International Governance Bodies

International governance bodies are central in overseeing seabed mineral activities in areas beyond national jurisdiction, where no single state holds sovereignty. These regions, collectively known under UNCLOS as "the Area", are governed by a multilateral legal framework designed to balance equitable access to seabed resources with environmental protection and long-term global stewardship. At the core of this system is the International Seabed Authority (ISA), the institution mandated to regulate licensing, environmental oversight, and benefit-sharing for exploration and future exploitation. Supporting this framework is the United Nations Convention on the Law of the Sea (UNCLOS), which provides the legal foundation for all seabed activities beyond national control.

Together, these instruments form the institutional and legal architecture for managing seabed mining in international waters, setting enforceable standards for environmental assessment, resource allocation, and global equity.

1. International Seabed Authority (ISA)

The International Seabed Authority (ISA) is the central global institution responsible for regulating mineral-related activities in the “Area”, the seabed, ocean floor, and subsoil beyond national jurisdictions. Established under Part XI of the United Nations Convention on the Law of the Sea (UNCLOS), the ISA operates as the legal and administrative body charged with ensuring that mineral resources in the Area are developed for the benefit of all humankind, in line with the principle of the common heritage.

Headquartered in Kingston, Jamaica, the ISA’s primary mandate includes issuing exploration licences and, in future, exploitation licences for deep-sea mineral resources such as polymetallic nodules, cobalt-rich crusts, and seafloor massive sulphides (SMS). As of 2025, the ISA has approved 31 exploration contracts covering more than 1.5 million km² of seabed. These contracts are held by a mix of state-sponsored entities, national governments, and private-sector contractors.

The ISA is also responsible for developing and enforcing the Mining Code, a set of legally binding regulations that govern exploration, environmental protection, and financial terms for resource extraction. While the ISA has finalised exploration regulations, the Draft Exploitation Code remains under negotiation, with unresolved debates on issues such as environmental thresholds, financial payment systems, and benefit-sharing mechanisms for developing countries. The outcome of these negotiations will determine when and how large-scale commercial mining can proceed in international waters.

In addition to regulatory oversight, the ISA coordinates environmental management and scientific research, including the designation of Areas of Particular Environmental Interest (APEIs), the development of Regional Environmental Management Plans (REMPs), and the review of Environmental Impact Statements (EISs) submitted by contractors.

As the only international body with legal authority over seabed mineral resources in international waters, the ISA plays a pivotal role in shaping the future of deep-sea mining, balancing commercial access with environmental stewardship and equitable global benefit-sharing. Its evolving regulatory framework will have far-reaching implications for critical mineral supply chains, ocean governance, and geopolitical competition over strategic subsea resources.

2. UNCLOS: The Foundational Framework

The 1982 United Nations Convention on the Law of the Sea, UNCLOS, provides the primary legal framework for the governance of international waters, including regulating subsea mining in areas beyond national jurisdiction. It defines the Area as the seabed, ocean floor, and subsoil beyond the limits of any state's Exclusive Economic Zone or continental shelf. It designates all mineral resources found there as the common heritage of humankind. This principle prohibits any state or private actor from asserting ownership over these resources and requires that benefits from their exploitation be shared equitably among all nations.

To manage activities in the Area, UNCLOS established the International Seabed Authority, ISA, under Part Eleven, granting it the exclusive mandate to organise, authorise, and oversee all exploration and exploitation activities on behalf of the global community. This framework is supported by several legal provisions that together form a distinct regulatory regime, combining international oversight, public trusteeship, and controlled access for corporate actors operating under the sponsorship of states. The system is designed to balance commercial development with environmental responsibility and global equity.

As of July 2025, UNCLOS has been ratified by 168 states, providing a strong legal foundation for international seabed governance. However, non-ratification by key players, particularly the United States, presents challenges. The United States regulates its flagged operators under the 1980 Deep Seabed Hard Mineral Resources Act, asserting unilateral rights without ISA-recognised licences, creating ongoing legal and diplomatic tensions.

The following articles within UNCLOS are particularly relevant to subsea mining:

• Article 136 – Common Heritage of Humankind: Declares that all mineral resources in the Area are the collective property of humanity, prohibiting any unilateral claims, ownership, or exclusive benefit. This principle underpins the obligation for equitable benefit sharing, especially with landlocked and developing countries.

• Article 137 – No Sovereignty Over the Area: Explicitly denies any state or private actor the right to claim, appropriate, or exercise sovereign rights over resources in the Area. The ISA has exclusive authority to organise, regulate, and manage all resource-related activities, reinforcing the legal principle that these resources belong to all of humanity and must be governed for the collective benefit of all states.

• Article 145 – Environmental Protection Obligations: Imposes a duty on the ISA to adopt measures to prevent, reduce, and control pollution and other hazards to the marine environment arising from mining operations. This includes setting rules, standards, and guidelines to protect vulnerable ecosystems, promote environmental baseline data collection, and manage cumulative impacts.

• Article 153 – Contract-Based Exploitation Regime: Sets the legal foundation for a contractual system in which states or state-sponsored private companies may apply to explore or exploit seabed minerals through ISA-issued licences. Contractors must be sponsored by a state party to UNCLOS and are subject to compliance with ISA regulations, including financial, environmental, and operational obligations.

