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 83 for “"lotic"”.
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Growth Correlates of Several Lotic Fishes
Relationships between growth rates of three fish species and stream morphology, riparian type, and fish community structure were examined in South Dakota wadeable streams during summer 2002 and 2003. Study sites represented all physiographic provinces in South Dakota and a variety of riverine …
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Aufwuchs communities of lotic systems: nontaxonomic structure and function
… for measurements of primary productivity in lotic systems. Assimilatory (sulfur-35) sulfate reduction was investigated as a method for estimating net microbial production rates. The ability of indices or ratios of structural and functional values to reduce variability and identify perturbed …
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Examining uncertainty in environmental DNA analyses in freshwater lotic systems
The use of environmental DNA (eDNA) to quantify aquatic biodiversity is a rapidly emerging technique used for academic, government, and private purposes. The ease and relative low costs of taking environmental samples versus other methods of sampling makes eDNA methods an attractive choice, …
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Environmental fate and effects of atrazine, metolachlor, carbaryl and chlorothalonil in lotic ecosystems
Pesticides have the potential to affect receiving aquatic ecosystems. These effects are dependent on compound physicochemical characteristics, susceptibility of aquatic organisms, abundance in streams, and stream characteristics. Atrazine, metolachlor, carbaryl, and chlorothalonil have high usage …
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Spatial and temporal heterogeneity in lotic systems : implications for defining reference conditions for macroinvertebrates
Spatial and temporal heterogeneity of lotic systems was examined by assessing variability in macroinbertebrate assemblages in two geographic regions, the Western Cape and Mpumalanga, in South Africa. Assemblages were assessed using the South African Scoring System (SASS), a rapid bioassessment …
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The fresh water mussel as a biological monitor of pesticide consentrations in a lotic environment
Thesis (M.S.)--Michigan State University. Dept. of Fisheries and Wildlife, 1967
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Stress-induced alterations in ecosystem function: the role of acidification in lotic metabolism and biogeochemistry
I investigated how anthropogenic acidification influences stream metabolism and nitrogen (N) cycling by considering the stress response of microbial compartments responsible for these ecosystem processes. Microcosm incubations of leaf biofilms from streams of differing pH revealed greater rates of …
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An ephemeral perspective of fluvial ecosystems: Viewing ephemeral rivers in the context of current lotic ecology
Hydrologic and material dynamics of ephemeral rivers were investigated in the Namib Desert to assess how hydrologic regimes shape the physical habitat template of these river ecosystems. An analysis of long-term hydrologic records revealed that the variation in mean annual runoff and peak discharge …
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Applying ecological models to positive interactions among lotic fishes: implications for population and community regulation at multiple spatial scales
Positive biotic interactions such as mutualism, commensalism and facilitation are ubiquitous in nature, but historically have received considerably less research attention than negative interactions such as competition, predation and parasitism. The paucity of research on positive interactions is …
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The Study of Benthic Invertebrate Communities in: -(a) Lotic Eutrophic Waters (b) A River in Stages of Recovery from Past Pollution
A two year survey into the ecological recovery of what was once one of the most grossly polluted rivers in Britain is documented. The R. Cole was subjected to gross organic pollution as a result of two sewage effluents, one of which was also metallically toxic, these effluents being abated in 1971 …
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Interannual Variability of Lotic Macroinvertebrate Communities in the Kootenay-Columbia Basin, BC: the Relative Contribution of Environmental Gradients vs. Stream Water Temperatures
Climate change is predicted to impact freshwater ecosystems through interannual variability in surface water temperature, discharge, and physiochemical water characteristics. Benthic macroinvertebrate communities (BMI) are often used to assess biological impacts of long-term environmental changes. …
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Spatial and Temporal Variability of In-Stream Functioning within a Forested, Headwater Piedmont Watershed
… loads threaten the health of the Chesapeake Bay, lotic processes throughout its headwaters may buffer increased nitrogen inputs by converting them to stable forms, ultimately through denitrification to N2 gas. However, the temporal environmental factors controlling baseflow nitrogen retention are …
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Effects of Light and Macroinvertebrate Consumers on Detrital Microbial Biofilms in Streams
<p>In lotic freshwater systems, aquatic macroinvertebrates are key processors of biofilms that grow upon organic matter. Although macroinvertebrate effects on biofilms may depend on light availability, the combined effects of consumers and light remain unexplored. Here, I conducted experiments to …
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An Ecotoxicological Assessment of a Treated Coal-mining Effluent in the Leading Creek Watershed, Meigs County, Ohio
… preparation facilities, however, can also impair lotic ecosystems through total dissolved solids (TDS) toxicity, caused primarily by the reagents used for pH modifications and the oxidation of reduced sulfur. Such impairment was best detected through application of (1) benthic macroinvertebrate …
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Distribution of Rotifera and Cladocera in a regulated river system
… for twelve months with a Juday trap in the more lotic upstream end of Winfield pool (UW), and the more lentic downstream end of Winfield pool (LW) to determine seasonal distribution. During the period of peak rotifer abundance, rotifers were sampled along a longitudinal transect of Winfield pool …
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Downstream Transport of Zebra Mussel (Dreissena polymorpha) Environmental DNA and its Implications for Analysis
… limited understanding of the ecology of eDNA in lotic systems. For example, flowing water may confound the relationship between eDNA concentration and target species biomass by influencing eDNA degradation, dilution, and resuspension. I aimed to quantify the effects of downstream transport on …
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Distribution Patterns and Taxonomy of Freshwater Ascomycetes Along the Florida Peninsula
… not significantly different between lentic and lotic habitats. One hundred species of freshwater ascomycetes were reported only on woody debris, 18 species were found on both woody and herbaceous debris, but only 14 species occurred exclusively on herbaceous debris. Most of the taxa reported …
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Watershed-scale patterns of seaward migration in Lentipes concolor, a Hawaiian stream goby
… are uniquely adapted to colonize and thrive in lotic habitats in this extremely isolated archipelago. Chapter 1 of this dissertation introduces the five native fishes of Hawaii's streams and describes the variety of lotic habitats they occupy. All five species have amphidromous life cycles, and, …
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