Polymetallic Manganese Nodules (PMN)

Polymetallic Manganese Nodules (PMN)

Polymetallic Manganese Nodules (PMN)

Polymetallic Manganese Nodules (PMN) are small potato-sized (from millimeters to tens of centimeters in diameter) lumps of material precipitated from seawater and sediment pore water at slow rates over millions of years and occur mainly on the deep seafloor.

They contain approximately 24% manganese, compared to 35 to 55% manganese in land ore bodies, but they also contain iron (14%), copper (>1%), nickel(>1%), and cobalt (0.25%).

Efforts by India to Extract PMN

Polymetallic Nodules Programme(PNP)

  • The program is oriented towards exploration and development of technologies for harnessing of nodules from the Central Indian Ocean Basin (CIOB) allocated to India.
  • It has 4 components viz. Survey & Exploration, Environmental Impact Assessment, Technology Development (Mining), and Technology Development (Metallurgy).
  • India is presently having an area of 75,000 square km, located about 1600 km away from her southern tip
  • India entered into a 15-year contract with the International Seabed Authority in the year 2002 to pursue developmental activities for polymetallic nodules in the Indian Ocean
  • India’s exclusive rights to explore polymetallic nodules from the seabed in the Central Indian Ocean Basin (CIOB) have been extended by five years.

Contract with International Seabed Authority

India’s exclusive rights to explore polymetallic nodules from the seabed in the Central Indian Ocean Basin (CIOB) have been extended by five years by the International Seabed Authority.

India’s Deep Ocean Mission

  • Deep Ocean Mission seeks to develop the technologies required for exploring and then, extracting minerals in the deep seabed.
  • Ministry of Earth Sciences (MoES) will be the nodal Ministry implementing this multi-institutional ambitious mission.
  • It would develop a manned submersible (MATSYA 6000) that can carry three people to a depth of 6,000 meters in the ocean with a suite of scientific sensors and tools.
  • It will pursue technological innovations for exploration and conservation of deep-sea biodiversity through “bioprospecting of deep-sea flora and fauna and studies on sustainable utilization of deep-sea bio-resources.
  • The mission will seek to explore the prospects of deriving energy and freshwater from the ocean through “studies and detailed engineering design for offshore ocean thermal energy conversion (OTEC)-powered desalination plants.


  •  India’s exclusive rights for exploration of Polymetallic Nodules in the allotted area in the Central Indian Ocean Basin will continue and would open new opportunities for resources of commercial and strategic value.
  • India is entirely dependent on imports to meet its requirements of cobalt, which is the most strategic of the three metals (cobalt, copper and nickel). As for copper and nickel, India is in a precarious position.

Economic significance

  • Empowerment of coastal communities and attaining greater social and economic inclusion by providing Employment opportunities, skill-sets and capacities.
  • Providing a boost to coastal and national economies and development of blue economy.
  • Promoting entrepreneurship in new areas of economic activity and new development in electronics industry.

Strategic advantages

  • Presently, China is controlling more than 95% of rare earth metals. This move will nullify the increasing influence of China.
  • It will strengthen the bilateral relationship of India with Japan, Germany and South Korea.


  • Commercial-scale mining is expected to operate 24 hours a day, causing noise pollution.
  • It can overlap with the frequencies at which cetaceans communicate, which can cause auditory masking and behaviour change in marine mammals.
  • Settlement of sediment plumes generated by mining vehicles could harm/kill the species at the bottom of the ocean (benthic species) in the vicinity.
  • Sediment discharged from processing vessels can also increase turbidity in the water column. Also, far from sight impacts could go largely unquantified.

Related Links:

CRISPR TechnologyNational Deep Tech Start-Up Policy
International Seabed Authority10000 Genomes Project