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Butcher, Melissa Rachelle. "Diffuse Nutrient Pollution from Residential Catchments". Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5194.
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Nonpoint source nutrient pollution is diffuse pollution lacking discrete origin and conveyance. This thesis synthesizes and critically reviews research on residential nitrogen and phosphorus loss to stormwater runoff and leaching. The evaluation pulls from research covering influential socio-demographic indicators, such as use of lawn maintenance services and homeowner fertilizer practices. The extent to which such social and economic factors may influence the prevalence and fate of diffuse nutrients in stormwater runoff from residential areas has not been adequately established. Understanding the source and influencing factors of diffuse nutrient pollution is important in order to effectively protect surface and groundwater resources.
Research based on sampling campaigns of catchments, sampling of controlled turf systems and models of residential catchments were compiled for this review. Based on the compilation reviewed for this thesis, there are wide differences in approaches researchers have taken to attempt to quantify and understand diffuse nutrient pollution from residential and urban areas. There is not consistency in the chemical nitrogen or phosphorus species evaluated or in reported measurements (i.e. concentration vs. loading vs. yield).
This review revealed several important knowledge gaps. Determination of correlation between residential system nutrient loss to the environment and social factors, demographic characteristics, local fertilizer ordinances or nutrient management education programs has not been substantiated. More exploration of nutrient leaching from different soil types and turf grass species is needed to develop a complete understanding of nutrient loss from turf grass systems. Further, other specific management practices such as leaving grass clippings on lawns has not been studied in depth for a variety of soil types and grass species. There is room for improvement in future research and additional studies are needed to guide future policy and implementation of best management practices. Based on these and other findings, I recommend a concerted effort to standardize a portion of the reporting details of future stormwater research and for reevaluation of nutrient/fertilizer education efforts.
2
Fretwell, Elizabeth A. "The Temporal and Spatial Relationship between Phosphorus and Nitrogen Concentrations, Algal Growth, and Nutrient Sources in the Meduxnekeag River Watershed". Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/FretwellEA2006.pdf.
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Hantsch, Nichole M. "Pattern and process of watershed nutrient dynamics in South Central New York". Diss., Online access via UMI:, 2008.
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Mariola, Matthew J. "Are Markets the Solution to Water Pollution? A Sociological Investigation of Water Quality Trading". Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1250015222.
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Sanyi, Hassan H. A. R. "Effects of liming of upland soils on nutrient mobilities in relation to water quality". Thesis, University of Aberdeen, 1989. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU020937.
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The work in this thesis relates to understanding the potential effects of using surface liming of upland soils to ameliorate water acidification. Effects on vegetation, soil, and drainage water chemistry are considered. Part I of this thesis reviews the environmental conditions of British Uplands (climate, soils and vegetation), and the relevant literature on water acidification in North-East Scotland. In Part II, each chapter deals with materials, methods used, discussion of the results and conclusion for one of a series of individual experiments. This pattern is followed for a number of laboratory, greenhouse and field studies. Liming of different organic soils significantly increased only the surface layer pH of the soils. The consequence of surface liming should be highly beneficial in terms of water quality, since most of the precipitation in the catchment under consideration (Glendye) during heavy storms, when river acid episodes occur, drains near or over the surface. The effect of lime on pH below the surface should be considered after a year or more. Liming on the other hand increased the mineralisation of organic N and released NH4+ and NO3-. The balance between N mineralization and immobilization by vegetation and microbial biomass should be considered carefully for each individual soil and site. If the mobile NO3- reaches the river or streams and increases the NO3- to beyond an acceptable limit, this could be considered an adverse effect of liming. Although within the timescale of this project there was no adverse effect noticed on the heather under field conditions, the long term effects should be considered carefully in terms of changing vegetation pattern as a result of liming, which will favour growth of grass.
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Shamblin, Michael D. "Evaluating runoff water quality and ammonia volatilization in three turkey litter application methods". Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2668.
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Thesis (M.S.)--West Virginia University, 2002.Title from document title page. Document formatted into pages; contains vii, 59 p. : ill. Includes abstract. Includes bibliographical references (p. 43-45).
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Klaewtanong, Wimalin. "Nutrient removal in anaerobic sequencing batch reactor combined with anaerobic/aerobic sequencing batch reactor for piggery wastewater treatment". Thesis, University of Newcastle Upon Tyne, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289241.
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Ross, Sarah Ysabel. "Relationships between hydrology, hydrochemistry and vegetation patterning on Scottish fens". Thesis, University of Stirling, 1999. http://hdl.handle.net/1893/24825.
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Fens are increasingly recognised as important habitats in terms of biodiversity, and this has been formalised in recent legislation (EC Habitats Directive, 92/43/EEC). The influence of groundwater and surface water inputs on the fen habitat increases its vulnerability to water pollution, particularly from nutrients. Despite the conservation importance and potential vulnerability of the habitat, fens have not been widely studied in Scotland, in terms of extent, location, sensitivity to increased nutrient inputs, or in comparison to similar European sites. This study found that fens were widespread throughout mainland Scotland, and that basin fens were the most commonly occurring fen type, representing 43% of the 355 sites assessed. A survey of 18 basin fens found that 72% were potentially vulnerable to elevated nutrient inputs, being surrounded by improved/modified land. Despite this, only four sites showed greater nutrient concentrations in sub-surface water samples or water inputs. There was, however, a significant amount of variation in hydrochemistry between the sites. Detailed studies further assessed spatial and temporal variations in hydrochemistry, and associated hydrologic regimes on two similar basin fens, one in an agricultural catchment, the other surrounded by unimproved grassland. Spatial patterning of vegetation was associated with both base-richness and nutrient concentrations of subsurface water, and the frequency of water inundation. General relationships between the six fen vegetation types and the observed hydrological and hydrochemical variation were presented.
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Lang, David A. King Ryan Steven. "Effects of nutrient enrichment on alkaline phosphatase activity and nitrogen fixation potential in stream periphyton". Waco, Tex. : Baylor University, 2007. http://hdl.handle.net/2104/5071.
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Chaston, Katherine A. V. "Sediment nutrient bioavailability in a sub-tropical catchment dominated by agriculture : the transition from land to sea /". [St. Lucia, Qld.], 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17118.pdf.
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Garrett, Keith John. "The role of sediment-associated transport in the nutrient budget of a small Devon catchment". Thesis, University of Exeter, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332295.
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Edwards, Richard Reginald. "The potential for the use of willow (Salix spp.) in buffer zones for reducing nitrate and atrazine pollution". Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322361.
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Costanzo, Simon. "Development of indicators for assessing and monitoring nutrient influences in coastal waters /". [St. Lucia, Qld.], 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16274.pdf.
