The task of collecting polymetallic nodules in bulk quantities for metallurgical process studies has been assigned to National Centre for Antarctic and Ocean Research (NCAOR), Goa. NCAOR is normally given a target to collect 20 to 40 tonnes of nodules every year for metallurgical studies. For achieving this task, using minimum ship time, acoustic geophysical techniques have been used for identifying areas of high nodule concentration and safe areas for deepsea dredging operations by using a nodule mining dredge. The acoustic geophysical techniques such as Multibeam Swath Bathymetric Echosounding (MBES) "Hydrosweep-DS2" and Shallow Acoustic Seismic Sub- Bottom Profiling (SBP) "Parasound", have been used for identifying the areas of high and low nodule concentrations and thereby maximizing the opportunities of recovery of nodules with each dredgehaul. Mapping using MBES provided realistic imaging of the bottom topography for selection of suitable dredging locations and SBP provided fairly good estimates of nodule concentration on the seafloor.
The exploration for polymetallic nodules deposits in Indian Ocean Basin was launched in 1981 and India was recognized as a Pioneer Investor in 1982 as per UNCLOS-III. India carried out exploration activities extensively between 1982 and 1987, and made her claim to the Preparatory Commission (PrepCom) for the International Seabed Authority and International Tribunal for the Law of the Sea for a Pioneer Area in the Central Indian Ocean Basin (CIOB) that was allocated on 17 August 1987. The Pioneer Area allocated to India was subsequently taken up for phase-wise relinquishment in three stages and India relinquished 50% of the allocated area, as per the UNCLOS resolutions and by the year 2002 India was licensed with 75,000 km2 of nodule-rich area in CIOB by the International Seabed Authority (ISA), Jamaica to carryout development activities short of commercial production.
