English: Primary production required (PPR) to sustain global marine fisheries landings expressed as percentage of local primary production (PP).

Estimates of PPR, PP and PPR/PP computed per 0.5° latitude/longitude ocean cells. PPR estimates based on the [www.seaaroundus.org Sea Around Us] catch database and PP estimates derived from SeaWiFS's global ocean colour satellite data. The maps represent total annual landings for 1950 (top) and 2005 (bottom). Note that PP estimates are static and derived from the synoptic observation for 1998.

See: Swartz, W., Sala, E., Tracey, S., Watson, R. and Pauly, D., 2010. "The spatial expansion and ecological footprint of fisheries (1950 to present)". PloS one, 5 (12): e15143.