An Analysis of Diatom Growth in Hypereutrophic Grand Lake St. Marys

Grand Lake St. Marys in Northwest Ohio provides the towns of St. Marys and Celina with recreational uses, tourism dollars and most importantly serves as the main water supply for town of Celina. However lake eutrophication has resulted in numerous chronic blooms of a toxic cyanobacterium, Planktothrix sp. As a result, tests are being done to see whether conditions can be manipulated so that the toxic cyanobacterium can be replaced by a more benign algal community dominated by diatoms. Newly formed diatom cell walls are detectable by virtue of their fluorescence when stained with the Lyso Sensor dye as it is specifically incorporated into the silica matrix of the wall. Thus the stimulation of the diatom community is directly measured by fluorescence. Additionally, tests have been unsuccessful in stimulating via additions of nitrogen, silica and phosphorous. Tests were done in parallel to the sodium aluminate (alum) treatments being performed in the lake to measure the effectiveness of the alum treatments. tests were done in parallel to the sodium aluminate (alum) treatments being performed in the lake to measure the effectiveness of the alum treatments