Influence of Abiotic Factors on the Density of Fecal Indicator Bacteria in the Urban Estuary of the Itanhaém River – São Paulo, Brazil

Author : Eliete R Ballesteros

Abstract :Urban estuaries are frequently impacted by microbiological contamination from various sources such as domestic and industrial sewage, organic and inorganic compounds. This study evaluated the influence of abiotic factors on the density of fecal indicator bacteria (FIB) at different salinity gradients and periods (Nov21-Aug22) in Itanhaém River, Brazil. Enterococcus sp density was positively correlated with rainfall (Φ = 0,72, p<0,05) and Escherichia coli density was correlated with salinity (Φ = 0.53, p<0,05). Escherichia coli exhibited densities above legislation (CONAMA 274/00) in 89% of all collection sites, while Enterococcus sp exhibited restrictive densities in 69% of all collection sites, indicating a high degree of contamination and potential risks to public health associated with the rivers use for recreational purposes, seafood consume among others. Escherichia coli densities were higher than Enterococcus sp densities, even in brackish and saline waters, during all campaigns. The results obtained indicate that Escherichia coli is a better indicator of contamination by domestic sewage, including brackish waters and Enterococcus sp better correlated with precipitation

Keywords :Escherichia coli, Enterococcus sp, Microbiological Quality, Estuary, Salinity, precipitation.

Conference Name :International Conference on Water Resources Sustainable Development (ICWRSD-25)

Conference Place Madrid,Spain

Conference Date 10th Dec 2025