Sand Mining and its Effect, Causes of Concern for Zooplankton: A Case Study from Kishanganj, Bihar, India

The Mahanadi River and its tributaries namely Dhok and Chenga, as like other rivers, serve to be a lifeline for thousands of individuals in the Kishanganj district falling within the Purnea sub-division of Bihar. The rapid escalation in the development of infrastructure within the state has imposed an elevated demand of sand. To meet this demand, the activities pertaining to sand mining have also escalated throughout the country comparatively from the past couple of decades. The report presented herewith was centered on evaluating the effect of sand mining on the zooplankton at three mining sites namely Belwa Ghat (river Donk), Thakurganj Ghat (river Chenga) and Arrabari Ghat (river Mahananda) in the Kishanganj district from March 2019 to March 2021. The observations from the study reported herewith showed that there was substantial increase (p<0.01) in the turbidity of the water at Belwa and Thakurganj Ghat due to increased mining activities. However, the turbidity of water was comparatively low at the Arrabari Ghat. Statistical evaluation also confirmed that the amount of species and mean Shannon diversity index for zooplankton at the reference or control sites of Belwa Ghat were different considerably however except for Arrabari Ghat. Thus the present case report made it evident scientifically that the increased mining activities in the Kishanganj district has led to a decline in the distribution and reduction in the number of species of zooplanktons in the Mahananda, Dhok and Chenga rivers of Kishanganj district in Bihar.