Harmful Algal Blooms(HABs) is phenomenon of massive phytoplankton bloom that live in the sea and freshwater which producing toxic or harmful effects on people, fish, shellfish, marine organism. In Korea, direct losses due to HAB from 2001 to 2012 amounted to about 52 million US dollars. Regular phytoplankton surveys are now being performed to monitor blooms in many countries, which is mainly conducted by the traditional optical observations. However, species-specific morphological characteristics are often indistinguishable, and it requires a lot of time and effort by well-trained experts. The next generation sequencing (NGS) technique is now being regarded because of its capacity to analyze entire community structures of the collected samples at a relatively low cost and over a short period of time. In order to monitor the potential harmful red tides species and to find the correlation between the microbial communities and the red tides species by metagenomic analysis, we analyzed water samples at seven stations in the Coastal Waters of Southern Korean from June to August, every two weeks.
Results/Conclusions
The number of contigs obtained after bioinformatics processes was 2,464 ~ 124,355. A total of 629 standard genotype were obtained. Chattonella marina type_1 showed a similar pattern in which the highest proportions were found in the 5th survey at station S3 (36.94 %), Y5 (9.77 %), Y7 (23.76 %) and T11 (15.31 %). In station Y11, it appeared at the highest proportion in the third period and gradually decreased and disappeared in the 6th survey. Chattonella marina type_2 appeared less than 10 % in all station. Alexandrium affine appeared only in 5th survey in four stations (S3, Y7, T6, T11) and disappeared at the next survey time. Heterosigma akashiwo appeared at a low proportion in most station, but it increased to 42.38% in 5th survey from 8.4 % in 4th survey in station Y11. The proportions of the other potential red tide species increased during the bloom in addition to a high degree of appearance in Alexandrium sp.. The station S1, Y7 and Y5 which belong to relative open sea, and the station S3, Y11, T11, and T6 belonging to coastal sea re are clearly distinguished. Chrysochromulina sp., Kryptoperidinium foliaceum and Cylindrotheca closterium showed a strong correlation to Alexandrium sp..