Challenges to UNCLOS Implementation in Subsea Mining Governance

The implementation of UNCLOS faces several geopolitical and operational tensions that complicate the regulation of subsea mining. For example:

• United States non-ratification – One of the most significant issues is the non-ratification of UNCLOS by the United States. As of July 2025, the Convention has been ratified by 168 countries, including the European Union, China, India, Japan, and the majority of Pacific Island States. However, the United States remains a notable outlier. Although it has signed the treaty, it has never ratified it, primarily due to long-standing concerns over national sovereignty and mandatory benefit-sharing provisions. In place of UNCLOS, the U.S. relies on its 1980 Deep Seabed Hard Mineral Resources Act (DSHMRA), which permits U.S.-based companies to pursue mining claims in international waters independently of the International Seabed Authority (ISA), so long as they comply with U.S. licensing rules. This parallel system introduces legal ambiguity and diplomatic friction, particularly in areas like the Clarion–Clipperton Zone (CCZ), where U.S.-affiliated firms operate alongside ISA-sanctioned contractors.

• Delay in the exploitation code – Another key challenge is the delay in finalising the ISA Exploitation Code. The legal framework for commercial-scale mining remains incomplete, creating uncertainty for both investors and operators. In 2021, the Republic of Nauru triggered the so-called “two-year rule,” obligating the ISA to adopt exploitation regulations by 2023. However, scientific, ethical, and environmental concerns have stalled progress. As of 2025, despite multiple pilot deployments, no commercial exploitation licences have been issued, and pressure continues to mount from industry stakeholders seeking clarity and authorisation to proceed.

• Sponsorship and liability – The requirement for state sponsorship of contractors also raises complex issues around liability and enforcement. Under UNCLOS, all companies conducting activities in the Area must be sponsored by a state party, which is jointly liable for the contractor’s compliance with ISA rules. This has prompted concern, particularly when small or developing states such as Nauru, Tonga, or Kiribati sponsor large international mining firms. While the ISA has established basic compliance mechanisms, practical enforcement remains constrained by limited regulatory capacity, unequal bargaining power, and the jurisdictional complexity of cross-border operations.

• Equity and benefit sharing – Lastly, operationalising Article 136’s mandate for equitable benefit-sharing remains an unresolved legal and political challenge. The ISA is responsible for ensuring that the financial benefits derived from seabed mining are distributed fairly, particularly to landlocked and developing countries. However, as of 2025, there is still no functioning system to manage or disburse these benefits. Ongoing negotiations continue over key components, including royalty frameworks, technology transfer obligations, and institutional sharing mechanisms, all of which are critical to realising the Convention’s vision of global equity.

Regional and Transboundary Governance Mechanisms

While the International Seabed Authority (ISA) governs activities beyond national jurisdictions, regional and transboundary frameworks play a critical supporting role in the management of seabed mineral resources—particularly where jurisdictions are shared or environmental sensitivity requires area-specific oversight. These mechanisms are increasingly important for ensuring coherence between international regulation, national sovereignty, and regional ecological stewardship.

1. Joint Management Areas (JMAs)

Joint Management Areas are formal frameworks through which two or more coastal states jointly govern an extended continental‑shelf zone that straddles or lies between their national maritime boundaries, as permitted by UNCLOS Articles 76, 82 and 83. Designed to turn potential boundary disputes into collaborative opportunities, JMAs provide a single jurisdictional platform for licensing, revenue sharing and environmental oversight in spaces that fall outside any one state’s 200‑nautical‑mile EEZ but remain within their lawful continental‑shelf claims.

The benchmark example is the Mascarene Plateau JMA between Mauritius and Seychelles. Established by twin treaties in 2012, the regime covers 396 000 km² across the Saya de Malha Bank, a region now recognised for cobalt‑rich ferromanganese crust potential.

A three‑tier governance structure is envisaged:

• Ministerial Council – sets high‑level policy and approves budgets.

• Joint Commission – issues research permits, screens exploration tenders and monitors compliance.

• Designated Authority (in formation) – day‑to‑day regulator that executes Environmental Impact Assessments (EIAs), enforces operating standards and collects royalties.
  
  

Core Operating Features

The Mascarene Plateau JMA is designed as a turnkey governance package: revenue sharing, science oversight, environmental safeguards, capacity‑building and conflict resolution are all built into a single operating system. Its principal components are as follows.

1. Legal and fiscal clarity is achieved through a two‑tier royalty model that combines a production royalty with a ring‑fenced environmental levy, ensuring benefits flow equitably to both partner states while underwriting ecosystem management costs. Crucially, the partners remit their Article 82 payments to the ISA as a single entity, simplifying administration and eliminating revenue‑sharing disputes.

2. Scientific rigour underpins every operational decision. An independent Scientific Advisory Committee peer‑reviews all environmental impact assessments, sets baseline sampling protocols and validates monitoring data. To foster transparency, the joint authority maintains open‑access data portals that publish bathymetry, biodiversity inventories and quarterly compliance audits, enabling real‑time scrutiny by researchers, investors and civil society.

3. Robust environmental safeguards complement this science‑based approach. Precautionary buffer zones and designated “no‑mine corridors” shield shallow seagrass meadows, tuna nurseries and biodiversity‑rich slopes from direct disturbance. Joint satellite surveillance and ROV patrols enforce licence conditions, deter illegal activity, and provide additional environmental oversight.

