What is Deep Sea Mining?
Key Points
Deep sea mining targets rich mineral deposits, including cobalt, nickel, copper, and manganese, critical to clean energy, defense, and advanced manufacturing.
The U.S. has historically stayed out of international seabed mining, but growing interest in supply chain security, industrial abundance, and strategic autonomy are driving a potential policy shift.
The Metals Company (TMC) and emerging startups are pursuing a new U.S.-based licensing path, enabled by dormant law and catalyzed by an upcoming Executive Order.
If activated, the U.S. framework could launch the first commercially viable deep sea mining industry within a few years, reshaping global critical mineral dynamics and ocean governance.
1. Introduction
An imminent Executive Order from the U.S. government signals an inflection point in deep sea mining. If enacted it will assert U.S. sovereignty over mineral extraction in the High Seas, accelerate domestic licensing processes, and establish a stockpile of seabed minerals.
Oceans cover about two thirds of the Earth and the deep ocean has substantial mineral resources, especially copper, nickel, and cobalt, as well as potential rare earth resources. Improving economics as and rising mineral needs are causing renewed interest in the industry. For decades, the International Seabed Authority (ISA) has been the primary regulatory forum for seabed mining plans. However, entrenched mineral economies have allied with environmentalists to block the issuance of regulations, hobbling the industry in the cradle. Regulation by international committee has proven to be a bad model (who could have guessed that?).
By activating a dormant domestic legal framework, the United States is becoming the first major power to sidestep international gridlock and offer a clear pathway to mine the deep ocean. It’s a shift that could reshape global supply chains, challenge existing governance models, and launch a multibillion-dollar industry. And, while highly controversial, it is not a moment too soon. In February, China secured a seabed mining deal with the strategic Cook Islands, seeking its own path around the ISA, a move several colleagues and I characterized as a “Sputnik moment” for the United states.
Indeed, I claimed in 2021 that deep sea mining could be a $100 billion industry by 2040 in light of the need for clean energy metals alone. This has only been validated in recent years by intensifying global focus on critical mineral supply. IEA recently projected that total global mineral demand could double to almost $800 billion by 2040, and the pace of building new terrestrial mines is not sufficient to meet most of that growth.
A recent RAND report found the new industry could create 10,000s of new jobs, while underscoring that marine mineral economic leadership is a geopolitical prize. The report also found that meeting a quarter of global 2040 minerals demand would only require 20-40 seabed mining vessels; a small fraction of the hundreds of offshore oil and gas vessels and a rounding error on a rounding error of the millions of vessels on the world’s oceans.
This article explains deep sea mining. It provides an overview of marine mineral deposits, extraction and processing technology, and applicable the legal/regulatory frameworks.
2. What are marine minerals?
Resource extraction from the ocean is not new. Beyond fisheries, industrial extraction now occurs with shallow water sand and diamond mining, offshore wind, and offshore oil and gas. From a technology, operational, and regulatory point of view, offshore O&G is the closest analog to modern deep sea mining.
Deep sea mining targets three main types of seafloor resources found across different geologic environments on the ocean floor, all of which are thousands of meters down. These deposits are rich in many of the metals most essential to the energy transition, digital infrastructure, and advanced defense systems.
1. Polymetallic Nodules
The most commercially promising resource today, polymetallic nodules are potato-sized lumps scattered across the seafloor. Each nodule contains high concentrations of manganese, nickel, cobalt, and copper (hence the qualifier “polymetallic”). These metals are critical for manufacturing electric vehicle batteries, high-performance alloys, and power grid technologies. Other metals are sometimes present, including rare earths, but these four metals are the primary economic target. The ore grades of these metals exceed some of the best terrestrial deposits, with more than 30% by mass being extractable.
Polymetallic nodules are the primary near-term marine mineral of interest.
Nodules form in deep ocean, “precipitating” over millions of year, and falling down to the abyssal plains. The highest concentrations of nodules per square meter is in the Clarion-Clipperton Zone (CCZ), a large area of remote ocean in the central Pacific between Hawaii and Mexico. This area is vast, spanning the length of the continental United States, and containing trillions of dollars of resources. Importantly the CCZ is almost entirely in international waters. The next best resource density is the Cook Islands, with several other Pacific islands (including some U.S. territories) having marginal resources.
2. Cobalt-Rich Crusts
Found on seamounts (underwater mountains), these crusts form over millions of years as minerals precipitate onto the rock. They’re especially rich in cobalt, platinum, and rare earth elements. Crust mining is more technically complex, requiring cutting and collection from irregular surfaces. These deposits are often found within Exclusive Economic Zones (EEZs) and are increasingly important for national mining strategies, especially for resource-constrained nations.
