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The Clarion-Clipperton Zone (CCZ) is a region of Pacific seabed, off the west coast of Mexico, where polymetallic nodules are abundant and where most of the International Seabed Authority’s nodule exploration contracts are located. This guide explains what the zone is and how the ISA governs it, with a checklist for reading ISA records.
Short answer
The Clarion-Clipperton Zone is a deep-sea area in the Pacific Ocean that holds abundant polymetallic nodules. Seventeen of the 19 polymetallic nodule exploration contracts issued by the International Seabed Authority (ISA) are in the Clarion-Clipperton Fracture Zone. Alongside those contracts, the ISA runs an environmental management plan that protects a network of 13 areas of particular environmental interest. Contracts authorise exploration, not commercial exploitation.
Definition and scope
The ISA describes polymetallic nodules as deposits made up mainly of manganese and iron, with silicates and hydroxides, and trace amounts of nickel, copper, cobalt and rare earth elements. Nodules commonly measure 2 to 8 cm. The ISA notes that economically important deposits are generally found at depths of 4,000 to 6,000 m where sedimentation is very low, and that nodules are abundant off the west coast of Mexico in the Pacific, which is where the Clarion-Clipperton zone lies. The boundaries used for management are set by ISA decisions, so the ISA’s own pages are the reference for contract areas.
How the ISA governs the zone
Governance of the zone runs on two parallel tracks, and they are often confused.
Track 1: exploration contracts
The ISA lists 32 exploration contracts held by 22 contractors, each with a 15-year term, covering polymetallic nodules, polymetallic sulphides and cobalt-rich crusts. Nineteen are for polymetallic nodules. Seventeen of those are in the Clarion-Clipperton Fracture Zone; the others are held by the Government of India (Indian Ocean) and Beijing Pioneer Hi-Tech (Western Pacific). UK Seabed Resources holds two of the nodule contracts (2013 and 2016).
Track 2: the environmental management plan
On the recommendation of its Legal and Technical Commission (LTC, document ISBA/17/LTC/7), the ISA Council adopted the first regional environmental management plan for the zone, ISBA/18/C/22, in 2012. It designated nine areas of particular environmental interest (APEIs), intended to protect biodiversity and ecosystem structure and function across the region from future mineral exploitation. In December 2021 the Council, by decision ISBA/26/C/58, approved four additional APEIs, giving 13. The ISA states that the network represents 1.97 million km2 of protected seabed.
The 2012 decision provides that no plan of work application should be granted in the listed APEIs. Under paragraph 42 of the plan, the LTC reviews the number, size and location of APEIs, and the plan itself is subject to periodic external review by the LTC every two to five years, as required.
Contracts versus protected areas
| Feature | Exploration contracts | CCZ environmental management plan |
|---|---|---|
| What it is | An ISA exploration contract held by a contractor | An ISA Council plan with a network of areas of particular environmental interest |
| Scale (ISA figures) | 32 contracts, 22 contractors overall; 19 nodule contracts, 17 in the Clarion-Clipperton Fracture Zone | 9 APEIs (2012), 13 after December 2021; 1.97 million km2 protected |
| Duration or review | 15-year contracts | Periodic LTC review every two to five years, as required |
| Key identifiers | Per-contractor records on the ISA site | ISBA/17/LTC/7, ISBA/18/C/22, ISBA/26/C/43, ISBA/26/C/58 |
Where it matters for researchers and data users
Environmental baseline data, biodiversity syntheses and contractor reports about the zone are tied to specific ISA documents and contract areas. The ISA convened a workshop on CCZ biodiversity synthesis in October 2019 with the Deep CCZ Project, and the LTC drew on its outcomes when it reviewed the plan (ISBA/26/C/43). When you cite or reuse zone data, a short checklist helps:
- Record the ISA document symbol (for example ISBA/18/C/22) and the date of the decision you rely on.
- Identify which contract area, if any, a dataset comes from, using the contractor’s page on the ISA site, and whether the sample sits inside an APEI.
- Note the date you read the ISA page, since the number of APEIs and contracts changes over time.
- Describe samples with consistent metadata and give datasets a persistent identifier, in line with the FAIR data principles.
For readers new to the field, our overview of marine biology covers the wider discipline that deep-sea baseline studies belong to.
Common misunderstandings
- Exploration is not exploitation. The exploration contracts described above do not by themselves authorise commercial mining.
- The zone is not one protected area. The protected APEIs are a network within the zone; the contract areas are separate.
- The numbers change. The count of APEIs rose from 9 to 13 in December 2021, and contract counts are updated by the ISA.
- Nodules are not all one thing. The ISA describes them as mainly manganese and iron with trace nickel, copper, cobalt and rare earth elements.
FAQ
What is the Clarion-Clipperton Zone?
It is a region of the Pacific seabed, off the west coast of Mexico, where polymetallic nodules are abundant and most ISA nodule exploration contracts are located.
How many exploration contracts are in the zone?
The ISA lists 19 polymetallic nodule exploration contracts, 17 of them in the Clarion-Clipperton Fracture Zone, as read on 8 November 2026.
How many protected areas are there?
Thirteen areas of particular environmental interest: nine designated in 2012 and four added by the ISA Council in December 2021, together covering 1.97 million km2.
What are polymetallic nodules made of?
Mainly manganese and iron, with silicates and hydroxides, and trace nickel, copper, cobalt and rare earth elements, commonly 2 to 8 cm across.
Sources
- International Seabed Authority, Polymetallic nodules exploration contracts (read 8 November 2026).
- International Seabed Authority, Exploration contracts (read 8 November 2026).
- International Seabed Authority, Environmental management plan for the Clarion-Clipperton Zone (read 8 November 2026).
