讲座题目：The impact of physical factors and processes on the functioning of aquatic ecosystems: Lake Kinneret as a case study
主 讲 人：Ilia Ostrovsky 教授
主 持 人：陈雪初 教授
开始时间：10月10日 13:00
讲座地址：闵行校区 资环楼273室
主办单位：生态与环境科学学院、科技处
报告人简介：
Ilia Ostrovsky教授是全球知名海洋湖沼学家，早在上世纪90年代前苏联时期就曾担任俄罗斯（前苏联）科学院水环境问题研究所首席科学家；现任以色列海洋湖沼研究所研究员、欧洲科学技术合作管理委员会成员。Ostrovsky教授为海洋湖沼学界所公认的科研成就包括：解析了深水湖泊蓝藻水华和有机颗粒物时空动态变化规律；率领团队研究开发了可以实时高频观测湖泊甲烷气泡排放的超声波技术，并揭示了深水湖泊甲烷气泡排放控制因子及其与水文扰动的关系等。
报告内容简介：
In this presentation, I will discuss the role of various physical phenomena in the formation of the biogeochemical processes in aquatic ecosystems, using the latest investigations on Lake Kinneret. The basin-scale internal seiches induce strong diapycnal mixing in the stratified water column. The strongest mixing occurs in proximity to the lake periphery. Such a mixing induces upward nutrient transport to the upper euphotic zone and can essentially enlarge primary productivity at the lake periphery, where organisms of the higher trophic levels (zooplankton and planktivorous fish) are concentrated. The internal seiche-induced resuspension transports the bottom particulate material toward the lake interior (pelagic zone) via the benthic boundary layer and metalimnetic jets. Such a transport induces lateral heterogeneity in sedimentation processes and focuses the light organic-rich particles in the deep lake areas. The organic-rich particles accumulated in the hypolimnetic anoxic sediments play an important role in the production of biogenic methane (a highly potent greenhouse gas), which is efficiently delivered to the atmosphere via gas ebullition. I will also discuss the impact of vertical turbulent mixing and diurnal stratification in the formation of blooms of toxic cyanobacterium Microcystis sp. Further, I will illustrate the short- and long-term effects of water level fluctuations on the reproduction and formation of fish productivity and sustainability of fisheries in subtropical Lake Kinneret. I will also show the importance of the implication of non-destructive remote-sensing technologies for studying fragile aquatic organisms.