Epilithic diatom as a biological indicator for the assessment of water quality in the East River

A group research project has been initiated to develop an integrated river management strategy and assessment criteria for the East River in Guangdong province. Four field surveys were conducted in 2004 to study the geomorphologic, hydrologic and environmental features of the basin. Epilithic diatom and water samples were collected from four sites in the upper and lower reaches of the river. A total of 23 diatom genera were identified from the study sites during the two sampling periods. The diatom genus Nitzschia represented the most pollutant dependent epilithic diatoms, comprising over 38% of the overall diatom population in the polluted sites. The correlation between water quality and the Shannon diversity index (H), generic index (GI), trophic diatom index (TDI) and diatom assemblage index to organic pollution (DAIpo) was investigated in this study. The results suggested that epilithic diatom might be used as a biological indicator for the environmental health assessment of the East River. Copyright © 2007 IWA Publishing.