Water quality assesment for aquaculture at Shasan GP, Barasat-II block, North 24 Paraganas, West Bengal

Abstract

Mangrove ecosystem being suitable for brackish water shrimp culture, large number of aquaculture ponds have been developed in Shasan area,Barasat block-II, North 24 Parganas, West Bengal, India. These ponds are regularly fed by brackish water from nearby Bidhyadhari river system and the same water is ultimately discharged into this aquacultural ponds. In the present study, some physico-chemical parameters such as pH, temperature, conductivity, dissolved oxygen, calcium, magnesium, total hardness, chlorine, phosphate, nitrate, and total dissolved solid contents of four aquaculture ponds have been analysed for assessment of pollution status with respect to canal water taken as control. Studies were undertaken for a period of from May 2022 to June 2022 (pre-monsoon season) during which the physico-chemical parameters were compared with the water quality standard of Bureau of Indian Standard (BIS) and Central and the State Pollution Control Board (PCB) and Aquaculture guidelines as per CIFA. The BOD values of the aquaculture ponds range between 13 -73mg/L as against the value of standard water quality. Nitrate, total hardness, calcium, magnesium, phosphate, and chlorine contents show variation within different sites. Ammonia concentration values vary from 11.0 to 26.0 mg/L during investigation, which is higher than standard value. Among these sites, Kholdanga ponds show the excessive values in respect of some parameters than other site. The water quality index WQI also met the criteria for aquatic species except Kholdanga pond. In weighted arithmetic index method, two ponds i.e. Kholdanga and Pranab pukur unsuitable for aquaculture and in respect of DOE index method, Kholdanga unsuitable for aquculture. Its require some treatment as soon as possible. Key Words:- Aquaculture, WQI, Arc GIS, Parameters, AWI index, DOE Index