Dissolved Oxygen Characteristics of Spring Algal Bloom in Xiangxi Bay of Three Gorges Reservoir

Dissolved oxygen characteristics of spring algal bloom in Xiangxi Bay of Three Gorges Reservoir were studied. In surveys, 12 stations have been investigated and 132 samples were collected weekly from February 24 to May 10 in 2008. Chlorophyll a, pH and water temperature could be the significant influence factors to dissolved oxygen in spring algal bloom by using stepwise multiple binomial regression and correlation analysis method. Mean value of dissolved oxygen in Xiangxi Bay during spring algal bloom was 8.555 2.414 mg/L with a minimum and maximum concentration of 4.719 and 19.543 mg/L respectively and dissolved oxygen increased to the peak level as a result of algal bloom occurred in Xiangxi Bay and oxygen released during phytoplankton photosynthesis. Dissolved oxygen decreased from the surface to the bottom in the water column. The spatial change of dissolved oxygen in the bottom was not significant and difference of dissolved oxygen between the surface and the bottom in Xiangxi Bay was more significant than Yangtze River.