title: Phytoplankton variation and its relationship with the environment in Xiangxi Bay in spring after damming of the Three-Gorges, China.
abstract: Following the completion of the Three-Gorges Dam, there was a strong spring phytoplankton bloom in Xiangxi Bay of Three-Gorges Reservoir. However, our knowledge of relationship between spring phytoplankton bloom and environmental factors was still limited. In this study, phytoplankton species composition, biomass, chlorophyll a concentration and environmental factors at two sampling sites in Xiangxi Bay were investigated during 25 March to 18 May 2007. The Xiangxi Bay was eutrophic with the lowest values of total nitrogen and total phosphorus being 0.80 and 0.07 mg/L, respectively. A total of 66 algal taxa belonging to seven phyla and 45 genera were identified. Peridiniopsis niei Liu was the most abundant species which preferred standing water. Canonical correspondence analysis and correlation analysis revealed that nitrate was significantly associated with phytoplankton growth. The phytoplankton chlorophyll a concentration was correlated significantly negatively with nitrate concentration, and nitrate concentration was very low during bloom periods. Heavy rainfall was the main reason of phytoplankton chlorophyll a concentration and biomass decreasing and blooms disappearing. In addition, heavy rainfall also brought more nitrate into the Bay which provided sufficient nitrogen source for blooms occurring again.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, The People's Republic of China. zhougj01@gmail.com
authors.forename: Guangjie
authors.initials: G
authors.lastname: Zhou
authors.forename: Xuemin
authors.initials: X
authors.lastname: Zhao
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Bi
authors.forename: Yubin
authors.initials: Y
authors.lastname: Liang
authors.forename: Jianlin
authors.initials: J
authors.lastname: Hu
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Yu
authors.initials: Y
authors.lastname: Mei
authors.forename: Kongxian
authors.initials: K
authors.lastname: Zhu
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Hu
mesh_terms: D002681:China; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D004784:Environmental Monitoring / Q000379:methods*; D005843:Geography; D010839:Phytoplankton / Q000145:classification* / Q000254:growth & development* / Q000378:metabolism; D045483:Rivers
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A