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 20 for “"Marine food webs"”.
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Linking Prey to Predator: Scale Dependence and Oceanographic Influence in Marine Food Webs
… a critical tool that can be used to investigate food web linkages at many spatial scales. At a broad scale, migratory top predators are often modeled relative to oceanographic structure as a proxy for the distribution of their prey. At a fine scale, combining novel technologies including …
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Bioaccumulation of persistent organic pollutants and trace metals in Scottish marine food webs and their relationship with trophic level and fatty acid signatures.
… of action in place for the protection of the marine environment to ensure our seas are clean and safe. One of the biggest threats to our oceans is man-made pollution and it is the responsibility of governments to conduct assessments to advise policy. Across the North-East Atlantic, Contracting …
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Uncovering Mechanisms of Phytoplankton Response to Climate Change
… half the primary production on earth, fueling marine food webs and driving the cycling of carbon and inorganic nutrients in the oceans. Climate change is predicted to alter the marine environment by elevating carbon dioxide, increasing temperature, and decreasing the availability of inorganic …
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Transformations of mercury in the marine water column
Methylation of mercury (Hg) in the marine water column has been hypothesized to serve as the primary source of the bioaccumulating chemical species monomethylmercury (MMHg) to marine food webs. Despite decades of research describing mercury methylation in anoxic sediments by anaerobic bacteria, …
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Transformations of mercury in the marine water column
Methylation of mercury (Hg) in the marine water column has been hypothesized to serve as the primary source of the bioaccumulating chemical species monomethylmercury (MMHg) to marine food webs. Despite decades of research describing mercury methylation in anoxic sediments by anaerobic bacteria, …
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Trojan horses in the marine realm: characterizing protistan parasite ecology in coastal waters
… drivers of energy and nutrient flow in the marine environment, with recent research suggesting significant roles in global carbon cycling throughout the water column. Top-down controls on planktonic protists include grazing and parasitism, processes that both contribute to nutrient transfer …
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Trojan Horses in the Marine Realm: Characterizing Protistan Parasite Ecology in Coastal Waters
… drivers of energy and nutrient flow in the marine environment, with recent research suggesting significant roles in global carbon cycling throughout the water column. Top-down controls on planktonic protists include grazing and parasitism, processes that both contribute to nutrient transfer …
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Birds of a Feather: Cultural and Ecological Relationships between the Unangax̂ and Seabirds in the Aleutian Islands, AK
This dissertation investigates how marine ecosystems and ancestral Unangax̂ communities in the Aleutian Islands of Alaska adapted to Holocene climate variability. Today, rapid warming in the Arctic/Subarctic is causing disruptions in marine ecosystems, threatening food webs and the economic and …
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Microplastic ingestion by two estuarine-associated mullet species, Chelon richardsonii and Chelon dumerili in the Breede Estuary, South Africa
… extremely hazardous, as they imitate a range of food items on which organisms feed. Rivers and estuaries are links between terrestrial and marine ecosystems; thus, these systems hold key evidence of the magnitude and nature of MP pollution. Research particularly in the southern hemisphere is …
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Microbial production and consumption of marine dissolved organic matter
Marine phytoplankton are the principal producers of oceanic dissolved organic matter (DOM), the organic substrate responsible for secondary production by heterotrophic microbes in the sea. Despite the importance of DOM in marine food webs, details regarding how marine microbes cycle DOM are …
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Molecular mechanisms of microbial interactions in model systems and natural environments
Marine microbes are dominant life forms in the ocean and comprise dynamic populations of viruses, bacteria, archaea and single-celled eukaryotes. Interactions between marine microbes impact global biogeochemical cycles and form the base of marine food webs. Interactions range from symbiotic to …
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Cloning and characterization of a novel ferritin from the marine diatom Pseudo-nitzschia multiseries
Diatoms play a fundamental role in marine food webs, and significantly contribute to global primary production and carbon sequestration into the deep ocean. In many offshore areas of the open ocean, iron (Fe) input is low, and its availability often limits phytoplankton biomass. Recently, gene …
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Seabird digestive physiology in relation to foraging ecology
… experimentally. Gut passage rates of different food types of tested in vitro digestibility may reflect dietary specialization, with favoured prey types excreted more rapidly than less frequently encountered prey. Mean retention times of solid digesta are significantly correlated with foraging …
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Microbial production and consumption of marine dissolved organic matter
Marine phytoplankton are the principal producers of oceanic dissolved organic matter (DOM), the organic substrate responsible for secondary production by heterotrophic microbes in the sea. Despite the importance of DOM in marine food webs, details regarding how marine microbes cycle DOM are …
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Examining the feeding ecology of two mesopelagic fishes (Lampanyctodes hectoris & Maurolicus walvisensis) off the west coast of South Africa using stable isotope and stomach content analyses
… mesopelagic fishes are an important component of marine food webs, the adaptive features used to facilitate niche partitioning among co-existing and presumably competing mesopelagic species is unclear. This study examined the trophic ecology of the two principal mesopelagic fishes off the west …
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Interazioni trofiche tra Condroitti in Mediterraneo
… ecological role, they tend to be high in the food web being very often predators at the top of marine food webs (Cortés, 1999; Ebert e Bizzarro, 2007). Sharks and rays appear to be particularly vulnerable to over-exploitation because of their K-selected life-history strategy (Cailliet et al., …
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The importance of interaction strength for food web dynamics and ecosystem functioning
… describe these complex interactions in detailed food webs, which encompass all the interactions in a community. This has led to recent calls for an integration of BEF research with the comprehensive study of food web properties and patterns, to help elucidate the mechanisms that allow complex …
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Assimilatory sulfur metabolism in marine microorganisms
… organic sulfur compounds was studied in aerobic marine bacteria, with emphasis on the relationship between sulfur metabolism and protein synthesis. The goal of the study was to develop and apply a method for the quantitative assay of total bacterial protein synthesis in aerobic ocean waters. The …
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The biogeography and trophic roles of coastal marine sponges (Porifera) from the west coast of the North Island, New Zealand: Influences of catchments.
Anthropogenic activities are degrading coastal marine ecosystems globally. While the ecological and biodiversity implications of some of these impacts are well understood, for others there is a need for a greater understanding of the effects of these activities on vulnerable sedentary species. For …
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Dynamics of baseline stable isotopes within a temperate coastal ecosystem: Relationships and projections using physical and biogeochemical factors
… energy flow and trophic positions in aquatic foodwebs; comparing food webs; and aiding in the tracking of wide-ranging consumers. However, each of these applications requires accurate measurements of isotopic signatures in organisms at or near the base of the food web (e.g. autotrophs and …