The Occurrence of Microcystins in the Naktong River

Algae > Volume 14(4); 1999 > Article

Algae 1999;14(4): 237-246.

Woo-Hyun Kim, Ae-Ran Choi, Jin-Ae Lee

School of Environmental Science & Engineering, Inje University

ABSTRACT

A survey of physico-chemical parameters, standing crops of the Microcystis and occurrence of microcystins was carried out at 4 lakes and 5 sites along the stream from mid to lower reaches in the Naktong River from April to October 1999. The Microcystis population was observed from May through October. The population peaked in the Microcystis was 85,750 cells·ml super(-1) in September at the Hapchon Lake. the standing crops of the Microcystis was not related to all the physico-chemical parameters obtained in the present study except the water temperature. The microcystin was detected in the algal cells from June through October, and the concentrations of microcystin-RR, -LR and -YR were determined. Microcystin-RR was the most dominant variant in general. Total microcystin concentration in the algal cells ranged up to 2,015μg·g super(-1) dry wt at the lakes, having the maximum at the Hapchon Lake. Microcystin in the algal cells was detected only in June at the Hagueon Site along the river from mid to lower reaches, having the maximum concentrations of 3,292 dry wt. There was significant relationship between microcystin-RR concentration and total microcystin concentration. The microcystin concentration of the algal cells was not related to the standing crops of the Microcystis, nor physico-chemical parameters obtained in the present study. No microcystin in the water column was observed throughout the study except 2 observations of September and October in the Youngchon Lake. The presence of microcystin with no Microcystis cells in the October at Youngchon Lake was assumed to be related to the decomposition of the Microcystis bloom in the previous even.

Key words: blue-green algae, eutrophication, microcystin, Microcystis, Naktong River, physico-chemical parameter