4. Revenue and capacity‑building mechanisms are woven into the financial architecture. A dedicated Blue‑Economy Fund diverts an agreed share of royalties into coastal resilience projects, vocational training and marine‑science scholarships for both countries. Initial programme financing has been bolstered by a US $2.2 million UNDP‑GEF grant, while supplementary technical assistance is under negotiation with the World Bank.

5. A standing arbitration panel, modelled on the Nigeria–São Tomé Joint Development Zone, offers binding dispute‑resolution for contractual or environmental conflicts, giving contractors and financiers the legal certainty required for long‑term capital deployment.

6. Finally, the joint authority integrates mineral allocations into a comprehensive marine spatial‑planning system. Mineral licence blocks, shipping lanes, marine protected areas and prospective offshore‑wind corridors are digitised in a single GIS platform, reducing user conflicts and aligning resource development with each nation’s climate and conservation commitments.

Similar structures are now being discussed for the Gulf of Guinea, the Red Sea’s Atlantis II Deep, and sections of the Caribbean, signalling a broader trend toward regional, multi‑stakeholder stewardship of transboundary seabed resources.

2. Regional Environmental Management Plans (REMPs)

Regional Environmental Management Plans (REMPs) are strategic, ISA‑endorsed blueprints for managing seabed minerals in areas beyond national jurisdiction. Drafted with input from contractors, coastal states, scientists, and NGOs, they are not regulations in themselves, yet they act as binding reference documents: every exploration contract, environmental impact assessment, and—ultimately—exploitation licence must align with the relevant plan. By mapping ecologically important zones, setting environmental baselines and indicators, and establishing clear management objectives, REMPs guide mineral exploration and potential mining while safeguarding vulnerable habitats.

Each REMP sets out five pillars of spatial and ecological governance. First, it maps ecologically important areas, such as habitat types, biodiversity hotspots, or larval‑connectivity corridors that warrant special attention. Second, it prescribes Spatial Management Measures such as no‑mine zones, buffer corridors, and designated reference sites for long‑term monitoring. Third, it codifies Environmental Baselines and Indicators, defining the physical, chemical, and biological metrics contractors must track. Fourth, it articulates clear Management Objectives covering conservation targets, priority research needs, and adaptive‑management triggers. Finally, it specifies Cumulative‑Impact Protocols, obliging contractors to assess and report overlapping pressures across multiple licence blocks rather than treating each block in isolation.

Key REMPs include:

• CCZ REMP (2012; updated 2021) – sets aside nine 160,000 km² conservation areas, standardises baseline protocols, and requires a rolling review tied to pilot‑mining milestones.

• Mid‑Atlantic Ridge REMP (due 2027) – will cover vent fields such as TAG and Rainbow, with vent‑specific protection zones and plume limits informed by the LIFEDEEPER science programme.

• Indian Ocean Nodule & Ridge REMP (scoping 2025‑26) – expected to introduce dynamic management blocks that can shift with monsoonal productivity.

REMP provisions are enforced through a four‑part compliance cycle: every exploration or mining licence must demonstrate alignment with the relevant plan, a check performed by the ISA’s Legal & Technical Commission; contractors then upload baseline and monitoring datasets to the ISA’s open‑access DeepData portal, allowing the Authority to track regional trends; the plan itself undergoes a formal review roughly every five years, so spatial rules and protection zones can tighten or shift if cumulative impacts exceed agreed limits; and, throughout, multi‑stakeholder workshops bring in Indigenous knowledge, academic research, and NGO feedback to refine zoning and monitoring indicators, ensuring the regime adapts to both new science and community concerns.

REMPs turn the ISA’s global mandate into region‑specific, science‑based rules that balance mineral access with ecosystem protection. As the Exploitation Code nears finalisation, REMPs will decide where, when, and under what conditions commercial mining can start, and they will frame the cumulative‑impact assessments that follow. For contractors, REMPs bring spatial certainty; for civil society, they offer transparency and enforceable safeguards. In short, REMPs are set to be the operational backbone of environmental governance for deep‑sea mining.

Geological Endowment and Deposit Typologies

Subsea mining targets three principal deposit types, each formed through distinct geological processes and associated with different mineral profiles, physical characteristics, and geographic distributions. These include polymetallic nodules, cobalt-rich ferromanganese crusts, and seafloor massive sulphides (SMS). Together, they represent a vast and largely untapped source of critical minerals essential for the energy transition, including cobalt, nickel, rare earth elements, and battery-grade metals.

1. Polymetallic nodules are potato-sized concretions lying loose on the abyssal plains of the deep ocean floor. They form over millions of years through the slow accretion of metal oxides around a core, typically at depths of 4,000 to 6,000 metres. Nodules are rich in manganese, nickel, copper, cobalt, lithium, and rare earth elements, often with relatively uniform and high-grade metal content across large areas. The most commercially significant region is the Clarion–Clipperton Zone (CCZ), located in international waters between Mexico and Hawaii, and administered by the International Seabed Authority (ISA). Other notable deposits include the Peru Basin and the Central Indian Ocean Basin, also in international waters, as well as deposits within national jurisdictions such as the Penrhyn Basin in the Cook Islands, the EEZ of Niue, and regions of French Polynesia. Compared to terrestrial sources, polymetallic nodules offer the potential for lower strip ratios, fewer waste volumes, and reduced need for large-scale land disruption.

