How can mariculture better help feed humanity?

Abstract

The primary production of the marine and the terrestrial domains are similar, ~49 and 56 Gt C year−1, respectively (Field et al., 1998), and the marine primary production must likely be more readily available for grazing animals because it is primarily in the form of unicellular phytoplankton. We harvest the ocean quite efficiently, perhaps beyond its sustainable yields (Marra, 2005), and it is therefore surprising that only some 2% of human food are from aquatic systems, including marine and freshwater aquaculture and fisheries (Figure 1A, faostat3.fao.org and fao.org/fishery/statistics/en). This number is valid for total weight based food production. For animal meat and for animal products totally (milk and egg included), the aquatic food acquisition is more important, contributing 34 and 12%, respectively, of the total production in terrestrial and aquatic systems (Figures 1A–C).