The Cause and Effects of a Sudden Blackening of the River Kameng/Jiya Bharali in October 2021

Abstract

A disastrous sudden blackening of the river Kameng in Arunachal Pradesh, known as the river Jiya Bharali in Assam, was studied to find its cause and effects. The water of the river suddenly turned turbid and black on October 29, 2021, causing a large-scale death of fish for several days creating panic among the surrounding people. Samples of water and sediment were collected from different locations of the river and were analysed. The results indicate an increase in TSS consisting of aluminosilicates and oxides of Fe, Mn, Co, Ni, etc., mixed with water due to landslides. Coloured metal oxides were found to cause the blackening while toxicity and suffocation due to excess of suspended microscopic particles may have led to the death of fish. Preventive and curative measures for the disaster have been suggested.