Vertical distribution and Diel migration patterns of phytoplankton in Xiangxi Bay, Three Gorges Reservoir of China, were investigated during the summer Microcystis bloom period (July 1, 2-3 and 7, 2008). Phytoplankton appeared to aggregate at daytime while be uniformly distributed at nighttime in the monitoring period, based on Morisita's index (MI) and the mean residence depth (MRD). Statistical analysis showed phytoplankton performed Diel vertical migration on July 1 and 2-3, but not on July 7. The results showed that solar irradiance was significantly correlated with MI and MRD (R-2>0.6, p<0.001) while relative water column stability accounted for more variations of both parameters (R-2>0.7, p<0.001). It indicated that solar irradiance and relative water column stability greatly affected vertical distribution patterns of phytoplankton in the Microcystis bloom period of Xiangxi Bay. The impact of wind velocity on vertical distribution of phytoplankton was not significant (p>0.05) in the monitoring period.
Wang, Lan; Cai, Qinghua; Zhang, Min; Xu, Yaoyang; Kong, Linghui; Tan, Lu.VERTICAL DISTRIBUTION PATTERNS OF PHYTOPLANKTON IN SUMMER MICROCYSTIS BLOOM PERIOD OF XIANGXI BAY, THREE GORGES RESERVOIR, CHINA,FRESENIUS ENVIRONMENTAL BULLETIN,2011,20(3):553-560