Global yield from aquaculture systems.

Aquaculture is expected to expand significantly in the coming decades to meet growing demand. A key variable for understanding the potential benefit of and impact from this growth is efficiency; yet a comprehensive assessment of on‐farm area use and yield is limited. Much like land‐based agriculture, range and variation in yields across space, species, and practice provide insights into area use and production efficiencies. Current estimates of aquaculture yields (production per area per time) aggregate on‐farm and off‐farm land use into one 'land use' category; in contrast, we disaggregate this category to provide on‐farm yield estimates and account for water area use. We use a quantitative review of scientific literature to synthesize and compare on‐farm area use and yield patterns across countries, taxa, aquatic systems, data source, and production mode (n = 378). Because recirculating aquaculture systems (RAS) have been touted as a particularly efficient production mode, we also found estimates for RAS from industry (n = 4). Median, mean and range in yields among countries and taxa vary by orders of magnitude, with algal production greatly exceeding that of crustaceans, fishes and molluscs. Yields in marine systems were on average roughly 5× greater than yields in freshwater systems. RAS had particularly high yields but sparse data and estimates from private corporations were approximately 3.7× higher than literature estimates, on average. This comprehensive assessment of global aquaculture yields offers critical insight into the production efficiencies of different aquaculture forms and the large amount of variability, which could help guide aquaculture policy and practice. [ABSTRACT FROM AUTHOR]