Applied Biology Program, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Ethiopia.
Aquatic Science, Fisheries and Aquaculture stream, Department of Zoological Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
Environ Sci Pollut Res Int. 2018 Sep;25(27):26861-26873. doi: 10.1007/s11356-018-2727-2. Epub 2018 Jul 12.
The composition and abundance of cyanobacteria and their toxins, microcystins (MCs), and cylindrospermopsins (CYN) were investigated using samples collected at monthly intervals from the Amudde side of Koka Reservoir from May 2013 to April 2014. Cyanobacteria were the most abundant and persistent phytoplankton taxa with Microcystis and Cylindrospermopsis species alternately dominating the phytoplankton community of the reservoir and accounting for up to 84.3 and 11.9% of total cyanobacterial abundance, respectively. Analyses of cyanotoxins in filtered samples by HPLC-DAD and LC-MS/MS identified and quantified five variants of MCs (MC-LR, MC-YR, MC-RR, MC-dmLR, and MC-LA) in all samples, with their total concentrations ranging from 1.86 to 28.3 μg L and from 1.71 to 33 μg L, respectively. Despite the presence and occasional abundance of Cylindrospermopsis sp., cylindrospermopsin was not detected. Redundancy analysis (RDA) showed that the environmental variables explained 82.7% of the total variance in cyanobacterial abundance and microcystin concentration. The presence of considerably high levels of MCs almost throughout the year represents a serious threat to public health and life of domestic and wild animals.
采用每月从 2013 年 5 月至 2014 年 4 月在科卡水库阿穆德一侧采集的样本，研究了蓝藻及其毒素微囊藻毒素（MCs）和柱孢藻毒素（CYN）的组成和丰度。蓝藻是最丰富和最持久的浮游植物类群，微囊藻和柱孢藻属物种交替主导水库的浮游植物群落，分别占总蓝藻丰度的 84.3%和 11.9%。通过 HPLC-DAD 和 LC-MS/MS 对过滤样品中的蓝藻毒素进行分析，在所有样品中均鉴定和定量了五种微囊藻毒素（MC-LR、MC-YR、MC-RR、MC-dmLR 和 MC-LA），其总浓度范围分别为 1.86 至 28.3μg/L 和 1.71 至 33μg/L。尽管存在并偶尔存在柱孢藻属，但未检测到柱孢藻毒素。冗余分析（RDA）表明，环境变量解释了蓝藻丰度和微囊藻浓度总方差的 82.7%。几乎全年都存在相当高水平的 MCs，这对公共健康以及家养和野生动物的生命构成了严重威胁。
