巢湖市水源地铜绿微囊藻(Microcystis aeruginosa)藻团粒径时空分布规律

Spatio-temporal distribution of Microcystis aeruginosa colony diameters in the water source region of Chaohu City

于2011年4-8月按月对巢湖市水源保护湖区不同水深及不同区位的铜绿微囊藻藻团粒径进行抽样调查,利用统计分析方法,归纳了巢湖水源保护湖区铜绿微囊藻藻团粒径的时空分布规律.湖区铜绿微囊藻藻团出现在4月中旬至5月中旬之间,S1与S2点位表层的藻团粒径与中、底层的均存在显著差异.粒径小于200μm的藻团在各水深的分布都比较均匀,没有明显的趋向性;粒径在200～800μm范围内的藻团更易集中在湖水表层;粒径超过800μm的藻团更易集中在湖水底层.各月份外湖区S2点位藻团粒径水平均高于内湖湾S1点位.由于易受短时气象条件的影响,藻团粒径按月时间尺度变化的规律性不强.藻团形状在整个空间分布上没有显著差异性,但随着季节变化,逐渐由狭长形向规则形变化.藻团粒径的分布范围表明,大型仿生式蓝藻清除设备的过滤筛网对水源湖区铜绿微囊藻藻团的理论过滤效率为99.81%.

An investigation of Microcystiz aeruginosa colony diameters in different water depths and locations was carried out month- ly in the protection zone of water source region of Chaohu City from April to August, 201 I. The spatio-temporal distribution charac- teristics of the colony diameter were summarized using statistical analysis. The M. aeruginosa colony appeared between mid-April and mid-May, there was significant difference between the surface layer and lower-middle layers on colony diameters at both sam- pling sites of S1 and S2. Colonies with diameters less than 200 txm distributed vertically homogeneously in the water column, colo- nies with diameters between 200 μm and 800 μm tended to gather in the water surface, and colonies with diameters greater than 800 μm were apt to aggregate in the bottom layer. The level of colony diameter of outer sampling site （ S2 ） was higher than that of inner sampling site （ S1 ） in each month. Because the colony diameters were easily affected by the short-term meteorological condi- tion, the variance of colony diameters didn＇t show conspicuously regular monthly. There was no significant difference in the spatial distribution of colony shape, while it shifted gradually from elongated to regular with seasons changing. The distribution range of colony diameters indicated that, in theory, 99.81% of the total M. aeruginosa colonies can be filtered by the large bionic equip- ment for clearing cyanobacteria.