Environmental considerations of nodule mining in Central Indian basin

Abstract

The status of benthic population and their physical and chemical environment in the CIB have been evaluated. The information on nodule populations and their association with benthic activity leads to prediction of potential mortality of benthic fauna as well as the area of seafloor and the volume of sediment expected to be disturbed due to nodule mining. The resulting environmental implications due to large scale mining are expected to be in the form of 'plume' at the seafloor, turbidity in the water column and addition of bottom waters to the surface resulting in change in productivity patterns. Hence, the desing of mining system should ensure that the sediments are sieved off at the seafloor, strip mining be carried out to allow repopulation by nearby organisms and that there is no effluent discharge in the water column or at the surface to avoid change in ecology due to transportation by currents. However, the location of the CIB is such that the impact of mining on environment is likely to be minimal.