3. Seafloor Massive Sulfides (SMS)
These deposits form around hydrothermal vents, where mineral-rich fluids spew from the ocean floor. SMS sites contain gold, silver, copper, zinc, and rare earths, often in high concentrations. While technically recoverable, SMS mining can directly threaten unique biodiversity hotspots around hydrothermal vents.
Collectively, these deep sea mineral resources represent an enormous untapped supply of critical metals. Unlike traditional mining, which often involves complex permitting, land use conflicts, and deep environmental scars, deep sea mining promises high-grade material with fewer impacts.
Multiple studies have shown reductions in greenhouse gas emissions and other major environmental impacts compared to terrestrial mining. For example, one found that lifecycle emissions from nodules are up to 80% less than terrestrial sources. The human impact, if there is any, is at best indirect, contrasting starkly with the fact that cobalt and many other metals are conflict minerals, and also involve child labor and trafficking.
3. How does deep sea mining work?
The basic process of deep sea mining builds on decades of offshore engineering and subsea robotics, much of it developed by the oil and gas industry. Though full commercial production has not yet begun, multiple companies and governments have successfully demonstrated key components of the technology stack.
Notional graphic of deep sea mining types. Source: Pew
1. Seafloor Collection
The process begins with remotely operated vehicles (ROVs) that traverse the seafloor. These machines use suction or cutting tools to collect mineral resources depending on the type of deposit:
For polymetallic nodules, harvesters gently vacuum the nodules from the sediment surface.
For cobalt crusts and sulfides, cutters grind down the deposit, collecting the material for transport.
2. Riser Transport
Collected material is sent upward through a large flexible or rigid tube called a riser that connects the seafloor collector to a surface vessel. A slurry of nodules, seawater, and sediment is pumped to the ship using hydraulic or airlift systems.
3. Shipboard Handling and Offloading
On the vessel, minerals are separated from water and sediment. Some preprocessing may occur, but in most models minerals are transferred to transport vessels which take them onshore.
4. Terrestrial processing
After extraction, minerals are then shipped to onshore processing facilities, either domestically or with allied partners (e.g., Japan, South Korea). China’s industrial strategy to dominate critical minerals supply chains means they are only a handful of mineral processing facilities outside of China. Those that exist are not necessarily designed or equipped to handle polymetallic nodule processing. Nevertheless, they can likely be readily adapted given the high ore grades involved.
The technical feasibility of deep sea mining is no longer theoretical:
In 2022, The Metals Company (TMC) and its partners conducted the first integrated nodule collection campaign in the CCZ, successfully lifting tons of nodules to a surface vessel. Many other contractors are conducting exploration campaigns under the ISA framework.
In early 2025, a Japanese company processed these nodules using existing smelting infrastructure, proving that commercial processing is achievable with current technology.
The core infrastructure—vessels, robotics, riser systems—already exists. In fact, much of it can be repurposed from offshore oil, reducing capex and deployment timeframes. The primary barriers are now regulatory, environmental, and financial, not technical.
4. What are the risks and challenges of deep sea mining?
Deep sea mining raises complex risks across environmental, legal, geopolitical, and market domains. These risks are not insurmountable, but they do require serious attention from policymakers, investors, and the public. And that are much more straightforward than conventional mining.
Despite complexities, seabed mining promises to be simpler, faster, and more scalable than conventional mines. Source: RAND
1. Environmental Risks
The deep ocean is one of the least understood ecosystems on Earth. It is generally characterized by a low level of biomass and limited but unique lifeforms. Mining operations could disturb:
Benthic habitats, where nodules support unique biological communities.
Sediment plumes, which may impact filter feeders and reduce water quality over wide areas.
Species unknown to science, as biodiversity studies remain incomplete.
A large environmental campaign has emerged, arguing for a moratorium on deep sea mining, ostensibly until more studies could be completed. This has included direct action, with Greenpeace boarding the seabed mining vessel Hidden Gem in 2023. Most importantly, this campaign has secured significant success at the national level, convincing many national governments to adopt moratorium stances. The countries supporting a moratorium constitute an unusual alliance of largely European countries and developing economies dependent on terrestrial mineral extraction.
Personally, the case is relatively straightforward at this point (and privately a lot of deep sea biologists will agree with this assessment):
Nodule mining, when conducted with modern safeguards, appears to have minimal ecological impact. The abyssal zone is, well, the abyss. There is just not a ton there. We know this, there have been at least dozens of deep sea mining funded research campaigns.
Improved technologies, such as Impossible Metals’ autonomous underwater vehicles, can further minimize impacts, as can remediation efforts.
