Why Deep-Seabed Mining Needs a Moratorium

Fact Sheet June 6, 2025

A sea star adhering to a metallic nodule.

Overview

The ocean is crucial for keeping the planet healthy, yet it’s under strain from damaging activities and climate change.¹Meanwhile, the threat of deep-seabed mining is putting pressure on member States at the International Seabed Authority (ISA) – the autonomous body created by the United Nations Convention on the Law of the Sea (UNCLOS) to oversee mining in areas beyond national jurisdiction – to evaluate mining applications even in the absence of agreed-upon regulations or hastily finalize a regulatory framework that lacks adequate safeguards to protect the world’s largest reservoir of biodiversity.

The deep sea begins at 200 metres below the surface and is home to a wealth of marine organisms enduring in extreme conditions and to unique ecosystems that contribute to the health of the global ocean. But there is increasing pressure to mine these ocean depths for commodities such as cobalt, nickel and manganese. While these are currently used in electric vehicle batteries, cell phone touch screens and some renewable energy mechanisms such as solar cells and wind turbines, there are new innovations and technologies that rely less on these minerals.

Further, the technology to mine at these depths at a commercial scale is largely untested and poses a significant risk of serious harm to marine life that is slow-growing and long-lived in the deep ocean. Investors, banks and insurers have raised important questions about the need for these minerals and whether the financial benefits of extracting them from the seabed are economically attractive in the first place. Others, including States, NGOs, scientists and industries, have expressed concerns about equity, effective governance and damage to marine ecosystems and long-term ocean health.

Interest in deep-seabed mining emerged in the 1960s, and in 1970 the U.N. adopted a resolution that called for the creation of an international regime to govern the seabed in areas beyond national jurisdiction.² At that time, scientists understood little about the biodiversity of the deep ocean, but governments still foresaw the risks of deep-sea mining. Through UNCLOS, the ISA was established to adopt laws and regulations that would protect the marine environment from the harmful effects of any mining. UNCLOS also classified minerals in areas beyond national jurisdiction as “the common heritage of [hu]mankind,” meaning that mining should be undertaken only for the benefit of all humanity, and it committed member States to the joint custodianship of those minerals – meaning that no one country or private interest can own them. Furthermore, benefits, including profits accrued from their extraction, must be shared equitably among all nations, especially developing States.

Today, 30 years after UNCLOS entered into force, scientists caution that there is still not sufficient baseline knowledge about deep-sea ecosystems, which would be necessary for measuring the impacts of deep-sea mining. Although the ocean is still an understudied part of the planet, scientists do know it is in rapid decline, with the U.N. declaring a “global emergency” for the ocean, especially because of worsening ocean acidification, warming, plastic pollution and overfishing, among other alarming trends. With the threat of commercial-scale mining looming and the scale of impacts unknown, it is imperative for ISA member States to implement a moratorium – a precautionary pause – on deep-sea mining.

Since 2019, the ISA has convened meetings several times a year at its headquarters in Kingston, Jamaica, for governments to negotiate seabed mining rules and regulations for exploitation. However, because of the technical complexities and differing priorities among negotiating States, numerous critical issues remain unresolved and far from completion, including thresholds of environmental harm that would be prohibited, monitoring and compliance mechanisms, and equitable sharing of benefits among nations. Questions also remain about how to address underwater cultural heritage, including concerns about artefacts and human remains as well as long-standing cultural connections of various Indigenous Peoples and communities to the ocean and seabed. Furthermore, the ISA is currently not equipped to act as a regulator for what could be one of the largest extractive industries the planet will have ever seen.³

Some of the most significant concerns about seabed mining fall into four areas: science, governance, equity and economics.

A translucent red-purple sea cucumber resting on the seabed. — This sea cucumber is relatively new to science and found in the Clarion-Clipperton Zone, located in the northeast Pacific Ocean. Also colloquially known as the “gummy squirrel,” it is just one of myriad species that could benefit from a moratorium on seabed mining within the region and beyond.

