*Corresponding Author: snahabiswas@gmail.com 40 DOI: 33TUhttps://doi.org/10.52756/ijerr.2022.v29.004 Int. J. Exp. Res. Rev., Vol. 29: 40-47 (2022) Idol immersion in Ichhamati river and its impact on water quality parameters Sejuti Roy 1 *, Niladri Sekhar Das 1 , Shubhajit Saha 2 and Dipshikha Ghosh 1 1 Department of Zoology, Dinabandhu Mahavidyalaya, Bongaon, West Bengal, India; 2 Department of Zoology, Sundarban Hazi Desarat College, Pathankhali, South 24 Parganas, West Bengal, India E-mail/Orcid Id: NSD, bioniladri@gmail.com; SS, s.saha.bgc.wbsu@gmail.com, https://orcid.org/0000-0001-5041-658X DG, dipsikhaghosh@yahoo.com Introduction Ichhamati is a transboundary river that flows through India and Bangladesh and forms their shared border (Ahmed, 2012). Due to siltation, the river has a restricted water flow during the dry season and overflows during the rainy season. Experts are addressing the situation, while the governments of both India and Bangladesh are discussing possible solutions (Basu, 2007). At the same time, human religious rituals such as idol immersion after Durga puja pose extra hazards to the river. India is a multiethnic nation with many different religious and cultural holidays. An idol is a sculpture or other material object representing a deity to whom religious worship is directed, or any person or thing regarded with admiration, adoration, or devotion, as well as a religious figure. A representation of a god used as an object of worship is known as an idol (Ahmed, 2012). Plaster of Paris, clay, fabrics, tiny iron rods, bamboo, and a variety of paints, including varnish, water colours, and other materials are used to construct these idols (Idol., 2014). Plaster of Paris (POP), which is less expensive and lighter, has become the preferred medium for creating these idols. POP comprises phosphorus, gypsum, sulphur, and magnesium, among other compounds. Plastic and thermocols are used to embellish these statues. The thermocol and plastic utilised in the idol's construction are non-biodegradable and so hazardous (Dhote et al., 2014). The heavy elements found in the chemical paints used to decorate these idols, including lead, copper, iron, cadmium, manganese, zinc, chromium, mercury and arsenic, affect the quality of the water (Table 1). Heavy metal bioaccumulation transports harmful materials from the producer to the consumer, posing health risks to the latter (Kaur et al., 2013, Reddy et al., 2012). When these poisonous compounds are randomly mixed with water, they cause significant qualitative and quantitative alterations in the inorganic and organic Article History: Received: 20 th Oct., 2022 Accepted: 10 th Dec., 2022 Published: 30 th Dec., 2022 Abstract: 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. Keywords: Idol immersion, phytoplankton, zooplankton, water quality parameters, pollution