In the Depths of Clarion-Clipperton, Each Dive Doubles the Number of Known Species
A study published in 2026 has just described 24 new species of amphipods in the abyssal plain of Clarion-Clipperton, as well as an entirely unknown superfamily to science, christened Mirabestioidea. Before this work, only a few species had been recorded in this zone. The known number has thus increased considerably in a single expedition.
This figure says something essential: the Clarion-Clipperton zone, as large as India, remains an interior continent we have barely opened. It has also, for a decade, been the primary target of industrialists seeking to extract its polymetallic nodules. Science and exploitation converge toward the same depths, with incompatible timelines.
The Essentials
- A 2026 study identifies 24 new amphipod species and an unknown superfamily (Mirabestioidea) in the Clarion-Clipperton zone, significantly multiplying the number of known species in a single expedition.
- The abyssal plain of Clarion-Clipperton extends over approximately 4.5 million km² in the Pacific, between Hawaii and Mexico — an area comparable to that of India.
- More than 25 States have called for a precautionary moratorium on deep-sea mining; the International Seabed Authority (ISA) has not yet granted commercial permits, but applications are accumulating.
- The polymetallic nodules in the zone contain nickel, cobalt, manganese, and copper — metals essential for manufacturing batteries for the energy transition.
Species Still Largely Unknown, Missions That Discover Dozens of New Ones
Amphipods are discreet crustaceans, rarely larger than a few centimeters, that inhabit sediments and deep waters. Their study does not make headlines. But their diversity in the Clarion-Clipperton zone has become a first-order scientific marker, because it illustrates a general phenomenon: each research expedition in the deep seas returns with a discovery rate that has no equivalent elsewhere in biology.
The 2026 study, published from samples taken in the zone, did not merely add 24 species to a list. It created an entire superfamily — Mirabestioidea — a taxonomic category grouping organisms distinct enough that they cannot be assigned to any known family. This is rare. In terms of taxonomic depth, it is like discovering not a new mammal, but an entirely new group of mammals that existing classification could not even have anticipated.
This discovery rate is not an anomaly. Previous work on other groups — polychaetes, holothuroids, isopods — had already shown that the majority of species sampled in the zone were new to science. The Census of Marine Life, an international program that closed in 2010, estimated that 70 to 80% of marine species globally remained undescribed. For the Clarion-Clipperton zone specifically, the figure of 90% of undescribed benthic species is cited by the Natural History Museum and the WoRMS registry — not by the Census of Marine Life. Data accumulated since has not substantially improved this picture.
What this concretely means: the inventories that would serve as the basis for environmental impact assessment before exploitation do not yet exist. Industrialists cannot know what they would destroy, because scientists do not know either.
What the Nodules Contain, and Why Industrialists Are Interested
The polymetallic nodules of Clarion-Clipperton are not exotic formations. They are mineral concretions that deposit slowly — at a rate of a few millimeters per million years — on abyssal sediments, concentrating manganese, nickel, cobalt, and copper. The zone would contain billions of tons of them, according to ISA estimates.
This geochemical profile has taken on strategic value over the past fifteen years, as the energy transition has increased demand for battery metals. Nickel and cobalt, in particular, are recognized bottlenecks in the electric vehicle supply chain. Pressure on terrestrial resources — notably in the Democratic Republic of Congo for cobalt, or Indonesia for nickel — has made the deep ocean floor more attractive to investors. As analyzed in a previous article on mineral sovereignty strategies in Africa, thirteen African countries have already chosen to ban the export of raw ores to enhance their processing chain — a decision that makes oceanic alternatives even more interesting for importing countries.
About fifteen States have obtained exploration contracts from the ISA for specific zones in Clarion-Clipperton. China, South Korea, France, Germany, and Russia are among the contractors. The Metals Company (TMC), a publicly traded Canadian enterprise, is the most advanced in its application for a commercial exploitation permit. It aims for large-scale extraction that would mobilize seabed mining equipment, riser pipes, and processing vessels on the surface.
The economic model rests on an assumption: that the costs of submarine extraction, currently prohibitive, will become competitive as technology matures and metal prices remain supported. This assumption remains contested. Several independent profitability studies estimate that the economic window is narrow and heavily dependent on nickel prices, which are historically volatile.
An Ecosystem That Formed Over Millions of Years
The question of irreversibility is not rhetorical in this context. It is physical and temporal.
The nodules of Clarion-Clipperton took several million years to form. The organisms that populate the abyssal sediments — the same sediments that mining equipment would dredge and discharge in turbid plumes — regenerate on timescales that vastly exceed our planning horizons. Disturbance experiments conducted in the 1970s and 1980s (notably the IOM Box Corer project in the DISCOL zone, off Peru) tracked the recolonization of mechanically disturbed seafloors. Thirty years later, communities had not returned to their initial state. Recent studies show that certain disturbed areas remain impoverished long after initial disturbances, for durations that defy our ordinary planning timescales.
This regeneration delay is not measured in decades. It is measured in centuries for the slowest species, likely in millennia for sedimentation processes. Large-scale mineral extraction in this zone would not be a repairable damage on a human timescale. It would be a permanent transformation of an environment we are only beginning to inventory.
This irreversibility has a direct generational dimension: decisions made in the next five to ten years will determine what scientists of the twenty-second century will find — or will no longer find. The Mirabestioidea described in 2026, if the seafloors it inhabits are disturbed before being properly studied, will remain a taxonomic entry with no possible continuation. One cannot reconstitute the ecology of a system whose baseline has not been established.
More Than 25 States Call for a Moratorium; the ISA Under Pressure
The governance of international seabeds rests on the United Nations Convention on the Law of the Sea (UNCLOS, 1982) and on the ISA, based in Kingston, Jamaica. The ISA is responsible for issuing exploration and exploitation permits, and for sharing benefits with developing States according to the principle of “common heritage of mankind.”
