faeces samples were identified ... -
The Suprachiasmatic Nucleus of The Reindeer (Rangifer tarandus tarandus) and it’s Circadian Outputs
(Master thesis; Mastergradsoppgave, 2023-05-14)The Earth is in constant movement around the Sun – this has created environments with changing light throughout the day and year. Through evolution animals have adapted to this change in light and circadian and circannual rhythms have evolved to enhance fitness and survival. Animals living in the Arctic region have a different relationship to light changes as for several months a year the Sun ... -
A survey of the riparian Coleoptera fauna along the river Altaelva after 15 years with regulation
(Master thesis; Mastergradsoppgave, 2005-05)The riparian Coleoptera fauna of the river Altaelva, Finmark County, Northern Norway, has been surveyed in summer 2002 and 2003. The river Altaelva has been regulated since 1987, and my objective was to investigate the effect of the regulation on the riparian fauna. In total, 37 localities were examined, and four methods were used: hand collecting, washing without area limitation, quadrate sampling ... -
Sympagic-pelagic coupling and vertical export in two seasonally ice-covered fjords. Study of the physical and biological drivers in the sub-Arctic Ramfjorden (Norwegian mainland) and the Arctic Van Mijenfjorden (Svalbard archipelago) during early spring bloom.
(Master thesis; Mastergradsoppgave, 2020-06-01)Fjords are important high latitudes ecosystems, many have beside planctonic ones, a unique ecosystem associated with seasonal ice cover. During the development of the spring season conditions, two major type of primary producers contribute highly to the biomass production: sea-ice algae inhabiting brine channels and bottom surface of the ice (sympagic algae) and phytoplankton, living in the water ... -
TBT-induced imposex related to age and length in Buccinum undatum at two localities in Balsfjorden
(Master thesis; Mastergradsoppgave, 2009-06-08)Background: The organotin compound tributyltin (TBT), used as an antifouling agent in ship hull paint, is known to cause imposex in several species of marine gastropods. Imposex is the imposition of male sexual characteristics on females, and can lead to female sterility. The common whelk, Buccinum undatum, is a common species in Norway and has received attention for its export potential. Because ... -
Temporal and spatial variation in a high Arctic bedrock macrobenthic community in Hinlopen, Svalbard. A baseline study related to possible climatic change
(Master thesis; Mastergradsoppgave, 2013-08-15)Zonation patterns within a high Arctic, hard bottom community within the Hinlopen Strait, Svalbard were investigated using image analysis of underwater photoquadrates. This long term study consists of depth transects taken over a six year period were on a sublittoral vertical wall permanent monitoring station. Analysis indicated that the depth in which the greatest number of species occurred increased ... -
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 ... -
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 ... -
Temporal trends of persistent organic pollutants in Svalbard polar bears (Ursus maritimus) in relation to climate-associated changes in feeding habits
(Master thesis; Mastergradsoppgave, 2018-05-15)Persistent organic pollutants (POPs) reach the Arctic ecosystems from lower latitudes mostly via air and ocean currents. They biomagnify through Arctic food webs and reach considerably high concentrations in top predators such as polar bears (Ursus maritimus). Although many of these compounds have been banned or restricted for decades, concentrations of polychlorinated byphenyls (PCBs), organochlorine ... -
Temporal trends of POPs in arctic foxes from Svalbard in light of a changing climate
(Master thesis; Mastergradsoppgave, 2013-11-15)The present study investigates concentrations and temporal trends of persistent organic pollutants (POPs) in arctic foxes (Vulpes lagopus) from Svalbard, Norway, adjusted for sex, age, body condition, diet, reindeer mortality and sea ice coverage. Number of reindeer carcasses in Adventdalen and sea ice coverage of Isfjorden in the spring preceding the trapping season were used as indexes for climate ... -
Terrestrial locomotion in the Svalbard ptarmigan (Lagopus muta hyperborea). How does treadmill running compare with running overground?
(Master thesis; Mastergradsoppgave, 2013-05-16)The Svalbard rock ptarmigan (Lagopus muta hyperborea) is a resident bird on the Svalbard achipelago, living in an environment where it experiences extreme climatic and photoperiodic conditions. The bird’s most striking adaption to this environment is, prior to the onset of winter, its deposition of fat, comprising up to 30% of body mass. Moving around with this excess mass may prove difficult as it ... -
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 ... -
Threat or opportunity? Landscape genetics in a coal mining area
(Master thesis; Mastergradsoppgave, 2013-05-15)Aknowledgment The area of Sveagruva have experienced several periods of coal mining. This study aim to evaluating changes in vegetation composition, species distributions and genetic structure using a combination of field and molecular analyses, to identify whether or not coal mining have effected plant life in Svea. Investigations on species and gene level were done on two Luzula species, L. ... -
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 ... -
Timing is everything: Within-plant flowering phenology impacts fruit production in the Arctic-Alpine cushion plant Silene acaulis (L.) Jacq.
(Master thesis; Mastergradsoppgave, 2022-05-16)Timing is everything for Arctic flowering plants. Early flowers might be destroyed by frost, while late flowers have less time and resources to mature fruit. With climate change, Arctic flowering phenology is shifting. Yet for many species, phenology studies only encompass the onset of flowering and lack baseline data on within-plant flowering times. I used the gynodioecious cushion plant Silene ... -
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 ...