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 41 for “"aquatic biota"”.
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Estimating Embeddedness From Bankfull Shear Velocity in Gravel Streambeds to Assess Sediment Impacts on Aquatic Biota
… in the U.S., degrading habitat quality for many aquatic species. Embeddedness (emb, %), a measure of fine sediment in gravel bed streams, is negatively correlated with bankfull shear velocity (u*, m/s). This relationship can be modeled by emb = au*b, with baseline coefficient values of a = 10 and …
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Impacts of Delayed Drawdown on Water Quality and Aquatic Biota in Seasonal Wetlands of the Grassland Ecological Area, Los Banos, California
The 178,000-acre Grassland Ecological Area in California’s San Joaquin Valley is managed to provide overwintering habitat to waterfowl on the Pacific Flyway. The major management activity is the fall flooding and spring drawdown of wetlands, timed to optimize the availability of forage vegetation …
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Effects of Extreme Flow Events on Community Composition and Habitat Complexity of Groundwater Dominated Systems
… and droughts are primary drivers in structuring aquatic habitats and communities. While floods and droughts can directly alter aquatic biota by displacement or by increased mortalities, extreme flow events can have an indirect and prolonged effect on biota by altering habitat complexity, which in …
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The effects of Hydroxypropyl-β-Cyclodextrin on the American Flagfish (Jordanella floridae) over one complete life-cycle
… and personal care products (PPCPs) on aquatic ecosystems is an important issue in aquatic toxicology. Many PPCPs have been shown to cause effects on aquatic biota within detected environmental ranges. One compound of particular interest is hydroxylpropyl-β-cyclodextrin (HPβCD), the …
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Relationships between water quality, species composition, biodiversity and ecosystem function in lakes and flooded pits exposed to uranium mining activities in Northern Saskatechewan
… mining activities have the potential to impact aquatic systems through mine drainage (runoff) and the release of treated effluent into nearby watersheds. Such anthropogenic exposure can lead to elevated concentrations of metals and major ions, which may impact aquatic biota. Previous studies …
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Laboratory and field studies of cadmium effects on Hyalella azteca in effluent dominated systems.
… used to assess the effects of contaminants on aquatic biota. Questions remain as to how accurately these controlled toxicity tests predict sitespecific bioavailability and effects of metals. Concurrent 42-day Hyalella azteca exposures were performed with cadmium and final treated municipal …
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An environmental study of the Lourens River estuary
… dominated during the wet season. Terrestrial and aquatic biota are generally depauperate. The poor ecological quality of the estuary may be attributed primarily to periodic pollution inputs from the AECI main drain discharge, but also to the complex arrangements of land ownership and …
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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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Spatial Patterns of Mercury in Atmospheric Deposition, Soils and Lake Biota in the Adirondack Park, New York
… of Hg in the terrestrial and especially aquatic biota. It is important to understand the mechanisms that contribute to the sensitivity of this region to Hg inputs. In my research, studies of the spatial patterns of Hg in atmospheric deposition, soils and lake biota were conducted as tools …
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Effects of Lithology, Structure and Stratigraphy on Surface Water Specific Electrical Conductance; South Fork of the Flathead River, Montana
… provide resource managers clues as to where aquatic biota might and do thrive.</p>
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Effects of Lithology, Structure and Stratigraphy on Surface Water Specific Electrical Conductance; South Fork of the Flathead River, Montana
… provide resource managers clues as to where aquatic biota might and do thrive.</p>
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Bioaccumulation of trace metals in biota (algae and chironomids) from Kenyan saline lakes (Bogoria and Nakuru): evaluation and verification of two compartment toxicokinetic models
This study aimed to assess the suitability of aquatic biota from some Kenyan Saline lakes as biomonitors of trace metals. The use of compartment models as predictive tools in assessment environmental quality was also evaluated. The test organisms (Algae Arthrospira fusiformis and chironomids …
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The influence of elevated arsenic concnetrations on stream biota and leaf breakdown in a headwater stream
… a naturally occurring element, which is toxic to aquatic biota especially in disturbed areas where it may be found at high concentrations. A headwater stream adjacent to an 85 year-old abandoned arsenic mine was investigated to determine the influence of arsenic on stream biota and processes using …
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The Exchange of Fine Muddy Sediment in Gravel-Bed Fluvial Systems
… system and those relying on it, both humans and aquatic biota. Previously, fine sediment was considered a washload and has been ignored in transport models. More recently, it has been treated as being transported once the surface gravel layer that stores it is able to be mobilized. We propose …
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A Survey of the Fishes and Habitat of the Cheyenne River in South Dakota
… three distinct habitat zones available to aquatic biota. Of several hydrological habitat features measured (i.e. discharge, velocity, surface width, and depth), only depth differed between years, although other qualitative habitat assessment techniques indicate flows may have been higher in …
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In situ monitoring and biogeochemical cycling of nutrients in estuarine waters
… of nutrients, how they are essential for aquatic biota, their general characteristics and the importance of their behaviour in estuaries. Commonly used analytical methods for nutrient determinations in natural waters are also evaluated. Chapter Two reports the use of chemometrics to …
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Assessment of the effects of impingement and entrainment on the fish community of the New River, Virginia
… has been identified as having an impact on aquatic biota. Impingement and entrainment of organisms are unavoidable if natural waters are to be used by utilities for cooling water purposes. This study was initiated to determine the effects of operation of the intake of the Glen Lyn Power …
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Metabolism and mechanistic toxicity of environmental pollutants in fish models : integrating in vitro and in vivo systems for ecotoxicological studies.
… of legacy and emerging contaminants in the aquatic environment represents a significant threat to aquatic biota, often leading to significant declines of biodiversity. This issue is further aggravated by the influence of abiotic environmental factors, such as climate change, which could …
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Factors influencing the uptake and fate of metallic nanoparticles in filter-feeding bivalves
… MetNPs are anticipated to be persistent aquatic contaminants. Despite their potential environmental significance, the persistence of surface- functionalized MetNPs as individually-stabilized nanoparticles in aquatic environments is largely unknown. Further, few studies have investigated …
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Assessing Biological Recovery of Cladocera from Sudbury-Area Lakes Using Paleolimnology
… stressors caused extreme damage to regional aquatic systems and their catchments, with aquatic biota experiencing reduced species richness and, in some cases, extirpations. Emission control measures markedly improved pH, however biotic recovery continues to lag water quality improvements, …
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