In practice, governance finds itself in an uncomfortable position. The Metals Company triggered in 2021 the so-called “two-year rule” clause: by partnering with Nauru, a small Pacific island State, it forced the ISA to finalize its mining code within two years. This deadline expired in 2023 without the code being adopted. The ISA continues to work on regulations; meanwhile, TMC formally announced its undertaking in March 2025 and filed its commercial permit application in April 2025 with the NOAA, under the American regime, rather than with the ISA.
Facing this pressure, a growing coalition of States has formed to call for a moratorium or precautionary pause. More than 25 countries have explicitly supported it, among them France, Germany, Chile, New Zealand, Costa Rica, and a majority of Pacific island States. The European Parliament voted in favor of a moratorium in 2023. France, which nevertheless has an exploration contract via Ifremer, has officially suspended all support for commercial exploitation pending sufficient scientific data.
The central argument of the coalition is precisely what the 2026 study illustrates: it is not possible to issue an exploitation authorization while respecting the precautionary principle when the scientific baseline has not been established. Authorizing extraction before describing the species involved amounts to accepting an environmental impact assessment that is structurally incomplete.
This debate is part of a broader reflection on the capacity of international institutions to manage common goods with high economic value and high scientific uncertainty — a problematic that global finance also illustrates in its own way when it diverts capital from uses whose impact is difficult to quantify in the short term.
What Scientists Are Doing, and What They Need
Behind the 24 new species of 2026 are concrete names: teams from the Natural History Museum in London, the Senckenberg Research Institute in Germany, and several American and Japanese laboratories coordinating their expeditions within the SMARTEX program (Seabed Mining And Resilience To Experimental Disturbance), funded in part by the British Natural Environment Research Council. The ISA DeepData program, a public ISA database, aggregates some of the results from these expeditions.
Ifremer in France, the University of Hawaii, and the Woods Hole Oceanographic Institution in the United States maintain research programs specific to the zone. The NOAA Ocean Exploration campaign has mapped significant portions of the tropical Pacific in high definition in recent years, combining multibeam acoustics and ROV dives. The aim is to build a sufficient ecological baseline to feed impact assessments.
The problem is one of scale and means. An oceanographic expedition in the abyss costs several million euros per week. The Clarion-Clipperton zone extends over 4.5 million km². The ratio between the area to be studied and available resources is unfavorable. At this pace, the inventory will not be complete for several decades — and applications for industrial exploitation are measured in years today.
Several researchers, notably within the ISA expert group, argue that exploration contractors should be required to fund a portion of biological studies in their contract zone. This mechanism exists in theory in current contracts, but requirements are insufficiently precise and rarely audited. The mining code under negotiation could formalize a requirement for minimal characterization before any extraction begins — one of the most disputed points between delegations.
The Principle of Prior Knowledge as a Governance Issue
The question posed by Clarion-Clipperton is not only ecological. It is institutional, and it could set a precedent for the entire governance of planetary commons.
The ISA must choose between two logics. The first: wait to have sufficient knowledge of ecosystems before authorizing their exploitation — this is the sense of the moratorium. The second: frame exploitation through strict rules while letting industrialists proceed, betting that the mining code can be sufficiently protective even in the absence of a complete baseline. This second option is more institutionally convenient, but it places the risk on ecosystems rather than on investors.
The 2026 study on amphipods strengthens the moratorium argument in a precise way: it shows that the inventory is not 80% or 90% complete, awaiting a few additional missions. It is, in all probability, less than 10% complete for many taxonomic groups. Multiplying the number of known species multiple times in a single expedition is not a marginal result — it is a result that says we are still on the first pages.
International governance has already known how to impose precautionary principles in other domains. The Antarctic Treaty, signed in 1959 and strengthened by the Madrid Protocol in 1991, protects an entire continent from mining exploitation, indefinitely, precisely because its scientific and ecological value was judged incompatible with extraction. The Clarion-Clipperton zone is not Antarctica, but the argument for prior knowledge has the same structure.
The ISA’s next session in 2026 could be decisive. If the mining code is finalized without a requirement for prior ecological baseline, TMC and other contractors could obtain commercial permits in the following years. If a majority of States imposes a condition of sufficient knowledge, this postpones exploitation and effectively funds the scientific programs that are lacking today.
The Mirabestioidea — this superfamily that no taxonomist had anticipated — may be the best available argument. Not as a symbol, but as empirical proof: we do not yet know enough to know what we would destroy.
Sources
- New species from the deep seas in the Clarion-Clipperton zone, 2026 — Dictionnaire Environnement
- International Seabed Authority (ISA) — ISA DeepData, public database of exploration results: isa.org
- SMARTEX Program (Natural Environment Research Council, United Kingdom) — results published in Progress in Oceanography, 2023-2025
- Study on the long-term recovery of disturbed deep-sea habitats — Current Biology, 2023 (teams from GEOMAR Helmholtz Centre for Ocean Research Kiel)
- European Parliament Resolution on a moratorium on deep-sea mining, 2023 — europarl.europa.eu
- Madrid Protocol to the Antarctic Treaty (1991) — ats.aq
- ZooKeys 2026 Study – 24 new amphipod species CCZ
- WoRMS – Mirabestioidea (official registry)
- Pew Charitable Trusts – CCZ Fact Sheet
- Official ISA FAQ
- ISA – Exploration Contracts (polymetallic nodules)
- TMC SEC Filing – May 2025
- Greenpeace France – July 2025 (moratorium)
- French National Assembly – moratorium resolution January 2023
- PLOS ONE – Census of Marine Life 2010
- PLOS ONE – Biological responses to disturbance (2017)