	Science When policymakers first drafted UNCLOS and anticipated future seabed mining, many believed the deep sea lacked life that would be affected. However, scientists now know the deep sea is home to an abundance of rare, vulnerable species, and they are just beginning to understand how this biodiversity supports complex ecosystems and critical ecosystem services (the benefits humans derive from the natural environment). And there is still a tremendous amount to learn about the deep ocean – and the damage that would occur from mining – making it impossible to finalize regulations right now that can ensure that mining will not harm the marine environment. Even in the most well-studied regions of the deep sea – including those the ISA has allowed companies to explore for minerals they could mine in the future – there are significant gaps⁴ in the world’s understanding of this environment and the species it supports. Take, for example, the most targeted deep-sea mining frontier, the Clarion-Clipperton Zone, which is located between Mexico and Hawaii in the northeast Pacific. Scientists estimate that thousands of species remain undiscovered and that up to 92% of the zone’s benthic species, or those living near the ocean floor, are new to science.⁵ The deep ocean is particularly sensitive to disturbance and slow to recover. Mining companies are targeting polymetallic nodules – rocklike deposits that contain nickel, manganese, copper, zinc, cobalt and other minerals – lying on the ocean floor. These nodules took millions of years to form and provide a vital habitat for an array of deep-sea life. Mining would essentially mean the permanent loss of those habitats and associated ecosystem services. Damage and tracks left on the ocean floor by vehicles during mining trials in 1989 are still clearly visible today, and those areas still lack microorganisms.⁶ There also could be risks to the climate system⁷ and other ecosystem services that humans rely on. For example, some scientific models predict that tuna populations could shift to areas targeted for seabed mining.⁸ The ways in which mining could affect fisheries are not fully understood, but some researchers are concerned that heavy metals could enter the wider ecosystem and food chain. Additionally, the noise generated by mining activity could have significant impacts. Researchers have found that noise from one mine alone could travel approximately 500 kilometres (roughly 300 miles) in calm weather conditions, with cumulative impacts likely in places where multiple mines operate.⁹ Scientists do not yet have enough information to evaluate with any certainty how intense, far ranging or long- lasting the environmental effects of deep-sea mining will be. This lack of data means the ISA cannot adequately identify acceptable thresholds or draft regulations that would avoid substantial harm to the marine environment.
	Governance Unresolved political, legal and logistical challenges make it clear that the ISA is not currently equipped to govern deep-sea mining and navigate the complexities it brings. Despite States’ hard work and some substantive progress, research¹⁰ indicates that the draft exploitation regulations have up to 30 major policy issues that still need to be resolved. Furthermore, a similar amount of subsidiary regulatory instruments – including binding standards, which are required to be concluded alongside the main regulations, and non-binding guidelines – have barely begun to be considered. And rifts remain between ISA member States on dozens of fundamental issues, ranging from what constitutes permissible environmental harm to how to address cultural connections to the deep sea. Apart from those substantive issues, it would be difficult – even for an established regulatory agency – to regulate, monitor and enforce rules around an activity such as deep-sea mining that would occur thousands of miles offshore and thousands of metres below the surface of the ocean.¹¹ Given that the ISA has thus far focused solely on facilitating multilateral negotiations and overseeing the exploration for minerals, it is unprepared to take on the roles of regulator and licensor as well as royalty receiver and distributor – functions typically undertaken (in comparable situations at the national level) by separate governing bodies with extensive expertise. Given the lack of scientific knowledge, the lack of a regulatory framework and the ISA’s limited institutional capacity for governance and oversight, eminent international law experts have also suggested that under the current circumstances, a moratorium or pause on mining is not only consistent with UNCLOS but required by it.