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Document Type:Latin Dissertation
Language of Document:English
Record Number:53488
Doc. No:TL23442
Call number:‭1481473‬
Main Entry:Rebecca O'Hearn
Title & Author:Nutrients, chlorophyll and bacterial fecal indicators in coves and open water areas of Lake of the Ozarks, MissouriRebecca O'Hearn
College:University of Missouri - Columbia
Date:2009
Degree:M.S.
student score:2009
Page No:165
Abstract:Lake of the Ozarks was constructed for hydropower and has become a popular recreational river-reservoir in the Ozark Plateau of Missouri. Wide spread use of septic tanks in porous soils of the region poses a threat to public health via leaching into drinking wells and coves used for whole body contact. During summers 2007 and 2008, phosphorus (TP), nitrogen (TN), chlorophyll (Chl), fecal coliform (FC), and Escherichia coli (EC) were measured in 35 coves and 3 main channel sites in the Grand Glaize-Turkey Bend area of the reservoir to assess anthropogenic influences on water quality in coves. Bacteroides thetaiotaomicron (BT), an obligate human gut anaerobic bacterium, was concurrently monitored to determine the specificity of conventional fecal indicators (FC and EC). Record discharges were recorded for both summers and relationships between anthropogenic metrics and water quality variables (TP, TN, Chl, FC and EC) were not apparent. Steady increases in pool level throughout sampling created backflow from the main channel into coves and likely diluted local anthropogenic influences among coves. In a cross-cove regression on the main-stem of the study reach (28 coves), location of a cove relative to the dam accounted for 74% of the variation in TP, about half the variation in TN (48%) and Chl (50%), 29% of the variation in FC and 21% of the variation in EC. Among these coves, TP, TN, Chl, FC and EC declined from up- to down-reservoir, which reflected basin sedimentary processes typical of large riverine reservoirs. In a regression analysis of daily means, local wind speed accounted for a large percentage of the variation in FC (69%) and EC (86%), and a local rain event elevated site means for FC and EC. The obligate human gut anaerobe (BT) did not decline from up- to down-reservoir, was not positively related to wind speed, and was not influenced by the rain event. Unlike TP, TN, Chl, and conventional fecal indicators, BT was positively related to a surrogate for anthropogenic activity among daily means. These results indicate (1) conventional fecal indicators (FC and EC) often represent bacteria from soil erosion and sediment resuspension. Factors controlling these processes often dilute or obscure anthropogenic influences, and (2) relationships between BT and anthropogenic factors are not obscured by hydrologic and climatic processes, which allows detection of anthropogenic influences during circumstances when conventional fecal indicators (FC and EC) fail to detect them.
Subject:Health and environmental sciences; Earth sciences; Biological sciences; Public health; Water Resource Management; Environmental science; Limnology; 0768:Environmental science; 0573:Public health; 0595:Water Resource Management; 0793:Limnology
Added Entry:J. R. Jones
Added Entry:University of Missouri - Columbia