title: Turbulence increases the risk of microcystin exposure in a eutrophic lake (Lake Taihu) during cyanobacterial bloom periods.
abstract: Toxic cyanobacterial harmful algal blooms (CyanoHABs) have posed serious water use and public health threats because of the toxins they produce, such as the microcystins (MCs). The direct physical effects of turbulence on MCs, however, have not yet been addressed and is still poorly elucidated. In this study, a 6-day mesocosm experiment was carried out to evaluate the effects of wind wave turbulence on the competition of toxic Microcystis and MCs production in highly eutrophicated and turbulent Lake Taihu, China. Under turbulent conditions, MCs concentrations (both total and extracellular) significantly increased and reached a maximum level 3.4 times higher than in calm water. Specifically, short term (∼3 days) turbulence favored the growth of toxic Microcystis species, allowing for the accumulation of biomass which also triggered the increase in MCs toxicity. Moreover, intense turbulence raises the shear stress and could cause cell mechanical damage or cellular lysis resulting in cell breakage and leakage of intracellular materials including the toxins. The results indicate that short term (∼3 days) turbulence is beneficial for MCs production and release, which increase the potential exposure of aquatic organisms and humans. This study suggests that the importance of water turbulence in the competition of toxic Microcystis and MCs production, and provides new perspectives for control of toxin in CyanoHABs-infested lakes.
authors.affiliation: Taihu Lake Laboratory Ecosystem Station, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Taihu Lake Laboratory Ecosystem Station, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, PR China. Electronic address: qinbq@niglas.ac.cn.
authors.forename: Boqiang
authors.initials: B
authors.lastname: Qin
authors.affiliation: Taihu Lake Laboratory Ecosystem Station, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, PR China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Han
authors.affiliation: Taihu Lake Laboratory Ecosystem Station, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
mesh_terms: D002681:China; D000458:Cyanobacteria / Q000737:chemistry / Q000502:physiology*; D004784:Environmental Monitoring; D057097:Harmful Algal Bloom; D060106:Lakes / Q000382:microbiology*; D052998:Microcystins / Q000378:metabolism*; D014872:Water Movements; D014919:Wind
chemical_list: D052998:Microcystins
keywords: CyanoHABs; Eutrophic lake; Microcystin; Toxic Microcystis; Turbulence