Rare species face extinction risk from deep-sea mining, scientists have warned, following the most comprehensive review of five decades of research into the practice. Researchers from the Natural History Museum analysed more than 200 studies together for the first time, concluding that the extraction of minerals from the ocean floor could drive unique creatures to the point of no return.
The threat to hydrothermal vents and seamounts
The review singled out hydrothermal vents — fissures on the seabed usually found near volcanic areas or tectonic plate boundaries — as being at critical risk. These features make up a tiny fraction of the ocean floor but are rich in copper, a mineral essential for the energy transition. They also host rare ecosystems full of species that exist nowhere else on Earth. The scientists found that mining at these sites would “likely lead to irrevocable biodiversity loss” and put those species at risk of extinction.
Seamounts, underwater mountains with cobalt-rich crusts, face similar dangers. Although the review noted that very little data exists for these habitats, the prevailing theory is that they too contain unique species and vulnerable marine ecosystems that could be destroyed by disturbance. Evidence from a large-scale seabed mining test in the Clarion-Clipperton Zone (CCZ) — a six million square kilometre area of the Pacific between Hawaii and Mexico — recorded a 37% decrease in the abundance of macrofaunal animals and a 32% reduction in species richness in directly impacted areas.
The physical destruction is only part of the problem. Mining operations churn up fine sediments, creating plumes of suspended particles that can travel hundreds of kilometres, smothering organisms, harming filter-feeders and potentially contaminating seafood supplies. The introduction of industrial noise and artificial light into a naturally dark and silent environment can disrupt the behaviour and communication of species, including marine mammals such as whales. Disturbing deep-sea sediments could also release stored carbon, accelerating climate change by damaging the ocean’s role as a carbon sink.
Prof Adrian Glover, merit researcher at the Natural History Museum who led the review, said the findings were “not actually that surprising.” He compared the impact to driving a six-to-ten-metre-wide vehicle over the seafloor. “Not surprisingly, you see decadal scales for any kind of recovery whatsoever. If you drive a large ploughing vehicle over a grassland habitat in the south-east of England it will take many decades to recover.”
The mining process and other habitats
Deep-sea mining involves extracting minerals such as cobalt, nickel and copper from the seabed to supply resources for laptops, phones, weapons, green technologies, electric vehicle batteries and infrastructure. Extraction is not yet taking place at a commercial scale, as policymakers, regulators and scientists scramble to understand the potential damage it could cause to different habitats on the ocean floor.
Besides vents and seamounts, mining exploration is also underway on abyssal plains — vast, flat areas that cover more than half of Earth’s surface. These regions are formed by thick layers of sediment in which thousands of species live, and they contain cobalt- and nickel-rich “nodules.” After reviewing the studies, the scientists said the risk of biodiversity loss at these sites remains largely unknown. However, species could be widespread across ocean floors beyond the zones ringfenced for exploration, making it “extremely difficult to prove” whether they would be lost.
In the Clarion-Clipperton Zone, researchers estimate that 6,000 to 8,000 species may live there, but only around 436 have been formally named. The Natural History Museum team has already described more than 50 new species, including a worm found living inside the nodules and two new species of hydrothermal vent tubeworm. Prof Glover said making data on species and their DNA available “is critical to understanding the risks of biodiversity loss” across these habitats.
The review also highlighted that, despite decades of research, significant knowledge gaps remain. Many deep-sea species are yet to be discovered, making it impossible to assess the full extent of potential losses. The long-term impacts on deep-ocean biodiversity, ecosystem functions and the services they provide are still poorly understood.
Policy and regulatory implications
The scientists concluded that major disturbance at hydrothermal vents and seamounts would not be aligned with United Nations policies on protecting biodiversity, to which most nations have agreed. These policies include the target to protect 30% of land and sea for nature by 2030. Mining on seamounts was also described as incompatible with the UN framework.
The International Seabed Authority (ISA), established under the UN Convention on the Law of the Sea, regulates mining in international waters. It has been developing a “mining code” for commercial exploitation for more than a decade but has yet to finalise it. A provision known as the “two-year rule,” triggered by the Pacific island nation of Nauru’s intention to mine, aimed to expedite the process, but the deadline was missed in July 2023.
Meanwhile, a growing number of countries — more than 30 — along with scientists, environmental organisations and Indigenous groups, are calling for a moratorium or precautionary pause on deep-sea mining. Some large corporations that use the targeted minerals have also supported a moratorium or committed to not sourcing seabed materials. In the CCZ, the international regulator has already protected 30% of the area targeted for development. However, the teams say there remains little understanding of how well this protected system will work to prevent ecosystem damage because of a lack of data from those sites.
Prof Glover suggested the next steps should be to recognise that mining rare ecosystems is not compatible with existing policy. “In other areas, such as polymetallic nodule regions, scientific data can support the creation and refinement of protected areas, helping policymakers determine whether mining could be considered sustainable,” he added. The economic case for deep-sea mining is also being debated, with advances in battery technology reducing reliance on cobalt and nickel, and a current oversupply of these metals weakening the market appeal.
The Natural History Museum has been leading efforts alongside colleagues in the global scientific community to identify and describe as many deep-sea species as possible, but the data gap remains steep. The potential for irreversible damage to one of the planet’s largest and least understood ecosystems underscores the urgency of these discussions — and the lack of data from already designated protected areas means no one can yet say whether the safeguards are working.
