Shoichi Ishii, program director of the Cabinet Office's Strategic Innovation Promotion Program (SIP), during an interview in Tokyo's Chiyoda Ward. (©Sankei/Yusuke Yoneoka)
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Rare earths are essential to cutting-edge technologies, from consumer electronics to military equipment. China, which dominates the global supply, has become increasingly open in using export controls as a tool of economic coercion. For Japan, building supply chains that do not depend on China is now a matter of economic security.
Against this backdrop, the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) achieved a major breakthrough under the Cabinet Office's Cross-ministerial Strategic Innovation Promotion Program (SIP). In the early hours of February 1, JAMSTEC succeeded in test-mining rare earth mud from the deep sea off Minamitorishima, part of Tokyo's Ogasawara Village.
The success marks a significant step toward producing rare earths domestically. Sankei Shimbun spoke with Shoichi Ishii, SIP program director, about what the achievement means and what comes next.
Rare Earth Mud Recovered off Minamitorishima
"No matter how promising a mineral resource may be, it remains little more than a pie in the sky unless it can actually be mined," Ishii said. "This achievement has raised rare earth mud to the level of a resource that can realistically be extracted."
According to Ishii, the continuous recovery of rare earth mud from the seabed at a depth of around 6,000 meters marks a world first in the development of marine mineral resources.
"Offshore oil and natural gas development has reached depths of around 3,000 meters off Brazil," he said. "But this was 6,000 meters—and we were bringing up a solid material. Technically, that is an extremely difficult thing to do."
Years of Accumulated Technological Expertise
"There are limits to what Japan can do on its own," Ishii said.
Some of the key equipment used in the project was made in Japan, including JAMSTEC's deep-sea drilling vessel Chikyu and the Edokko No. 1 seafloor-mounted unmanned probe. But other systems came from overseas, including a remotely operated vehicle, or ROV, built in Norway that can dive to depths of 6,000 meters (about 19,685 ft).
"What we were able to confirm was that all of these components could operate properly and function together as a single system," Ishii said.
The project also demonstrated that development and environmental protection need not be mutually exclusive. By monitoring conditions both on the seabed and aboard the vessel, the team made the marine environment "visible" in real time and demonstrated that resource development can coexist with environmental safeguards.
International Response
According to Ishii, they have not received environmental criticism from any country so far.
Overseas, however, there are calls for a moratorium on the development of marine mineral resources. Proponents argue that such projects cannot coexist with environmental protection and should be suspended until science and technology advance further.
"One major purpose of the monitoring was to help those people understand what we are doing," Ishii said.
Economic Viability
From February 2027, the team plans to begin a trial demonstration with a target recovery volume of 350 tons per day. That, Ishii said, should provide the data needed to assess the feasibility of long-term operations and calculate whether the project can be economically viable.
"We want to make a comprehensive assessment and clarify whether this can be developed on an industrial scale," Ishii said.
No Radioactive Materials and No Need for Crushing
Ishii further explained that the first step would be to mine continuously for nearly a month.
The recovered mud will then be landed on Minamitorishima, where it will undergo specific gravity separation and dehydration to reduce its volume to around one-fifth. That will make it easier and cheaper to transport. From there, it will be shipped to mainland Japan, where separation and refining will also be carried out.
The demonstration will also examine the logistics needed for full-scale operations, including crew rotations and resupply. Chartered aircraft and helicopters will be used to connect the mainland, Minamitorishima, and the research vessel, allowing the team to compare costs and operational methods.
"What makes the waters off Minamitorishima remarkable is that, unlike land-based ores, the mud does not produce radioactive or toxic substances," Ishii said. "Researchers can even handle the rare earth mud with their bare hands."
There is another advantage. Land-based ore must usually be crushed into fine particles before processing. Rare earth mud is already mud so there is no need for a crushing stage.
"Because we do not have to dissolve ore using strong hydrochloric acid, the process produces far fewer unwanted byproducts," Ishii explained.
