Coastal population density as a proxy for intertidal habitat destruction. For more details on the variable construction, see the original sources:

CIESIN & CIAT (Center for International Earth Science Information Network /Columbia University & Centro Internacional de Agricultura Tropical) (2005). Gridded Population of the World, Version 3 (GPWv3): Population Density Grid, Future Estimates. Palisades, NY.

and

NASA Socioeconomic Data and Applications Center (SEDAC)

and

Halpern, B. S. et. al. (2008) A global map of human impact on marine ecosystems. Science, 3199(5865): 948-952.

When using this variable, please cite both the OHI project and the original sources.