Tiny animals live inside deep-sea metal lumps as Washington weighs a commercial mining permit.
Metal-rich lumps targeted by deep-sea miners shelter communities of tiny animals not found elsewhere on the ocean floor, according to a study published in Scientific Reports, raising fresh concerns about plans to harvest them. The research examined 244 polymetallic nodules from the Clarion-Clipperton Zone in the Pacific, finding creatures smaller than a millimetre living inside cracks and pores, Oceanographic Magazine reported.
Researchers from the University of Bremen’s MARUM centre and the Royal Netherlands Institute for Sea Research counted 4,139 animals across the samples, averaging 17 per nodule with one specimen holding 245. These nodules lie 4,000 to 6,000 metres down and grow only a few millimetres every million years, providing a valuable source of manganese and copper for deep-sea miners, as Scientific American noted.
Organisms collected 1,000 kilometres apart showed more similarity to each other than to communities in the sediment nearby, suggesting the rocks themselves are necessary for certain species’ survival, including a common single-celled protist named “Thurammina sp. 1.”
“The crevices in the polymetallic nodules function as small shelters and provide a home to animals that we do not encounter in the soft sediment of the seafloor,” said Dr Coral Diaz-Recio Lorenzo, a postdoctoral researcher at Sorbonne University in France.
Sabine Gollner, a researcher at the Royal Netherlands Institute for Sea Research and honorary professor at the University of Groningen, said that commercial mining could cause irreversible damage. “Our findings point out that commercial mining may result in an irreversible loss of undescribed and unique biodiversity associated to nodules,” Gollner said in a statement.
Meanwhile, the firm Impossible Metals tested an autonomous robot using artificial intelligence to retrieve nodules without disturbing nearby marine life.
The findings arrive as the deep-sea mining industry edges closer to production. A US subsidiary of the Metals Company has applied for an exploration licence and commercial recovery permit, which the National Oceanic and Atmospheric Administration found in full compliance with information requirements.
The company expects a permit before the end of the first quarter of 2027, though NOAA must still finalise an environmental impact statement. Washington backed the move following an executive order aimed at expanding deep-sea mining to reduce reliance on foreign mineral imports. This route bypasses the International Seabed Authority, the UN-backed regulator that delayed commercial recovery rules again in July.
| Research Metric | Recorded Data |
|---|---|
| Nodules Examined | 244 |
| Total Animals Counted | 4,139 |
| Average Per Nodule | 17 |
| Maximum in One Nodule | 245 |
| Depth | 4,000 to 6,000 metres |
It remains unclear whether the loss would lead to global extinctions, and the lead author, Dr Tanja Stratmann, is on a new expedition to the zone to find out.