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Hejna, MaryAnne. "Nutrient and Water Quality Analysis of a Lake Erie Headwater Tributary". University of Akron / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1594576287454459.
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Sanchez, Jaime F. "Water and nitrate movement in poultry litter amended soils". [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004020.
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Fulton, Barry A. Brooks Bryan William. "Assessing interactions between nutrients and toxicity influences of nitrogen and phosphorus on triclosan toxicity to the aquatic macrophyte "lemna gibba" /". Waco, Tex. : Baylor University, 2009. http://hdl.handle.net/2104/5351.
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Kerr, Barry Douglas. "Multiple Regression Equations to Estimate Mean Nutrient Concentrations in Streams of North Central Texas from Landsat Derived Land Use". Thesis, University of North Texas, 1994. https://digital.library.unt.edu/ark:/67531/metadc278778/.
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Nutrients are of critical concern in water quality assessment. The development of empirical models to estimate mean nutrient concentrations, based on satellite derived land use, could aid water resource managers. Models using land use acreages outperformed those using percentages, and discrete urban land uses were superior to lumped urban. Regressions of the combinations of two, three and four of the eight possible land use variables were investigated. Sensitivity analyses, with one stream deleted each series, identified robust combinations of variables at each level. Although uncertainty exists regarding the final regression coefficients, five of the six actual measured nitrate and total phosphorus mean concentrations were within the 95 percent confidence limits.
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Williams, Marlyse K. "Evaluation of land application of wastewater as a nutrient reduction control strategy in the Chesapeake Bay watershed". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 207 p, 2006. http://wwwlib.umi.com/dissertations/fullcit/1435842.
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Matheny, Sarah E. "Nutrient analysis of sediment interstitial water of the Prairie Creek Reservoir, Indiana". Virtual Press, 2007. http://liblink.bsu.edu/uhtbin/catkey/1366301.
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Prairie Creek Reservoir in east central Indiana serves as a secondary water supply for the city of Muncie and is also used as a recreational facility. Due to water quality concerns, this study was conducted to characterize spatial and temporal variability of physical and chemical parameters, specifically nutrients, in the sediment interstitial (pore) water at three reservoir locations. The pH, temperature, specific conductivity, ammonia, nitrates, total nitrogen, orthophosphates and total phosphorus, were monitored twice per month from June through September 2006. Spatial variations in the sediment interstitial water were evident for all water quality parameters, except phosphorus and orthophosphates. Variability in temporal nutrient concentrations in pore water was most likely affected by decomposition of organic matter and presence of anoxic conditions in the overlying water. The results showed high internal nutrient loading, especially from phosphorus, in the sediment interstitial water. Under anoxic conditions, these excessive nutrient concentrations within the sediment can be released into the water column and exacerbate eutrophication of the reservoir. This study provides useful assessment of internal nutrient loading in the Prairie Creek Reservoir sediment that should be considered in the implementation of land management strategies and future land development practices in the reservoir watershed.Department of Natural Resources and Environmental Management
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Chen, Juan. "Sediment remediation as a technique for restoring eutrophic wetlands and controlling nuisance Chironomidae /". Access via Murdoch University Digital Theses Project, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050817.102759.
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Love, Danielle M. Matthews Robin A. "Effects of salmon-derived nutrients on an artificial stream system /". Online version, 2009. http://content.wwu.edu/cdm4/item_viewer.php?CISOROOT=/theses&CISOPTR=321&CISOBOX=1&REC=9.
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Brousseau, Jennifer Peterson. "Growth of natural phytoplankton populations of Wilson Bay : a nutrient bioassay approach /". Electronic version, 2005. http://dl.uncw.edu/etd/2005/brousseauj/jenniferbrousseau.html.
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Reuben, Thomas Nyanda. "Nutrient Contribution of the Shallow Unconfined Aquifer to Pineview Reservoir". DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/1482.
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Pineview Reservoir, near Utah's populous Wasatch Front, could play an important role in modulating water supply as water demands and water uses change in response to increasing population densities. The reservoir is currently mesotrophic but threatens to become eutrophic. Ground water in the shallow water table aquifer that surrounds the reservoir contributes a large proportion of the reservoir's inflows in summer and fall because most of the stream flow is diverted for irrigation. Ground water flow and its subsequent nutrient loading to the reservoir were studied from February 2010 through November 2011. The objectives were to: 1) characterize nutrient transport from the water table aquifer to the reservoir; 2) quantify and characterize the spatial variability of ground water flow and nutrient loading in a mountainous irrigated valley; and 3) estimate nitrate leaching to ground water from cropland, lawns and septic drain fields. The first objective was achieved by monitoring stream flows, and modeling ground water flow and nutrient loading towards Pineview Reservoir. Ground water from the water table aquifer contributed 22 percent and 2.6 percent nitrate + nitrite nitrogen and total dissolved phosphorus, respectively, to the annual reservoir loads. The aquifer contributed a total inflow of 3.4 x 106 m3 yr-1 (2 percent of the total inflows) to the reservoir. Large variations in both ground water nutrient concentrations (6 - 310 µg P L-1 as total dissolved phosphorus and 3.3 - 21 mg N L-1 as nitrate + nitrite) and ground water flows among aquifer subdivisions were observed. Study of the second objective employed GIS-based interpolation techniques in analyzing the spatial distribution of ground water flow and nutrient loading towards the reservoir. Large spatial variations in ground water flows and nutrient loadings were observed. The 67 percent confidence intervals (geometric mean ± 1 standard deviation) for total dissolved phosphorus ranged from 0.014 - 0.400 kg P d-1. Nitrate + nitrite nitrogen had a 67 percent confidence interval of 0.954 - 39.1 kg N d-1. The variations were attributed to agricultural and domestic non-point sources. Under the third objective, ground water nitrate loadings in the near-reservoir drainage area of the reservoir's major tributary, the South Fork of the Ogden River, were simulated in the GIS-based Nitrogen Loss and Environmental Assessment Package. Annual leaching rates (kg N ha-1 yr-1) from drain-fields and the lawns were, respectively, more than 2.6- and 1.1-fold higher than the croplands. However, differences in the spatial extent of contributing sources resulted in 70- and 50-fold higher total leaching losses from croplands and lawns, respectively, than drain-fields. The findings would help water managers, town planners, and stakeholders in their decisions relative to land use, water distribution and use to protect and/or improve water quality in the reservoir.
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Bird, Paul. "Benthic microalgae on the Heron Island reef flat sediment and responses to nutrient enrichment /". [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19096.pdf.
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Stamatis, Allison Davis Kennedy James H. "Organic carbon dynamics of the Neches River and its floodplain". [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-5118.
