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 28 for “"Aquatic food webs"”.
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Influence of Resource Pulses Following Stochastic Disturbances on Aquatic Food Webs
… affect higher trophic levels. In the aquatic realm, resource pulses of anadromous Pacific salmon Oncorhynchus spp. have garnered most of the attention from ecologists due to their ability to deliver inland aquatic and terrestrial environments an important marine-derived nutrient pulse. …
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Are aquatic food webs vulnerable to copper and gold engineered nanoparticles?
… remains poorly understood within the context of aquatic food webs. To address this interaction, I examined the impacts of a citrate-coated gold nanoparticle (AuNPs) and a commercial pesticide containing Cu(OH)2 nanoparticles (CuNPs) on aquatic food webs under both ambient and enriched nutrient …
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Exploring Fish Diversity as a Determinant of Ecosystem Properties in Aquatic Food Webs
I examined the effect of common carp across a gradient of fish richness in mesocosms. The invader reduced native fish production and the effect was reduced with increasing fish richness. The invertebrate community was modified by a top-down effect from the richness treatment, whereas the invader …
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Crayfish: Scavenger or deadly predator? Examining a potential predator-prey relationship between crayfish and benthic fish in aquatic food webs
Benthic food webs are complex and often poorly understood. Crayfish in particular play a key role in the transfer of energy to higher trophic levels, and can constitute the highest proportion of benthic invertebrate biomass in an aquatic system. Commonly referred to as a keystone species, crayfish …
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The effects of select non-steroidal anti-inflammatory drugs on green and brown hydra
… are released at low concentrations into aquatic ecosystems through waste water treatment plants (WWTPs). Non-steroidal anti-inflammatory drugs (NSAIDs) are important contaminants in water cycles. In this study, several NSAIDs were assessed for their potential toxicity to Hydra. Chronic …
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Radiocarbon reservoir effects in the American bottom flood plain of the Mississippi River and adjacent uplands in southern Illinois
… with atmospheric 14CO2 activity. Within aquatic systems, old (14C-depleted) carbon may dilute the current carbon pool by soil erosion, decomposition of old botanical and fauna remains, and dissolution of ancient carbonate rocks. Aquatic food webs assimilate the older carbon, and consumers …
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Interpreting Predator – Prey Interactions in Cayuga Lake Fishes Using Fatty Acid Signature Analysis
… can be used to assess trophic interactions in aquatic food webs. Therefore, to better understand Cayuga Lake food web dynamics, fatty acid signatures (FAS) of lake trout (Salvelinus namaycush) were compared to two major prey species in the lake; alewife (Alosa pseudoharengus) and round goby …
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Zooplankton abundance, community composition and grazing in the James River Estuary (Virginia, USA)
… (Virginia, USA) exploit the available algal-food resources. Zooplankton abundance, community composition and grazing rates were assessed at three locations which included a site with high algal production (near the VCU Rice Center) and two sites where algal production was lower. Grazing rates …
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Influence of Agricultural Land Use on Allochthonous Input and Leaf Breakdown in Southern Appalachian Streams
… material makes up the energy base for forested aquatic food webs. Therefore, removal of riparian vegetation associated with agricultural land use affects stream ecosystem structure and function. The objectives of this study were to measure and compare allochthonous input and leaf breakdown rates …
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Freshwater Invertebrate Assimilation Nutrients from Detrital Biofilms Under Light and Phosphorus Manipulation
… are increasing algal biomass and activity within aquatic ecosystems, stimulating debate regarding interactions between “green” and “brown” food webs. Specifically, in forested streams, the removal of forest canopy or riparian zones increases light exposure and nutrient fluxes to streams affecting …
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Thyroid hormones and their receptor gene expression as biomarkers of endocrine disruption in harbour seals (Phoca vitulina)
… lipophilic, slow to degrade, bioaccumulate in aquatic food webs and threaten the health of both humans and wildlife. Predatory marine mammals, such as harbour seals (Phoca vitulina), are at particularly risk for the accumulation of high POP concentrations and resultant increased risk of toxic …
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Single-Cell Measurements of Element Concentration In Phytoplankton Using Synchrotron X-Ray Fluorescence
… of introduction for metal contaminants into aquatic food webs. Single-cell analysis of phytoplankton elemental composition enables determinations free of interferences from abiotic material and other (non-target) cells present in natural particle assemblages. Synchrotron x-ray fluorescence …
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Patterns of Evolutionary Conservation and Divergence in the Short-Term Hyposalinity Stress Response of a Euryhaline Diatom, Skeletonema marinoi
… Given the crucial ecological roles of diatoms in aquatic food webs, understanding the various strategies of marine diatoms to overcome freshening of their environments is central to predicting the impacts of climate change on coastal primary production. </p>
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Eukaryotic Parasites of Toxic and Bloom-forming Diatoms: Molecular insights in their diversity and physiology
… the importance of eukaryotic microbes in aquatic food webs, human / wildlife health, climate and biogeochemical cycles; their diversity is still widely underinvestigated. This statement is particularly truthful in the case of heterotrophic protists, more difficult to establish as clonal …
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The influence of spatiotemporal variation in food web models
Aquatic ecosystems are constantly adapting to fluxes in season, temperature, nutrient cycling, and prey availability. Consequently, aquatic food webs are dynamic, and relationships between species are perpetually changing as organisms and primary producer communities adapt to current environmental …
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Influences of a <i>Cladophora</i> Bloom on the Diets of <i>Amblema Plicata </i>and <i>Elliptio Dilatata</i> in the Upper Green River, Kentucky
… becoming an increasingly common method to study aquatic food webs. Carbon (C) and nitrogen (N) are two of the most frequently employed elements in food web studies. Differences in natural abundance of<sup> 13</sup>C/<sup>12</sup>C can indicate which food sources are the basal sources of carbon …
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Geochemical controls on production and transport of methylmercury in the St. Louis River Estuary
… concern due to its bioaccumulative properties in aquatic food webs and potential neurotoxicity of consumers of fish, including predatory fish, wildlife, and humans. Transformation of inorganic mercury to MeHg is primarily driven by naturally occurring sulfate and iron reducing bacteria (SRB and …
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Microbial Degradability of Terrigenous, Marsh-Exported, and Estuarine Colored Dissolved Organic Matter in Long Island Sound
… part of the carbon cycle and serves as a primary food source for aquatic food webs. Additionally, the colored portion of DOM (CDOM) impacts coastal optical properties, ocean color, and light attenuation. High levels of CDOM have been shown to inhibit the growth of phytoplankton and limit …
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Effects of lake trophic state and seasonal cycling on production and bioaccumulation of methylmercury in Te Arawa Lakes
… is the ability of MeHg to bioaccumulate in aquatic food webs, leading to increased toxicity in higher trophic organisms. Given that fish constitute a significant component of the local diet, comprehensive monitoring of Hg and MeHg concentrations is essential for developing effective …
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