India’s Deep-Ocean Exploration and Polymetallic Nodules

Why in News?

The Ministry of Mines has notified two offshore mineral blocks near Great Nicobar Island for granting composite licences to explore polymetallic nodules and crusts. The development has brought India’s critical-mineral security, blue economy, deep-ocean research and marine environmental protection into focus.

Newly Notified Offshore Blocks

West Sewell Ridge-01

• It is located off Great Nicobar Island in the Andaman Sea and covers 1,000 square kilometres.

Sewell Rise-01

• It is located in the southern part of Sewell Rise near Great Nicobar Island and covers 632 square kilometres.

Combined Area

• The two blocks together cover 1,632 square kilometres and have been notified for composite licences covering polymetallic nodules and crusts.

What is a Composite Licence?

• A composite licence does not immediately permit mining.
• The successful bidder must undertake further exploration and establish the mineral potential of the block before proceeding towards mining operations.

Great Nicobar Island

• Great Nicobar is situated at the southern end of the Andaman and Nicobar Island group in the Bay of Bengal.
• It is also the site of a proposed ₹72,000-crore infrastructure project comprising a transshipment port, airport, gas-and-solar power plant and two greenfield coastal cities.
• The project has faced criticism over its possible impact on coral reefs, leatherback turtle nesting sites, Nicobar megapode nesting mounds and the ancestral lands of the Great Nicobarese Scheduled Tribe community.

What are Polymetallic Nodules?

• Polymetallic nodules are mineral deposits found on the deep-ocean floor.
• They contain several valuable metals, including nickel, cobalt, manganese, copper and rare-earth elements.
• They develop through autogenetic crystallisation around a crystalline nucleus on the deep seabed.
• Their economic value arises from the concentration of multiple critical minerals within a single deposit.

Distribution of Polymetallic Nodules

The International Seabed Authority identifies three major areas with abundant polymetallic nodules:

• Clarion–Clipperton Fracture Zone: Located off the west coast of Mexico in the Pacific Ocean.
• Central Indian Ocean Basin: An important area for India’s deep-sea mineral interests.
• Peru Basin: Located in the south-eastern Pacific Ocean.

Why are Polymetallic Nodules Important?

Electric Mobility

• Nickel, cobalt and manganese are important for batteries used in electric vehicles.

Renewable Energy

• Critical minerals are required for renewable-energy systems and energy-storage technologies.

Advanced Manufacturing

• Copper, rare-earth elements and other metals are used in electronics and high-technology manufacturing.

Supply Diversification

• Deep-sea deposits can provide an additional source of critical minerals and reduce dependence on limited land-based sources.

Polymetallic Sulphides

• Polymetallic sulphides are another category of deep-seabed mineral deposits.
• They contain metals such as copper, zinc, lead, iron, silver and gold.
• Although both are sources of valuable minerals, polymetallic sulphides are distinct from polymetallic nodules.

India’s ISA Exploration Contracts

2025 Contract

• India signed a contract with the International Seabed Authority (ISA) in September 2025 for exclusive polymetallic sulphide exploration rights in an Indian Ocean ridge area.

2016 Contract

• India’s earlier contract, signed in 2016, covers the Central Indian Ridge and Southwest Indian Ridge.
• It covers the largest area allocated in the international seabed for polymetallic sulphide exploration.

India’s Position

• India became the first country to possess two ISA contracts for polymetallic sulphide exploration.
• These contracts have scientific, economic and strategic importance.

Role of NCPOR

• The Goa-based National Centre for Polar and Ocean Research is responsible for India’s polymetallic sulphide exploration.
• It begins with geophysical and hydrographic surveys in the licensed areas.

Importance of Deep-ocean Exploration

Blue Economy

• India has an 11,098-km coastline, giving it significant potential to use ocean resources for economic growth.
• Deep-ocean exploration can support fisheries, aquaculture, tourism, coastal livelihoods and blue trade.

Mineral Resources

• The deep ocean contains deposits of minerals required for clean-energy and high-technology industries.

Food and Biological Resources

• The oceans contain fisheries and biodiversity resources that may support food security and nutraceutical development.

Fuel and Gas Hydrates

• Deep-ocean regions contain fuels, hydrocarbons and gas hydrates with potential importance for energy security.

Undersea Cables

• Undersea cables laid on the ocean floor form a critical part of global telecommunications.
• Mapping the seabed and maintaining awareness of underwater infrastructure are important for communication security.

Maritime Security

• Deep-sea mapping and underwater domain awareness strengthen India’s maritime and strategic interests.

Scientific Research

• Ocean exploration improves understanding of marine biodiversity, seabed geology and ocean processes.

UN Ocean Science Decade

• The United Nations has declared 2021–2030 as the Decade of Ocean Science for Sustainable Development.
• It promotes scientific knowledge for the conservation and sustainable use of oceans.

Regulatory Framework

Offshore Areas within India

• Domestic offshore mineral development is governed by the Offshore Areas Mineral (Development and Regulation) Act, 2002.
• The government maintains that the law contains safeguards for ecological balance, biodiversity and the interests of fishermen.

Exclusive Economic Zone

• Under the United Nations Convention on the Law of the Sea (UNCLOS), a country’s Exclusive Economic Zone extends up to 200 nautical miles, or approximately 370 km, from its coastal baseline.
• A coastal country has exclusive rights over living and non-living resources in the waters and seabed within its EEZ.

