Physical Sciences and Mathematics Commons^™

Nutrient Transport And Storage In A Karst Spring-Reservoir System During Baseflow, Missouri Ozarks, Heather A. Moule

MSU Graduate Theses

Urban and agricultural land uses are important sources of nitrogen and phosphorus which, if in excess, can cause eutrophication in lakes and rivers. There have been few studies of nutrient transport and storage in karst spring and reservoir connected stream systems draining the Missouri Ozarks. This study aims to link the baseflow nutrient contributions of Sanders Spring to downstream reservoir outflow and the Headwaters South Dry Sac River Watershed in Springfield, Missouri. Water samples were collected seasonally and analyzed for total nitrogen (TN), total phosphorus (TP), and several other water quality parameters. Discharge was also monitored to calculate water and …

Estimating Nitrogen Fixation Rates, Importance, And Short-Term Efficiency In Small, Temperate Reservoirs Using Delta15n Techniques, Bryant Christopher Baker

Graduate Theses and Dissertations

Nitrogen (N2) fixation can give certain species of cyanobacteria a competitive advantage in lake and reservoir phytoplankton. These species of cyanobacteria, along with others that cannot fix N2, can form toxic compounds that impair water quality when present in high concentrations. N2 fixation rates may be substantial in small (< 1.0 km2), temperate reservoirs since these systems experience thermal stratification and often nitrogen (N) limitation throughout a substantial proportion of the year. However, the effects of N2 fixation on N cycling, alleviation of short-term N limitation, and water quality are not well-understood. A mesocosm experiment and ecosystem-scale observational study were conducted to 1) determine the efficiency of N2 fixation under varying N relative to phosphorus (P) supply, 2) examine the effects of N2 fixation on autotrophic biomass accumulation and microcystin production, and 3) measure N2 fixation rates and importance to autotrophic N demand and zooplankton N assimilation. Results of the mesocosm experiment indicated that N2 fixation was increased at low N:P supply under high P. However, N2 fixation was inefficient at alleviating N limitation when fixed N was the primary source of N. Additionally, microcystin production occurred only at high N:P supply when N2 fixation was low, indicating that reducing external N inputs may have a positive effect on water quality. Results of whole-reservoir determination of N2 fixation using seston δ15N natural abundances indicated that N2 fixation rates throughout the warm season were substantial and influenced by water temperature. Annual N2 fixation rates ranged from 2.2 - 6.6 g N m-2 yr-1, and contributed up to 19% of the annual autotrophic N demand. Zooplankton were assimilating fixed N in most of the study reservoirs, representing a possible mechanism of ecosystem fixed N retention. Collectively, these results suggest that N2 fixation plays a substantial role in N cycling in small, temperate reservoirs, but likely cannot alleviate short-term N limitation.

Shallow Groundwater Monitoring Associated With The Deep Saline Reservoir Co2 Storage Test In Hancock County, Kentucky, E. Glynn Beck

Report of Investigations--KGS

A carbon dioxide injection test well was drilled in 2009 to a depth of 8,126 ft below ground surface in Hancock County, Kentucky. Six hundred ninety tons of CO₂ was successfully injected into Knox Group saline aquifers. Two domestic wells (MB and GB) and two domestic springs (CA and RC) were sampled to monitor any potential changes in groundwater quality associated with possible migration of CO₂ from deeper saline aquifers into shallow freshwater aquifers. The four sites were sampled for pH, bicarbonate, total dissolved solids, turbidity, anions, total dissolved metals, dissolved inorganic carbon, total CO₂, and …

Degree-Day Accumulation Influences Annual Variability In Growth Of Age-0 Walleye, Christopher S. Uphoff, Casey W. Schoenebeck, W. Wyatt Hoback, Keith D. Koupal, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The growth of age-0 fishes influences survival, especially in temperate regions where size-dependent over-winter mortality can be substantial. Additional benefits of earlier maturation and greater fecundity may exist for faster growing individuals. This study correlated prey densities, growing-degree days, water-surface elevation, turbidity, and chlorophyll a with age-0 walleye Sander vitreus growth in a south-central Nebraska irrigation reservoir. Growth of age-0 walleye was variable between 2003 and 2011, with mean lengths ranging from 128 to 231 mm by fall (September 30th–October 15th). A set of a priori candidate models were used to assess the relative support of explanatory variables using Akaike’s …

Socio-Environmental Considerations At The Usuma Reservoir In Abuja, Nigeria, Fanan Ujoh Mr, James Ikyernum Mr, Olarewaju O. Ifatimehin Dr

Dr. Fanan Ujoh

Reservoirs are Man’s attempt towards water re-distribution from regions/seasons of abundance/surplus to regions/seasons of scarcity. This study focuses on socio-environmental impacts of the Lower Usuma dam in Abuja, on its four surrounding communities. Stratified random sampling technique was employed in the administration of a questionnaire to 200 respondents. Using descriptive statistics and the student t-test for the analysis, the study discovered that: (i) there has been no significant improvement in infrastructure provision by Government; (ii) cases of water-borne diseases are high; (iii) the communities have lost land for cultivation; and, (iv) the communities believe that the resettlement scheme is not …

Interactions Of Zooplankton And Phytoplankton With Cyanobacteria, Rebecca Alexander

School of Natural Resources: Dissertations, Theses, and Student Research

Cyanobacteria are a major concern in Nebraska reservoirs and are capable of producing toxins that can cause skin irritations and gastrointestinal problems, as well as affect the nervous system. It is important to determine the mechanisms that can cause cyanobacteria blooms due to the effect they can have on human health. The interaction of zooplankton and other phytoplankton groups with cyanobacteria is important because there is a biological component in surface waters that should be taken into consideration along with the physical and chemical parameters that have been noted to promote cyanobacteria. For example, zooplankton have the ability to alter …

Slides: Collaborative Planning And Lessons Learned, Matt Sura

Best Management Practices (BMPs): What? How? And Why? (May 26)

Presenter: Matt Sura, University of Colorado Law School

48 slides

Development Of A Reservoir Embayment Characterization Process To Prioritize Water Quality Improvement., Terry Shannon O'Quinn

Electronic Theses and Dissertations

To simplify water quality improvement in reservoirs, it has been suggested that efforts should be focused on smaller and more manageable units such as reservoir embayment areas. Embayments are prime locations to locate marinas, parks, beaches, and residential homes. Current data and information on reservoir embayments in Tennessee was assembled into a GIS-based database. Embayments of 11 main reservoirs were mapped and digitized in ArcGIS. Initial characterization criteria include watershed size, embayment area-watershed ratio, maximum residence time, and stream influence on embayments. The characterization process was then applied to the mapped reservoir embayments in Tennessee to identify and prioritize embayments …