Phytoplankton development and ecological status during a cyanobacterial bloom in a tributary bay of the Three Gorges Reservoir, China

• Published in: The Science of the total environment Vol. 409; no. 19; pp. 3820 - 3828
• Main Authors: Wang, Lan, Cai, Qinghua, Tan, Lu, Kong, Linghui
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.09.2011; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Ceratium hirundinella; China; Chroomonas; Chroomonas acuta; Communities; Cryptomonas; Cyanobacteria - growth & development; Cyanobacterial bloom; Cyclotella; Cyclotella stelligera; Ecological monitoring; Ecological status; Ecology; Ecosystem; Environmental Monitoring; Eudorina; Eudorina elegans; Eutrophication; floods; Functional groups; Fundamental and applied biological sciences. Psychology; Longitudinal pattern; Pandorina; Pandorina morum; Pediastrum; Pediastrum duplex; Phytoplankton; Phytoplankton - growth & development; Phytoplankton functional groups; Population Dynamics; Pyramimonas; Q index; Reservoirs; Sea water ecosystems; Sphaerocystis; Sphaerocystis schroeteri; Stephanodiscus; Stephanodiscus hantzschii; surveys; Synecology; Tributary bay; Upstream; Water Quality; Asia; China; China, People's Rep., Sichuan Prov., Changjiang R., Three Gorges Dam; China, People's Rep; Phytoplankton functional groups; Cyanobacterial bloom; Longitudinal pattern; Q index; Tributary bay; Ecological status; Marine environment; Ecosystem health; Bloom; Cyanobacteria; Development; Bacteria; Phytoplankton; Bay; Functional group
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2011.06.041

Reservoirs can provide suitable conditions for cyanobacterial bloom development, which may impact on water quality and biological communities. Weekly surveys in a cyanobacterial bloom process were carried out in the mainstream and Xiangxi Bay of the Three Gorges Reservoir (China), from June 6 to July 18 in 2008. By application of the phytoplankton functional group approach, the spatiotemporal pattern, impact factors, and the ecological status based on Q index (assemblage index) were analyzed. The depth of euphotic layer was apparently the key factor driving the phytoplankton functional group variations. Longitudinal patterns of phytoplankton distribution were detected during this bloom: in the beginning phase, groups D (mainly Stephanodiscus hantzschii) and B ( Cyclotella stelligera) dominated in the mainstream of the Three Gorges Reservoir and the mouth area of Xiangxi Bay, group Y ( Cryptomonas species) dominated in the upper area, while groups J (mainly Pediastrum duplex), F (mainly Sphaerocystis schroeteri) and G ( Pandorina morum and Eudorina elegans) were important in other areas; in the mid phase, group M became absolutely dominant in the whole region; and in the ending phase, besides groups M and Y, groups X2 ( Chroomonas acuta, Pyramimonas nanella, etc.) and Lo ( Ceratium hirundinella) became more important in the lower and upper area respectively. Generally the ecological status was bad, temporally varied with the bloom process. No spatial difference of ecological status was found in the mainstream, while longitudinal patterns in Xiangxi Bay were detected for different phases: firstly a few sites had relatively better status than the others, then nearly all the sites were in the bad condition, and at last the status in the downstream was better than that in the upstream. The longitudinal patterns of ecological status were related to phytoplankton distribution, disturbed by jacking from the downstream and flood from the upstream of Xiangxi Bay. ► Spatio-temporal dynamics of cyanobacterial bloom was studied using phytoplankton functional group approach. ► Light seemed more important in driving phytoplankton functional group changes. ► Special longitudinal pattern existed in phytoplankton distribution and also the ecological status.