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 231 for “"aquatic ecosystems"”.
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Drivers and effects of plastic contamination in aquatic ecosystems
… marine litter is plastic, which is found in all aquatic ecosystems, even in remote areas far from human activities. Plastic already dispersed in the marine environment undergoes through environmental degradation and is further fragmented into smaller particles which called MicroPlastics (MPs), …
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Status and remediation of mercury in fish and aquatic ecosystems
… from laboratory experiments, I analyzed aquatic samples collected from the watershed treatment and reference streams. Preliminary analysis of surface waters by Fourier Transform Ion Cyclotron Resonance Mass Spectroscopy (FTICR-MS) reveals an increase in the proportion of thiol functional …
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Values-based communication strategies for promoting conservation behavior in aquatic ecosystems
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-05-01
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Groundwater Dependence of Aquatic Ecosystems associated with the Table Mountain Group Aquifer
… interactions in the TMG, particularly regarding aquatic ecosystems. It has also highlighted the necessity to do proper impact assessments before proceeding with bulk abstraction from this important aquifer. The results also demonstrated the importance of differentiating between real groundwater …
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Nuclear Characteristics of Cells and Organisms Exposed to Agrochemicals Contaminating Aquatic Ecosystems
The final objective was to adapt a recently developed cytogenetic technique for use in anurans. The primed in situ labeling (PRINS) technique was applied to localize a specific developmentally important DNA sequence in anuran chromosomes. This technique has the potential to be an important tool in …
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Modeling species geographic distributions in aquatic ecosystems using a density-based clustering algorithm
… and symbiotic organisms in terrestrial and aquatic ecosystems. More recently, distributional ecology has been used to map disease transmission risk. The implementation of distributional ecology for disease transmission has, however, been erroneous in many cases. The inaccurate representation …
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Bayesian Methods to Characterize Uncertainty in Predictive Modeling of the Effect of Urbanization on Aquatic Ecosystems
… disrupting the structure and function of stream ecosystems. Urban development introduces contaminants (human waste, pesticides, industrial chemicals). Impervious surfaces and artificial drainage systems speed the delivery of contaminants to streams, while bypassing soil filtration and local …
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Alternative approaches for monitoring aquatic ecosystems: a study on the effects of municipal sewage effluent on biota in the South Saskatchewan River
… in the evaluation of effluent impacts on river ecosystems. Artificial stream studies were conducted to address questions on chronic effluent toxicity, and possible nutrient-toxicant interactions on growth and energy storage of the common stream scraper, Baetis tricaudatis. Larvae exposed to …
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An Analysis of the Effects of Temperature and Other Environmental Factors on Microorganismal Productivity within Aquatic Ecosystems using Long-Term Data from Various Lter and Ilter Sites
<p>Global climate change is a phenomenon resulting in more extreme weather patterns and species diversity loss. In this study, I explore the impacts of climate change on regional patterns of microbial productivity. Variation in microbial productivity was explained using temperature, salinity, and …
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Investigations of freshwater surface microlayers: comparisons of methods for sampling various microlayer thicknesses with observations on select chemical and microbiological features of microlayers of three aquatic ecosystems relative to the bulk of subsurface water
… microlayers and the subsurface water of three aquatic environments with different trophic levels. The parameters studied were: (1) particulate matter, (2) major inorganic ions, (3) select metals, (4) fungal populations, (5) bacterial populations, (6) most probable numbers of coliform bacteria, …
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The impacts of century-old, arsenic-rich, mine tailings on multitrophic level biological assemblages in lakes from the Cobalt, Ontario, Canada region
… to examine the impacts that arsenic has had on aquatic ecosystems in the region, diatom, cladoceran, chironomid, and zooplankton assemblages from lakes along a gradient of surface water arsenic contamination (0.4 - 1,113 µg/L) were sampled. Our results show that present-day arsenic concentration …
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Analyzing longitudinal patterns of river metabolism in five distinct rivers
… how rivers should behave, the reality is that aquatic ecosystems are being changed and degraded due to dams which regulate flow and changes to land use and land cover that can negatively impact aquatic ecosystems. Ecosystem metabolism is an increasingly common way to monitor and assess river …
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Winter dynamics in mountain lakes and impacts of an introduced species to the endangered Devils Hole pupfish
Having intrinsic knowledge of our aquatic ecosystems lets us predict how they will respond to change and allows us to make better management decisions. Changes in climate and introduced species are two major threats to aquatic ecosystems. This research explores inherent characteristics of two …
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UTTERBACKIA IMBECILLIS (BIVALVIA: UNIONIDAE) AS A BIOLOGICAL INDICATOR OF COPPER POLLUTION
… is an ideal biological indicator of aquatic ecosystems because of its widespread geographic distribution, abundance, and sedentary, filter-feeding lifestyle. The present study evaluated the physiological responses of <italic>U. imbecillis</italic> to copper. This heavy metal is an …
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Logging impacts the ecology of molecules in headwater streams
… large amounts of C from forest soils into aquatic ecosystems. My dissertation seeks to understand the fate of this forest C as dissolved organic matter (DOM) into various aquatic endpoints by tracing its molecular composition along the ephemeral water film that begins in upland soils and …
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Investigating sources of microplastics and effects of plastic pollution on biofilm function in the Huron River
… 5 mm in size, and they have become ubiquitous in aquatic ecosystems. MPs enter aquatic ecosystems through non-point sources such as urbanization, runoff, or atmospheric fallout or through point-sources such as wastewater treatment plants (WWTPs). To determine MP sources in the Huron River, we …
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Effects of abiotic and biotic factors on population dynamics of brook trout (<i>Salvelinus fontinalis</i>) within Shenandoah National Park, Virginia
Aquatic ecosystems are facing numerous threats that are products of anthropogenic activity, including habitat destruction and climate change. Monitoring aquatic ecosystems is important so that we can better understand and remedy the consequences of these threats. Native fish species found within …
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A geochemical investigation into the occurrence and fate of nitrogen and phosphorus in the lower Oliphants River, Western Cape
Knowledge of nutrient dynamics within aquatic ecosystems are of fundamental importance for water quality management, especially in cultivated areas where irrigation farming pose a salinization and eutrophication risk to water bodies. A range of water quality problems is associated with …
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