Miners Want the Rock. Tiny Animals Live in Its Cracks.

Metal nodules that miners want from the Pacific seabed are also habitat, a new study finds: tiny animals live in their crevices, in communities unlike those in nearby mud. ^[1]

The paper, "Polymetallic nodules provide a distinct habitat for abyssal meiofauna," was published in Scientific Reports on November 11, 2026. It looks at the eastern Clarion-Clipperton Zone, a stretch of Pacific seabed where nodules of iron and manganese oxides also hold nickel, copper and cobalt, the metals that make them a commercial target. ^[1]

What lives in a rock

The animals involved are meiofauna, a catch-all for creatures too small to see easily, here mostly nematodes (roundworms) and copepods (tiny crustaceans). Foraminifera, single-celled organisms, live there too. ^[1]

The researchers counted animals in 244 nodules and studied the physical structure of 24 of them. ^[1] That is a sizeable sample, and the structural work looks at the cracks and pores where the animals sit.

An institutional release from the research team's institute reports 4,139 animals in the 244 nodules, an average of 17 per nodule. One nodule held 245. ^[2]

They then compared genetic data from the nodule animals with data from sediment in the same exploration areas. The nematode and copepod communities in the crevices differed from those in the surrounding mud. ^[1]

The nodules are not crowded. Nematodes in the crevices reached about a tenth of their abundance in nearby sediment, copepods about a quarter. ^[1][2] The point is not that nodules are packed with life. It is that the life they hold is of a different make-up from the life next door.

One single-celled organism, Thurammina sp. 1, was particularly common in the nodules. The release says it appears adapted to their sheltered spaces. ^[2]

The material came from the SO268 expedition in 2019, and the paper presents its work as baseline data for environmental management. ^[1] A baseline is a record of what lived in a place before anyone disturbed it. Without one, nobody can say afterwards what was lost.

What a mined patch loses

Nodules take millions of years to form, according to the researchers. Take them away and the hard surfaces and crevices go with them, and nothing replaces them on human timescales. ^[1][2]

That changes the arithmetic. Mining is often described as scooping up a resource that lies on the seabed. This study says the resource is also the roof over a community of animals, and a collector that lifts the nodules lifts the roof.

The cost-benefit question has a time dimension too. A mine could run for years. A habitat that took millions to build cannot be rebuilt in that time.

Mining would also disturb more than the nodules. An expedition source describes how sediment stirred up by collection can settle around a site, burying animals attached to nodules and affecting some that filter food from the water. ^[5] Those are separate potential harms, and the new study did not measure them.

What the study does not show

The study does not prove that these animals exist nowhere else, and it does not show that losing them would cause extinctions. ^[1] The authors say further work is needed to learn whether the loss of local nodule communities would mean global extinctions, or whether the organisms can live elsewhere. ^[2]

The zone is already known to be rich and poorly catalogued. The paper notes more than 5,000 recorded but undescribed species of seabed animals there, with estimates of richness still rising. ^[1] What fraction of the nodule lineages are new to science is an open question.

The rulebook that is not finished

The International Seabed Authority, the UN-linked body that governs mineral activity on the international seabed, has been drafting rules for commercial extraction since 2014. Those draft exploitation rules, known as the Mining Code, are still before its Council. ^[3]

The Council met from July 13 to 24, 2026, and the Assembly from July 27 to 31. ^[6] Mongabay reported that the meetings ended without finalizing the rules, and that the Council's next scheduled session is in March 2027. ^[4] So the study lands in a gap, with a good many months for the argument to be made before negotiators sit down again.

The science is not standing still in the meantime. A research expedition aboard the ship RV SONNE is revisiting a Clarion-Clipperton site five and a half years after a 2021 test there of a remotely controlled collector prototype. In that test the machine ran for 74 hours, travelled about 32 kilometres and collected nodules from 54,000 square metres of seabed. ^[5] Averaged over the run, that is roughly 430 metres of seabed an hour.

The crew is looking at how far sediment plumes spread and whether artificial hard surfaces could help animals recolonize. ^[5] No results are out yet. When they come, they will show whether a disturbed patch of this seabed recovers at all, and the nodule study suggests part of the answer may depend on whether anything is left to settle on.

The Council's March 2027 session is the next point at which delegates can turn these findings into rules.