2. Cobalt-rich ferromanganese crusts are thin, hard layers that form on the flanks and summits of seamounts, typically at depths of 800 to 2,500 metres. These crusts grow through hydrogenetic precipitation of metals from seawater and are a promising source of cobalt, nickel, manganese, rare earth elements, tellurium, and platinum. They tend to occur in rugged terrain that complicates extraction, but the metal grades, particularly for cobalt and tellurium, can exceed those of many terrestrial deposits. Key locations include the Prime Crust Zone in international waters between Hawaii and the Mariana Trench, as well as within the EEZs of Japan (notably the Minamitorishima Seamounts and Izu–Bonin Arc), the United States (Hawaiian Seamount Chain), and several Pacific Island nations such as the Marshall Islands and Kiribati. Crusts have also been identified in the Mascarene Plateau in the Indian Ocean, spanning both national EEZs and international waters.

3. Seafloor massive sulphides (SMS) are hydrothermal ore deposits formed by the precipitation of metal-rich fluids at or beneath the ocean floor, particularly at mid-ocean ridges, back-arc basins, and volcanic arcs. These deposits contain high concentrations of copper, zinc, gold, silver, and lead, often in compact, high-grade zones. The most studied SMS sites include the Mid-Atlantic Ridge (TAG and Rainbow fields) and the Southwest and Central Indian Ridges, all in international waters. Within national jurisdictions, prominent examples include the Solwara Field in the Bismarck Sea (Papua New Guinea), the Lau Basin between Tonga and Fiji, the Okinawa Trough in the Japanese EEZ, and the Atlantis II Deep in the Red Sea, a rare example of a joint EEZ zone between Saudi Arabia and Sudan. These deposits are often geologically analogous to massive volcanic sulphide (VMS) deposits on land, but they can offer superior grades, particularly for precious metals like gold and silver.

Extraction Methods, ESG risks and Challenges

The extraction of deep-sea mineral resources requires highly specialised technologies capable of operating under extreme pressure, low light, and fragile ecological conditions. Each deposit type presents unique engineering and environmental challenges. For polymetallic nodules, extraction typically involves tracked collector vehicles deployed to the seafloor, which scoop or vacuum nodules from the sediment and transfer them through riser systems to a surface vessel. These systems are designed to minimise disturbance to the surrounding substrate, but inevitably generate sediment plumes, both at the seafloor and midwater column. These plumes can reduce water clarity, interfere with filter-feeding organisms, and potentially spread contaminants over large distances, with uncertain effects on microbial and benthic communities.

For cobalt-rich ferromanganese crusts, extraction involves cutting or stripping crust layers from hard rock surfaces on seamount flanks and summits. This is mechanically complex and may involve cutting tools or drills mounted on remotely operated vehicles (ROVs), with higher risks of habitat destruction due to the permanence of seamount communities and their slow recovery rates. Seafloor massive sulphides (SMS) require more intensive mechanical removal, often resembling small-scale open-pit mining, with excavation tools used to dislodge sulphide chimneys and underlying deposits. These activities can disrupt hydrothermal vent ecosystems, which are characterised by unique and often endemic species, many of which are poorly studied or undocumented.

Environmental and social governance (ESG) risk profiles vary significantly by deposit type. Polymetallic nodules, which lie on soft sediment plains, present relatively lower physical habitat disruption compared to crusts and sulphides, but pose serious concerns over sediment plume dispersion, faunal displacement, and long-term ecosystem function. In contrast, crust mining threatens to damage biologically rich and structurally complex seamount habitats, which are exceptionally slow to regenerate. SMS deposits are typically smaller in spatial extent but may host some of the most vulnerable biological communities, including chemosynthetic organisms adapted to hydrothermal environments. The destruction of these habitats could lead to irreversible biodiversity loss, particularly given the short spatial ranges of many species.

Mitigation strategies remain in the early stages of development. Operators have proposed various technical solutions, including low-sediment collectors, plume containment mechanisms, and real-time environmental monitoring. Environmental baseline studies are underway in several contract areas, most notably the NORI-B environmental programme in the CCZ, which has conducted multi-year studies on sediment dynamics, biodiversity mapping, and ecosystem response modelling. These efforts are intended to inform impact assessments and guide the development of adaptive management strategies, although the long-term effectiveness of proposed mitigation remains uncertain.

Civil society organisations and independent scientists have expressed increasing concern over the pace and transparency of ISA decision-making. Many argue that the precautionary principle is not being adequately applied and call for a moratorium on commercial exploitation until more comprehensive scientific data are available. Over 800 marine scientists have signed declarations urging restraint, and several countries, including France, Chile, and New Zealand, have publicly supported temporary bans. This resistance has shaped a more adversarial science-policy interface within the ISA, with growing demands for independent review processes, improved public consultation, and enhanced legal protection for vulnerable marine ecosystems.

1.1 Clarion–Clipperton Zone (CCZ)

Spanning 4.5 million km² between Mexico and Hawaii, the Clarion–Clipperton Zone (CCZ) is the most extensively explored and technologically advanced region for polymetallic nodule development. As of 2025, it hosts 17 of the International Seabed Authority’s (ISA) 19 active nodule exploration contracts, covering a vast swathe of the Northeast Pacific. These contracts are held by contractors sponsored by states including Canada, Belgium, Germany, China, the United Kingdom, and South Korea—reflecting broad international interest in the region’s resource potential.

