碩士 / 國立臺灣大學 / 環境工程學研究所 / 100 / Algal blooms in reservoir will not only result in increased water purification costs, may also cause many environmental problems. Microcystis, which is one of the most notorious bloom-forming cyanobacteria occurring in freshwaters, forms large colonial aggregates. Forming Colonies is helpful to vertical migration, nutrient storage, and to defense against predation pressure. Therefore, aggregation or formation of bigger colonies is believed to be a special ability of Microcysits to dominate over other phytoplanktons in the thermally stratified lakes or reservoirs.
Water samples from Hsin‐shan water Reservoir from 2010 to 2011 were examined for the particle size distribution of Microcystis colonies. The result shows that the particle sizes were larger in 2011 when Microcystis was dominant in summer. On the contrary, the averaged particle size was smaller in 2010 when Microcystis was not dominant. In addition, we have used different calculation methods to represent particle size and analyse the correlations among the water quality parameters in Hsin‐shan reservoir. The results show that the colony size is significantly correlated with CTSI, concentration of chlorophyll a and water conductivity. Because the source of the major conductivity in reservoir water may be from polluted inflow, which also has higher nutrient concentration and leads to the growth of Microcystis. Higher conductivity gave rise to chlorophyll a concentration, and larger colonies of Microcystis, which all are the advantages of Microcystis in the water.
In this study, the relationship of the Microcystis colony size and light intensity was also examined under different light intensity (25μEm-2s-1, 65μEm-2s-1 and 125μEm-2s-1). No significant difference on the change of colony size was observed. The particles grew bigger for the first and second days then became unchanged. The reasons may be that Microcystis do not need to compete for nutrients under high nutrient concentration and the value of light intensity is too small to influence Microcystis to form colony.
| Identifer | oai:union.ndltd.org:TW/100NTU05515013 |
| Date | January 2012 |
| Creators | Chan-Peng Chou, 周展鵬 |
| Contributors | Shian-Chee Wu, 吳先琪 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 67 |
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