sum up:

In a vast storage room at a nickel plant in Hachinohe, northern Japan, a group of men in suits and hard hats are squatting on the floor admiring a row of trays. One contains a jet-black, rubble-like ore, which crumbles to dust when handled. In another, there are bright cubes of metal, which they are examining enthusiastically.

These men, traders from commodities powerhouses Mitsubishi Corporation and Glencore, as well as managers from Chinese and Korean metals groups and the Japanese battery producer Panasonic Energy, have been assembled by the Canadian mining group The Metals Company (TMC). The ore had been sucked up from the seabed roughly 4,000 metres beneath the surface of the Pacific Ocean before being shipped here to be melted down and processed. The company is eager to show off its wares.

“With the same energy, we can get more materials: nickel, cobalt, copper and manganese,” says Daisuke Sasaki, a representative of Pacific Metals, which owns the plant. “It’s more economic and environmental than land-based mining.”

Deep-sea mining has been a fantasy for a century or more. The prospect of extracting minerals that lie on the seabed, hauling them to the surface and transforming them into useful — and valuable — elements has persisted since deposits were first discovered. Some hope it might reduce the toxic waste and human rights abuses associated with mining on land.

Until recently, though, undersea mining has remained largely science fiction. Operating at enormous depths in one of the most hostile environments on the planet is both technologically complex and expensive. Fears that disturbing the seabed could destroy life that thrives there poses an even greater challenge, with full-scale mining subject to a de facto ban in international waters since the 1990s.

Contractors based in countries including the US, China, India, Japan and Norway have launched tests without proceeding to commercial-scale extraction. And negotiations on how to make mining in international waters a reality have been running for years.

Yet as competition for minerals used in batteries, power grids and steel manufacture grows fiercer than ever and the global trade war highlights China’s stranglehold on supply chains, the issue has been thrust into the spotlight.

Last month, Donald Trump made it clear that he wants the US to lead what his administration has called “the next gold rush”. After his administration was lobbied by the Nasdaq-listed TMC, which is believed to lead the pack among private companies, last month Trump signed an executive order asserting that the US was entitled to issue licences to mine in international waters. Calling for such licensing to be expedited, the order also suggested that seabed metals could be stockpiled as strategic assets.

This is one of a series of moves designed to secure access to critical minerals, which has included efforts to strike deals with countries such as Ukraine, Greenland and the Democratic Republic of Congo.

The order was promptly attacked by the European Commission and China — not least because it contradicted a long-established consensus that licences for international waters can only be issued by a UN-mandated body, the International Seabed Authority. Last month, China’s foreign ministry warned that “no country should bypass the ISA or international law”.

US Democratic congresswoman Maxine Dexter framed seabed mining as a “high-risk, low-reward endeavour” whose backers want a “bailout”, speaking at a House committee on natural resources hearing last month.

Environmentalists fear this could ignite a free-for-all and cause permanent harm to one of the planet’s most untouched and little understood ecosystems. Analysts worry it could also initiate maritime disputes over everything from subsea cables to fishing rights, from the Arctic to the South China Sea. 

Criminals use the high seas to trade guns and drugs, says Monica Medina, who was an assistant secretary of state for oceans in the Biden administration. “I would hate to see mining become yet another one of those activities,” she says.

There is also uncertainty over whether deep-sea mining can ever succeed without the involvement of China, which controls three-quarters of global battery production and has competitive technology for shipping infrastructure, extraction and smelting.

And many question whether it is even feasible commercially. “The industry’s financial models are based on wildly optimistic assumptions” that underestimate the “extreme challenges” of working at “intense pressure, [in] freezing temperatures and corrosive conditions”, Dexter said at the hearing.

“It is a good opportunity for states to come together [in opposition],” says Pradeep Singh, a legal expert at the Lisbon-based Oceano Azul Foundation. “There will be rallying behind the need to ensure it doesn’t become a tragedy . . . just because one country wants to go its own way.”

During a mission to map the world’s seabeds in the 1870s, scientists on board the British ship HMS Challenger were bemused to dredge up “peculiar black oval bodies” that turned out to be composed of metallic elements.

