The Millennium Coral Reef Mapping Project (MCRMP) aimed to map coral reefs worldwide at geomorphological thematic scales using Landsat satellite images at 30 m spatial resolution. The 5-level hierarchical classification scheme implemented by MCRMP identified at Level 2 ‘Atolls’ as one of the main types of coral reef complexes.

Here we provide a global census of atolls, as a consistent geomorphologic GIS database. A total of 598 atolls are identified and mapped. The quantitative database provides surface areas for all geomorphologic units at Level 4 and 5 of the MCRMP classification scheme. It allows further work on atoll and coral reef classifications, regionally and globally, in order to identify geomorphic trends and outliers. It is also a convenient database to use in multivariate analyses with ancillary biodiversity, fishery, socio-economic or climate data.

Related publication: Andréfouët, S., Paul, M. 2023. Atolls of the world: A reappraisal from an optical remote sensing and global mapping perspective. Marine Pollution Bulletin 194, 115400. https://doi.org/10.1016/j.marpolbul.2023.115400