Capture fisheries and aquaculture provide nearly equal shares of total seafood supply, but the composition of species in fisheries landings and aquaculture is very different. Understanding these differences are important to increasing the capacity of seafood to sustainably meet the nutritional needs of a growing population.
We use country-level fisheries and aquaculture production data from the Food and Agriculture Organization of the United Nations to calculate a Herfindahl-Hirschman index, a quantitative measure of species diversity. Linear regression analyses were conducted to examine drivers of heterogeneity in the species composition of fisheries and aquaculture production. Predictor variables included biophysical, governance, social and economic indicators, such as sea surface temperature, human population, and government effectiveness.
We find a larger average Herfindahl index for aquaculture compared to fisheries production indicating that the nearly equivalent amount of seafood produced by aquaculture is significantly less diverse and concentrated within fewer species groups. This implies that aquaculture has surpassed the productivity constraints of natural fisheries resources and can achieve larger within-species production scales . This has important implications for producing an overall greater supply of seafood and maintaining seafood accessibility among vulnerable populations.
Linear regression analyses indicate that Population and Government effectiveness are positively related to species diversity in fisheries whereas biophysical variables are of greater importance to species diversity in aquaculture. Implications on the role of blue foods in future food security will be discussed.