Millions of years ago, on the floor of what we now call the Pacific Ocean, trace metals in seawater began to accumulate around debris like shark teeth or grains of sediment. These eventually formed small knobbly lumps known as “polymetallic nodules”. 

While metals are also found in mud and rocky crusts near sites of underwater volcanic activity or ridges between tectonic plates, the dense collection of nodules found lying on the seafloor of the eastern Pacific Ocean has drawn the most attention.

It was not until a century later that some of the first attempts were made to exploit seabed ore. In 1970, the US company Deepsea Ventures began conducting tests off the coast of North Carolina, using crude hydraulic vacuum technology to hoover up nodules. The UN declared that year that the seabed was the “common heritage of mankind”.

Four years later, the company wrote to then secretary of state Henry Kissinger requesting diplomatic immunity to expand its tests into international waters, a declassified CIA document shows — a request refused on legal grounds.
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© FT • Sources: International Seabed Authority, USGS

By the time the 1982 UN Convention on the Law of the Sea (Unclos) created a legal framework, a collapse in metal prices had made the idea less attractive. In 1994 the treaty finally came into force and a regulator, the Jamaica-based ISA, was founded, in effect leading to a moratorium on deep-sea mining in international waters.

The US refused to ratify Unclos but has signed an agreement recognising the treaty’s seabed provisions. It attends ISA meetings on an informal basis.

The modern deep-sea mining industry was born in the 2010s, when hunger for metals required by the green transition started to grow. Leading companies now include TMC and Belgium’s Global Sea Mineral Resources. Although the technology is not hugely different from before — huge hoover systems suck up nodules to collector ships waiting at the surface — both operators have tried to find ways to minimise disturbance to marine life.

Governments including Singapore, France, Belgium, the UK, India and Russia have all backed exploration contracts granted by the ISA in recent years. China has supported more exploration contracts than any other nation, according to ISA disclosures.

A 2022 US Geological Survey said that mineral-rich crusts and nodules “constitute a significant metal reservoir”. TMC has told investors there is more nickel, cobalt and manganese available in the deep ocean than on land, a comparison disputed by some experts. 

Analysts say that while finding minerals is one thing, collecting them and turning them into something usable — let alone making a profit — could be far harder. 

“We’ve got sufficient proof that it’s technically viable,” says independent consultant Lyle Trytten. “Will it be economic, [socially] acceptable, will the supply chain develop? Those are all the question marks.” 

In the months before Trump’s executive order was issued, TMC executives lobbied the administration hard. Its chief executive, Gerard Barron, says he made a personal gift to the president of a nodule from the deep Pacific last month. (The White House did not respond to a request for comment.)

In April, the company said it had applied for a permit for mining in international waters using the new expedited process administered by the US National Oceanic and Atmospheric Administration. It says it expects to receive this as early as next year, paving the way for commercial-scale extraction in 2027.

“Whatever we don’t have on land we need to harvest it,” US commerce secretary Howard Lutnick said at his Senate confirmation hearing in January. Cantor Fitzgerald, the Wall Street brokerage firm that Lutnik led at the time, was acting as “lead banker” to TMC in December, according to a document posted by Barron online.

Cantor Fitzgerald says: “Our former chairman no longer has any operating role — formal or informal — at our firm.”

In an attempt to woo US lawmakers, TMC has proposed that its nodules be processed in Texas to bolster domestic battery-making, and claimed that they could help keep supply chains local.

Some have interpreted the administration’s enthusiasm for the seabed as a geopolitical play. In recent years, some security officials and politicians in Washington have become increasingly concerned that China has a head start in developing offshore mining technologies. 

Chinese state media reported that Chinese scientists had trialled nodule collection at depths below 4,000m in the western Pacific Ocean last June. The Chinese companies China Minmetals Corporation and Beijing Pioneer Hi-Tech Development Corporation have said they are preparing exploratory seabed tests for later this year.

China has also been pushing its case at the ISA. A mining consultant who did not wish to be named says China has run a clear “influence operation” in recent months. It has committed more funding to the regulator this year than any other country.

As with securing the Ukraine minerals deal, some US lawmakers hope that beating China to the ocean floor might blunt its ability to retaliate in a trade war or military conflict. TMC and the US-based Impossible Metals have both highlighted the industry’s potential to bolster US independence from Chinese supply chains.