It is likely critical that any mining activities include substantial monitoring to ensure compliance with permit conditions.
A recent retrospective found that after four decades, an area explored with 1970s vintage technology had some lasting impacts as well as species recovery. This may seem long, but its actually consistent with recovery plans and patterns we see in sustainable forestry (with the caveat that after nodules are removed the area is unlikely to ever be disturbed again).
However, the other types of mining, vents and crusts, can have severe and lasting impacts. Hydrothermal vents are biodiversity hotspots and even after vents go extinct they support many unique species. Significant care is needed before pursuing technologies (although these are generally decades off from an technological and economic perspective).
2. Legal and Institutional Risks
The governance of seabed resources is in flux. Key challenges include:
Jurisdictional disputes between national licensing (e.g., U.S. via DSHMRA) and the ISA framework.
Flag state complexity, especially for mining vessels operating in international waters.
Litigation threats from environmental groups or states seeking to block non-ISA activities.
U.S. action could set legal precedent but it may also face international scrutiny if not paired with transparent, science-based standards.
3. Geopolitical Risks
As nations assert control over seabed resources, new points of friction could emerge:
China, with more ISA licenses than any other nation, may use diplomatic or economic pressure to shape global norms to its benefits.
Allied coordination is still developing and knee-jerk reactions to the U.S. move could undermine a free world approach to marine minerals. In its absence, the Chinese will set the [lowest] standards.
International retaliation, like sanctions or boycotts, may target early operators like TMC or their partners.
The risk of lawfare and infrastructure sabotage also rises as seabed activity expands.
Expect a lot of blowback against U.S. actions, which is not necessarily unwarranted but it should be contextualized. China and Russia are already attacking U.S. and allied seabed infrastructure without regard to the consequences. The U.S. is literally just trying to pick some rocks off the ocean while China is proudly announcing a new deep sea cable cutting technology. Regardless of the current administration, it is clear that China and Russia are the greatest threat to ocean freedoms.
4. Market and Investment Risks
Though the long-term demand outlook is strong, near-term risks include:
Basic economic feasibility. Modern terrestrial mining is silly easy. Its digging/blasting giant holes in the ground and driving house sized Tonka trunks to move rock. To compete, deep sea mining will need to demonstrate scalability, speed, and new financial models.
Permit delays or denials, particularly for environmental review (e.g., under NEPA in the U.S.).
Capital intensity under conditions of uncertainty, as projects require hundreds of millions in vessel upgrades and processing infrastructure.
Public resistance, including ESG-focused funds and political opponents.
Volatility is likely to persist until the first production milestones are hit and long-term contracts begin.
5. Governance of the Seabed
About half the ocean floor lies outside national governance. This region, referred to as “the Area” under international law, is considered part of the global commons, or at least as an area beyond national jurisdiction. Since 1982, the governance of these zones has been most heavily influenced by the United Nations Convention on the Law of the Sea (UNCLOS), with mineral governance managed by ISA.
The best deposits of marine minerals are largely concentrated in the High Seas/Area, a primary reason for ISA’s dominance in recent regulatory plans. Source: ISA
The ISA was created to oversee the exploration and eventual exploitation of seabed mineral resources in the Area, based on the principle that these resources are the “common heritage of mankind.” In practice, the ISA has issued dozens of exploration contracts to state-backed companies and research consortia, including those affiliated with China, Russia, France, Japan, and South Korea.
But despite more than three decades of discussion, the ISA has not finalized rules for commercial-scale exploitation. Key decisions on environmental standards, benefit-sharing, and liability remain unresolved. ISA is supposed to set up benefit sharing so that deep sea mining revenues can benefit all nations. Among other issues, it has not figured out how to do that. Arguably, international licensing is unresolved for a simpler reason: politics. Extractive nations and environmental interests seek to thwart marine minerals.
[As an aside the intensity of environmental opposition to deep sea mining is somewhat confounding. Conventional mining, especially outside of highly regulated economies, is an environmental and human rights atrocity. Vague assertions about the feasibility of recycling instead of deep sea mining misses the reality that a clean energy economy is central to safe climate, and it depend on metals. Personally, I’d rather those metals come from a hidden and desert-like corner of the ocean than a populated and biodiverse rainforest.]
The impasse reached a breaking point in 2021, when TMC’s sponsoring state of Nauru invoked a UNCLOS provision that gave the ISA two years to finalize its rulebook. That deadline expired in July 2023, without agreement. At the same time, geopolitical tensions, deepening mistrust in multilateral governance, and China’s growing influence inside the ISA have undermined the entire regime.
