The world runs on rock · Current events

The Deep the race for metal on the seabed

Four kilometres down in the Pacific, billions of tonnes of black lumps lie on the mud, each holding manganese, nickel, copper and cobalt, the metals of batteries and steel. They took millions of years to grow. In 2025 the United States moved to start mining them.

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Going down

Into the dark

Sunlight fades out within the first few hundred metres. Below that, the only light is from living things, and a steady fall of "marine snow": bits of dead plankton drifting to the floor.

The abyssal plain

Between Hawaii and Mexico

The richest known nodule field is the Clarion-Clipperton Zone, a stretch of Pacific floor between Hawaii and Mexico about 4 million km² in size, close to the area of the European Union, at depths of 3,000 to 6,000 metres.^1,2

Lying on the mud

Potatoes of metal

The nodules sit loose on the sediment, from pebble to fist size. The zone is estimated to hold more than 21 billion tonnes of them, containing about 5.95 billion tonnes of manganese, 0.27 billion tonnes of nickel, 0.23 billion tonnes of copper and 0.05 billion tonnes of cobalt.¹

A pale seafloor stretching into the blue distance, scattered with thousands of dark round nodules — A nodule field seen by the remotely operated vehicle Deep Discoverer on Dive 10 of NOAA's 2026 American Samoa expedition. NOAA Ocean Exploration (public domain).

How they grow

A few millimetres per million years

A nodule starts as a small hard core, a chip of rock, a bit of shell or a shark's tooth, and grows as manganese and iron oxides build up round it, layer on layer, taking nickel, copper and cobalt with them. In the Clarion-Clipperton Zone they grow about 1 to 10 millimetres per million years.^1,2

MnFeNiCuCo

Our sum

Centuries of cobalt

The world's mines produced about 310,000 t of cobalt and 3.9 million t of nickel in 2025.³ The cobalt estimated in Clarion-Clipperton nodules is about 160 times that year's output, and the nickel about 70 times. That is metal in place, not what could actually be recovered.

A white glass sponge on a short stalk rising from a carpet of black nodules — A glass sponge among nodules, Cook Islands, 2026.

A small white spiny urchin perched on a large dark nodule half sunk in pale sediment — An urchin on a nodule at about 5,526 m, American Samoa, 2026.

A dense bed of dark nodules with a flat triangular shark tooth lying among them — A large shark tooth on a bed of nodules: teeth like it can become a nodule's core.

Not empty

Life on the nodules

Sponges, anemones and corals need something hard to hold on to, and on the abyssal mud the nodules are it. In surveys of the Clarion-Clipperton Zone, more than half the species collected were new to science.¹ Photos: NOAA Ocean Exploration, public domain.

How it would be mined

A harvester on tracks

The plan most companies have tested: a robot collector crawls across the floor, lifts the nodules from the top few centimetres of sediment and sends them up a riser pipe to a ship, kilometres above.⁴ Wherever it passes, the nodules, and the animals living on them, are gone.

The cloud behind it

Sediment plumes

The collector stirs up a cloud of fine sediment near the floor, and the ship returns waste water that makes a second plume higher up. Scripps scientists found such discharge plumes dilute quickly, but plumes remain one of the main ways mining could do harm, and the International Seabed Authority is still setting limits.⁴

Slow to heal

Tracks that last decades

In DISCOL, a test off Peru in 1989, scientists ploughed the seabed and went back for decades. Microbial life there is estimated to need more than 50 years to return to its undisturbed state, and the nodules themselves will not come back for millions of years.^2,4

An open question

"Dark oxygen"

In 2024 a study in Nature Geoscience reported oxygen being produced on the abyssal floor in the dark, and proposed the nodules as a kind of natural battery splitting seawater. Other scientists have criticised the study's methods; it is unresolved.⁴

On the globe

1 · The zone

The Clarion-Clipperton Zone lies in international waters. Under the UN Law of the Sea, the International Seabed Authority in Jamaica regulates mining there, and has so far issued exploration contracts only.^1,4

2 · Against the land

On land, DR Congo mined 74% of the world's cobalt in 2025, Indonesia 67% of its nickel, and South Africa 38% of its manganese.³ Supporters of seabed mining argue the nodules would add a new source outside those countries; opponents argue the price would be paid in an ecosystem barely studied.

3 · The rules stall

Jun 2021Nauru, sponsoring a subsidiary of The Metals Company, starts a two-year clock for the ISA to finish its mining rules.⁵
2023The deadline passes without a mining code.⁴
Dec 2024Norway pauses plans to license seabed mining in its Arctic waters.⁴
Feb 2025The Cook Islands sign a seabed minerals deal with China.⁴

4 · The US goes its own way

On 24 April 2025 an executive order told NOAA to speed up seabed mining licences under the Deep Seabed Hard Mineral Resources Act, a US law of 1980 that predates the ISA.⁶ TMC USA filed a combined exploration and commercial recovery application on 6 February 2026 for about 65,000 km² of the zone, with an estimated 619 million tonnes of wet nodules.^7,8 NOAA found it complete; public comment closed on 19 October 2026. Next come certification and an environmental impact statement before any permit.⁷

Why "critical"

Battery metals, on the ocean floor

Manganese, nickel, cobalt and copper are all on critical-minerals lists because of batteries, steel and the grid. The nodules hold them together, in quantities larger than many mines. Whether they should be mined, and under whose rules, is one of the open questions of the energy transition. We take no side here: these are the facts as published.

MnManganeseSouth Africa 38% NiNickelIndonesia 67% CoCobaltDR Congo 74% CuCopperChile 23%

Next: The Ice, Greenland's rare earths. Before this: SpaceX and The Drone War. For batteries, see The Battery.

Sources

Shares of world output are from USGS Mineral Commodity Summaries 2026 via our minerals data; other figures are cited where they appear. The comparison of nodule metal with mine output is our own arithmetic. The 3D scenes are schematic illustrations, not any company's design. Photos: NOAA Ocean Exploration, public domain.