Leading operators such as The Metals Company (TMC) and Global Sea Mineral Resources (GSR) are pioneering commercial pathways. In 2024, TMC’s NORI-D project marked a significant milestone with a 60-day pilot collector trial, successfully lifting 3,000 tonnes of nodules from 4,000 metres below the surface at a continuous rate of 86 tonnes per hour. The nodules recovered from the CCZ contain, on average, 1.3% nickel, 1% copper, 0.2% cobalt, and trace amounts of lithium and rare earth elements, grades that, when scaled, rival or exceed many terrestrial sources of these metals.

All contractors have submitted Environmental Impact Statements (EISs) and extensive baseline datasets addressing key ecological parameters such as sediment plume behaviour, benthic biodiversity, and mid-water column dynamics. Despite this progress, the lack of a finalised ISA Exploitation Code continues to delay commercial development. As of July 2025, the code remains under negotiation, leaving timelines for large-scale production uncertain. Most projections suggest first production is unlikely before 2031 to 2033, contingent on regulatory clarity and investor confidence.

Adding further complexity, the United States, which has not ratified UNCLOS and is therefore not a party to the ISA system, issued a 2025 executive order enabling U.S. firms to apply for CCZ exploration blocks under the Deep Seabed Hard Mineral Resources Act (DSHMRA). This unilateral approach creates legal ambiguity and geopolitical tension, particularly as American entities begin to operate alongside ISA-sanctioned contractors. The result is a highly dynamic regulatory and competitive environment in what is likely to be the world’s first industrial-scale deep-sea mining zone.

1.2 Penrhyn Basin, Cook Islands EEZ

Transitioning from international waters to national jurisdictions, the Penrhyn Basin within the Cook Islands’ Exclusive Economic Zone (EEZ) illustrates a sovereign-led model for deep-sea mineral development. Covering approximately 160,000 km² within the country’s 1.9 million km² EEZ, the basin holds one of the largest known national nodule resources. In 2023, licensees Moana Minerals and CI Resources reported an inferred resource of 6.7 billion tonnes of polymetallic nodules, with average grades of 0.8% nickel, 0.6% copper, 0.09% cobalt, and 30% manganese. Located in relatively shallower waters than the Clarion–Clipperton Zone, up to 4,500 metres, the nodules here also contain lower concentrations of radioactive thorium, a characteristic that simplifies downstream processing and residue management.

Governance is led by the Seabed Minerals Authority, established under the Seabed Minerals Act (2020). This framework mandates a two-phase Environmental Impact Assessment (EIA) process before any mining licence can be granted. It includes large-scale collector system trials and independent modelling of sediment plumes and benthic disturbance. This ensures that environmental protection standards meet or exceed emerging international benchmarks.

Beyond regulation, the Cook Islands have proposed a sovereign royalty fund designed to return 50% of future mining revenues to public services, notably healthcare and climate adaptation infrastructure. This fiscal approach aligns resource development with long-term national resilience goals. While some regional NGOs and customary groups have raised concerns about ecological disruption and the cultural significance of the ocean, public consultations in 2024 revealed broad conditional support, especially if community benefits are transparently allocated and marine ecosystems are properly safeguarded.

With pilot nodule lifts scheduled for 2027, the Penrhyn Basin is on track to become the world’s most advanced EEZ-based deep-sea mining initiative, setting an important precedent for how small island developing states (SIDS) can exercise sovereign control over seabed resources while embedding ESG safeguards and inclusive development strategies.

1.3 Central Indian Ocean Basin (CIOB)

In the Central Indian Ocean Basin (CIOB), India stands out as the sole ISA contractor operating in this region, holding a polymetallic nodule exploration licence covering 75,000 km² of deep-sea floor between 4,800 and 5,800 metres depth. The licence is managed by the National Institute of Ocean Technology (NIOT), which has undertaken extensive geophysical and environmental mapping since 2019. This includes over 10,000 line-kilometres of high-resolution geophysical surveys and the collection of 1,200 box-core samples. The nodules in this region contain 1.2% nickel, 1% copper, and 0.18% cobalt, with a notably high manganese content. While these grades are slightly lower than those found in the Clarion–Clipperton Zone, they remain commercially viable, particularly given India’s domestic processing capabilities.

In 2024, NIOT conducted a successful wet test of a 17-tonne tracked collector prototype, designed to operate at depths of up to 6,000 metres. Parallel laboratory trials demonstrated 92% nickel recovery using a combination of acid leaching and solvent extraction, validating India’s metallurgical approach. The CIOB project forms part of a broader dual-resource strategy, with NIOT also applying for an ISA licence to explore seafloor massive sulphides (SMS) on the adjacent Central Indian Ridge. This aligns closely with India’s national priorities, supporting critical inputs for stainless steel production, energy storage, and electric vehicles under the Critical Minerals Strategy 2030.

India’s subsea mineral initiatives are geopolitically significant, positioned as a direct response to Chinese dominance in terrestrial and processing-stage critical minerals. The CIOB programme also reflects India’s intent to establish itself as a vertically integrated deep-sea mining actor. While environmental activism has been relatively muted, NIOT has committed to adhering to the ISA’s forthcoming Indian Ocean regional environmental management plan, expected in 2026. This includes sediment plume modelling, benthic biodiversity studies, and baseline oceanographic monitoring.