International Seabed

• UNCLOS governs the high seas and the international ocean floor beyond national jurisdiction.
• The seabed and its mineral resources beyond national jurisdiction are treated as the common heritage of mankind.
• These resources must be managed through economic benefit-sharing, support for scientific research and protection of the marine environment.

International Seabed Authority

• The ISA regulates mineral-related activities on the international seabed.
• India’s polymetallic sulphide exploration rights in international waters operate through contracts with the ISA.

India’s Deep-ocean Initiatives

Deep Ocean Mission

• The Ministry of Earth Sciences launched the Deep Ocean Mission in 2021 with an outlay of ₹4,077 crore.
• It seeks to strengthen India’s capabilities in deep-ocean research and exploration.

Samudra Manthan Scheme

• The Union Cabinet approved the Samudra Manthan Scheme, or National Offshore Exploration Scheme, in August 2026.
• It is a Central Sector Scheme of the Ministry of Petroleum and Natural Gas.
• It has an outlay of ₹84,084 crore for implementation up to 2030-31.
• It focuses specifically on offshore oil and gas exploration and should not be confused with deep-seabed mineral exploration.

Objectives

• Support exploratory drilling in deep-sea and ultra-deep-sea areas.
• Fund offshore seismic-data acquisition.
• Create common infrastructure for producing discovered hydrocarbons.
• Establish oil-and-gas manufacturing and services zones.
• Reduce dependence on imported energy.

Expected Outcomes

• The scheme is expected to support reserve accretion of more than 600 million tonnes of oil and oil-equivalent gas.
• Subject to successful exploration, it aims to increase domestic oil and gas production from around 62 mtoe to 80 mtoe annually.
• It also aims to expand India’s hydrocarbon-resource base from 1,600 mtoe to 2,200 mtoe.

Financial Support

• The government will provide support of up to 50% of the drilling cost or ₹675 crore per well, whichever is lower.

Components of the Samudra Manthan Scheme

Offshore Seismic Data

• ₹28,534 crore has been allocated for acquiring and processing modern offshore seismic data.

Deepwater Exploration Wells

• ₹43,200 crore has been allocated for drilling 60 deepwater exploration wells.
• Government support can cover up to 50% of the eligible drilling cost or ₹675 crore per well, whichever is lower.

Common Offshore Infrastructure

• ₹10,000 crore has been allocated for common offshore infrastructure hubs to facilitate commercialisation of discoveries.

Manufacturing and Services Zones

• ₹2,000 crore has been allocated for oil-and-gas manufacturing and services zones to promote domestic manufacturing and localisation of critical equipment.

Sagar Manthan Ocean Research Vessel

• Garden Reach Shipbuilders and Engineers Limited launched the indigenous Sagar Manthan Ocean Research Vessel on September 9.
• It is being constructed for NCPOR under the Ministry of Earth Sciences.

Technical Features

Length: 89.5 metres | Width: 18.8 metres | Gross tonnage: 5,900 tonnes | Speed: Up to 14 knots at 90% maximum continuous rating

Significance

• Critical-Mineral Security: Diversifies access to minerals needed for batteries, renewable energy and advanced manufacturing.
• Energy Security: Increases domestic offshore oil and gas production and reduces import dependence.
• Scientific Capability: Strengthens deep-ocean research through ISA contracts, NCPOR surveys, the Deep Ocean Mission and Sagar Manthan.
• Blue Economy: Supports fisheries, aquaculture, tourism, livelihoods and blue trade.
• Maritime Security: Improves seabed mapping and underwater domain awareness.
• Domestic Manufacturing: Promotes localisation of offshore equipment, technology and services.

Challenges

• Environmental Uncertainty: Limited knowledge makes the long-term impact on deep-sea ecosystems difficult to predict.
• Biodiversity Loss: Exploration and mining may disturb seabed habitats and marine organisms.
• Sensitive Ecosystems: Activities near Great Nicobar may affect coral reefs, turtles and Nicobar megapode nesting sites.
• Community Concerns: Projects may affect fishermen and the ancestral lands of the Great Nicobarese community.
• Technological and Financial Constraints: Operations require specialised technology, skilled personnel and substantial investment.
• Regulatory Compliance: Exploration beyond national jurisdiction must comply with UNCLOS and ISA rules.
• Commercial Uncertainty: Exploration may not result in commercially viable discoveries.

Way Forward

• Precautionary Approach: Conduct detailed environmental assessments before exploration or mining.
• Scientific Research: Expand seabed mapping, biodiversity studies and long-term monitoring.
• Community Participation: Consult fishing communities and the Great Nicobarese Scheduled Tribe.
• Indigenous Technology: Develop domestic research vessels, sensors and offshore equipment.
• Regulatory Compliance: Follow domestic laws, UNCLOS and ISA regulations.
• Exploration–Mining Separation: Establish mineral potential and complete regulatory requirements before mining.
• Benefit-Sharing: Manage international seabed resources according to the common heritage of mankind principle.
• Skill Development: Train marine scientists, engineers, environmental experts and technicians.

Conclusion

Deep-ocean exploration can strengthen India’s critical-mineral, energy, scientific and maritime capabilities. However, it must advance through rigorous research, transparent regulation, environmental safeguards and protection of coastal and indigenous communities.