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Delibas, Adem 1980. "A systems approach to managing nutrient pollution in Cape Cod's coastal waters". Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/100359.
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Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 101-104).
Pressing problems are facing the coastal waters of the world due to the growing human activity. Increasing population and economic development around coastal areas have left many embayments throughout the world severely impaired. Excessive nutrient enrichment in water bodies, also known as nutrient pollution, is one of the leading impairments in coastal waters. Algal blooms, dead zones, and fish kills are spreading because of the nutrient pollution. This thesis presents a systems analysis of the nutrient pollution problem in the context of Cape Cod, Massachusetts, where the continuous degradation in coastal waters is considered as one of the greatest threats to the region's environmental and economic future. It proposes a system dynamics model created with a diverse stakeholder team to uncover the underlying system structure that has created the degradation in Cape Cod's coastal waters since 1960s. An important goal of this work was to support the development of a regional water quality management plan on Cape Cod by creating a shared understanding of the nutrient pollution problem across a wide range of stakeholders. Therefore, the proposed model was created with direct contributions of a diverse stakeholder team including representatives from residents, local municipalities, regional authorities, the state government, and the U.S Environmental Protection Agency. In addition to identifying the causal structure of the system through a set of qualitative diagrams, this thesis also proposes a formal simulation model and presents results of an in-depth policy analysis exploring how the degradation in Cape Cod's coastal waters could evolve under different future scenarios. Both the model-building process and the simulation experiments reveal several critical insights, including nonlinearity of the system behavior, delay in the system's response to interventions, and the importance of timely actions.
by Adem Delibaş.
S.M. in Engineering and Management
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Ellis, Bonnie Kathleen. "Alternate states in a large oligotrophic lake a retrospective analysis of nutrient loading and food web change /". [Missoula, Mont.] : The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-03292007-094249/unrestricted/ellis06.pdf.
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Marshall, Michael C. "Hyporheic transformation and retention of salmon-derived nutrients in southeast Alaska streams". Laramie, Wyo. : University of Wyoming, 2006. http://proquest.umi.com/pqdweb?did=1225123041&sid=7&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Bratt, Anna-Lena. "Managing agricultural nutrient leaching within the EC Water Framework Directive in Sweden". Doctoral thesis, Linköping : Univ, 2003. http://www.ep.liu.se/diss/arts_science/2003/284/index.html.
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Upton, Alexandra C. "Simulation of local watershed nutrient and sediment delivery to Lake Texoma". Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4479/.
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A hydrologic model and watershed export model was used to estimate the loading of nutrients and total suspended solids from un-gaged local watersheds associated with Lake Texoma. Discharge to the reservoir from local watersheds was predicted using a modification of the curve number method in HEC Hydrologic Modeling System (HEC-HMS). Event mean concentrations were applied to land use to estimate loadings of nutrients and TSS. Total discharge from the local watersheds was estimated to be 3.02 x 107 cubic meters for a study window of March 1 to May 31, 1997, less than 10 percent of the input to the lake from the Red River and Washita River systems. Loadings were estimated to be 33,553 kg nitrogen, 4,401 kg phosphorus, and 3,423,140 kg TSS. The models and results obtained from their application appear to have potential utility for use in a water quality management decision support system for the reservoir.
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Cary, Brian S. "Hypoxia in Hood Canal using modern science and traditional ecological knowledge to enhance our understanding of a degraded ecosystem /". Online pdf file accessible through the World Wide Web, 2007. http://archives.evergreen.edu/masterstheses/Accession86-10MES/Brian%20Cary%20thesis.pdf.
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Secoges, Joseph Michael. "Nutrient Movement in Streamside Management Zones and Piedmont Streams Following Forest Fertilization". Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/33497.
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Many statesâ Best Management Practices (BMP) programs established Streamside Management Zone (SMZ) widths based on limited or inadequate data with regard to nutrient fluxes from silvicultural activities. Previous studies in forested watersheds have shown slight post-harvest increases of several nutrients in streams. Also, in agricultural settings, increased nitrogen (N) and phosphorous (P) levels have been detected in streams. However, little is known about the effectiveness of recommended forested SMZ widths for controlling nutrient fluxes following fertilizer application. Diammonium phosphate (DAP) and urea fertilizers were applied to subwatersheds of 2 to 3 year-old loblolly pine (Pinus taeda L.) plantations upslope from SMZ study areas throughout Buckingham Co., VA. Three replications of four SMZ treatment widths (30.5m, 15.2m, and 7.6m plus a thinned 15.2m SMZ) were studied using surface water collectors, cation/anion exchange membranes, lysimeters, and stream grab-samples. Measurement devices were spaced symmetrically across the SMZ from the uphill SMZ edge to stream edge with grab samples being collected approximately 20m upstream and 20m downstream of the fertilized area. Little nitrogen and phosphorous movement was detected in surface water which was monitored using surface water collectors. Near-surface water flow sampling using ionic exchange membranes resulted in our most complete dataset and showed infrequent lateral ion transport in the litter and upper soil layers even after water passed over an approximately 1m wide, seeded firebreak located between the SMZ dripline and fertilized area. Results from lysimeter samples used to measure subsurface flow were limited due to dry conditions; however, the limited samples indicate that only minute levels of nitrogen and phosphorous are transported laterally via shallow subsurface and surface flow. Overall, sampling indicated that only minute quantities of nitrogen and phosphorous were ever transported from the fertilized clearcut to the riparian area. Results indicate that even a 7.6m wide SMZ with a seeded firebreak is adequate to protect streams from industrial fertilizer application in a relatively dry year, but wider SMZs may be necessary for other benefits.Master of Science
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Wilson, Alan Elliott. "Cyanobacteria-Grazer Interactions: Consequences of toxicity, morphology, and genetic diversity". Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-04072006-125946/.
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Thesis (Ph. D.)--Biology, Georgia Institute of Technology, 2006.Klausmeier, Christopher, Committee Member ; Montoya, Joseph, Committee Member ; Snell, Terry, Committee Member ; Sarnelle, Orlando, Committee Member ; Hay, Mark, Committee Chair.
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Lee, Wen-Hsiung. "The effect of salinity on nutrient release from riverine and tributary estuarine sediments to the Chesapeake Bay under oxidizing and reducing conditions". Thesis, Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/80053.
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The primary objective of this study was to determine the salinity effect on nutrient release and the denitrification rate in a sediment-water system. To accomplish this objective, bench-scale microcosm studies of York River sediments and Occoquan Reservoir sediments were conducted. Seawater and freshwater were mixed in various ratios to simulate seasonal, salinity-varying environments in the Chesapeake Bay and its tributary estuaries.
