Spatial and Seasonal Bioanalysis of Bacterial Indicators and Limnological Parameters in the Gangan River

Abstract

The present study assesses the water quality status of the Gangan River (February 2022-January 2023) on spatial and seasonal variation of physicochemical and bacteriological parameters. Two-way ANOVA (without repetition) and Pearson correlation were employed to analyze the mutual relationship through the set of limnological parameters / microbial indicators. There were relatively strong spatial heterogeneities, with turbidity, COD, ammonia, and total coliform bacteria as well as fecal coliform counts being significantly higher at the urban-impacted site (> 10 times), suggesting heavy anthropogenic influence. Seasonal variation revealed relatively constant pH and dissolved oxygen, but substantial variation in nutrients and fecal coliforms, especially during monsoon and winter. Pearson correlation showed strong positive relationships between bacterial indicators and turbidity, organic load, and nutrients, indicating organic pollution and nutrient enrichment drive microbial contamination. Altogether, the Gangan River shows heavy physicochemical and microbiological degradation, making it unfit for domestic and recreational purposes without proper treatment, suggesting process-based integrated monitoring and pollution abatement strategies.