• 关键词：蓝藻  微囊藻毒素  水体富营养化  时空分布  山仔水库  福州

• 基金项目：福建省自然科学基金项目(No.B0910098);福建省教育厅项目(No.03BE654,03WE711)

• 王菲凤
• 1. 福建师范大学环境科学与工程学院, 福州 350007; 2. 福建师范大学地理科学院, 福州350007

• 仝川
• 福建师范大学地理科学院, 福州350007

• 杨芳
• 福州市环境监测站, 福州 350003

• 陈祖亮
• 福建师范大学环境科学与工程学院, 福州 350007

• 杨红玉
• 福建师范大学地理科学院, 福州350007

• 摘要：在福州市第二饮用水源地山仔水库选取七里(库区入口)、库心(库区中心)和坝前(库区出口)3个典型断面,研究了2008年7～12月蓝藻水华发生至消退后期水体中溶解性微囊藻毒素(Extracellular Microcystins,EMCs)和藻细胞内微囊藻毒素(Intracellular Microcystins,IMCs)₂种主要异构体(Microcystin-LR、Microcystin-RR)的时空分布特征,并采用固相萃取-超高效液相色谱法分析了这2种异构体MC-LR、MC-RR的浓度水平.结果表明,山仔水库蓝藻水华产生的最主要微囊藻毒素亚型是MC-LR,其次为MC-RR.MC-LR浓度的时空分布特征明显,季节性分布表现为:秋季>夏季>冬季,最高浓度出现在10月份,分别为IMC-LR11.43μg·L^-1、EMC-LR1.403μg·L^-1;水平方向空间分布呈现从水库入口到出口沿水流方向逐渐降低的显著特征;水华暴发期垂向空间分布呈指数型衰减,浓度峰值位于0.5～2.0m的近表层水体,消退后期垂向分布呈"W"型或"N"型波动,浓度峰值出现在10～25m的中下水层.MC-RR总体上在低浓度范围内波动,没有明显的时空分布规律.EMCs、IMCs浓度水平和变化特征受水温、光照、氮磷营养盐、水生生物和底泥环境生态特征等综合因素的共同影响.

• Abstract：Shanzai Reservoir,one of the drinking water resources in Fuzhou city,was examined for microcystin contamination at three locations-Qili (the entrance),Kuxin (the center) and Baqian (the exit). The concentrations of extracellular (EMCs) and intracellular microcystins (IMCs) in the samples,including two isomers of microcystin-LR (MC-LR) and microcystin-RR (MC-RR)-were monitored from July to December in 2008 to study their temporal and spatial distribution. The results demonstrated that MC-LRwas the major microcystin in the Shanzai Reservoir,but its concentration changed obviously with time and location. Seasonally,the concentration of EMC-LRand IMC-LRreached 11.43 μg·L^-1 and 1.403 μg·L^-1,respectively,in October,but their concentrations decreased in the order of autumn > summer > winter. For spatial distribution,the concentrations of EMC-LRand IMC-LRgradually reduced horizontally,while vertically they exhibited an exponential attenuation trend in the cyanobacterial bloom stage,where the peak content levels ranged from 0.5～2 m below the surface. However,in the later stage of the algae fading period,their vertical distribution showed "W" or "N" type fluctuations,where the peak content levels occurred in the 10～25 m deep water layer. Since the concentrations of EMC-RRand IMC-RRwere lower,they did not exhibit any apparent spatial or temporal distribution. The concentrations of EMCs and IMCs could result from the influences of water temperature,illumination,nitrogen and phosphorus concentrations,hydrophytes and sediment characteristics.

• Key words：cyanobacteria  microcystin  eutrophication  spatial and temporal distribution  Shanzai Reservoir  Fuzhou

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