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.
Results
Showing 1 to 20 of 22 for “"Lotic Systems"”.
-
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 …
-
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, …
-
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 …
-
Downstream Transport of Zebra Mussel (Dreissena polymorpha) Environmental DNA and its Implications for Analysis
… analysis has been applied extensively in lentic systems, there is a 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 …
-
Environmental DNA is an Effective Method to Monitor Species in Various Freshwater Habitats
… detection of species across both lentic and lotic systems throughout the study area through efficient multiplexing (detection of multiple species in one reaction) via quantitative Polymerase Chain Reaction. Results from this study, overall, showed that eDNA methods can produce results that …
-
Isolating Confounding Abiotic and Biotic Effects on the Phenotype on Physa Acuta Snails
… and their corresponding downstream reservoir. In lotic systems shells were rotund with larger apertures, while those from lentic systems were more elongate with smaller apertures. In a reciprocal transplant lab experiment that crossed flow regime and crayfish predator cues, I tested for the …
-
Measuring variation in body morphology and life history traits in Brook Stickleback (Culaea inconstans), Eastern Washington, USA
<p>For freshwater ecosystems, invasive species are considered a major threat to biodiversity, and pose a challenge to those attempting to advance management strategies aimed at conserving natural populations. An invasive species’ ability to successfully invade a new ecosystem may be influenced by …
-
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 …
-
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 …
-
Analysis of QA/QC Protocols and Value of Data to the Development of Reference Criteria in the Georgia Ecoregions Project
… metric scores may demonstrate that the lotic systems across the state of Georgia naturally have high variability from year-to-year and spatially within catchments. This in turn may indicate that the established precision thresholds of the MQOs may not be indicative of the data quality …
-
Crayfish: Scavenger or deadly predator? Examining a potential predator-prey relationship between crayfish and benthic fish in aquatic food webs
… as a potential predator of benthic fish in lotic systems, where they co-occur, has yet to be addressed. Competition exists between crayfish and Percid benthic fish in Illinois streams, for food resources and refuge from larger predators. Previous research, though, has ignored a potential …
-
Evaluation of the relationships between watershed-scale land use and contaminants in aquatic environments and the use of freshwater snails as indicators of impairment
… transmission dynamics of trematode parasites in lotic systems.
-
Forces Structuring Caddisfly Communities: Biogeographical to Anthropogenic Effects
… primarily on communities in running-water (lotic) systems in the United States and Canada. Much of my research on Trichoptera specimens and freshwater habitat was generated from publicly available data. First, I examined the biogeography of caddisflies in the US and Canada by quantifying …
-
Hydrodynamic controls on the movement of invertebrate larvae and organic matter in small streams
The movement of organisms and resources within ecosystems are essential elements in the productivity, stability, and distribution of communities. This thesis examines how water velocity, a defining factor of lotic systems, influences the dispersion of benthic organisms and particulate organic …
-
Evaluating the population control of invasive crayfish using removals and male sterilisation.
… difficulty of managing invasive crayfish in open lotic systems.
-
Effect of Macrograzers (Campostoma spp. and Faxonius spp.) on Periphyton in Ozark Streams with Considerations Given to Macrograzer Biomass, Phosphorus, and Season: Mensurative and Manipulative Studies
… guide numeric nutrient criteria development in lotic systems. However, herbivorous macrograzers may confound this relationship by reducing the slope of the positive relationship between nutrients and periphyton biomass in streams. I conducted a mensurative field study to determine if stoneroller …
-
Microbial and metazoan effects on nutrient dynamics during leaf decomposition in streams
… during organic matter decomposition in stream ecosystems, and 2) what affect will the global increase in biologically active N have on these factors and resulting fluxes? I conducted studies in natural streams and laboratory mesocosms to address these questions and used general stoichiometric …
-
Studies of Benthic Macroinvertebrates in Western Virginia Streams as Related to the Implementation of Rapid Bioassessment Techniques
… in assessing the biological condition of lotic systems. I compared a typical standardized qualitative sampling method with subsampling with a typical quantitative sampling method on a stream with varying degrees of impairment. Although some metrics did respond to differences in sample …
-
Effects of water temperature on life history traits of selected South African Aquatic insects: implications for the ecological reserve
… for conservation and management of aquatic systems. Given the large research gap that has existed in this regard for Southern Hemisphere lotic systems, there has been an urgent need to gather such data if effective management policies are to be implemented regionally, especially in the face …
-
An Ecotoxicological Assessment of a Treated Coal-mining Effluent in the Leading Creek Watershed, Meigs County, Ohio
… of the coal mining industry on freshwater systems has focused on abandoned-mined land, and the associated acid drainage and metals toxicity. Treated discharges from active mining and preparation facilities, however, can also impair lotic ecosystems through total dissolved solids (TDS) …
Page 1 of 2