Experiments were conducted under aerobic, anaerobic, and anoxic conditions. The results showed that high salinity can cause flocculation of particles and result in lower concentration of phosphate under aerobic conditions, but the flocculation effect was not obvious under anaerobic conditions. The release of ammonia was governed by the salinity; the increasing salinity accelerated the release of ammonia by ion exchange. The denitrification rate under anoxic conditions in the system was not influenced by the salinity.Master of Science
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Langlois, Jacques. "Nutrient and sediment movements from soil to surface water in a forested watershed and two agricultural fields". Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19751.
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In North America, the acceleration of the eutrophication of surface waters due to nutrient pollution is still present. Soil studies have not entirely succeeded in linking nutrient and sediment losses to field hydrology because relationships between discharge and dissolved ions/sediments are complicated by a hysteresis effect which has been only described qualitatively. The objective of this thesis was to better understand the effects of hydrology on N, P, and sediment transfer from agricultural and forest soils to surface waters. This was done by developing a technique, called the H index, to quantify the hysteretic behaviour of ion and sediment transport in stream/overland water. The chemical and sediment concentrations in a stream of a forested watershed in the Sierra Nevada during snowmelt and in overland runoff of two agricultural fields during rain events in the Montreal area were examined. In the stream of the forested watershed, H indices for suspended sediment increased (looser hysteresis loop) with the availability of sediments and the lag between peaks in suspended sediment concentrations and discharge. In agricultural fields, nutrient concentrations increased with time during each event with presence of counterclockwise and clockwise hysteresis. The hysteretic behaviour of suspended sediments was not significantly related with either prior soil moisture content or rainfall characteristics. In order to simultaneously monitor P and N in the stream and soils of the forested watershed, a laboratory study was conducted to investigate the efficacy of various mixedbed exchange resins in absorbing dissolved organic and inorganic N and P. Results showed that mixed-bed resin was adequate for characterizing P on a short-time scale but longer exposure periods were required for N. Results from the resin exchange reveal the possibility that the spring time pulse of NOs'-N in stream water was due to the melting of the snowpack.
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Saltos, Theodore Nicholas. "Assessment of Agricultural Nutrient Pollution to Lake Erie from the Maumee and Sandusky Watersheds: Analyzing Trends in Hydrology, Nutrient Loading, and Policy Using a Statistical Approach". The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1531928517302473.
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Wang, Lei. "Developing an integrated catchment-scale modelling approach for supporting the sustainable management of water nutrient pollution from diffuse agricultural sources". Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54893/.
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Water is one of our most vital natural resources for life sustaining and human's economic development and social well-being. Agricultural diffuse water pollution (ADWP), the biggest remaining problem of water pollution in the world, has been realised as a major threat for water quality and the implementation of the EU Water Framework Directive (WFD). Indicative estimates of the costs of water pollution from ADWP are about £225 M per year in the UK, whilst failure to meet the requirements of the EU WFD by 2015 may incur heavy fines. From the technical and scientific points of view, there are three major gaps, namely, "method and tool", "research scale" and "fundamental knowledge" gaps between current ADWP research and the successful implementation of the EU WFD. It is timely to develop integrated catchment-scale numerical modelling tools or methods to handle the ADWP problem at the catchment scale. This thesis describes the development of an integrated catchment-scale modelling approach, ICEMAN, for supporting the effective decision-making of the ADWP sustainable management at the catchment scale, thus helping the implementation of the EU WFD in handling ADWP. In order to quantitatively describe the nutrient process in the complete hydrological cycle, it is necessary to integrate numerical water models into ICEMAN to calculate or simulate the groundwater pollution pathway vulnerability, groundwater pollution risk, water balance in soil, nutrients biochemical cycling in soil, and surface water quality and quantity processes. This study showed that GIS and the Arc Hydro model consisting of the modules of data mining, hydrological analysis, and visualisation can facilitate the developing and applying the ICEMAN by providing data support and powerful functions of spatial analysis. The DRASTIC model was applied in the case study area - Upper Bann Catchment, Northern Ireland for assessing the groundwater pollution pathway vulnerability of general pollutants and pesticide. The results showed that DRASTIC is suitable to be introduced into the ICEMAN for catchment-scale groundwater pollution vulnerability assessment. However, DRASTIC has drawbacks in the groundwater pollution risk assessment, namely, having no risk concept and considering no pollutant dynamic nature with runoff. A D-DRASTIC approach was developed in this study for reliable groundwater pollution risk assessment from diffuse agricultural sources based on DRASTIC within an ArcGIS environment. D-DRASTIC overcomes the pitfalls of applying DRASTIC in groundwater risk assessment. The results of applying D-DRASTIC in the case study showed that D-DRASTIC is helpful in guiding the activities of groundwater pollution prevention at the catchment scale and can be used in the development of ICEMAN. A numerical catchment-scale surface water model capable of the simulation of ADWP is necessary in developing the ICEMAN method. A HSPF model was selected based on the review of popular surface water models and tested in the study area. The calibrated and validated HSPF model can well represent the characteristics of surface water quantity and quality in the study area. Climate change scenario evaluation results in five years showed that when the annual mean temperature increase 3 Celsius the mean yearly total runoff volume will decrease by 11% and the mean daily river flow of five years will decrease by 11%. The results showed that HSPF is a suitable model in simulating the diffuse source surface water pollution and can be integrated into the ICEMAN. ICEMAN was developed by integrating the models of Arc Hydro, DRASTIC, D-DRASTIC, HSPF into an ArcGIS environment. ICEMAN can describe the nutrient biochemical cycles in soil, whole hydrological quantity and quality processes, and groundwater pollution vulnerability and risk, by considering factors in the catchment ADWP process, namely, meteorology, nutrient loading from different land uses, nutrient biochemical cycling in soil, nutrient dynamic nature with runoff and interflow, topography, depth to water, net recharge, aquifer media, soil media, impact of the vadose zone media, hydraulic conductivity of the aquifer, and the relationships between soil water and groundwater. The results of applying ICEMAN in the study area showed that ICEMAN can well support the decision-making of the catchment ADWP sustainable management. In the study area, ICEMAN provides satisfied simulation of river flow and quality, groundwater pollution vulnerability and risk zones, and quantitative descriptions of ADWP process including nutrient biochemical cycle in soil and can help better understand the ADWP characteristics in a specific catchment. In addition, ICEMAN can evaluate the impacts of water management plans on water processes under the climate change. For example, when changing 20% farming land into forest land in the Gamble's Bridge watershed of the study area, the mean concentrations of nitrate, nitrite, NH4, and P04 in river will decrease by 19%, 33%, 31%, and 31% respectively. ICEMAN, transferable to other areas, can bridge gaps of "method and tool" and "research scale" in the implementation the EU WFD in handling ADWP and can act as an important complement of the River Basin Management Plans. This multi-disciplinary study may provide a good starting point for tackling ADWP at the catchment scale in an integrated, quantitative, and sustainable manner. Therefore, the results in this multi-disciplinary study are not only useful for better implementation of the EU WFD, but also helpful for tackling the ADWP problem outside the EU.