¹² Recent international agreements have demonstrated a growing interest in biodiversity conservation, including in the ocean. Once it enters into force, the 2023 Agreement on the Conservation and Sustainable Use of Marine Biological Diversity in Areas Beyond National Jurisdiction – also known as the BBNJ Agreement – will provide a platform to coordinate efforts to protect marine life in these areas. The 2022 Kunming-Montreal Global Biodiversity Framework calls for at least 30% of ocean, land and freshwater to be conserved by 2030, a goal known as “30 by 30.” It is vital that countries honour their various international obligations at all intergovernmental processes, rather than considering them in isolation. The principle of “systemic integration” requires that treaties be interpreted in light of relevant rules of international law, and legal experts have stated that in considering the evolving standards of environmental protection, it is both “necessary and appropriate to refer to other international conventions.”¹³ The principle of systemic integration is crucial for maintaining coherence in international law and is applicable to UNCLOS.
	Equity The spectre of deep-sea mining raises a host of equity concerns over who will benefit and who will be harmed. Although UNCLOS mandates that benefits from deep-sea minerals must be shared equitably,¹⁴ the ISA has not agreed on a mechanism to do so. Additionally, no studies have shown that financial gains from deep-sea mining would be sufficient to offset the costs of long-term damage or remediation nor provide any significant benefits to future generations.¹⁵ There has also been little progress around the ISA’s separate obligations to carry out marine scientific research for the benefit of humankind as a whole, as well as to build capacity and transfer marine technology to developing States. Countries negotiating UNCLOS were keenly aware that the economies of developing nations dependent on export revenues from terrestrial mining may be adversely affected by deep-sea mining. Research on which developing countries might be most affected has identified 12 such countries, which have economies highly dependent on the minerals targeted by miners – representing $560 billion in export earnings.¹⁶ If deep-sea mining adversely affects those economies, then UNCLOS requires that those developing countries be compensated for losses. It is unclear, however, how such a system would work, and how that compensation would be calculated. The negative impacts of deep-seabed mining could even violate fundamental human rights. Between 2023 and 2024, U.N. Special Rapporteurs on human rights indicated that “if deep-seabed mining becomes an industry, there will be irreversible human rights impacts, particularly related to the rights to a clean, healthy and sustainable environment, food, cultural rights and Indigenous Peoples’ rights, amongst others.”¹⁷
	Economics Deep-sea mining, which is mandated to benefit all of humankind including future generations, should not forge ahead in the absence of safeguards and regulations, especially when the commercial case is uncertain. While proponents of deep-sea mining cite the large estimates of mineral resources on the seabed, it’s important to understand that these do not equate to reserve estimates of economically recoverable minerals. Despite some small-scale mining trials demonstrating proof of concept, the technology to extract large commercial-scale quantities of material – while operating at deep depths far offshore for extended periods – remains untested.¹⁸ The commercial viability of deep-sea mining is also unclear, as it depends on future global demand for minerals, which is uncertain, with economists’ predictions varying widely.¹⁹ This change in outlook is due, in part, to rapid advances in battery technology and recycling that are making these minerals less relevant.²⁰ For example, many companies have developed lithium- and sodium-based batteries, some of which do not rely on materials sourced from the deep sea and others that rely on those materials far less than prior technologies did. And an increasing number of investors, insurers and re-insurers, and downstream mineral users such as private companies have expressed significant concerns about deep-sea mining, threatening its viability as an emerging industry. A growing number of automakers and technology companies support a moratorium on deep-sea mining and have said they will not use materials harvested from the deep sea.²¹ Within the international community, some have noted the concentration of mineral supplies from a handful of countries and the need to diversify the sourcing and processing of these minerals. However, opening the deep sea as a new frontier for extraction of primarily copper, cobalt, nickel and manganese will not address this market dominance concern, nor fill gaps in supply for other critical minerals or rare earth metals.²²

