북한강 수계의 남조 Anabaena 대발생과 강우의 관계

Abstract

To evaluate the relationship between dynamics of Cyanobacterial bloom and rainfalls, a monthlymonitoring of water quality and phytoplankton from the three serial lakes (Lake Ui-am, Lake Chung-pyeongand Lake Pal-dang) in the North Han River System were examined 12 times from May 2012 to March 2013. Adense bloom of cyanobacterium Anabaena spp., was occurred over three lakes in the summer season of 2012.In Lake Ui-am, the Anabaena population appeared in June, showed a peak in July (43,850 cells mL-1) anddisappeared in November 2012. In Lake Chung-pyeong and Lake Pal-dang, Anabaena population commonlyappeared in July, showed the peaks (31,648 cells mL-1 and 7,136 cells mL-1, respectively) in August, andentirely disappeared in September 2012. Over the three lakes, the phytoplankton community was commonlydominated by diatoms before Monsoon, cyanobacteria during Monsoon, and diatoms after Monsoon, respectively,indicating a Monsoon-dependent succession. A correlation analysis revealed that dynamics of Anabaenapopulation was strongly related with rainfall (r=0.72, r=0.83, r=0.88, P⁄0.01 for three lakes), and partlywith nutrients, inflow and outflow of lakes. Therefore, this study indicates that the outbreak and destruction ofAnabaena bloom in North Han River System between 2012 and 2013 was impacted by rainfalls. However, ahigh density of cyanobacteria in Lake Ui-am remained after Monsoon, and thus, may produce bad-order andtoxins from phytoplankton.