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Xu, Kejun. "Total suspended solids, discharge, conductivity, and nutrients in three watersheds of the Upper White River, IN". Virtual Press, 2004. http://liblink.bsu.edu/uhtbin/catkey/1307378.
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Three watersheds of Upper White River were chosen for this study. Stream samples were tested for total suspended solids and conductivity. Fourteen percent of the total suspended solids samples were above 80 mg L-1 which can cause negative effects to aquatic life. Total suspended solids results were tested with a general linear model and in linear regressions with discharge and nutrients. Conductivity results were tested with a general linear model. Concentrations of the total suspended solids were significantly related to watershed, Julian date, the interaction of watershed and Julian date, and discharge. Increasing total suspended solids concentrations were significantly related to increasing concentrations of orthophosphate, nitrate, and ammonia. Conductivity levels were significantly related to watershed, location within watershed, and Julian date. Total suspended solids, discharge, and nutrient concentrations were high in the spring, but decreased in the following seasons.Department of Natural Resources and Environmental Management
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Fiallos, Celi Diana E. "Water quality assessment of Prairie Creek Reservoir in Delaware County, Indiana". Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1391474.
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The Prairie Creek Reservoir, located in east central Indiana in an agricultural watershed, serves as a secondary drinking water source as well as a recreational facility. Limited research of water quality performed at the reservoir has affected management decisions over the past years, threatening its future.. Consequently, additional investigation was necessary to examine the reservoir dynamics, and continue to provide data to determine long-term water quality trends. Basic water quality parameters were measured using a Hydrolab Sonde, nutrients were measured spectrophotometrically, and a Secchi disk was used to determine water transparency. The Prairie Creek Reservoir was categorized as an eutrophic water body. Concentrations of the measured nutrients were higher in the hypolimnion and increased as summer progressed. Concentration of ammonia and soluble reactive phosphorus exceeded the recommended water quality guidelines. Increased concentration of phosphorus has resulted in nitrogen limitation in the reservoir. Internal loading of nutrients, especially phosphorus, was found to deteriorate water quality. Dissolved oxygen concentrations varied vertically and anoxic conditions frequently reached 50% of the total reservoir depth. Reservoir restoration and watershed protection programs need to address internal P load and nitrogen limitation to prevent development of toxic algal blooms and eutrophication in the future.Department of Natural Resources and Environmental Management
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Kelly, Joann. "The effect of nutrient limitation on the growth and toxicity of the dinoflagellate Gyrodinium instriatum". View electronic thesis (PDF), 2009. http://dl.uncw.edu/etd/2009-3/kellyj/joannkelly.pdf.
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Dobrowolski, Edward G. "Assessment of water quality changes resulting from municipal sewer installation in the Killbuck-Mud Creek Watershed, Indiana". Muncie, Ind. : Ball State University, 2008. http://cardinalscholar.bsu.edu/725.
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Hargiss, Michael John. "Incorporating Adaptive Management and Translational Ecology into the North Dakota Total Maximum Daily Load Program: A Case Study of the Fordville Dam Nutrient TMDL". Master's thesis, North Dakota State University, 2012. http://hdl.handle.net/10365/21663.
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Translational ecology and adaptive management strategies were incorporated into the Fordville Dam Nutrient Total Maximum Daily Load (TMDL) case study to determine if these two techniques were compatible to the North Dakota TMDL Program. A case study summary of the Fordville Dam Nutrient TMDL was discussed to provide contrast and comparison of the current TMDL program strategy and systematic improvements that could be made with the incorporation of translational ecology and adaptive management. Translational ecology is an effective way to bridge the information barrier through open communication between the stakeholders and scientists while creating a mutual learning experience. Adaptive management is beneficial to a TMDL implementation plan because it allows stakeholders and resource managers to become involved in management decisions and develop a better understanding of the ecosystem. Therefore, combining translational ecology and adaptive management would make the TMDL process more effective, through better communication and a flexible management plan.
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Meinikmann, Karin. "Groundwater-Surface Water Interactions in a Eutrophic Lake – Impacts of Lacustrine Groundwater Discharge on Water and Nutrient Budgets". Doctoral thesis, Humboldt-Universität zu Berlin, 2017. http://dx.doi.org/10.18452/18203.
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Die Arbeit besteht aus mehreren Studien zur Quantifizierung des Grundwasserstroms in Seen (Exfiltration; engl.: lacustrine groundwater discharge, LGD) und damit verbundener Nährstoffeinträge. In zwei einleitenden Kapiteln dieser Arbeit werden eine Gründe für die Vernachlässigung der Grundwasserexfiltration (LGD) in Seen und der daran gekoppelten Nährstoffeinträge identifiziert. Diese Literaturstudien fassen den aktuellen Kenntnisstand zum Einfluss des Grundwassers auf die Hydrologie von Seen und ihre Nährstoffhaushalte zusammen.
Den Kern der vorliegenden Arbeit bilden zwei empirische Studien, die sich mit der Quantifizierung der grundwasserbürtigen Phosphor (P)-Fracht in den Arendsee in Deutschland befassen. Das Gesamtvolumen des Grundwasserzustroms wird basierend auf der Grundwasserneubildung im Einzugsgebiet des Sees ermittelt. Lokale Muster der Grundwasserexfiltration werden anhand von Temperaturtiefenprofilen des Seesediments bestimmt. Eine Kombination der Ergebnisse ermöglicht es, die quantitativen Daten mit lokalen Informationen zu unterstützen. Die Untersuchung der Grundwasserqualität zeigt, dass die P-Konzentrationen im Grundwasser im besiedelten Bereich teilweise stark erhöht sind. Als Konsequenz daraus haben die grundwasserbürtigen P-Frachten einen Anteil von mehr als 50% an der gesamten externen P-Last des Arendsees. Das Grundwasser ist damit eine maßgebliche Ursache für die Eutrophierung des Gewässers.
