title: Use of a generalized additive model to investigate key abiotic factors affecting microcystin cellular quotas in heavy bloom areas of Lake Taihu.
abstract: Lake Taihu is the third largest freshwater lake in China and is suffering from serious cyanobacterial blooms with the associated drinking water contamination by microcystin (MC) for millions of citizens. So far, most studies on MCs have been limited to two small bays, while systematic research on the whole lake is lacking. To explain the variations in MC concentrations during cyanobacterial bloom, a large-scale survey at 30 sites across the lake was conducted monthly in 2008. The health risks of MC exposure were high, especially in the northern area. Both Microcystis abundance and MC cellular quotas presented positive correlations with MC concentration in the bloom seasons, suggesting that the toxic risks during Microcystis proliferations were affected by variations in both Microcystis density and MC production per Microcystis cell. Use of a powerful predictive modeling tool named generalized additive model (GAM) helped visualize significant effects of abiotic factors related to carbon fixation and proliferation of Microcystis (conductivity, dissolved inorganic carbon (DIC), water temperature and pH) on MC cellular quotas from recruitment period of Microcystis to the bloom seasons, suggesting the possible use of these factors, in addition to Microcystis abundance, as warning signs to predict toxic events in the future. The interesting relationship between macrophytes and MC cellular quotas of Microcystis (i.e., high MC cellular quotas in the presence of macrophytes) needs further investigation.
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Tao
authors.forename: Ping
authors.initials: P
authors.lastname: Xie
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Boqiang
authors.initials: B
authors.lastname: Qin
authors.forename: Dawen
authors.initials: D
authors.lastname: Zhang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Niu
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.forename: Laiyan
authors.initials: L
authors.lastname: Wu
mesh_terms: D002681:China; D000458:Cyanobacteria / Q000378:metabolism*; D060766:Drinking Water; D004784:Environmental Monitoring; D005618:Fresh Water / Q000382:microbiology; D005843:Geography; D006863:Hydrogen-Ion Concentration; D060106:Lakes; D052998:Microcystins / Q000378:metabolism*; D046931:Microcystis / Q000378:metabolism / Q000502:physiology*; D010100:Oxygen / Q000737:chemistry; D012621:Seasons; D013696:Temperature; D014871:Water Microbiology; D014876:Water Pollution
chemical_list: D060766:Drinking Water; D052998:Microcystins; C078588:microcystin; D010100:Oxygen