Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 40 for “"Krill"”.
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Modelling the krill-predator dynamics of the Antarctic ecosystem
The main objective of this thesis is to model the krill-predator dynamics of the Antarctic ecosystem so as to determine whether predator-prey interactions alone can broadly explain observed population trends of the species considered in the model without any appeal to systematic effects possibly …
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The spatial distribution of Antarctic krill (Euphausia superba Dana) aggregations
In nature, many biota exhibit recognisable spatial groupings, commonly termed "clumps" or "patches" (Hutchinson 1953; Diggle 1983; Wilson 1978). Attempts to devise measures of such aggregation are usually based on statistically determining the frequency distributions of selected organism parameters …
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An updated model of the krill-predator dynamics of the Antarctic ecosystem
… update the Mori-Butterworth (2006) model of the krill-predator dynamics of the Antarctic ecosystem. Their analysis aimed to determine whether predator-prey interactions alone could broadly explain the observed population trends of the species considered in their model. In this thesis, the …
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Modeling Studies of Antarctic Krill (<i>Euphausia superba</i>) Survival During Transport Across the Scotia Sea and Environs
<p>The Antarctic krill (<em>Euphausia superba</em>) populations at South Georgia, which is in the eastern Scotia Sea, are hypothesized to be sustained by import of individuals from upstream regions, such as the western Antarctic Peninsula. To test this hypothesis a modeling framework consisting of …
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Ecosystem impacts of variable recruitment in Antarctic krill investigated with long-term monitoring and archived ADCP backscatter data
… impacts of anthropogenic climate change on the krill-reliant marine ecosystem of the western Antarctic Peninsula. I use long-term ecological monitoring data to examine the impact of highly variable krill recruitment on a krill predator population, and I use archived backscatter data from an …
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Seasonal and Mesoscale Variability in the Distribution of Antarctic Krill, <i>Euphausia superba</i>, West of the Antarctic Peninsula
… in the distribution and abundance of Antarctic krill, Euphausia superba, within continental shelf waters west of the Antarctic Peninsula and to investigate possible relationships between variability in krill distributions and variability in selected environmental parameters. Acoustic …
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Linked Changes in Prey Availability and Population Structure: Using Antarctic Fur Seals to Sample Marine Systems
… to the abundance and availability of Antarctic krill, where the mean length of krill consumed is used a proxy of krill availability. Over six years, 1568 foraging trips were measured for 178 individual seals, foraging from Bird Island, South Georgia. The relationships between the duration of …
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Multi-species models of Antarctic krill predators : do competitive effects influence estimates of pre-exploitation whale abundance and recovery?
Includes abstract. Includes bibliographical references (leaves 92-111).
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Distribution, patchiness, and behavior of Antarctic zooplankton, assessed using multi-frequency acoustic techniques
… with particular emphasis on the Antarctic krill, Euphausia superba. This was accomplished by the application of acoustic, video, and environmental sensors during surveys of the region in and around Marguerite Bay, west of the Antarctic Peninsula, in the falls and winters of 2001 and 2002. …
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Spatiotemporal variability in Antarctic krill (Euphausia superba) around South Georgia from Antarctic fur seal (Arctocephalus gazella) diets at two long term monitoring sites
… importance, there is much about Antarctic krill (Euphausia superba Dana, 1852) that is still poorly understood. This is especially true for its recruitment into South Georgia’s waters, which is highly variable and difficult to predict. Krill fluctuations exert bottom-up pressures on the …
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Circulation of the Western Antarctic Peninsula: Implications for Biological Production
… by large persistent populations of Antarctic krill (<em> Enphausia superba</em>) and by regions of enhanced concentrations of marine mammals and other predators (hot spots). This study focused on understanding the role of ocean circulation in providing retention/connectivity of wAP Antarctic …
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Legal aspects of the conservation and exploitation of off-shore living marine resources in Antarctica
… finfish, there appears to be great potential in krill fisheries. Krill are small, shrimp-like crustaceans which swarm in major concentrations in Antarctic waters. Estimates of krill fisheries vary considerably from standing stocks of 125 million metric tons as much as 6 billion metric tons. It is …
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Distributions of <i>Euphausia Superba</i>, <i>Euphausia Crystallorophias</i>, and <i>Pleuragramma Antarcticum</i> with Correlations to Environmental Variables in the Western Ross Sea, Antarctica
<p>Antarctic krill (<em>Euphausia superb</em>a), crystal krill (<em>Euphausia crystallorophias</em>), and Antarctic silverfish (<em>Pleuragramma antarcticum</em>) are key mid-trophic level species in the Ross Sea food web that provide connectivity between primary production and the upper trophic …
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Distribution, patchiness, and behavior of Antarctic zooplankton, assessed using multi-frequency acoustic techniques
… with particular emphasis on the Antarctic krill, Euphausia superba. This was accomplished by the application of acoustic, video, and environmental sensors during surveys of the region in and around Marguerite Bay, west of the Antarctic Peninsula, in the falls and winters of 2001 and 2002. …
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The Role of n-3 Fatty Acids in Cardiometabolic Risk
… has led to investigation of alternative sources. Krill oil, obtained from the crustacean Euphausia superba, contains n-3 fatty acids as phospholipids and triglycerides, astaxanthin and related carotenoid pigments, and has been proposed as a more effective alternative than triglyceride oils. Some …
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Lipid Biomarkers of Bering and Chukchi Sea Euphausiids and Their Application to Diet History
… raschii</em> are the most abundant krill species and a keystone trophic member that serve as both an important grazer and link to upper level consumers. In this system krill experience large annual variation in food resources, especially during ice advance and retreat; multiple lipid …
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Microbial responses to environmental forcing and implications for trophic transfer through the lens of lipidomics
… of lipid, which is critical for filter feeding krill, the primary link between the base of the food web and higher trophic levels in this ecosystem. Finally, I examine the energy derived from lipids in the diets of two higher order predators along the WAP: Adelie and gentoo penguins. I aimed to …
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Variability of zooplankton and sea surface temperature in the Southern Ocean
… patterns in the distribution of Antarctic krill (Euphausia superba) resulting from social behavior. Turbulence of the flow is found to provide favorable conditions for the evolution social behavior in an idealized biological-physical model. Second, I analyze observations of sea surface …
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Herstellung von Chitosan und einige Anwendungen
… DD und gleichzeitig hoher mittlerer Mv, während Krill-Chitin (Euphausia superba) ein gutes Ausgangsmaterial zur Herstellung von Chitosan mit hohem DD und niedrigem Mv ist. Chitosan, das aus Insekten (Calliphora erythrocephala), unter milden Bedingungen (Temperatur: 100°C, NaOH-Konzentration: 40 …
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Comparative foraging ecology of macaroni and rockhopper penguins at the Prince Edward Islands
… The diet of both species was dominated by two krill species (Thysanoessa vicina and Euphausia vallentini). Diving behaviour varied between years, with both species diving deeper when the SAF was located farther away and geostrophic flow was reduced. During these conditions, macaroni penguins …
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