Author

Mary B. Price

Document Type

Thesis - Open Access

Award Date

1990

Degree Name

Master of Science (MS)

Department

Biology

Abstract

Lake management, from a water quality perspective, emphasizes the reduction of nutrient loadings to mitigate the eutrophication of lakes. Phosphorus is the nutrient of greatest concern as increases in annual phosphorus loadings are directly related to increases in the trophic state of a lake (Vollenweider 1968). Phosphorus is often the limiting nutrient regulating aquatic primary productivity and theoretically can generate 500 times its weight in algal biomass if all other elements necessary for phytoplankton growth are present (Wetzel 1983). Lake restoration projects involving the elimination of external phosphorus sources did not always reduce algal production within the expected recovery period. The delay in recovery has been attributed to the ability of lake sediment to function as an internal phosphorus reservoir capable of sustaining algal productivity in the absence of external phosphorus sources (Bengtsson 1975; Theis and DePinto 1976; Ahlgren 1977; Lee 1977; Ryding and Forsberg 1977). It is therefore essential to have an understanding of the sediment’s role in the cycling of phosphorus when attempting to predict the effect of lake restoration projects on water quality. A principal factor regulating the release of phosphorus from lake sediment is the dissolved oxygen concentration at the sediment-water interface (Mortimer 1941, 1942). Aerobic conditions generally enhance phosphorus uptake by sediment and anaerobic conditions facilitate the release of sediment phosphorus has been measured in laboratory experiments with intact sediment cores (Kamp-Nielsen 1974; Freedman and Canale 1977; Bates and Neafus 1980; Holdren and Armstrong 1980; Riley and Prepas 1984) and by mass balance studies that compared phosphorus input and output with changes in the lake water phosphorus levels (Ahlgren 1977; Stevens and Gibson 1977; Ryding and Forsberg 1977; Lee 1977). This study utilizes both the experimental and mass balance method to investigate the extent of sediment phosphorus release in the Oakwood Lakes system. The objectives of this study were to: 1) develop a hydrologic and phosphorus budget for Oakwood Lakes; 2) quantify the phosphorus content of the lake sediment; 3) quantify the magnitude of the phosphorus flux to or from intact sediment cores during aerobic and anaerobic conditions; 4) determine the relative importance of the tributary phosphorus loads and sediment phosphorus loads; 5) determine the in-situ release of sediment phosphorus by mass balance analysis.

Library of Congress Subject Headings

Lake sediments -- South Dakota
Eutrophication -- Control
Water -- Phosphorus content
Lake renewal

Format

application/pdf

Number of Pages

69

Publisher

South Dakota State University

Included in

Biology Commons

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