Path Toward Commercialization
Ishii said the aim is to move smoothly into industrial-scale development starting in fiscal 2028, once the demonstration phase is complete. To make that possible, he wants to establish a broad direction by March 2027, roughly one year before the planned transition.
"That does not mean production can begin immediately once commercialization starts," he cautioned.
There are also security concerns. In June 2025, the Chinese aircraft carrier Liaoning sailed within Japan's exclusive economic zone near Minamitorishima, raising questions about possible shows of force.
"Since then, there has been no particular navigation within the EEZ," Ishii said. "China may be waiting to see whether Japan's development efforts succeed."
However, he noted that in international waters outside Japan's EEZ, there are manganese nodule mining areas allocated to China, where Chinese vessels appear to be conducting surveys.
Cost and the Strategic Value of Supply Security
Another question is whether Japan can compete with China on cost. Chinese-produced rare earths are cheap, and Minamitorishima lies in the middle of the Pacific, so the costs of extraction and transport remain uncertain.
"But we also have to consider what will happen to rare earth prices going forward," Ishii said. "When China played the export-control card last year, the price of yttrium, one type of rare earth, surged in Europe. Those factors need to be assessed as well."
China also manages the entire rare earth supply chain, from production to exports, at the state level. That raises the risk that Beijing could deliberately push prices down to undermine competitors.
"No country can beat China on price alone when China has such strong market power," Ishii said.
At the same time, he noted that the Trump administration in the United States has designated rare earths as critical materials for national security and is investing heavily in them. The aim is to prevent key components used in rockets, missiles, fighter jets, and other defense systems from falling under Chinese control.
"Other major countries are likely to think in the same way," Ishii said.
International Cooperation
But price is not the only issue.
Ishii pointed to rare earth mines in the mountainous region around the border between northern Myanmar and southern China, where there are concerns that toxic substances from mining operations may be flowing into the Mekong River.
"How the world evaluates that kind of environmental pollution will matter," he said. "There are no such concerns off Minamitorishima, so the project may gain an additional advantage in environmental assessments."
Other countries are also moving quickly to secure alternative sources of rare earths. But Ishii does not believe that increased global production will necessarily lead to oversupply.
"No, the market will continue to expand," he said. "The progress in unmanned systems and robotics is remarkable. Large quantities of high-performance magnets using rare earths are needed in areas such as the joints that move robotic arms."
The same technology is already part of everyday life.
"Even the vibration function in smartphones uses them," Ishii said.
Meeting Demand with a Stable Supply Network
The more important question is how to build a stable supply chain capable of meeting strong demand.
"Countries need a system that allows rare earths produced through new mine development and other projects to be exported efficiently. The idea is that we should cooperate to make that happen."
Minamitorishima, however, is not yet ready for immediate production.
"Its contribution will probably come a little further down the road," he said.
Another key question is whether Japan's full-scale push to develop resources off Minamitorishima was shaped by the lessons of 2010, when China effectively halted rare earth exports to Japan.
Lessons from China's 2010 Export Halt
Full-scale work in the current area off Minamitorishima began in fiscal 2018. At the time, there were strong voices arguing that such development was unnecessary.
"Relations with China had actually improved, and Japan was able to import cheap rare earths," Ishii said. "Within the government, the dominant view was that launching a full-scale survey would only revive past problems and worsen relations."
He compared the thinking to Japan's dependence on Chinese-made masks during the COVID-19 pandemic.
"The argument was that if importing from China made economic sense, then that was good enough," he said. "In the end, we were only able to start because of backing from the Liberal Democratic Party."
That experience points to a broader problem. If Japan's access to critical materials fluctuates depending on the state of relations with China, it cannot secure true autonomy in procurement.
"That's right," Ishii said. "If a country becomes overly dependent on one particular nation, its foundations are weakened. The same applies to food and energy."
A country with stronger foundations, he added, is better able to withstand crises.
"Building that resilience is the responsibility of the state," Ishii said.
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(Read the article in Japanese.)
Author: Hideyuki Hasegawa, The Sankei Shimbun
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