Diatomic remains in sediments of Le An River flowing into Po Yang Lake

This study has shown the concentration of diatomas and heavy metal ions (Cu , Pb,Zn and Cd) in the sediment samples from Le An River,a main tributary to Po Yang Lake. 38 diatom species in 19 genera were microscopically found on the sample slides prepared from the sediment of 4 ecologically characterized sites along this river.The occurrence of diatoms might be associated with the local water quality which was determined from the concentration of organic halogen-sub-stances and heavy metal ions,particular Cu and Pb contained in the seditnent samples.