两座高原水库蓝藻群落结构与微囊藻毒素的分布对比研究

为了了解贵州高原水库蓝藻群落组成特征和微囊藻毒素分布,于2009年10月对贵州高原2座水库——万峰湖和百花湖采样调查。结果表明：万峰湖以蓝藻为主要优势藻,蓝藻中的拟柱孢藻（Cylindrospermopsis sp.）占绝对优势,浮游植物丰度在13.05×104～55.80×104 cells.L-1之间,蓝藻的丰度值占到了总量的82.55%,6个采样点中有3个（大坝、野鸭滩和革布）检出了微囊藻毒素MC-RR,且有1个点（革布）质量浓度超标,另外3个点（坝艾、坝达章和九里堡）未检出;百花湖以蓝藻、绿藻和硅藻共同构成优势藻,蓝藻中的假鱼腥藻（Pseudanabaena limnetica）是主要优势藻,浮游植物丰度在6.16×104～65.00×104 cells.L-1之间,蓝藻的丰度值在总体中所占比例为33.25%,3个采样点（大坝、岩脚寨和码头）均未检出微囊藻毒素。形成2个高原水库蓝藻群落结构和微囊藻毒素分布差异的原因可能是：2个水库中氮、磷营养盐水平不同引起浮游植物群落组成不同,进而导致了微囊藻毒素的分布出现差异。

Cyanobacteria composition and microcystins distribution of Wanfeng Reservoir and Baihua Reservoir on Guizhou Plateau

Aim： To understand the cyanobacteria composition and microcystins distribution of reservoirs in Guizhou Plateau,Wan-feng Reservoir and Baihua Reservoir were chosen to be investigated in October 2009.Results： The dominant phytoplankton species was cyanobacteria in Wanfeng Resevoir in which Cylindrospermopsis sp.took preponderance absolutely.The phytoplankton abun-dance ranged between 13.05×104 cells·L-1 and 55.80×104 cells·L-1 with cyanobacteria taking up to 82.55% in total.Mycrocystins-RR was detected in 3 sampling sites（Daba,Yeyatan and Gebu） while not in the other 3 sites（Baai,Badazhang and Jiulibao）,and the concentration of mycrocystins reached above the limitation in 1 site（Gebu） according to Chinese standard.In Baihua Reservoir,the dominant species were mainly composed of cyanobacteria,chlorophyta and bacillariophyta.Pseudanabaena limnetica.dominated cyanobacteria.The phytoplankton abundance varied from 6.16×104 cells·L-1 to 65.00×104 cells·L-1 with cyanobacteria accounting for 33.25% in total.None of the 3 sampling sites（Daba,Yanjiaozhai and Matou） found Mycrocystins.The reason for the differences between Wanfeng Reservoir and Baihua Reservoir in cyanobacteria composition and microcystins distribution is possibly that dif-ferent nutrients level of nitrogen and phosphorus caused distinction of phytoplankton community structure,and then resulted in the diversity of microcystins distribution.