Figure 22.22 Patterns of marine biodiversity. In the ocean, the greatest number of species exists in the tropics and declines toward the poles. At a given latitude, more species exist near the coasts and fewer species exist in the open ocean. The number of species is calculated using sample blocks of 880 km per side.
After D. P. Tittensor et al., Global patterns and predictors of marine biodiversity across taxa, Nature 466 (2010): 1098–1103.