INTERVIEW: TMC CEO says seabed metals to become big part of supply chain

North America-based The Metals Company (TMC), which aims to pioneer deep-sea mining at the turn of the decade, believes that polymetallic nodules will become a big part of the metals supply chain, driven by strong policy tailwinds in the US, and environmental benefits of shifting extractive activities to the part of the planet with the least life, TMC CEO Gerard Barron told Platts, part of S&P Global Energy, in an interview.

"It wasn't many decades ago that there was zero oil and gas produced offshore, whereas today that share is more than 30%. The same will happen for metals," said Barron.

As with oil and gas, the US will be the first to deliver the first offshore metals.

"The US imports half of the copper it consumes, is 100% import-reliant for manganese, nickel, and cobalt," said Barron. "It's critical for the country to become mineral-independent, as it did in the energy space, where in a short span of time, it turned from a net importer of hydrocarbons into a big exporter."

The US has been studying polymetallic nodules -- seabed minerals containing copper, nickel, cobalt, manganese and even rare earths -- since the 1970s and has put in place mining rules to allow their commercialization as early as 1980. Unlike more than 170 countries, it did not sign the UN Convention on the Law of the Sea, maintaining that deep-sea mineral exploitation beyond national jurisdiction is a freedom of the high seas, like the freedom to traverse the ocean, or lay cables and pipes.

The UN-mandated International Seabed Authority has been compiling its own set of deep-sea mining rules since 1994, but the work remains incomplete, making the US the only country with such regulations, according to TMC.

Money heading to US

The company submitted its application for exploitation rights to the US regulator, the National Oceanic and Atmospheric Administration, in April 2025, following President Trump's signing of "Unleashing America's Offshore Critical Minerals and Resources," an executive order on deep-sea mining.

More than a dozen applications totaling 1.5 million square kilometers of seafloor have since been submitted to NOAA by American companies, containing $5 trillion-$8 trillion in estimated mineral value, according to TMC.

However, it said, the applications that followed its exploitation submission are for exploration only. TMC claims it has been the only company in a position to seek a commercial recovery permit, thanks to its 14 years of offshore exploration work. The company, whose shareholders include Korea Zinc and Allseas, has invested $750 million to reach this point, including $250 million spent on the environmental impact assessment alone.

Unlike parties demanding a moratorium on deep-sea mining, TMC says more than 50 years of scientific research into the impacts of collecting nodules shows they can be extracted at a fraction of the environmental costs of land-based alternatives, and their environmental benefits are worth shifting mineral mining to the deep sea.

Pros over terrestrial supply routes

Collecting nodules requires no digging, no drilling or community displacement and because they sit unattached at depths of 4 kilometers in complete darkness, no deforestation. TMC also says its operation will generate 80% to 90% fewer carbon emissions, and its processing flowsheet, designed in partnership with Hatch, implies near-zero solid waste, while eliminating tailings.

"It makes a lot of sense that we carry out extractive activities in parts of the planet with the least life, not the most. Today, most of the growth in nickel production is coming from our rainforests, with 65% of the world's supply provided by Indonesia," Barron compared the advantages of deep-sea over terrestrial mining.

"If rainforests occupy one end of a bar scale measuring living biomass, on the other end, you have the abyssal plains. These fields of mud at 4,000-meter-plus depths in the ocean form the most common environment on our planet, covering over half of it. That's where we find nodules," he said and added that nodules with particularly high grades -- 1.1% copper, 1.4% nickel, 0.2% cobalt and 30% manganese -- are conveniently concentrated in a small part of the ocean - the Clarion Clipperton Zone.

On the abyssal plain, biomass is measured in grams. On TMC's license area, it's 10 grams per square meter, and over 60% of that living matter is microbial.

The company told Platts it monitored the ecosystem during test mining and revisited the site two months and one year after the disturbance, finding no impact on the microbes living on the seafloor and that pioneer species had begun to return, with impacts to other organisms limited to tens of meters from the robot's tracks.

To protect against biodiversity loss, half of the Clarion Clipperton Zone is already set aside for protection, and the company notes it will leave parts of its exploitation areas that are too hilly or contain reduced nodule densities untouched. But even if all the areas licensed in the Clarion Clipperton Zone went into production, the total area impacted would comprise only 0.4% of the global seafloor, it says.

Flexibility that does not exist on land

TMC expects to begin production in early 2028. Its Hidden Gem vessel, a former oil and gas drillship, is undergoing modifications to be part of a commercial production system that will harvest 3 million mt/year of nodules. Subsurface infrastructure will consist of two robots crawling along the seafloor, and a 4-kilometer-long riser pipe to lift nodules to the surface.

"The ability to reuse existing vessels is a bit of a boon," said Barron. "On land, when you're building a mine, the question is, how big do you build the port, the rail, how much housing you install, how big the tailings dam is going to be? Those numbers end up being big capital items, and they can be big obstacles, whereas we can simply convert one of these drillships and be in production within a week, and scale it up quickly," he said.

TMC's investor, Allseas, with 40 years of experience in the oil and gas industry and known for laying the Nord Stream 2 pipeline, will operate the boat on TMC's behalf.

Four minerals in one rock

When it comes to processing nodules onshore, the risk is low, said Barron, adding that after four years of trials in Japan, TMC found that nodules can be processed the same way as "the rainforest nickel."

TMC estimates its cost of producing seabed metals to be in the bottom quartile of the nickel cost curve, and the revenue per ton of rock to be higher than for land-based alternatives, as the latter would require two or three mines for the same basket of metals.

The company says it will be cost-competitive with Indonesian nickel and able to withstand almost any pricing environment by virtue of having three other metals and byproducts.

TMC envisages its end products being nickel sulfate, cobalt sulfate, copper cathode and manganese silicate. It wants to establish industrial-scale processing in the US, where it has secured a lease option for a site in Brownsville, Texas, but building this plant would ultimately be contingent on the government's support, said Barron.