2.1 Prime Crust Zone (PCZ), Western Pacific

Straddling the Marshall Islands and the Mariana Trench, the Prime Crust Zone (PCZ) is the leading frontier for cobalt-rich ferromanganese crust exploration under the governance of the International Seabed Authority (ISA). Exploration licences in this region are held by Japan’s JOGMEC and China’s COMRA, targeting clusters of seamounts where crusts up to 8 centimetres thick yield cobalt concentrations of around 1%, approximately three times higher than many terrestrial laterite deposits. These crusts also contain significant levels of nickel, manganese, and trace rare earth elements (REEs), positioning the PCZ as a strategic resource zone for energy transition metals.

The region’s complex topography, with vertical relief exceeding 1,500 metres, prevents conventional tracked collectors typically deployed in nodule fields. Instead, operators are trialling crawler-mounted drum-cutters paired with high-pressure slurry pumps to detach and transport crust material. In 2024, JOGMEC successfully retrieved 12 tonnes of saw-cut crust slabs from a depth of 1,800 metres, demonstrating the technical feasibility of mechanical extraction under real seafloor conditions.

Despite these advancements, the ecological risks remain substantial. Footage from remotely operated camera sleds has revealed that crust mining could severely damage slow-growing coral and sponge communities that dominate seamount ecosystems. These findings raise the ESG risk profile of crust extraction above that of polymetallic nodules. In response, the ISA is drafting seamount-specific environmental thresholds, focusing on biodiversity protection and sediment plume mitigation strategies.

From a strategic standpoint, Japanese projections suggest that cobalt sourced from the PCZ could reduce the country’s reliance on the Democratic Republic of the Congo by up to 20% by 2035, assuming that processing technologies for high-manganese feedstocks continue to advance. However, the absence of a finalised ISA Exploitation Code, still under negotiation as of July 2025, continues to delay commercial progress. As a result, full-scale mining in the PCZ is unlikely to begin before 2032–2035, contingent on regulatory clarity, environmental safeguards, and industrial-scale system integration.

2.2 Japanese EEZ: Minamitorishima & Izu–Bonin Arc

Through legislative clarity, targeted public investment, and advanced offshore technologies, Japan is positioning itself as a global leader in the sustainable development of high-value seabed resources.

Within its Exclusive Economic Zone (EEZ), Japan is advancing exploration of both cobalt-rich ferromanganese crusts and rare earth element (REE)-rich muds, particularly at the Minamitorishima Seamount and the Izu–Bonin Arc. Located approximately 1,850 km southeast of Tokyo, Minamitorishima hosts deep-sea pelagic muds with REE concentrations reaching up to 5,000 ppm total rare-earth oxides—20 to 30 times the average concentration found in continental crust. Additionally, crusts in the region grade 1.1% cobalt and contain elevated scandium levels, a strategic element for lightweight alloys and clean energy technologies.

In 2023, JOGMEC conducted a successful drilling campaign that confirmed a 1.4 gigatonne inferred resource, intersecting up to 31 metres of REE-rich mud. To accelerate development, the Japanese government has allocated ¥7 billion for a 2026 pilot lift of 1,000 tonnes, using a barge-mounted plant to test in situ separation techniques for REE recovery. This operation will provide essential data on the feasibility of offshore extraction and processing in one of the world’s most geochemically promising EEZ settings.

Parallel efforts in the Izu–Bonin Arc and Okinawa Trough target seafloor massive sulphide (SMS) deposits, which average 7% zinc, 6% copper, and 4 g/t gold, adding diversification to Japan’s subsea mineral strategy. A 2023 environmental impact study warned that removal of active hydrothermal vent chimneys could create trenches up to 30 metres deep, prompting researchers and regulators to explore active habitat recolonisation measures to mitigate long-term ecological disruption.

These initiatives are governed by Japan’s 2022 Seabed Mineral Development Act, which imposes stricter sediment plume limits and environmental standards than the draft ISA Exploitation Code, reflecting Japan’s strong domestic commitment to marine conservation and biodiversity protection within its territorial waters. Aligned with the country’s Critical Minerals Strategy and industrial decarbonisation goals, Japan’s EEZ projects aim to reduce its 60% dependency on Chinese REE imports by 2030. 

2.3 Mascarene Plateau Joint Management Area (JMA)

The Mascarene Plateau, spanning 396,000 km² and jointly governed by Mauritius and Seychelles, represents a pioneering transboundary governance model for seabed mineral exploration in the Indian Ocean. Established through a pair of 2012 bilateral treaties, the Joint Management Area (JMA) covers parts of the Saya de Malha Bank, a large undersea plateau where initial reconnaissance dredging has recovered 5–8 cm-thick cobalt-rich crusts, grading up to 1% cobalt, 0.8% nickel, and enriched tellurium. These early samples signal promising potential for future cobalt supply, especially for countries seeking alternatives to Pacific seamounts.

To support responsible development, a 2024 UNDP-funded capacity-building programme allocated US$2.2 million to help establish governance instruments, including a Marine Scientific Research Code, an Environmental Code of Practice, and a fiscal-sharing framework for future resource revenues. Complementary domestic legislation was passed in both countries in 2023—Seychelles’ Mascarene Plateau Act and Mauritius’ Seabed Minerals Bill—paving the way for exploration tenders once comprehensive environmental baselines are completed.

