Occurrence and seasonal variation in distribution of fecal indicator bacteria in Tapi estuary along the West coast of India.

Abstract

Distribution and occurrence of fecal indicator bacterial in nine different locations along the inner to coastal areas of Tapi estuary during three different seasons like, post-monsoon, pre-monsoon and monsoon were analyzed for the period of one year. It was found that monsoon was inhabited by the highest number of investigated bacteria, while lower numbers of them were found in other two seasons. Concentrations of fecal microorganisms in sediment were found to be significantly high. Overall percentage occurrence for the enteric bacteria in water and sediment were maximum accounted for fecal coliforms (64%), and moderate for Pseudomonas aeruginosa (22.2%). Higher microbial populations were recorded in stations close to coastal areas and inner estuarine as compared to middle and outer area of Tapi, while according to the analysis of surface water the highest degree of pollution was reached on its estuary. Bacterial populations showed strong correlations with biological oxygen demand and negative relationship with salinity, indicating the dominating influence of human activities resulting fecal pollution in the estuarine area