RESUMEN
The abundance of aerobic heterotrophic bacterial population in the sediment sample of six experimental stations (S1 to S6) at Rajakkamangalam estuary was studied for a period of one year from March, 1998 to February, 1999. The important bacterial genera encountered were Pseudomonas, Bacillus, Vibrio, Escherichia, Micrococcus, Enterobacter, Salmonella, Aeromonas, Shigella, Klebsiella, Proteus, Alkaligenes, Staphylococcus, Citrobacter and Flavobacterium. The bacterial population based on numerical counts showed wide fluctuations in their distribution at different stations. Among the bacterial genera Pseuaomonas was found to be the dominant genus during the experimental period. The qualitative and quantitative distribution of microflora in the sediment samples are discussed.