Cultural eutrophication of West Point Lake ? a 10-year study

Abstract

Urban development, primarily in the Atlanta, Georgia, metropolitan area, caused a significant rise in the volume of treated wastewater discharged into the Chattahoochee River from 1976 to 1985. West Point Lake, 109 km downstream from Atlanta, responded to the increased nutrient loading with an increase in mean annual phytoplankton primary productivity of from 550 mg C m -2 day -' in 1976 to 1580 mg C m -2 day -' in 1985, a move from mesotrophic to eutrophic status. Monthly water quality measurements in the lake headwaters failed to detect the trend of increasing enrichment. Phytoplankton chlorophyll a concentrations did not indicate a trend of increasing algal biomass. Increased productivity was caused by improved photosynthetic efficiency that resulted from a shift in the size distribution of algae comprising the phytoplankton community. Larger centric diatoms with relatively slow turnover rates that were dominant during the early years (1976)(1977)(1978)(1979)(1980) of impoundment were replaced by smaller green and blue-green algal taxa with faster turnover rates during later years (1981)(1982)(1983)(1984)(1985).

Lake Eutrophication at the Urban Fringe, Seattle Region, USA

“…ies (4,14,16,17). However, there have been instances of human lakeshore development that did not lead to eutrophication (18).…”

“…Lakes in urban centers may be more eutrophic because they have higher densities of humans and associated human impacts (4,5,14). If so, then we would predict that lake eutrophication would be correlated with shoreline residential development.…”

“…Population growth, and specifically residential development, is associated with many environmental impacts (3), including nutrient pollution and subsequent eutrophication of lakes (4)(5)(6). Eutrophication of lakes refers to a group of symptoms that lakes generally display when they have been overloaded by nutrients, namely nitrogen and phosphorus (7,8).…”

Evaluación del estado trófico y comparación de modelos relativos al fósforo en los embalses de Cernadilla y Valparaíso (río Tera, Zamora)

“…Esto condiciona un aumento de su estado trófico, paliado en parte por la salida hipolimnética, que favorece la eliminación de las sustancias acumuladas. En este caso, el deterioro de la calidad del agua durante la estratificación, no se debe a un incremento de la carga externa, como es frecuente en otros embalses (BAYNE et al, 1990;KOUSSOURIS et al, 1991;KILIKIDIS et al, 1992), sino a cambios favorece la desestratificación temprana en Cernadilla, lo que puede tener un efecto ambiguo sobre la calidad del agua. Por un lado favorece la difusión de oxígeno hacia las zonas profundas, que ya no están aisladas por una termoclina efectiva, pero por otro, al contar con una gran extensión de sedimento epilimnético, puede poner a disposición de los productores primarios abundantes nutrientes, aumentando su productividad (NÜRNBERG, 1987 b;JAMES & BARKO, 1991).…”