太湖梅梁湾水华蓝藻复苏过程的研究

Recruitment dynamics of bloom-forming cyanobacteria in Meiliang Bay of Taihu Lake.

采用在底泥表面设置藻类细胞捕捉器的方法,测定其中的色素含量变化,并与水柱和底泥中的色素含量变化相比较.结果表明,藻类复苏与底泥环境中的温度、光照、溶解氧、氧化还原电位均有密切关系,叶绿素a、b和藻蓝素所表征的总藻类、绿藻以及蓝藻的上浮率分别为59.84%、76.83%和466.98%,3种藻的上浮量分别占相应浮游藻类最大生物量的7.18%、3.71%和9.33%.蓝藻复苏对太湖水华的形成具有很重要的意义.

A collection trap was installed on the sediments in Meiliang Bay of Taihu Lake during the period from March to June to investigate the recruitment of phytoplankton,and cyanobacteria in particular.The algal abundance in the trap was monitored,and compared with that in water column and surface sediments.The results showed that the algal recruitment was related to the temperature,irradiance,DO content,and oxidation-reduction potential (ORP) in surface sediment.After over-wintering on the sediments,the colonies of cyanobacteria experienced a prior developmental process before re-invasion of the water column.During the investigation period,the recruitment rates of chlorophyll a and b and PC were 59.84%,76.83% and 466.98%,and the recruitment amounts accounted for 7.18%,3.71% and 9.33% of their maximum pelagic counterparts in water column,respectively.These results showed that shallow lake was the important seed bank to the pelagic populations,and water bloom was formed as the result of the recruitment and biomass accumulation of cyanobacteria.