Ecological concerns are central to the JMA’s regulatory design. The plateau hosts shallow seagrass meadows, critical blue-carbon ecosystems, and key tuna nurseries, raising the stakes for managing plume dispersion from future mining along deeper slopes. These sensitivities have led to stringent draft thresholds for sediment plume impacts and strengthened precautionary approaches to ecosystem protection.

Reflecting growing geopolitical interest in the Indian Ocean’s mineral potential, both India and France have proposed joint expeditions to the JMA in 2026, with research focused on geochemical mapping and biodiversity assessments. If environmental assessments progress as planned, a competitive bidding round could launch in 2027, positioning the Mascarene Plateau as a regionally significant cobalt supply alternative.

3.1 Mid‑Atlantic Ridge: TAG & Rainbow Fields

The Mid-Atlantic Ridge, home to the TAG, Rainbow, and Snake Pit hydrothermal areas at depths of around 3,600 metres, represents Europe’s primary frontier for seafloor massive sulphide (SMS) exploration. Two International Seabed Authority (ISA) plans of work are active in the region—one held by France’s Ifremer and the other by a Polish-sponsored entity. The region hosts some of the most geologically studied SMS systems in international waters.

The TAG field features an inactive mound estimated to contain 3.9 million tonnes of ore, grading 5% copper and 4% zinc, while the Rainbow vent field remains hydrothermally active, discharging 365°C fluids enriched with copper, gold, and rare earth elements. These deposits offer high-grade potential but are also located in ecologically sensitive environments, requiring rigorous assessment before any exploitation can begin.

In response, the LIFEDEEPER programme was launched in 2024 to integrate geological, ecological, and policy research, with the goal of delivering a regional environmental management plan by 2027. This plan will be a key prerequisite for moving from exploration to pilot mining, as required by the ISA.

Although France imposed a ban on deep-sea mining in its national waters in 2023, it continues to support Ifremer’s international SMS research, demonstrating a nuanced policy stance that separates scientific inquiry from commercial development. Meanwhile, baseline studies using remotely operated vehicles (ROVs) have documented more than 200 endemic species living at these vent systems—many of which are highly adapted to their extreme environments. These findings have intensified calls from NGOs and scientific bodies for a broader European moratorium on SMS mining.

Some commercial strategies under consideration include a hub-and-spoke model, where ore slurries would be pumped to the Azores for processing. However, these concepts remain at a preliminary stage. With the ISA’s Draft Exploitation Code still unresolved as of July 2025, no commercial operations are expected before the early 2030s.

3.2 Bismarck Sea (Solwara Field), Papua New Guinea

In stark contrast to other SMS developments, the Solwara 1 deposit in Papua New Guinea’s Bismarck Sea stands as a cautionary tale for deep-sea mining. Discovered at a depth of 1,600 metres, Solwara 1 was once hailed as the world’s first commercial seabed mining project, boasting exceptionally high ore grades—7% copper and 6 g/t gold. Operated by Nautilus Minerals, the project was set to revolutionise seabed resource extraction. However, financial collapse in 2019 halted all progress, leaving behind an unfinished production support vessel, three seafloor production tools, and a trail of unresolved debts.

In 2024, Papua New Guinea’s prime minister reaffirmed the country’s national moratorium on deep-sea mining, citing a lack of robust scientific data and unresolved environmental risks. However, some provincial leaders continue to advocate for the project’s revival, hoping to unlock its economic potential. The Solwara site complicates matters further with its active hydrothermal vent systems, which host unique endemic species such as the "sea-dragon" worm and giant snails—organisms that raise significant ethical and regulatory challenges around biodiversity protection.

Recent marine studies indicate that copper-rich chimneys at hydrothermal vents regenerate slowly, over decadal timescales, making post-mining habitat restoration highly uncertain. These findings further reinforce concerns from scientists and NGOs about the long-term impacts of disrupting such fragile ecosystems.

Currently under review, the Seabed Mining (Moratorium) Bill proposes halting new deep-sea mining licences until at least 2030, establishing a legal framework for precautionary governance. Meanwhile, investors continue to explore joint venture options, potentially pairing Solwara’s mineral resource with onshore hydrometallurgical processing facilities in Rabaul.

Despite renewed interest, Solwara 1 remains emblematic of the risks facing early-stage SMS ventures. As investors reassess the project’s future, opportunities may lie in integrated development models that combine subsea extraction with onshore processing infrastructure in centres like Rabaul. 

3.3 Red Sea: Atlantis II Deep

The Atlantis II Deep, a 2,000 metre-deep brine pool located in the Suakin Trough of the Red Sea, represents one of the world’s most geologically unique SMS prospects. Governed under a joint jurisdictional arrangement between Saudi Arabia and Sudan, the site hosts metalliferous sediments up to 20 metres thick, with average grades of 2.3% zinc and 0.5% copper, alongside notably high concentrations of gallium and germanium, metals of growing strategic importance in electronics and advanced technologies.

Despite its promise, commercial development has remained elusive. A 2010 mining licence issued to the Red Sea Development Company lapsed without pilot activity, and although bilateral discussions resumed in 2024, no operational progress has been achieved—largely due to ongoing regional instability and cross-border political sensitivities. The deposit also presents formidable technical challenges. The brine itself is hypersaline, exceeds 60°C, and is chemically aggressive, which renders conventional lift and pumping systems highly susceptible to corrosion. These factors have significantly slowed technological readiness and increased capital risk.

