India's Deep-Sea Mining Push: ORV Sagar Manthan & Ridge Exploration

Overview

India’s launch of the oceanographic research vessel ORV Sagar Manthan marks a major strategic expansion in deep-sea mineral exploration across the Indian Ocean ridge systems. The vessel enables high-resolution resource mapping of polymetallic hydrothermal sulphides to secure critical minerals for the nation's clean energy transition.

Built indigenously to replace the four-decade-old ORV Sagar Kanya, the 89.5-metre vessel supports deep-water geophysical surveys down to 6,000 metres under the Ministry of Earth Sciences' Deep Ocean Mission. This capability underpins India's exclusive exploration contracts with the International Seabed Authority across the Central, Southwest, and Carlsberg Ridges.

Rising global demand for copper, cobalt, and nickel drives deep-sea prospecting. This work establishes sovereign access to seafloor mineral wealth while intensifying scientific debates over benthic habitat conservation.

The Ministry of Earth Sciences launched the indigenous oceanographic research vessel ORV Sagar Manthan on September 9, 2026, to lead deep-sea mineral mapping across the Indian Ocean. Built by Garden Reach Shipbuilders & Engineers (GRSE) at an estimated cost of ₹840 crore, the vessel replaced the four-decade-old ORV Sagar Kanya. As of September 2026, this commissioning represents India's largest capital investment in marine scientific infrastructure.

The commissioning advances India's seabed strategy through three core dimensions:

• Mission Operationalisation: The vessel directly operationalises Vertical-4 ('Deep Ocean Survey and Exploration') of the Deep Ocean Mission, approved by the Cabinet Committee on Economic Affairs with a total outlay of ₹4,077 crore over five years.
• High-Seas Prospecting: India is accelerating seabed prospecting to secure non-living marine resources within the high seas.
• Regulatory Readiness: Under the international legal framework established by the United Nations Convention on the Law of the Sea (UNCLOS), mineral exploitation in areas beyond national jurisdiction requires strict contractual compliance and specialised technological readiness.

Polymetallic hydrothermal sulphides are seafloor mineral deposits formed along mid-ocean ridges. Volcanically heated seawater precipitates high concentrations of base, precious, and critical metals along these boundaries.

Seawater percolates through fissures in the oceanic crust and is heated by magma chambers to between 350°C and 400°C. This thermal reaction leaches metals from the surrounding rocks.

When this superheated, mineral-laden fluid vents into cold abyssal seawater, rapid cooling causes minerals to precipitate into column structures known as black smokers or massive sulphide mounds. According to the Geological Survey of India, these deposits form rich repositories of high-grade copper, zinc, lead, gold, and silver, alongside critical trace elements such as cobalt and platinum group metals.

Garden Reach Shipbuilders & Engineers built the 89.5-metre ORV Sagar Manthan to execute deep-sea geophysical mapping and seabed sampling at extreme ocean depths down to 6,000 metres. The multidisciplinary vessel integrates multi-beam echo sounders, sub-bottom profilers, gravimeters, and dynamic positioning systems to generate high-resolution bathymetric charts of ridge topography.

The vessel's operational architecture serves three central scientific objectives:

1. High-Resolution Bathymetry: Mapping the volcanic terrain of slow-spreading oceanic ridges to locate active and inactive hydrothermal vent fields.
2. Geophysical and Magnetic Profiling: Running seismic and magnetic surveys to identify subsurface mineralised zones and structural fault lines.
3. Seabed Coring and Water Sampling: Deploying deep-tow cameras, remotely operated systems, and heavy-duty grab corers to retrieve physical ore samples and detect hydrothermal plume chemical anomalies.

Deep-sea exploration is further augmented by Project Samudrayaan. Under the Deep Ocean Mission, the National Institute of Ocean Technology (NIOT) is developing Matsya 6000, an indigenous crewed submersible designed to carry three scientists to depths of 6,000 metres for direct observation and targeted resource sampling.

The International Seabed Authority administers mineral rights in international waters under UNCLOS Part XI, designating the ocean floor as the common heritage of humankind. Operating from Kingston, Jamaica, the International Seabed Authority (ISA) regulates all prospecting, exploration, and eventual exploitation of non-living marine resources in the Area (the international seabed outside national exclusive economic zones).

India’s seabed exploration footprint spans three major ISA contracts:

• Polymetallic Nodules Contract: India obtained exclusive rights to explore 75,000 square kilometres in the Central Indian Ocean Basin (CIOB) in 2002, with the contract extended to March 2027.
• Ridge Sulphides Contract (CIR & SWIR): In September 2016, the Ministry of Earth Sciences signed a 15-year exploration contract for polymetallic sulphides covering 10,000 square kilometres across the Central Indian Ridge and Southwest Indian Ridge.
• Carlsberg Ridge Contract: In September 2025, India signed a second 15-year contract with the ISA covering 10,000 square kilometres on the Carlsberg Ridge in the Northwest Indian Ocean. The Carlsberg Ridge forms a slow-spreading divergent tectonic boundary between the Indian and Arabian plates, extending from the Rodrigues Triple Junction to the Owen Fracture Zone.