But the environmental effects of deep-sea mining being conducted at scale are still unclear. Scientists have spent years debating issues such as how far the plumes of sediment raised disturb deep sea life. The barren scars on the ocean bed from the Deepsea Ventures tests off North Carolina in 1970 are still visible, according to a recent survey.

Proponents say that mining could help the scientific community gain more knowledge about one of the planet’s most mysterious areas and fund more research. Impossible Metals says it has designed an autonomous underwater vehicle that uses AI imaging to make sure it only collects nodules with no visible signs of life — such as octopus eggs — on them. 

But for Douglas McCauley, professor of ocean science at the University of California Santa Barbara, proceeding without resolving environmental issues would “mark the United States as pirate miners”.

The French nickel and manganese miner Eramet has said it will not explore underwater mining as a matter of “principle”. The mining major Rio Tinto has also said that mining should not go ahead if environmental harm is likely to occur.

Even Pacific Metals, the Japanese smelter operator, cannot proceed at any cost, says its president Masayuki Aoyama. “I think we’ll have to make our judgments while carefully observing how society as a whole is moving.”

In July, diplomats from over 150 countries will gather in Jamaica for the final ISA meeting of the 2025 session. Their goal is to finalise a framework covering undersea mining that would clarify rules around taxation, royalties and environmental impact. It will also include sanctions for non-compliance. 

Leticia Carvalho, the Brazilian oceanographer who leads the ISA, has warned that the US push to issue mining licences without the regulator’s approval could be a “violation of international law”. Going it alone would create risks from “intergovernmental relations to investment security”, she said in a statement in April.

China is positioning itself as the adult in the room when it comes to negotiating seafloor rights. But it has not ruled out upping the ante, says a consultant linked to China who asked not to be named. “If things head in the wrong direction they would be weighing options in terms of trade, sanctions, tariffs.”

The Trump administration shows no signs of backing down. Fears that the US move to grant mining licences could lead to a boycott of seabed metals are little more than “Chicken Little rhetoric”, says Steven Groves, an international law specialist at the conservative Heritage Foundation. “I don’t see why one thing like this would suddenly cause a collapse of the global maritime order.”

If it is accused of breaking international law, the US would simply refer to China’s own violations, says a Congressional aide who asked not to be named. Beijing has laid claim to most of the South China Sea and has ignored a 2016 ruling that a submerged reef in the Spratly Islands was within the Philippines’ exclusive economic zone, among other alleged offences. 

China, if it is ignored, “may well say, ‘Great, we’ll take the South China Sea then, thanks very much,’” said Duncan Currie, a lawyer and activist at the Deep Sea Conservation Coalition.

There are also questions about TMC’s claims that it will help provide an alternative to Chinese-dominated supply chains for deep-sea minerals. Three Chinese groups including CNGR, a leading producer of battery chemicals, visited Hachinohe as prospective customers last month.

Speaking to the FT at the smelter visit, Tao Wu, vice-president of CNGR, says his company had been in discussion with TMC for years, and adds that he had advised TMC to use Chinese suppliers. “It’s either that money goes into Canada, Africa and Australia to build a mine or backs companies like TMC,” he says. “Mining [on land] has problems.”

Meanwhile, commercial appetite remains low. Google, the battery-maker Samsung SDI and the carmakers BMW and Volvo Group have backed “precautionary pauses” or moratoriums on deep-sea mining, joining countries including Brazil, the UK and Fiji. Lloyds has said it would not back clients that undertake deep-sea mining, while Standard Chartered has ruled out directly financing projects.

Mining company Glencore has hedged its bets by selling its equity stake in TMC last year while maintaining a contractual right to buy nickel and copper from the company.

Lockheed Martin, which helped develop seabed mining technologies between the 1970s and 1990s, has remained quiet on what it plans to do with two Pacific exploration licences that are thought to have been dormant in recent years. The company says it “appreciates” Trump’s executive order, but has not made its next steps public.

“Whether the industry is viable totally depends on who you talk to,” said Tom LaTourette, a scientist at the Rand Corporation think-tank. But “there is a chance the US comes out not smelling so good.”