环境微生物学.pptx

环境微生物学 ;第九章 有害藻类水华与微生物;主 要 内 容;水体富营养化已成为当今世界上水体普遍存在的环境难题。有害藻类水华 (harmful algal bloom,HAB) 的爆发那么是富营养化引起的生物污染现象。 ;水华和赤潮是指在适宜的化学物理等条件下,水体中的藻类短时间内大量繁殖并聚集的生态异常现象,这一现象假设发生于淡水通常称作水华,在海洋那么被称为赤潮.;太湖美，美在太湖水。然而在无锡鼋头渚景区，藻类密生，厚如油漆，发臭的湖水令人掩鼻，游客在这里拍完纪念照便急忙“逃离〞 。在湖畔的小渔港，渔船也被绿藻包围着，渔民们的生产、生活环境受到富营养化湖水的威胁 。;左：在滇池蓝藻水华收集区里，自动吸藻器在吸取厚达5厘米的微囊藻水华。;“滇池蓝藻水华污染控制技术研究〞课题的负责人、?我国著名藻类专家、中科院水生生物研究所研究员刘永定在滇池采集蓝藻水华样品。;;;Microcystis blooms can appear patchy as in the photo on the left, or thick like a carpet as in the picture on the right.;A dense accumulation close to a shore by the cyanobacterium Microcystis aeruginosa in Lake M?laren. Note the variations in the colours, which depends on cyanobacteria of different ages. Photo: Kerstin Bohm, County Administrative Board of Stockholm*.;Water bloom outbreak in Lake Biwa ; Diatom bloom. Found in both fresh and saline water. These blooms may colour the water brown.;A dense bloom of the dinoflagellate Noctiluca scintillans at a beach in the Limfjord, Denmark. Photo: Helene Munk S?rensen, County Board of ?rhus, Denmark ;Microcystis aeruginosa bloom in Crawley Bay, Swan-Canning Estuary, WA. Photo courtesy of West Australian Newspapers and used with permission of the Waters and Rivers Commission of Western Australia.;;Eutrophication and Algae Blooms;Men made eutrophication leads to an overgrow of algaes, a so called algae bloom, which results in scum formation and a reduced transparency of the water. ;These consequences do not only reduce the bathing water quality and are a nuisance but they might also be harmful, especially to bathing small children. ;Eutrophication especially occurs in coastal waters near the shore where a large amount of nutrients are transported by rivers. ;2.有害藻类水华的危害;二、有害藻类水华的防治;1.物理除藻 ;2.化学除藻 ;3.生物除藻 ;生物操纵论者提出的治理对策是:强调生态学的“下行效应〞,即“鱼类—浮游动物—浮游植物—理化因子〞,通过浮游动物来控制浮游植物。主要是水生无脊椎动物(如轮虫、枝角类和原生动物等)通过食物链产生影响。现在国外流行“生物操纵〞(Biomanipulation),以改变鱼类的组成和多少为主要手段,借助滤食性的鱼类对于小型藻类的牧食作用,直接遏制藻类的生长。;许多生物都能对藻类的生长