Drei weitere Studien widmen sich der Entwicklung und Optimierung von Ansätzen zur qualitativen und quantitativen Bestimmung der Grundwasserexfiltration in Seen. Die kritische Auseinandersetzung mit den Ergebnissen der Studien zeigt die Notwendigkeit weiterer Forschung zur Verbesserung und Standardisierung der Methoden zur Bestimmung von LGD und damit verbundenen Stofftransporten auf. Der Fall des Arendsees sollte alle, Wissenschaftler und Praktiker, dazu motivieren, das Grundwasser als relevante Eutrophierungsquelle in Betracht zu ziehen.The present work is a collection of studies on lacustrine groundwater discharge (LGD) and groundwater-borne phosphorus (P) loads. For a number of reasons, groundwater exfiltration (i.e., LGD) is often not considered in water and nutrient budgets of lakes. This is also and especially true for P which was often regarded to be immobile in groundwater until recently. Two chapters review the scientific literature regarding the impacts of groundwater on hydrology and nutrient budgets of lakes, respectively. They present mechanisms and processes of LGD as well as techniques and methods to measure LGD and related nutrient transports. Moreover, numbers of LGD volumes and loads reported in literature are presented. The core of the present work is represented by two case studies dealing with the quantification of P loads from LGD to a lake in Germany. A combination of different methods is applied to overcome the problem of quantitative large scale LGD determination without losing local spatial information. P concentrations in groundwater and LGD are investigated by detailed spatial water sampling. The results reveal that P is actually present in concentrations far above natural background concentrations in the urban groundwater. LGD-derived P loads account for more than 50% of the overall external P loads to the lake and by that contribute significantly to lake eutrophication. Three further studies are devoted to the development and improvement of approaches to determine LGD. Critical reviews of the above mentioned studies reveal the need for further research in order to standardize and improve methods for LGD and mass load determination. It is found that the appropriate method for LGD determination depends on the spatial scale of interest. The identification of P introduced by LGD as a main driver of lake eutrophication is an important finding which should encourage scientists, policy makers, and lake managers to consider groundwater as a relevant P source for lakes.
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Weng, Weizhe. "Essays on Water Policy and Coupled Human and Natural Systems". Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/102031.
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Human and freshwater ecosystems are intrinsically interconnected. To better design effective policies, modeling tools and valuation methods are necessary to help understanding the complex reciprocal linkages between ecosystem processes and human actions, and coupled human and natural systems (CNHS) sets up a critical paradigm to do so. It is thus of both academic and empirical appeal to integrate reliable economic valuation methods with tools and models from multiple disciplines in order to quantify the feedbacks between human and natural systems and to inform better policy design.
Using freshwater resources as an example, this dissertation contains three essays which integrate natural science and economics models to understand how changes in human behavior and societal policies lead to changes in ecosystem services, and how changes in ecosystem services, in return, affect human decisions. The first two essays focus on agricultural nonpoint source pollution problems in United States and examines the impacts of potential water polices on both water polluters and water demanders. Specifically, in the first essay, a novel coupling between an ecological model of within-lake hydrodynamics and an economic model of hedonic property prices has been developed to quantify the connections between nutrient loading, lake water quality, and economic outcomes. Linking ecological processes with human decision-making provides a basis for enhanced evidence-based decision making in the context of reducing nonpoint-source pollution. In the second essay, an economic mathematical programming model is coupled with an agro-ecosystem model to investigate the behavioral adjustments and environmental pollution outcomes of water quality policies. A complete quantification of costs from all regulating sources are necessary to help pinpoint the efficient water policy design and reflecting the connection between human decisions and ecosystem processes. The third essay focus on the water quantity problem in another developed country, Australia. A discrete choice experiment method has been explored and used to provide estimates of willingness to pay for purchasing irrigation rights to restore a Ramsar-convention wetland. Water policy scenario described in this essay could directly affect the feedback between human and ecosystem processes and serve as a baseline for future planning and policy designs.
By offering both conceptual and methodological advancements, this dissertation aims to improve the understanding of coupled human and natural systems and the implementation of water policies. This dissertation also provides a framework to establish multi-disciplinary dialogues and cooperation between scientists and economists in the search of efficient water polices.Doctor of Philosophy
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Duthie, Troy, i mikewood@deakin edu au. "Nutrients in Pirron Yallock Creek, southwestern Victoria : paleolimnological and management considerations". Deakin University. School of Ecology and Environment, 2000. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20060706.124148.
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The concentrations of various forms of nitrogen and phosphorus in the main stream and selected tributaries of Pirron Yallock Creek, southwestern Victoria were examined over a two-year period. Exceedingly high levels of both nutrients were found within a particular tributary, while generally high nutrient levels were observed throughout the catchment. The speciation results indicated that dairy effluent was the primary source of nutrients to Pirron Yallock Creek.
A palaeolimnological study was undertaken to determine the impact of European settlement upon waterway nutrient concentrations within the region. The palaeolimnological study focused primarily on the diatom flora preserved within the sediments of nearby Lakes Corangamite and Bullen Merri. Lack of preservation of diatoms within the sediments of Lake Corangamite resulted in no water quality inferences for this lake. The preserved diatoms within Lake Bullen Merri suggested an increase in trophic status of this lake during the last 500 years. While a change in the diatom flora of Lake Bullen Merri was evident, it was not possible to differentiate the impact of European settlement upon nutrient status of this waterway from long-term trophic status change.
In light of the particularly high nutrient concentrations observed in Pirron Yallock Creek, improved nutrient management strategies are proposed for the catchment. These strategies, which consider current nutrient management activities, are predominantly focussed on the dairy industry, which occupies the majority of the catchment.
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Mansor, Maria Teresa Castilho. "Potencial de poluição de aguas superficiais por fontes não pontuais de fosforo na Bacia hidrografica do Ribeirão do Pinhal, Limeira- SP". [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257255.
