Distribution of faecal indicator bacteria in Cochin Backwaters

Abstract

Seasonal variations in indicator bacteria (total coliforms - TC; faecal coliforms - FC; <i>Escherichia coli</i> - EC; and faecal streptococci - FS) in water, sediment and zooplankton from 3 selected stations in Cochin backwaters studied. FC and EC showed a bimodal trend in sediment at all stations. Fluctuations of EC closely followed that of FC in sediments. AT st 2 (mouth region disturbed by frequent dredging for shipping purposes) this was observed in water and zooplankton also. Monsoon rains played a major role in EC distribution. Significant correlation was found between bacterial parameters of water, sediment and zooplankton. Faecal pollution in Cochin backwaters increased enormously and crossed the standards specified for shellfish culture or recreational activities in most of the months.