Yezin Dam is a man-made reservoir located close to Yezin village in Myanmar. Its water is used for irrigation, domestic purposes and as drinking water for many urban communities in the watershed area. In recent years, increased pollution due to the concurrent development around the dam has led to water quality deterioration. No detailed study on the distribution of cyanobacteria and toxin production has been conducted so far. In order to provide insight into the extent of cyanobacteria and cyanotoxins in the dam, water samples were collected once in January 2014 for the isolation of cyanobacterial strains and eight times between March 2017 and June 2018 for the investigation of physical, chemical and biological parameters. A total of 99 phytoplankton taxa belonging to 50 genera were recorded from Yezin Dam. Microscopic examination showed that a Dolichospermum sp. was the dominant cyanobacterium followed by small numbers of Microcystis, and Raphidiopsis raciborskii in all samples throughout the sampling period. 15 isolated cyanobacterial strains were classified morphologically and phylogenetically as Dolichospermum smithii, R. raciborskii and Microcystis and tested for microcystins (MCs), cylindrospermopsins (CYNs), saxitoxins (STXs) and anatoxins (ATXs) by liquid chromatography-tandem mass spectrometry (LC–MS/MS) and enzyme-linked immunosorbent assay (ELISA). The toxin analysis of all isolated Dolichospermum strains by ELISA and LC–MS did not indicate the presence of ATXs, STXs, CYNs nor MCs. Four of the five isolated Raphidiopsis strains produced CYN and deoxyCYN. One of the isolated Microcystis strains (AB2017/08) from Yezin Dam produced 22 MC congeners. Concentrations of 0.12 μg L⁻¹ CYNs and 0.34 μg L⁻¹ MCs were also found in an environmental sample from Yezin Dam by ELISA. The potential therefore exists for the use of untreated water from Yezin Dam to cause harmful effects on humans, domestic and wild animals.

耶津大坝是一个人造水库，位于缅甸耶津村附近。其水用于灌溉、家庭用途以及流域地区许多城市社区的饮用水。近年来，由于大坝周围的同步开发造成的污染增加，导致水质恶化。迄今为止，还没有对蓝藻分布和毒素产生进行详细研究。为了深入了解大坝中蓝藻和蓝藻毒素的范围，2014 年 1 月采集了一次水样用于分离蓝藻菌株，2017 年 3 月至 2018 年 6 月采集了 8 次用于物理、化学和生物参数的调查。叶津坝共记录浮游植物50属99个。显微镜检查表明，Dolicospermum sp. 在整个采样期间，所有样品中的主要蓝藻是微囊藻，其次是少量的微囊藻和Raphidiopsis raciborskii。15 株分离的蓝藻菌株在形态学和系统发育上被分类为Dolicospermum smithii、R. raciborskii和Microcystis，并测试了微囊藻毒素 (MCs)、圆柱藻毒素 (CYNs)、石房蛤毒素 (STXs) 和液相色谱法 (ATX-LC-mass) 毒素 (ATX-LC-MS) MS/MS) 和酶联免疫吸附测定 (ELISA)。全分离紫草的毒素分析通过 ELISA 和 LC-MS 检测的菌株未表明存在 ATX、STX、CYN 或 MC。五个分离的Raphidiopsis菌株中有四个产生了 CYN 和 deoxyCYN。从 Yezin Dam分离出的一种微囊藻菌株 (AB2017/08) 产生了 22 个 MC 同源物。通过ELISA在来自Yezin Dam的环境样品中还发现了0.12 μg L ^-1 CYNs和0.34 μg L ^-1 MCs的浓度。因此，Yezin 大坝未经处理的水有可能对人类、家畜和野生动物造成有害影响。