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Orientadores: Denis Miguel Roston, Jose Teixeira FilhoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola
Made available in DSpace on 2018-08-04T08:27:27Z (GMT). No. of bitstreams: 1 Mansor_MariaTeresaCastilho_D.pdf: 2529546 bytes, checksum: 5e7bcdd25d9104de1649f7fade2168ac (MD5) Previous issue date: 2005
Resumo: Em áreas rurais onde há intensa atividade agrícola, a eutrofização de corpos de água pode ser acelerada pelo influxo de nutrientes, provenientes de fertilizantes, transportados por escoamento superficial. A eutrofização pode provocar mudanças indesejáveis na estrutura e funções do ecossistema, bem como na qualidade da água destinada ao abastecimento. O controle dos níveis de P nas águas superficiais é tido como a melhor maneira de minimizar a eutrofização, uma vez que o P é identificado como um nutriente limitante para o crescimento de algas. As águas da bacia do rio Piracicaba recebem grande aporte de efluentes domésticos e industriais pontuais, bem como grande aporte de efluentes agrícolas difusos, tendo sido documentado aí um elevado grau de eutrofização. Uma avaliação preliminar das contribuições difusas de nutrientes às águas superficiais da bacia hidrográfica do rio Jaguari - formador do rio Piracicaba - feita a partir de dados oficiais em uma área de estudo de 3394 Km2, mostrou que 68,2% da carga total anual de Ntotal e 77,3% da carga total anual de Ptotal foram transportados nos meses de chuva. Ao se estimar a razão entre a carga média anual de origem rural (difusa) e urbana (pontual), obteve-se o valor de 1,3 para o Ntotal e 2,6 para o Ptotal; os coeficientes de exportação a partir da área rural foram estimados em 2,3 Kg Ntotal.ha-I.ano-l e 0,4 Kg Ptotal.ha-l.ano-l. A área de drenagem da bacia do ribeirão do Pinhal - afluente do rio Jaguari e manancial de abastecimento de Limeira, SP - foi o foco principal deste estudo, ocorrido entre fevereiro de 2003 e fevereiro de 2004. Estimou-se, para uma área de 301,4 Km2 de ocupação majoritariamente agrícola, a quantidade de P aplicada ao solo como fertilizante, obtendo-se um total de 820 ton.anoo1, dos quais inferiu-se que 23% foram exportados pela biomassa. Monitorou-se, no mesmo período, as concentrações de Ptotal e SStotais em cinco pontos da bacia do ribeirão do Pinhal, objetivando a estimativa de fluxos. As cargas anuais de Ptotal e SStotais obtidas na entrada do reservatório do Tatu foram iguais a 5,7 e 2160 ton.ano-I, respectivamente, sendo que 67,5% do Ptotal e 84,5% dos SStotais foram transportados no período chuvoso. Os coeficientes de exportação obtidos na entrada do reservatório foram iguais a 0,2 KgPtotal.haol.anool e 7,4 tonSStotaiS.Km-2.ano-l. Ao se inferir sobre as cargas difusas de Ptotal transportadas por escoamento superficial pelo ribeirão do Pinhal, obteve-se uma razão de 0,6 entre a carga anual de origem difusa e aquela pontual, apontando a importância desta última na bacia. Por fim, fez-se um levantamento limnológico do reservatório do Tatu, e observou-se que o IET referente ao Ptotal e à clorofila a indicou estado eutrófico na cabeceira e barragem; entretanto, é provável que a alta taxa de descarga esteja limitando a proliferação de algas no reservatório. De modo geral, verificou-se preliminarmente a importância da poluição difusa de Ptotab de origem rural, na degradação das águas superficiais da bacia do rio Jaguari. Por outro lado, focando na bacia do ribeirão do Pinhal, concluiu-se que as altas concentrações de Ptotal aí obtidas foram influenciadas pela atividade industrial e ocupação humana, influência esta que se sobrepôs àquela do arraste de partículas causado pelo escoamento superficial decorrente das precipitações
Abstract: Intensive agricultural activities are known to cause anthropogenic inputs ofnutrients to surface waters in rural areas. The nutrient enrichment of water bodies, or eutrophication, can lead to highly undesirable changes in ecosystem structure and function, as well as in water quality for human consumption. It is known that nutrient loading restriction - specially the limiting nutrient phosphorus - is the essential comerstone of aquatic eutrophication controI. In a preliminary study, official water quality and flow data from Jaguari River were used to assess the diffuse loads of nutrients from rural areas into surface waters. Results showed that, in average, 68.2% of the TN annualloads and 77.3% of the TP annualloads were transported through a 3394 Km2 area during the raining season. The annual diffuse loads obtained coming primarily from rural sources - were equivalent to 55.1% and 69.4% ofthe total annual loads of TN and TP transported through the sub-basin, respectively. The mean export coefficients from diffuse loads were equal to 2.3 Kg TN.ha-1.year-1 and 0.4 Kg TP.ha-'.year-1. The main part of this study was realized at the Ribeirão do Pinhal - a Jaguari River affluent from February 2003 to February 2004. The annual phosphorus load applied as fertilizer to an area of301.4 Km2 ofthe ribeirão do Pinhal watershed was estimated to be 820 ton.year-', and 23% of it was calculated to be exported by the biomass of the agricultural fields. These results were based on the soil use and occupation of the area, mainly rural, producing basically sugarcane and citrus. The field sampling of Ribeirão do Pinhal superficial waters was done twice a month, in five locations at the watershed. Samples were analyzed for TP and TSS; the totalloads obtained were equal to 5.7 e 2160 ton.year-', respectively, at the entrance ofTatu reservoir; 67.5% of TP and 84.5% of TSS were transported during the raining season (October-March). The export coefficients obtained were equal to 7.4 ton TSS.Km-2.year-1 and 0.2 Kg TP.ha-1.year"'. A limnological profile of the Tatu reservoir was determined through field sampling in three locations on both dry and wet periods; results showed a eutrophic state at the entrance of the reservoir as well as at the damo Yet, the flushing rate is the possible limiting factor for the occurrence of eutrophication at the reservoir. In general, the importance of diffuse pollution, originally from rural areas, was verified at the Jaguari River watershed. On the other hand, at the Ribeirão do Pinhal watershed, the high TP concentrations observed were most1y influenced by the industrial and human activities occurring in the area
Doutorado
Agua e Solo
Doutor em Engenharia Agrícola
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Lakish, Benjamin. "Nutrients and chlorophyll dynamics in Fort Cobb Reservoir". Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4956.
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Thesis (M.S.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 31, 2008) Includes bibliographical references.
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Astill, Helen Lee. "The role of benthic macroalgae in sediment-water nutrient cycling in the Swan-Canning estuarine system, Western Australia". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2000. https://ro.ecu.edu.au/theses/1344.
