Sewage and industrial effluents from Ennore, Chennai harbour and surrounding area have a greater impact on the Royapuram back water affecting the aquatic animals and in tum the human population. These waste carry enormous number of microbial pathogens and other heavy metals resulting in greater economic loss. The current study is aimed at analysing the total viable count of bacteria and pathogenic bacterial species in the water and sediment samples taken from different places of Royapuram fishing area, from where many kind of fishes and molluscans are taken for human consumption .The samples werc collected in pre monsoon, monsoon and post monsoon seasons. Water analysis was done by multiple tube tests to assess the MPN values. The bacteria were isolated using Zobell's agar medium, selective and non selective medias and identified
using biochemical test. The organisms were identified to genus, level according to Bergey's manual. Results of field
Investigations showed a definite association between the levels pollution and microbial population. Results showed a higher distribution of pathogenic and non pathogenic bacteria in the sediment than in the water sample both in monsoon and post monsoon seasons. Analysis showed the prevalence of human pathogens and fecal indicator organisms like Escherichia coli, Salmonella sp.,Vibrio sp., Shigella sp. in water and in the sediment samples
