Benthic Diatoms in River Influenced By Urban Pollution, Bhavani Region, Cauvery River, South India

The present-day study assesses diatom communities in river with relation to environmental conditions. Diatoms are susceptible to environmental conditions in river and their distribution is mainly governed by the physicochemical composition of the water. Diatoms and water samples were collected in 5 locations during summer season (May 2012). Analysed data were interpreted and the results are represented. Four statistical methods were used in this study, Cluster analysis, Canonical correspondence analysis (CCA), Principal component analysis (PCA) and Detrended correspondence analysis (DCA) were determined the species distribution and environmental gradients along polluted and unpolluted area with physical and chemical variables. A total of 37 diatom species distributed among 17 genera were recorded. The significance of water quality difference among the sampling sites was expressed by four strastical methods. Highly polluted water contain diatom species like Pleurosigma salinarum, Nitzschia thermalis, Gomphonema parvulum, Gomponema lanceolatum, Fragilaria intermedia in the densely populated and highly industrialized locations and slightly polluted water present the diatom species like Achnanthes minutissiuma Kutz, Cyclotella catenata and Cymbella tumida among sampling sites.