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 30 for “"Freshwater Ecology"”.
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From landscape to freshwater invertebrates: understanding the effects of peatland restoration on Atlantic Salmon (Salmo salar) habitat in the Flow Country
… on the effects of peatland restoration on freshwater ecology, particularly regarding Atlantic Salmon (Salmo salar) populations that inhabit many peatland-dominated upland river catchments. This study examines the effects of two common peatland restoration techniques, drain blocking and …
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Influence of Spatiotemporal Variables in Structuring the Nematode Community of a Freshwater System
ABSTRACT Kyle E. Luth INFLUENCE OF SPATIOTEMPORAL VARIABLES IN STRUCTURING THE NEMATODE COMMUNITY OF A FRESH WATER SYSTEM Thesis under the direction of Gerald W. Esch, Charles M. Allen Professor of Biology, Wake Forest University, Department of Biology The influence of spatiotemporal variables on …
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Inter-specific hybridization in the fish family Cyprinidae
… will have implications for fisheries management, freshwater ecology, genetic conservation and species integrity.
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Relationships Among Swimming Ability, Habitat use, and Morphology of Freshwater Fishes from Texas and Louisiana
… selection and morphology were assessed for freshwater fishes from Gulf slope, Rio Grande, Red River, and Canadian River drainages in Texas and Louisiana to better understand the influence that flow has on structuring fish assemblages. Swimming ability, relative (body lengths per second, …
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Assessing the Role of Declining Calcium in Biological Recovery on Zooplankton in Historically Acidified Lakes
Throughout much of the 20th century, industrial emissions caused the widespread acidification of thousands of lakes in North America and Europe. Acidification has led to unprecedented damage on zooplankton communities, with reductions in species richness, and in extreme cases, local extirpations. …
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Genomic adaptation to a century of environmental change in zooplankton from the Canadian Shield
… by integrating population genetics with palaeoecology and exploiting a ‘’natural experiment’’ of 12 environmentally similar lakes exposed to different environmental stressors. This thesis specifically focuses on the introduction of the spiny water flea (Bythotrephes longimanus) in the Canadian …
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Enhancing the conservation of freshwater biodiversity through improved freshwater conservation planning techniques
Freshwater ecosystems and biota are among the most endangered in the world. This current situation is even more disturbing when future threats of escalating human demand and global climate change are considered. Urgent measures are therefore needed to conserve freshwater ecosystems and sustain the …
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Climate induced impacts on lake functioning in summer
Es gibt bereits viele Hinweise dafür, dass Seen sehr sensibel auf die anthropogen verursachte Klimaerwärmung reagiert haben. Bis jetzt haben sich die Studien der Klimafolgenforschung hauptsächlichst auf die Auswirkungen der Erwärmung im Winter und Frühling konzentriert. Über den Einfluss der …
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Modeling Ecological Risks at a Landscape Scale: Threat Assessment in the Upper Tennessee River Basin
There is no single methodology toward freshwater conservation planning, and few analytical tools exist for summarizing ecological risks at a landscape scale. I constructed a relative risk model, the Ecological Risk Index (ERI), to combine the frequency and severity of human-induced stressors with …
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Food Habits of Dicamptodon Ensatus and Associated Fish Species of Maratta Creek, Washington
Three cold-blooded vertebrates, Dicamptodon ensatus, Cottus tenuis, and Salmo gairdneri were investigated as to food habits for a period of one year. The existence of competition between these animals for food was determined by means of stomach analysis. The results were compared relative to each …
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Microbial adaptation to dissolved organic matter in freshwater ecosystems
… composition of terrestrial DOM that enters into freshwaters, with unknown consequences for the resident bacterial communities and wider ecosystem processes. This thesis aims to characterize how bacteria adapt to compositionally-distinct DOM sources and assess the implications of these adaptations …
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Evaluating the effects of rainbow smelt on native piscivores in freshwater systems with a special focus on walleye recruitment and larval bioenergetics
… mordax)have been introduced into many new freshwater inland systems outside of its native range. In freshwater systems the interaction between rainbow smelt and native piscivores differs from species to species. In some cases predation or competitive interactions between juvenile piscivores …
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Headwater stream network connectivity: biogeochemical consequences and carbon fate
… resolving questions about the contributions of freshwaters to the global carbon cycle.
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Factors Effecting Phytoplankton Assemblages in the Lafayette River Estuary
<p>Chemical and physical parameters were measured with phytoplankton species composition and abundance in the Lafayette River from August to October 1981. Stations located in four distinct areas of the river were statistically analyzed to determine data relationships. Environmental factors …
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Ecological effects of water hyacinth (Eichhornia crassipes) on Lake Chapala, Mexico
… I explore the effects of water hyacinth on freshwater ecosystems worldwide and specifically on Lake Chapala. In chapter 1, I reviewed studies conducted on water hyacinth worldwide and found that the effects of water hyacinth on water quality are similar but the magnitude of effects is …
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Untersuchungen zur Wirkung von östrogenwirksamen Stoffen auf die Gonadenentwicklung bei Fröschen (Rana temporaria und Xenopus laevis) sowie ultrastrukturelle und immunhistochemische Untersuchungen an Froschgonaden (Rana temporaria)
… carried out by the Institute of Freshwater Ecology and Inland Fisheries in Berlin showed a minor increase in females of Xenopus laevis which were exposed to sewage in the ration of a 2:1 dilution in contrast to the unexposed animals. Taking into account the synergistic effects of …
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FACTORS CONTROLLING NICKEL BIOAVAILABILITY AND EFFECTS ON BENTHIC INVERTEBRATES IN HARDWATER FRESHWATER STREAMS
… has better elucidated the toxicity of Ni in freshwater ecosystems, demonstrating the importance of a range of physicochemical factors on Ni bioavailability, and the relative importance of the three primary exposure routes: water, sediment, and food.</p>
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The terrestrial carbon cycle in transition: tracking changes using novel tracers on multiple timescales
… contributing to the global climate crisis. In freshwater systems, DOC is considered a pollutant because of its detrimental impact on freshwater ecology and biodiversity (by blocking light and reducing photosynthesis and altering thermal-mixing regimes in lakes), increasing freshwater acidity, …
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Quantification of Variability, Abundance, and Mortality of Maumee River Larval Walleye (Sander vitreus) Using Bayesian Hierarchical Models
The estimation of abundance is complicated by factors contributing to spatial and temporal variability. Many organisms are highly variable across both of these scales, thereby violating assumptions of conventional abundance estimation methods. Larval walleye in the Maumee River are extremely …
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