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 24 for “"Water clarity"”.
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Ecosystem impacts of the invasive rusty crayfish (Faxonius rusticus) over time
… declines of macrophytes, leading to decreases in water clarity in shallow lakes and wetlands in Asia and Europe. In my first study, I used remote-sensed estimates of Secchi disc depth and chlorophyll-a concentration to investigate if F. rusticus similarly decreases water clarity in north temperate …
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Economic Valuation of Water Quality Improvements in New Zealand
… full assessment of the benefits of better water quality has been a challenge because some of the component values cannot be directly measured. The advent of non-market valuation techniques has made it possible to estimate these values. In this thesis, the travel cost random utility model …
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Influence of Resource Pulses Following Stochastic Disturbances on Aquatic Food Webs
… processes, and stabilizing the turbid-water state. However, how resource pulses derived from stochastic disturbances affect eutrophic food webs is unknown. The objectives of this study were: 1) to estimate the range of common carp carrion biomass and nutrients released following …
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Echolocation in wild killer whales (Orcinus orca)
… the relationships between echolocation and water clarity, ambient noise, and behavioural activity. I compare echolocation by two populations with different feeding habits and foraging patterns. The study provides new insight into the functional role of odontocete echolocation, and into the …
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Empirical Relationships between Water Quality and Agricultural Land Use in Rural Maine
Anthropogenic eutrophication of freshwater lakes due to land use change is a growing global problem with economic consequences, such as a reduction in shoreline property value. Managing eutrophication is of utmost importance in Maine, USA due to the large number of inland fresh waterbodies and …
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Biological control of Culex mosquitoes using multiple predators
… contexts (temperature, habitat complexity, water clarity), and thus propose their efficacy in supressing mosquito populations is robust to different aquatic environments where mosquitoes breed. <br/><br/>Copepod-mosquito interaction strengths increased concurrently with temperature, v …
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Exploring light transmission through ice-snow cover and water in lakes
… heating destabilizes the upper part of the water column, which is inversely stratified in ice-covered lakes, leading to radiatively driven convection. While the importance of irradiance (solar radiant flux per unit area, Wm−2) in lakes is well-established, having in-situ measurements or …
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Evaluating recovery in aquatic production in the Bay of Quinte: A perspective based on changes in sedimentary diatom assemblages
… in littoral production coincident with enhanced water clarity from both nutrient abatement and zebra mussel establishment.
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Optical coordination of surface and subsurface autonomous vehicles
… technology has focused on the surface of the water. However, it is desirable to be able to perform measurements at varying depths. In order to expand swarm capabilities, this work investigates using low-cost cameras and light communication to provide navigation for a subsurface sensing …
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Survival strategies of eelgrass in reduced light
… to understand its sensitivity to reduced water clarity, and (iv) documented worldwide losses of eelgrass caused by light reduction (Chapter II). An outdoor mesocosm experiment explained eelgrass response to a gradient of light conditions, improving the understanding of the relationship …
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Applications of Reservoir Limnology Theory and Steady-State Modeling to Eutrophication Management in Beaver Lake, Arkansas
… zones leading to an inverse pattern in water clarity. These theoretical patterns were utilized to create a statistical model of chlorophyll-a (Chl-a), an indicator of PB, and Secchi transparency (ST), an indicator of Chl-a, in Beaver Lake, Arkansas, a 12,800-ha reservoir, in order to …
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Characterization of amorphous silica and crystalline silica from rice husk ash on water filtration application
The presence of water pollution which consists of heavy metals, fecal and others has produced a major problem. These can lead the water to the toxicity and the impurity of water will be disrupted. Therefore, it would not be safe to drinks and could be threatening to live health. In addition, the …
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The role of red-backed salamanders in ecosystems
… systems, tadpoles can alter sedimentation, water clarity, and filamentous algae growth. Additionally, amphibians affect ecosystem functions, including nutrient cycling, decomposition, and primary production. Amphibians can alter the transfer of nutrients and energy between aquatic and …
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Mercury concentration and aquatic food web alterations associated with zebra mussel invasion in Minnesota lakes
… with zebra mussel invasion, including increased water clarity, depleted pelagic energy resources, expanded littoral zones, deposition of benthic organic matter causing anoxic sediments, and increased benthic energy reliance of food webs. However, the effects of zebra mussels vary among lakes, and …
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Food Habits and Consumption Estimates of Walleyes Stocked as a Tool to Suppress Fathead Minnow Populations in West-Central Minnesota Wetlands
… wildlife habitat and food resources for waterfowl. The management of wetland ecosystems to exist in a clear-water, macrophyte-dominated state is desired by state and federal waterfowl biologists. Higher macrophyte biomass results in greater habitat complexity and increased food …
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Essays in Suface Water Quality Valuation
… of three essays examining methods for surface water quality valuation. The first essay uses Zillow's ZTRAX property transaction database to investigate variation in hedonic price effects of water clarity on single-family houses throughout the United States. I consider five spatial scales and …
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How seabirds respond to a changing oceanic environment: a biologging approach
… 2 investigates the diving behaviour of Manx shearwaters (Puffinus puffinus) and how this correlates with water clarity, which is predicted to deteriorate with increasing urbanisation, eutrophication, and climate impacts. Chapter 3 highlights the relative importance of commercial fisheries compared …
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Assessing the current status of local floodplain fisheries in the Okavango river, Kavango region, Namibia
… river’s and is an integral part of a healthy watercourse. It is believed that flooding may nurture life in and around rivers as the waters transport nutrient-rich sediments that contribute to a fertile environment for growth of plants that maintain and support biota. Particularly, these …
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Smelt (Retropinna retropinna) population dynamics and predation by rainbow trout (Salmo gairdneri) in Lake Taupo
… were scattered over sandy areas along beaches in water less than 3.0m deep and in the lower reaches of tributary streams where water currents were sufficient to prevent formation of algal mats and deposition of silt or detritus. Egg mortalities were correlated with water temperature but not with …
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<i>Trichodesmium</i> spp.: Numerical Studies of Resource Competition, Carbohydrate Ballasting, and Remote-Sensing Reflectance
… </em>vertical distribution in quiescent waters. The model results indicate that mean population depth is controlled primarily by environmental conditions (incident irradiance and its vertical attenuation) and physiological rate parameters for ballast processes. Morphologic parameters have …
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