The global surge in demand for metals such as cobalt and nickel has created unprecedented interest in deep-sea habitats with mineral resources. The largest area of activity is a 6 million km2 region known as the Clarion-Clipperton Zone (CCZ) in the central and eastern Pacific, regulated by the International Seabed Authority (ISA). Baseline biodiversity knowledge of the region is crucial to effective management of environmental impact from potential deep-sea mining activities, but until recently this has been almost completely lacking. The rapid growth in taxonomic outputs and data availability for the region over the last decade has allowed for the first comprehensive synthesis of CCZ benthic metazoan biodiversity for all faunal size classes.

The CCZ Checklist was originally published in: Rabone, M., Wiethase, J.H., Simon-Lledó, E., Emery, A.M., Jones, D.O.B, Dahlgren, T.G., Bribiesca-Contreras, L., Wiklund, H., Horton, T. and Glover, A.G, 2023. How many metazoan species live in the world’s largest mineral exploration region? Current Biology, 33, 1-14, doi:10.1016/j.cub.2023.04.052

This paper provided the first checklist for the Clarion Clipperton Zone (CCZ) metazoan fauna and indicated that:

• 5,142 unnamed species (informal names) are recorded from the CCZ
• Total estimates of species richness range from >6,000–>8,000
• An estimated 88%–92% of species in the CCZ region in total are undescribed

The CCZ Checklist is now available through the World Register of Deep-Sea Species, facilitating access to the names of the species that have been described from the CCZ, as well as those that have been recorded as occurring in the CCZ. The Checklist is updatable as new species are described, and new occurrences are recorded from the CCZ.

Please contact the list editors (Tammy Horton & Muriel Rabone) if you notice any errors or omissions.