Idol immersion in Ichhamati river and its impact on water quality parameters

A preliminary study was undertaken in Ichhamati river, Bongaon, N-24 Parganas, West Bengal to evaluate the impact of idol immersion after Durga puja on water quality parameters. Different important physico-chemical parameters were considered for this study as temperature, dissolved oxygen (DO), Biological Oxygen Demand (BOD), pH, nitrate, phosphate, silicate and phytoplankton, as well as zooplankton community structure. Dissolved oxygen (DO) showed an inverse relation with pH showing the maximum (5.68) and minimum (2.3) values during and after immersion, respectively. During the immersion time, the turbidity and nutrient readings were much higher, indicating a high pollution level. During the whole study period, There was no perceptible difference in temperature. During immersion, the plankton population displayed maximum abundance and little variety, characterised primarily by one or two species that thrived in dirty water. Overall diversity was found to be highest prior to immersion and steadily deteriorated after immersion. The study clearly demonstrates the negative effects of religious activity on the river, and the essential actions should be properly followed in accordance with government requirements.