Characteristics of Harmful Algal Blooms during a Low Water Temperature Season in Lake Hachiro
Characteristics of Harmful Algal Blooms during a Low Water Temperature Season in Lake Hachiro
复制标题
DOI：
10.2965/jwet.17-058
复制
发表时间：
2018
影响因子：
--
通讯作者：
Miho Araki;K. Okano;S. Ohta;E. Suzuki;Megumu Fujibayashi;N. Miyata
中科院分区：
文献类型：
--
作者：
Miho Araki;K. Okano;S. Ohta;E. Suzuki;Megumu Fujibayashi;N. Miyata
在这项研究中，我们调查了叶绿素a（Chl. a）、微囊藻毒素和基于16 S rRNA基因的蓝藻群落结构，使用16 S rRNA基因扩增子分析日本秋田县八代湖的地表水。此外，我们还研究了四种微囊藻的生长特性。分离自八郎湖的菌株（N1、N6、N7和0824）。2014年，Chl. a和总微囊藻毒素浓度（分别为173.4和1.7 μg/L）在10月份最高，此时水温低于20°C。虽然2015年观察到的藻华时间较长，但叶绿素浓度仍高于2015年。a和总微囊藻毒素在9月底也短暂增加。藻类水华的蓝藻组成包括2014年的Aphanizomenon，Anabaena，Prochlorothrix和Microcystis，以及2015年的Aphanizomenon，Anabaena和Microcystis。在这两年的10月，藻华以微囊藻属为主，这表明在此期间存在微囊藻毒素的主要生产者。在实验室培养中，微囊藻0824菌株在15°C下显示出高比生长率（0.17 l/d）。低温适应微囊藻，如菌株0824，可能是造成八郎湖在低水温季节发生有害藻华的原因。
In this study, we investigated seasonal changes in chlorophyll a (Chl. a ), microcystin, and the 16S rRNA gene-based cyanobacterial community structures using 16S rRNA gene amplicon analysis of the surface water of Lake Hachiro, Akita Prefecture, Japan. Moreover, we examined the growth characteristics of four Microcystis spp. strains (N1, N6, N7, and 0824) isolated from Lake Hachiro. In 2014, Chl. a and total microcystin concentrations (173.4 and 1.7 µg/L, respectively) were the highest in October, when the water temperature was less than 20°C. Although algal blooms were observed for a longer term in 2015, the concentrations of Chl. a and total microcystin also increased transiently at the end of September. The cyanobacterial compositions of algal blooms included the genera Aphanizomenon , Anabaena , Prochlorothrix , and Microcystis in 2014 and Aphanizomenon , Anabaena , and Microcystis in 2015. In October of both years, algal blooms were dominated by Microcystis spp., suggesting the presence of major producers of microcystins during this term. In laboratory cultures, Microcystis strain 0824 showed a high specific growth rate at 15°C (0.17 1/d). Low temperature -adapted Microcystis spp., such as strain 0824, may be responsible for the occurrence of harmful algal blooms during the low water temperature season in Lake Hachiro.