A coral no one had ever documented was growing on a rock that a mining company wants to scrape off the ocean floor. That single detail, drawn from a peer-reviewed taxonomy paper published in the Zoological Journal of the Linnean Society, captures the collision now unfolding roughly 4,000 meters beneath the central Pacific. In the Clarion-Clipperton Zone, a belt of abyssal seabed stretching from Hawaii toward Mexico and spanning an area roughly the size of the contiguous United States, researchers have cataloged 788 metazoan species. The vast majority had never been formally described by science. And the mineral deposits they depend on are already being tested for industrial extraction.
A biodiversity count that keeps climbing
The 788-species figure comes from a synthesis of CCZ biodiversity records led by Muriel Rabone and published in Current Biology in 2023. The study compiled thousands of sampling records collected across the region by multiple research teams and confirmed that a striking proportion of the organisms found remain unnamed and undescribed, making the CCZ one of the least-documented biological frontiers on the planet.
That number almost certainly understates the true richness. Sampling coverage across the zone is uneven, concentrated around particular exploration license blocks and logistical hubs. Large swaths of the CCZ have never been surveyed at all. Species that appear rare in existing datasets may simply live in places no submersible has visited, or they may be genuinely scarce and therefore especially vulnerable to localized disturbance. Researchers have cautioned that the exact proportion of undescribed species varies by taxonomic group and collection method, and that different teams working in different contract areas may be encountering overlapping or entirely distinct populations.
“We share this planet with all this amazing biodiversity, and we have a responsibility to understand it and protect it,” Rabone said when the synthesis was published, underscoring how little is known about the organisms that inhabit the CCZ even as extraction plans advance.
What makes the count more than an academic exercise is what these organisms live on. Polymetallic nodules, potato-sized mineral deposits rich in manganese, nickel, cobalt, and copper, are the primary target of deep-sea mining interest in the CCZ. They also happen to be the only hard substrate available in an otherwise soft-sediment environment. The newly described coral species documented in the Linnean Society paper was found growing directly on nodule surfaces. Researchers used imaging transects to estimate its density and standing stock, and they noted its vulnerability to nodule removal in plain terms: take the rocks, and you take the habitat.
Two field trials, two sets of measurable damage
The ecological risks of nodule mining are no longer hypothetical. Two separate industrial collector tests in the CCZ have now produced peer-reviewed evidence of biological harm.
A study published in Nature Ecology & Evolution in 2025 examined a large-scale collector trial conducted by Nauru Ocean Resources Inc. (NORI), a subsidiary of The Metals Company, and found that the abundance of macrofauna, organisms 0.3 millimeters or larger, dropped by approximately 37 percent at the test site. The study used a multi-year baseline and a before-and-after impact design, strengthening the case that the decline was linked to the mining test rather than natural variability. “The impacts we documented are significant and measurable,” the study’s authors noted, adding that the results highlight the need for caution before scaling up operations.
A separate study in Frontiers in Marine Science examined the Patania II collector test, conducted in a CCZ exploration contract area held by the Belgian firm Global Sea Mineral Resources (GSR). That research documented post-collection effects on meiofaunal communities, including sediment blanketing of 2 to 3 centimeters of deposited silt across nearby seafloor. The disturbance patterns were, in the authors’ words, “complex and variable,” with sediment plumes and physical disruption affecting different organism size classes in different ways.
Both studies draw on direct field observations rather than modeling alone. Together, they establish a consistent signal: mining-like activity reduces the abundance of seafloor life and alters community composition at the sites where it occurs.
Recovery measured in decades, not years
If the damage were temporary, the calculus might look different. But the longest available evidence suggests otherwise. A paper published in Nature analyzed ecological signals from historical mining disturbance tracks in the CCZ and found that those tracks can persist for decades, with biological communities showing only partial recovery over that timeframe.
That study did not examine the same collector trials described above. Instead, it drew on older disturbance experiments, offering the longest window researchers have into what happens after extraction equipment moves on. The finding directly challenges any assumption that deep-sea ecosystems bounce back quickly. Partial recolonization over decades suggests that full restoration, if it occurs at all, would unfold on timescales far longer than typical mining licenses or investment horizons.
No published study has yet traced a complete recovery arc for either macrofauna or meiofauna after industrial-scale nodule collection. Projections about long-term ecosystem trajectories remain provisional.
The regulatory gap
The International Seabed Authority (ISA), the United Nations body that regulates mineral activities on the international seabed, has been working to finalize a mining code for years. In July 2023, a two-year deadline set by the Pacific island nation of Nauru expired without a completed regulatory framework, and as of mid-2026, the ISA Council has continued negotiations on environmental standards and exploitation regulations without reaching final agreement.
That timeline matters because companies holding CCZ exploration contracts, including subsidiaries of The Metals Company, have signaled their intent to move toward commercial-scale extraction. Gerard Barron, chief executive of The Metals Company, has publicly argued that seafloor nodules represent a lower-impact alternative to terrestrial mining for battery metals, a claim that the peer-reviewed field data described here have not supported. The studies have been published during this regulatory window, but how much weight they will carry in the ISA’s permitting decisions remains unclear. The authority has held technical workshops and commissioned environmental reviews, yet no binding exploitation regulations incorporating these specific biodiversity and impact findings have been adopted.
Equally thin is the empirical work on mitigation. Proposals for preservation reference zones, areas set aside from mining within each contract block, exist on paper. Modified collector designs intended to reduce sediment plumes have been discussed. But peer-reviewed field data evaluating whether these measures actually protect biological communities are scarce. The question of how much harm could realistically be avoided, rather than merely documented after the fact, remains largely unanswered.
What the evidence supports and where it stops
Four peer-reviewed primary sources anchor this story, each addressing a distinct piece of the puzzle. The Current Biology synthesis, led by Rabone and published in 2023, provides the species-level baseline. The Linnean Society taxonomy paper puts a specific, recognizable organism on what might otherwise be an abstract biodiversity tally. The Nature Ecology & Evolution study quantifies macrofaunal loss from a real collector trial operated by NORI. And the Frontiers in Marine Science paper captures disturbance in a different size class of organisms, highlighting the role of sediment redistribution.
The Nature paper on decadal recovery adds a time dimension, demonstrating that even relatively small-scale disturbances leave marks that persist far longer than early optimists assumed.
Important caveats apply. The 37 percent macrofauna decline comes from one collector trial at one site. Whether that figure scales to full commercial operations covering vastly larger areas is not established. The 0.3-millimeter size cutoff means the reported decline applies only to organisms above that threshold; smaller creatures showed different response patterns. And the studies collectively demonstrate that mining-like disturbance can reduce abundance and alter community composition, but they do not yet provide a complete picture of ecosystem function, food-web restructuring, or potential tipping points.
Still, the verified findings as of June 2026 point in a consistent direction. The Clarion-Clipperton Zone is more biologically rich than once assumed. Much of that richness remains unnamed and unstudied. Early mining trials have already produced detectable harm to seafloor communities. And recovery, where it has been tracked at all, is measured in decades. Regulators weighing commercial mining permits are working from an incomplete but steadily growing body of evidence, and so far, the strongest signals all lean toward caution.
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*This article was researched with the help of AI, with human editors creating the final content.