In January 2024, India submitted an application to the ISA for exploration rights over cobalt-rich ferromanganese crusts on the Afanasy Nikitin Seamount, a 400-kilometre-long undersea structure in the Central Indian Basin. This application remains subject to technical evaluation due to overlapping extended continental shelf claims presented by Sri Lanka under UNCLOS Article 76 provisions.

The Ministry of Mines identified deep-sea hydrothermal minerals as alternative sources of critical metals essential for clean energy generation, grid storage, and electric mobility. Terrestrial deposits of high-grade copper, cobalt, and nickel face declining ore grades, supply chain bottlenecks, and severe land-use conflicts.

Ocean exploration aligns directly with the objectives of the National Critical Minerals Mission:

• Clean Energy Hardware: Copper and zinc from hydrothermal sulphides are fundamental components for electrical wiring, wind turbine generators, and photovoltaic cells.
• Battery Chemistries: Seafloor crusts and nodules provide nickel and cobalt, mitigating import dependencies for cathode manufacturing in energy storage systems.
• Geopolitical Resilience: Developing sovereign extraction capabilities in the Indian Ocean strengthens India's resource independence against foreign supply disruptions.

India's maritime strategy bridges physical oceanography, mineral economics, and international diplomacy. These ocean operations establish deep-sea assets as pillars of economic security.

Hydrothermal vent systems harbour fragile, chemosynthetic ecosystems that face irreversible habitat loss, sediment plume smothering, and heavy metal toxicity from prospective seafloor mining operations. Unlike sunlight-dependent marine zones, vent communities derive primary energy from chemosynthetic lithoautotrophic bacteria that oxidise dissolved hydrogen sulphide discharging from hydrothermal chimneys.

These extreme, lightless environments host highly specialised, endemic taxa:

• Scaly-Foot Snail (Chrysomallon squamiferum): A unique hydrothermal gastropod possessing iron-sulphide shell plates, listed as Endangered on the IUCN Red List due to prospective deep-sea mining threats.
• Specialised Vent Fauna: Endemic communities including rimicaris shrimp and bathymodiolin mussels adapted exclusively to narrow temperature gradients around black smokers.

The United Nations Environment Programme highlights multiple direct environmental risks:

1. Physical Habitat Destruction: Extracting massive sulphide deposits involves demolishing chimney structures, obliterating benthic habitats that require millennia to regenerate.
2. Sediment Plumes: Extraction and surface separation generate suspended particulate plumes that travel across ocean currents, suffocating benthic filter-feeders and blocking biological light cues.
3. Toxic Leaching and Acoustic Disruption: Crushing sulphide ores releases dissolved toxic heavy metals into the water column, while machinery creates continuous noise and vibrations that disorient abyssal organisms.

The International Seabed Authority mandates that contractors conduct multi-year baseline environmental surveys, hydrodynamic monitoring, and comprehensive Environmental Impact Assessments (EIAs) before commercial mining codes can be ratified.

Sustainable ocean governance requires India to balance critical mineral exploration under the Deep Ocean Mission with rigorous baseline environmental impact assessments mandated by international law. As exploration activities transition toward potential exploitation, marine resource policies must adopt precautionary, science-based approaches.

Key institutional and policy priorities include:

• Expanding Long-Term Benthic Baselines: Utilising ORV Sagar Manthan to execute continuous biodiversity monitoring and physical oceanographic profiling across the Central Indian and Carlsberg Ridges.
• Active Participation in the ISA Exploitation Code: Collaborating with international scientific bodies to formulate strict environmental thresholds, regional environmental management plans, and equitable benefit-sharing mechanisms.
• Developing Low-Impact Extraction Technologies: Investing in closed-loop extraction tools that minimise sediment plume dissemination and benthic acoustic pollution.
• Integrating Circular Economy Frameworks: Strengthening domestic metal recycling and secondary recovery to temper unconstrained primary extraction demands on marine ecosystems.

• ORV Sagar Manthan Launch: Indigenously built by GRSE at ₹840 crore, the 89.5-metre vessel replaces ORV Sagar Kanya and can operate at depths up to 6,000 metres.
• Deep Ocean Mission Alignment: The vessel directly implements Vertical-4 ('Deep Ocean Survey and Exploration') within the ₹4,077-crore mission outlay.
• Hydrothermal Sulphide Genesis: Formed along mid-ocean ridge spreading centres at 350°C–400°C, precipitating rich concentrations of copper, zinc, gold, and silver.
• ISA Contract Allocations: India holds exclusive exploration rights for polymetallic sulphides across 10,000 sq km in the CIR/SWIR and 10,000 sq km in the Carlsberg Ridge, alongside 75,000 sq km for polymetallic nodules in the CIOB.
• Benthic Ecosystem Vulnerability: Mining poses acute risks to chemosynthetic ecosystems supporting endemic species like the scaly-foot snail (Chrysomallon squamiferum), requiring strict adherence to ISA environmental regulations.