The extraction of minerals from the ocean floor, Earth's last mining frontier. The industry centres on polymetallic nodules—typically the size of goose eggs—rich in nickel, copper, cobalt, manganese and other minerals. The Clarion-Clipperton Zone (CCZ), covering some 4.5m square km in the north Pacific, 800km south-east of Hawaii, contains an estimated 21bn tonnes of nodules that may hold four times all known cobalt reserves on land, including some 270m tonnes of nickel and 44m tonnes of cobalt. The nodules lie at depths of up to 5,500 metres.
Specialised remote-controlled vehicles, typically truck-sized, scoop up seabed nodules along with sediment and send them in tubes to the surface. Once collected above water, the residue is thrown back into the sea.
The International Seabed Authority (ISA), created under UNCLOS, currently forbids mining but has issued prospecting-only licences. Its 169 members failed to agree on a common rule book for exploitation in March 2025. On April 24th 2025 Donald Trump signed an executive order authorising seabed mining for critical minerals, applying to both American waters and international waters beyond American jurisdiction—breaching what even non-signatories had long accepted as customary international law. The National Oceanic and Atmospheric Administration (NOAA) is to issue mining licences under the order.
The EU insists that UNCLOS provisions represent customary international law binding even on non-signatories such as America. France, which will co-host a UN ocean conference in June 2025 with Costa Rica, declared: "The abyss is not for sale." More than two dozen countries, including Canada, New Zealand, Britain, France, Spain and Germany, have favoured at least a "precautionary pause" on deep-sea mining. Costa Rica and a number of Pacific island states favour an outright ban.
Douglas McCauley, a professor at the University of California, Santa Barbara, describes the deep oceans as "among the least resilient ecosystems on the planet". Organisms live long and reproduce slowly, meaning deep-sea ecosystems take an age to recover. Mining might cause the extinction of species not yet recorded. Stirring up sediment may also harm fisheries. Mining interests counter that far more biomass resides in a tropical forest in Sulawesi, one of the world's most heavily mined nickel sources, than in the deep ocean.
China has invested billions in deep-sea research. Japan has collected nodules in trials around Minami-Torishima in its southern exclusive economic zone. The Metals Company, a Canada-based firm listed in America, has pulled up several thousand tonnes of polymetallic nodules prospecting in the CCZ and on April 29th 2025 applied to the Trump administration for a licence to exploit minerals on the seabed.
In February 2025 China signed a strategic partnership with the Cook Islands, whose prime minister, Mark Brown, carries a handful of nodules—"batteries in a rock"—almost wherever he goes.
Global demand for minerals by clean-energy industries alone could quadruple by 2040, the International Energy Agency estimates.
As long as war is regarded as wicked, it will always have its fascination. When it is looked upon as vulgar, it will cease to be popular.