Impact of Instream Sand Mining on Physico -Chemical Parameters and Phytoplankton Composition in the River Sone at Koelwar, (Bihta), Bihar, India

In stream sand mining disturbs dynamic equilibrium of aquatic ecological factors which have repercussive effects on physicochemical parameters and on phytoplankton. Water samples collected on the basis of mining load at three key points, no mining sites, mining sites and down of mining sites in pre monsoon, monsoon and post monsoon. Selected physicochemical parameters were analyzed following standard protocols of APHA and phytoplankton by Sedgwick Rafter counting cell and identified with the help of Bellinger and Sigee. In the river water, measured mean value of cations TZ + (52.96 mg/L) predominate over anions TZ - (29.35 mg/L). Hike in mean value of silica particles (33.94 mg/L) and turbidity (31.96 mg/L) also noted at sand mining sites, which attenuate transmission of sun rays in to water by reflecting most of the incident rays when it strikes on nano particles dispersed in turbid water. Phytoplankton also depleted with heaps of sand taken out from river bed. All these reduce primary productivity of the aquatic ecosystem. Bacillariophyceae identified as dominant group due to abundance of silica particles and alkaline nature of Sone water. Other genera of Chlorophyceae, Cyanophyceae and few species of Chrysophyceae were also identified.