Trophic state of three North Carolina Coastal Plain impoundments / by Phillip Joe Smith.
| Author/creator | Smith, Phillip Joe author. |
| Other author | Bellis, Vincent J., 1938- degree supervisor. |
| Other author | East Carolina University. Department of Biology. |
| Format | Theses and dissertations |
| Production | 1977. |
| Description | 155 leaves : illustrations ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | Trophic status was evaluated for three North Carolina impoundments subjected to differing degrees of cultural influence. Bi-weekly sampling of each impoundment was carried out from October, 1973, through October, 1974. Water quality parameters measured included pH, conductivity, turbidity, major nutrients, dissolved oxygen profile, BOD, chlorophyll a phytoplankton species composition, density, diversity, and gross primary productivity. Hardee Lake, surrounded by an urban subdivision and cultivated fields, was influenced by both domestic and agricultural enrichment. The algal floral composition, high cell density, low diversity, and high Cyanophyte productivity in Hardee Lake during summer were indicative of advanced eutrophication. Carson Lake was influenced by agricultural runoff and showed a trend toward eutrophication as evidenced by a blue-green algal dominance during summer. Agricultural source of nutrients appeared to have less effect on the trophic state of Carson Lake than the combined effect of both agricultural and urban stress had on the trophic state of Hardee Lake. Sheppard's Millpond, a brown-water impoundment, was the least affected by cultural influence because the watershed has not experienced urban development and the millpond receives little agricultural runoff owing to a buffer zone. Lower trophic state may have resulted from growth constraints inherent in dark acidic water, reduced availability of phosphorus complexed by particulate organic matter, and filtering out of nitrates by the forested watershed. Based on nitrogen-to-phosphorus ratios all three impoundments appeared to be phosphorus limited. Greater concentrations of orthophosphate during spring and summer in Hardee Lake were accompanied by higher phytoplankton densities and greater frequencies of blue-green algal blooms. The contribution of nitrogen and phosphorus from agricultural and lawn fertilizer applications and septic tank seepage appeared to stimulate phytoplankton density and production in Hardee Lake. Trophic evaluation based on direct measures of biological eutrophication showed that nutrient concentrations, phytoplankton density, diversity, and production in Hardee Lake were indicative of a hypereutrophic condition. Annual gross primary production-rate of Carson Lake was indicative of an oligotrophic condition Sheppard's Millpond on the basis of its phytoplankton composition, high diversity, and low productivity was characteristic of oligotrophy. |
| General note | "A thesis presented to the faculty of the Department of Biology ... in partial fulfillment of the requirements for the degree Master of Science in Biology." |
| General note | Advisor: Vincent J. Bellis |
| Dissertation note | M.S. East Carolina University 1977 |
| Bibliography note | Includes bibliographical references (leaves 87-90). |