Nonetheless, scientific drilling campaigns in 2023 reaffirmed the deposit’s critical mineral potential, drawing renewed attention to its untapped value. However, the path to economic viability remains uncertain, given the need for breakthrough hydrometallurgical techniques and specialised processing systems capable of handling extreme brine conditions.

4) Emerging National Initiatives: Norway and the United States

Norway’s Arctic Shelf pause and the U.S.’s fast-track under DSHMRA, exemplified by TMC’s Q2 2025 permit applications, highlight the spectrum of national approaches to subsea mining governance. Norway’s ESG-driven caution, delaying licensing to prioritise environmental data, contrasts with the U.S.’s unilateral push, driven by supply-chain security concerns and dissatisfaction with China’s ISA contract dominance. These strategies underscore the challenges of aligning national priorities with global standards, navigating ESG risks, geopolitical tensions, and regulatory uncertainties. By 2035, their success in contributing to critical mineral supplies will depend on balancing innovation with robust environmental and diplomatic frameworks.

National initiatives for subsea mining within Exclusive Economic Zones (EEZs) and beyond are reshaping the global supply of critical minerals like cobalt, nickel, and copper, which are vital for the energy transition. Norway’s Arctic Shelf and the United States’ rapid approach under the Deep Seabed Hard Mineral Resources Act (DSHMRA) highlight contrasting strategies, reflecting the tension between environmental stewardship, economic ambition, and geopolitical priorities. Norway’s 2024 pause on its Arctic licensing round underscores the growing influence of environmental, social, and governance (ESG) pressures, prioritising ecological data over immediate resource extraction. Conversely, the U.S.’s 2025 executive order accelerates unilateral mining to secure supply chains, bypassing international frameworks like UNCLOS.

4.1 Norway’s Arctic Shelf Pause

In 2019, Norway became the first nation to legislate commercial seabed mining with its Seabed Minerals Act, targeting cobalt-rich ferromanganese crusts and seafloor massive sulphides (SMS) within its 2 million km² Arctic EEZ, particularly off Svalbard. The act aimed to position Norway as a leader in supplying critical minerals for batteries and renewable energy, leveraging deposits grading up to 1% cobalt and 5% copper, with a resource potential of millions of tonnes. Preparatory seismic and geochemical mapping, supported by NOK 150 million for impact studies, assessed risks to Arctic ecosystems known for fragile benthic communities and slow recovery rates.

However, a December 2024 coalition deal halted Norway’s planned 2025 licensing round, driven by intense pressure from environmental NGOs citing insufficient data on sediment plumes and biodiversity loss. Critics argued that mining could disrupt Arctic marine food chains and carbon sequestration processes. The pause reflects Norway’s internal conflict between green-industrial ambitions and its global environmental leadership image. Public consultations in 2024 revealed polarised views, with industry stakeholders emphasising economic benefits and coastal communities raising concerns over fisheries impacts. The government continues mapping and impact studies, with licensing now potentially delayed to 2028, pending comprehensive environmental baselines. Norway’s case illustrates how ESG pressures can stall even advanced legislative frameworks, underscoring the need for robust scientific data to secure social licences.

4.2 United States Fast‑Track under DSHMRA

In April 2025, the United States accelerated its deep-sea mining agenda with the executive order “Unleashing America’s Offshore Critical Minerals and Resources,” directing the Bureau of Ocean Energy Management (BOEM) and NOAA to streamline leasing and environmental reviews under the 1980 Deep Seabed Hard Mineral Resources Act (DSHMRA). This legislation, predating the U.S.’s non-ratification of UNCLOS, enables unilateral exploration and exploitation beyond its EEZ, targeting polymetallic nodules and cobalt-rich crusts. The Metals Company USA LLC (TMC USA), a subsidiary of The Metals Company, initiated a process with NOAA in March 2025 to apply for exploration licenses (199,895 km²) and commercial recovery permits (25,160 km²) in the Clarion-Clipperton Zone (CCZ), with formal submissions planned for Q2 2025. These deposits grade up to 1.3% nickel, 1% copper, and 0.2% cobalt, aiming to reduce U.S. reliance on Chinese-controlled supplies (70% of cobalt, 90% of rare earth elements). TMC’s decision reflects frustration with the ISA’s failure to adopt Exploitation Regulations, compounded by U.S. objections to China’s three exploration contracts (for nodules, sulphides, and crusts), which are seen as consolidating Beijing’s influence over critical minerals.

The DSHMRA framework bypasses ISA oversight, offering faster permitting than the ISA’s unresolved Draft Exploitation Code (July 2025). NOAA’s proposed 18-month environmental review timelines raise concerns about inadequate assessments of sediment plumes and benthic impacts. The U.S.’s non-ratification of UNCLOS sparks diplomatic friction with ISA member states, who view unilateral actions as undermining the "common heritage of humankind" principle (UNCLOS Article 136). Proponents, including TMC, which has invested $500 million in CCZ exploration and environmental data, argue domestic licences are critical for strategic autonomy, with projections suggesting U.S.-controlled seabed resources could meet 10–15% of domestic cobalt demand by 2035. The approach positions the U.S. as a wildcard, prioritising speed over multilateral cooperation, but risks international legal challenges and ecological uncertainties.