Personally, it is fair to now say that the ISA has failed. Despite being around for decades and working on the exploitation regulations for almost fifteen years, it lacks clarity on whether it can even establish a system. Let alone when. Environmental groups leveraged the forum to try to stop mining in an utterly irresponsible manner, one which primarily advantages a Chinese-led model of deep sea extraction (which I can guarantee will not involve Greenpeace protesters boarding Chinese mining vessels).
Regulatory design is always hard but designing a system by international committee is impracticable, especially when half the committee are countries who depend on terrestrial minerals for their economies. Space mining is an entirely different conversation, but it is clear that the U.S-led bilateral approach to space mining is likely to be a much better framework than the ISA.
Anyways, we get to the present controversy. The United States, notably, has never ratified UNCLOS. However, in 1980, Congress passed the Deep Seabed Hard Mineral Resources Act (DSHMRA), a domestic legal framework designed to authorize U.S. entities to explore and recover minerals from the deep seabed independently.
Under DSHMRA, the National Oceanic and Atmospheric Administration (NOAA) was empowered to issue licenses for exploration and commercial recovery, subject to environmental review and public oversight. NOAA has issued four licenses, with two currently active (having been renewed in 2022). Any U.S. person can literally apply for a license today. As part of its strategic shift to the U.S., TMC plans on going through this pathway and has started pre-application engagement.
DSHMRA has remained largely dormant. But with the failure of ISA rulemaking, and rising demand for critical minerals, the U.S. is now poised to use it. The new Executive Order is expected to reaffirm U.S. sovereign rights to permit seabed mining, accelerate NOAA’s licensing authority, and begin building an American-led approach to seabed resource development.
This does not need to be the end of the “law of the sea” or the rules-based order, as some claim. From a historic perspective, its actually the literal status quo. The U.S. has never repealed DSHMRA. Parts of UNCLOS are certainly customary international law (a point the U.S. has long acknowledge, driven in large part by Navy interests), but the ISA is almost certainly not. For evidence, look no further to recent Chinese and Russian objections to U.S. continental shelf claims; if it was customary law, it would not actually matter whether the U.S. was a party. A fundamental principle of international law is that states cannot be held to treaties they do not consent to. The U.S. is well within its rights to mine the seabed [and I’m eating crow on this one, I’ve publicly called several times for the U.S. to ratify UNCLOS so it can participate in ISA-regulated deep sea mining].
There is major bipartisan interest in enabling U.S. deep sea mining, driven by the convergence of mineral demand, technological readiness, and intensifying strategic competition. Over the past two years, Congress has commissioned studies on the feasibility of onshoring deep sea mineral processing. The U.S. has also concluded a multi-decade campaign, the largest oceanic exploration project in history, to map and subsequently claim an U.S. Extended Continental Shelf. Expect such efforts and support to accelerate.
After the largest deep sea exploration campaign in history, the U.S. issued an extended continental shelf claim in 2023, primarily in the strategic Arctic Ocean. Source: CRS
6. Conclusion: A Seabed Frontier?
For decades, the ocean floor was seen as too remote, too complex, and too politically fraught to support commercial resource extraction. But that calculation has changed. Deep sea mining is no longer just a policy debate or scientific curiosity. It is becoming an industrial reality, a frontier up for grabs.
The convergence of mineral demand, geopolitical urgency, and the emergence of credible legal pathways. The United States, long absent from the arena, now appears poised to activate its domestic licensing authority and offer companies a viable route to production. At the same time, venture capital, industrial players, and international partners are aligning around the possibility that seabed minerals could play a critical role in the future of clean energy, digital infrastructure, and national security.
There are many major policy challenges ahead: international backlash, environmental responsibility, protection of freedom of the seas, and impact on broader macro-econo-geopolitics. But for the first time, a major power is laying the foundation for a functional deep sea mining economy. That future is not guaranteed but it is now undeniably in motion.
Policymakers, investors, and technologists should be paying attention because the era of industrial deep sea mining is beginning now. It can be American-led freedom of the seas, with attendant environmental standards, or it can be Chinese-led, whose fishing fleets, cable cutting, and grey zone lawfare are fundamentally destabilizing.
Additional resources
The Congressional Research Service has a great explainer on DSM and policy issues for Congress.
This 2018 Frontiers article by Miller et. al. is still the best summation of the overall industry I have found.
Perhaps surprisingly, TMC’s most recent investor presentation has a lot of valuable information about deep sea mining, in part reflecting their political shift to U.S. policymaker audiences.
The ISA is bad at establishing a regulatory framework but, like most U.N. agencies, is great at creating paperwork. They have a lot of valuable technical and legal resources for those that want a deep dive into the subject.
