[Microcystin contamination of fish on Poyang Lake in Jiangxi province]

In order to investigate the level of microcystin contamination of fish and its dynamic change in fish body, samples of freshwater as well as fish were collected from Poyang lake in Jiangxi province in July and October in 2000 respectively. Microcystin were tested for all samples via ELISA method. The results showed that: all freshwater samples collected in July and October contained blue-green alga and it has become a dominant alga. Microsystin content was higher in freshwater collected in October than that of in July. The average content level of microcystin in freshwater of river bank and Yongxiu river was 888.8 ng/ml, being ten times higher than that of water of Bang lake 1, Bang lake 2 and Big lake pool (83.6 pg/ml). The highest level of microcystin was 1036.9 pg/ml in freshwater of Yongxiu river. Microcystin could be detected in all samples of fish muscle and fish liver. The level of microcystin in muscle of fish collected in October was 1.2 to 2.0 times higher of that collected in July, and microcystin in liver of fish collected in October was 2.0 to 20 times higher of that collected in July. The average level of microcystin in fish liver in river bank and Yongxiu river was 27.2 ng/g, being significantly higher than that of in Bang lake1, Bang lake 2 and Big lake pool (2.8 ng/g).