Hydrodynamic and biochemical interactions of cyanobacterial blooms with the air-water interface in lakes

蓝藻水华与湖泊空气-水界面的水动力和生化相互作用

• 批准号: 448586515
• 负责人: Professor Dr. Andreas Lorke
• 金额: --
• 依托单位: Institute of Hydrobiology
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/448586515?language=en
• 关键词: Hydrodynamic; biochemical; interactions; cyanobacterial; blooms

Cyanobacterial surface blooms (surface scum layers) are a harmful phenomenon that negatively affect water quality, human and animal health. Colony-forming Microcystis is one of the most important and ubiquitous genera that can suddenly accumulate at water surfaces. Improved knowledge about the physical processes and environmental conditions that govern and promote Microcystis scum formation is critical for successful prediction and for the development of lake management and mitigation strategies. The objective of this project is improvement of the mechanistic understanding on the formation, persistence and decline of Microcystis surface blooms in inland waters. As a novel aspect, we study the interactions of surface blooms with interfacial hydrodynamics at the air-water interface. We expect that extracellular polymeric substances, which are released by Microcystis, promote colony formation and surface bloom development. In addition, also the physical properties of the water surface are affected by these surface-active substances, leading to more stable conditions and therewith to more favorable conditions for bloom persistence. While the microlayer at the water surface, surface scum and colony growth are promoted by weak levels of turbulence, they are susceptible to mechanical stress and vertical mixing at high turbulence intensities. The project aims at identifying the main environmental controls on these interactions in laboratory and field experiments. The multidisciplinary project combines the complementing expertises of the Chinese and German team in phytoplankton ecology and in physical limnology, respectively. Joint experiments will be conducted in Germany and in China and involve extensive exchange of researchers and students from both countries.

蓝藻表面水华(表面浮渣层)是一种有害的现象，对水质、人和动物的健康都有负面影响。集落形成微囊藻是最重要、最普遍的藻类之一，它可以突然聚集在水面上。增进对支配和促进微囊藻浮渣形成的物理过程和环境条件的了解，对于成功预测和制定湖泊管理和缓解战略至关重要。本项目的目标是提高对内陆水域微囊藻表面水华的形成、持续和衰落的机理的认识。作为一个新的方面，我们研究了表面水华与空气-水界面的界面流体动力学的相互作用。我们期望微囊藻释放的胞外聚合物促进菌落形成和表面水华的发展。此外，水表面的物理性质也受到这些表面活性物质的影响，导致更稳定的条件，从而产生更有利的水华持续条件。弱湍流度对水面微层、表面浮渣和菌落生长有促进作用，但在高湍流度下易受机械应力和垂直混合的影响。该项目旨在确定实验室和现场实验中对这些相互作用的主要环境控制。该多学科项目结合了中国和德国团队在浮游植物生态学和物理湖沼学方面的互补专业知识。联合实验将在德国和中国进行，两国的研究人员和学生将进行广泛的交流。