A STUDY ON PHYSICO-CHEMICAL WATER QUALITY AND BIO-DIVERSITY LOSS OF A RIVER IN A SMALL TOWN OF WEST BENGAL.

Abstract

The physico chemical parameters such as water temperature, turbidity, pH, total dissolved solid,

total suspended solid , total solid conductivity (?s/cm), dissolved oxygen, free CO₂,salinity, BOD, nitrate , phosphate ,silicate , chloride , total alkalinity were measured at  three sites of Shutunga river, a tributary of Jaldhaka river traversing through Coochbehar district of West Bengal, India to study the seasonal variation of physico-chemical factors .The study was executed in pre-monsoon, monsoon and post-monsoon period from January,2016 to May,2017. Agricultural field uses the river water for plantation and drain off the used excess water with variety of pesticides and fertilizers to the river .The fisherman make the most of the downstream market, drainage materials from hospital, leaching of fertilizers & pesticides from agriculture land, use of ichthyotoxic substances for fish capture and also ashes of cremation directly mix up with Shutunga river.of this river for fish capture. Slum-dwellers uses water resource for bathing, washing of cloths etc. Sewage from municipality, garbage from market openly mixed with the river. As a result the physical, chemical and biological characteristics of the river water are regularly changing and creating the unsafe effect on aquatic biota and also human beings.