| Title |
Toxic Cyanobacterial Blooms in Korean Lakes |
| Authors |
김범철 ; 김은경 ; 표동진 ; 박호동 ; 허우명 ( Bom Chul Kim ; En Kyong Kim ; Dong Jin Pyo ; Ho Dong Park ; Woo Myung Heo ) |
| Abstract |
Cyanobacterial blooms in eutrophic lakes often produce algal toxins causing death of cattle, wild animals, and fish. Many lakes and reservoirs in Korea are eutrophic and suspected for toxic cyanobacterial blooms. Phytoplankton were collected in late summer at the surface of 5 middle-stream reservoirs(Soyang, Choongju, Daechong, Jangsong, Hapchon), one estuarine reservoir(Yongsan), and a coastal lagoon(Yonglang). Phytoplankton communities were examined and the occurrence of toxic bloom was examined with mouse bioassay. In all the study lakes cyanobacteria were dominant phytoplankton. Especially, the appearance of Microcystis aeruginosa in all the study lakes that is a well-known toxin-producer species implies the possibility of toxic water bloom. Dried cells were extracted in saline solution and injected to mouse intraperitoneally for the test of toxicity. Mouse bioassay showed lethal effect for L. Yonglang, L. Hapchon, L. Jangsong, and L. Yongsan. The content of two cyanobacterial hepatotoxins(microcystin-RR and microcystin-LR) that have been reported to be most common were analyzed with HPLC. Microcystin-RR was detected in L. Daechong, L. Choongju, and L. Soyang. And microcystin-LR which has higher toxcicity was detected in L. Hapchon, L. Jangsong, L. Yonglang, and L. Yongsan. The coincidence of the microcystin-LR occurrence and the lethal effect in bioassay imply that microcystin-LR exerted more critical toxicity. From this study it was found that toxic cyanobacterial bloom is common in Korean lakes that are used for water supply. |