Coral Reef Area by Marine Ecoregion

Area of coral reefs (square kilometers), by marine ecoregion.

We extracted coral reefs from version 7.0 of the global one-kilometer raster data set compiled by the UNEP-WCMC update of 2003 (for more information about the source data set, e-mail spatialanalysis@unep-wcmc.org), which is almost entirely identical to the data published in the World Atlas of Coral Reefs (Spalding et al. 2001). They represent a combination of line and polygon information converted to a one-kilometer grid to smooth data originally drawn at different scales. We made minor modifications to the global map, by removing reef areas from West Africa and the Leeuwin and Southern California Bight ecoregions. The latter represents erroneous data, but other areas, while having some reef-building corals, lack true reef structures (original sources used by UNEP-WCMC were highly schematic sketches of possible locations for reef-building corals). A further modification we made was the addition of a nominal small reef area to the Marquesas ecoregion; limited areas of fringing reefs are found around these islands, but no maps were available when the global map was compiled (more information about corals in these modified regions can be found in Spalding et al. 2001).

These data were derived by The Nature Conservancy, and were displayed in a map published in The Atlas of Global Conservation (Hoekstra et al., University of California Press, 2010). More information at http://nature.org/atlas.

Data derived from:
UNEP World Conservation Monitoring Centre (UNEP-WCMC). 2003. Global 1 km raster data on coral reef locations, v.7.0. Cambridge: Author. Digital media.

A published version of these data was produced in the following work:
Spalding M. D., C. Ravilious, and E. P. Green. 2001. World Atlas of Coral Reefs. Berkeley: University of California Press.