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This study documented the macroalgal assemblages of the Swan-Canning Estuarine System (SCES) over a two year period, and the influences of several environmental parameters on the assemblages. In addition, the Impacts of unattached macroalgal accumulations on benthic nutrient fluxes and microbial communities were investigated. Benthic macroalgal assemblages and physico-chemical regimes were monitored in the SCES, to determine temporal and spatial changes in macroalgal communities and the influence of environmental factors in these changes. Physico-chemical regimes demonstrated strong seasonal changes, which revolved around the onset and cessation of freshwater flows in winter (May to September). In the months after freshwater flows, strong spatial variability in physico-chemical profiles was observed. However, by summer the system was essentially marine. Macroalgal biomass and species richness was lowest in winter. Species number was maximal during periods of greatest hydrological variability in the estuary (spring and autumn). It may be inferred from results of statistical analyses that substrate type (i.e. hard/soft) and waterflow were the most Influential factors over temporal and spatial distribution of macroalgal species in the SCES. These factors ware reflected by the patchiness of macroalgal distribution in the system- attached macroalgal species distributed unevenly according to availability of limited hard substrate and presence/absence of unattached macroalgal species corresponding to seasonal freshwater flows. One species, Gracileria comosa, dominated macroalgal biomass and was the most widespread species and commonly occurred as extensive, unattached accumulations. As G. comosa was the most abundant unattached macroalga, accumulations of this species were investigated to determine the characteristics and behaviour or accumulations in the Swan-Canning Estuarine System. Accumulations were characterised by seasonally measuring height and biomass of accumulations in three regions or the estuarine system over one year. The height of accumulations was generally between 5 and 25cm, regardless of water depth, location, or season. Biomass was highly variable, but generally between 100 and 500 dw/m2 . The persistence of macroalgal accumulations was monitored at 28 sites within 10 estuarine regions, over a three month period, during which the first freshwater flows were recorded. Accumulations persisted between one week and one month, depending on the region, with accumulations persisting for longer periods in areas of low flow such as embayments and the regulated Canning River, and for shorter periods In regions of higher flow such as the channalised Swan River. Field and laboratory studies were performed to determine If the presence of G. comosa accumulations had an Impact on sediment-water nutrient exchange. Field studies established that accumulations affected benthic nutrient fluxes within a 24 hour period. However, this effect was site-dependent, occurring at an estuarine site of relatively high sediment organic content, but not at a site of relatively low sediment organic. Diurnal changes in water quality inside algal accumulations corresponded to photosynthetic/respiratory activity of the macroalgae - most notably, Increases In orthophosphate and ammonium fluxes from the sediment after approximately 8h of darkness. Since this effect was on time scales less than the period of persistence (weeks to months), It was concluded that macroalgal accumulations have an impact on benthic nutrient fluxes from sediments of relatively high organic content in the system. Laboratory studies investigated the effect of depth and density of an algal layer on sediment- water nutrient exchange. The experimental results concurred with field observations; water column concentrations of inorganic nutrients were significantly higher in sediment cores overlain by an algal layer over a 7 day period. In addition, Inorganic nutrient concentrations increased With Increasing height of the layer and ammonium concentrations increased with increasing density of the algal layer. Additional laboratory experiments tested the effect of an algal layer on sediment denitrification rates, and the composition and distribution of benthic microbial populations, Benthic nitrogen (N2) release rates were low irrespective of the presence of macroalgae and sediment types (less than 1mmo N/m2/d). However, release rates were significantly higher in sediment cores covered by algae than in comparable bare sediment cores, provided the algal layer was relatively high (5cm in height} and sediment organic content was high. The presence of an algal layer did not have a significant effect on the composition or distribution of microbes in the sediment. In all cases, microbial populations contained relatively few denitrifiers/nitrate reducers compared to nitrifiers and ammonifiers. High ammonium release rates from the sediment to the water column, and the low release rates of elemental nitrogen, suggested that even II the nitrate reducing bacteria were active they were not reducing nitrate to nitrogen, suggesting the possibility of Dissimilatory Nitrate Reduction to Ammonium (DNRA). Subsequent analysis confirmed that the nitrate reducers were reducing nitrate to nitrite, a result compatible with the hypothesis that the main microbial processes occurring were ammonification, nitrification, and DNRA, but not denitrification. These processes, regardless of the presence of a benthic algal layer, contribute to high ammonium flux rates from the sediment and provide a mechanism of internal inorganic nitrogen regeneration. In conclusion, this study has established that unattached macroalgal accumulations are a prominent component of the macroatgal community in the Swan-Canning Estuarine System. Accumulations may remain within an estuarine region for up to one month, particularly in regions of low water flow. In seasons and regions of relatively high water flows (e.g. the Swan River), accumulations become highly transient, if present at all. At times, and in regions where they may persist, algal accumulations of 5cm or more in depth have an impact on benthic nutrient fluxes. In particular, their presence over sediments of high organic content appears to exacerbate the release of ammonium from the sediment to the overlying water column. Of note, the benthic process Dissimilatory Nitrate Reduction to Ammonium appears to dominate in summer while denitrification rates are minimal, regardless of the presence of a macroagal layer. From these findings, it is recommended that high fluxes of ammonium in the system be recognised In water quality management and nutrient budgets for the system, as It appears that Internal ammonium regeneration Is a large source of Inorganic nitrogen for organisms In the overlying water body, and may support algal blooms In summer. In addition, it appears that the most appropriate method of managing macroalgal distribution and biomass in the system is ensuring strong freshwater flushes during winter periods when macroalgal biomass is largely removed. If seasonal flushes were inhibited, it is predicted that macroalgal biomass and distribution would increase, extending the period that thsy can influence benthic nutrient cycles. The physical removal of macroalgae as a management option in such a scenario would require much time and effort, as the Swan-Canning Estuarine System is such a large system, and macroalgae are spread throughout. Therefore, in modifying river flows into the estuarine system, the quantity, composition and distribution of macroalgae, and possibly other flora and fauna, will be altered. This is already evident in the Canning River, which is regulated and suffers management problems, such as altered species composition, bathymetric changes, toxic algal blooms, and eutrophication.
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Farthing, Tessa. "Impact of a Forested State Park on Nutrient Concentrations in an Agriculturally Dominated Watershed in Southwest Ohio". Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1626999681372348.
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Penick, Mary Douglas. "Algal Biomass Accrual in Relation to Nutrient Availability along a Longitudinal Gradient in the Upper Green River, Kentucky". TopSCHOLAR®, 2010. http://digitalcommons.wku.edu/theses/190.
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Nutrient limitation in aquatic ecosystems results from a deficiency in nitrogen or phosphorus levels relative to cellular growth needs. Nutrient limitation of freshwater systems is a function of biotic and abiotic factors. Biotic factors include vascular and nonvascular plant community composition. Abiotic factors include underlying bedrock and land-use activities (e.g. agriculture, septic systems). Nutrient availability directly affects growth, productivity, and community structure of primary producers. The purpose of this study was two-fold: (1) to assess the relationship between ambient algal biomass. and in-stream nutrient levels along the longitudinal course of a river through a transition from weak to well-developed underlying karst bedrock, and (2) experimentally assess if periphyton was nitrogen or phosphorous limited between weak and well-developed karst sites. Sestonic and filamentous biomass (= chlorophyll-a) levels increased monthly along the longitudinal gradient. In contrast, periphyton biomass levels increased minimally monthly and displayed no longitudinal pattern. Nitrate and soluble reactive phosphorus levels exhibited distinct longitudinal increases, whereas total phosphorous displayed minimal change and ammonia levels decreased in the downstream direction. Total nitrogen (TN) levels increased upstream but decreased sharply in the well-developed downstream karst sites. The nutrient limitation assays revealed that the highest periphyton levels were with N + P treatments at the most upstream sites. Overall, in Kentucky's Green River algal biomass accrual appears to be mainly P-limited but likely also by TN availability during late summer.