A red, spiky sea urchin found on the seabed. — The world still has much to learn about the deep sea and its immense reservoir of unique biodiversity, such as this spiky sea urchin.

Conclusion

While scientists are making new discoveries at a rapid pace, there is still insufficient scientific understanding of the impact on the marine environment to make informed decisions about mining the international seabed while ensuring safeguards for marine ecosystems. Research indicates that the ISA would struggle to generate economically significant benefits or equitably share them among nations, while scientific evidence demonstrates that deep-sea mining threatens substantial and potentially irreversible damage to marine ecosystems. At the same time, with scores of unresolved issues in the draft regulations, the ISA still has a lot of work to do before any rules to govern deep-sea mining are completed.

Given these considerable challenges, States should agree on a moratorium or precautionary pause on deep-seabed mining. This could provide sufficient time for the ISA to collect scientific data to properly understand the long-term risks and associated impacts, including to vital ecosystem services such as the healthy functioning of fisheries and climate regulation, and to inform any future decision-making. The ISA also needs time to develop – in response to this evidence – precautionary, robust and enforceable regulations and create oversight and governance systems to ensure that it can effectively protect deep-sea ecosystems if commercial mining eventually begins.

This approach fulfills the founding principle of UNCLOS, ratified by 170 countries – that “the deep sea and all that it holds are the common heritage of [hu]mankind and should be looked after for the benefit of future generations.”²³

Endnotes

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O.Sparenberg, “A Historical Perspective on Deep-Sea Mining for Manganese Nodules, 1965–2019,” The Extractive Industries and Society 6, no. 3 (2019): 842-54.
P.A. Singh, A. Jaeckel, and J.A. Ardron, “A Pause or Moratorium for Deep Seabed Mining in the Area? The Legal Basis, Potential Pathways, and Possible Policy Implications,” Ocean Development & International Law 56, no. 1 (2025), https://doi.org/10.1080/00908320.2024.2439877.
P. Edwards and C. Pickens, “More Science Is Needed to Manage Deep-Seabed Mining and Minimize Its Impact,” March 2, 2022, https://www.pewtrusts.org/en/research-and-analysis/articles/2022/03/01/more-science-is-needed-to-manage-deep-seabed-mining-and-minimize-its-impact.
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D. Amon et al., “Climate Change to Drive Increasing Overlap Between Pacific Tuna Fisheries and Emerging Deep-Sea Mining Industry,” npj Ocean Sustainability 2, no. 1 (2023), 10.1038/s44183-023-00016-8.
R. Williams et al., “Noise From Deep-Sea Mining May Span Vast Ocean Areas,” Science 377, no. 6602 (2022): 157-58.
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R. Deberdt and C.B.G. James, “Self-Governance at Depth: The International Seabed Authority and Verification Culture of the Deep-Sea Mining Industry,” Resources Policy 89 (2024), https://doi.org/10.1016/j.resourpol.2023.104577.
T. Fisher et al. “In the Matter of a Proposed Moratorium or Precautionary Pause on Deep-Sea Mining Beyond National Jurisdiction (Opinion)” (2023).
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D. Wilde et al., “Equitable Sharing of Deep-Sea Mining Benefits: More Questions Than Answers,” Marine Policy 151 (2023), https://doi.org/10.1016/j.marpol.2023.105572.
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Special Procedures of the Human Rights Council, Open Letter by the Working Group on the Issue of Human Rights and Transnational Corporations and Other Business Enterprises, the Special Rapporteur on the Implications for Human Rights of the Environmentally Sound Management and Disposal of Hazardous Substances and Wastes and the Special Rapporteur on the Issue of Human Rights Obligations Relating to the Enjoyment of a Safe, Clean, Healthy and Sustainable Environment to the International Seabed Authority, https://www.ohchr.org/sites/default/files/documents/issues/business/activities/2024-03-15-open-letter-to-isa.pdf.
The Ocean Foundation, “Deep Sea Mining Isn’t Worth the Risk: High Costs, Financial Developments Since 2021, and Externalities Stand to Diminish Theoretical Returns on Investment” (2024), https://oceanfdn.org/wp-content/uploads/2024/02/dsm-finance-brief-2024.pdf.
J.L. Calderon et al., “Critical Mineral Demand Estimates for Low-Carbon Technologies: What Do They Tell Us and How Can They Evolve?” Renewable and Sustainable Energy Reviews 189, Part A, no. 113938.
European Academies Science Advisory Council, “Deep-Sea Mining: Assessing Evidence on Future Needs and Environmental Impacts” (2023), https://easac.eu/fileadmin/user_upload/EASAC_Deep_Sea_Mining_Web_publication_.pdf.
World Wildlife Fund, “Brands Back Call for Moratorium on Deep Seabed Mining,” March 3, 2021, https://wwf.panda.org/wwf_news/?1909966/Brands-Back-Call-for-Moratorium-on-Deep-Seabed-Mining.
A. Khurshid et al., “Critical Metals in Uncertainty: How Russia-Ukraine Conflict Drives Their Prices?” Resources Policy 85 (2023), https://doi.org/10.1016/j.resourpol.2023.104000.
R.R. Holst, “Exploiting the Deep Seabed for the Benefit of Humankind: A Universal Ideology for Sustainable Resource Development or a False Necessity?” Leiden Journal of International Law 37, no. 2 (2023), https://doi.org/10.1017/S092215652300064X.