Blue food demand across geographic and temporal scales

ARTICLE https://doi.org/10.1038/s41467-021-25516-4 OPEN Blue food demand across geographic and temporal scales 1234567890():,; Rosamond L. Naylor 1 ✉, Avinash Kishore2, U. Rashid Sumaila 3, Ibrahim Issifu 3, Blaire P. Hunter1, Ben Belton4,5, Simon R. Bush6, Ling Cao7, Stefan Gelcich 8, Jessica A. Gephart 9, Christopher D. Golden10, Malin Jonell11,12,13, J. Zachary Koehn 1, David C. Little 14, Shakuntala H. Thilsted4, Michelle Tigchelaar 1 & Beatrice Crona 12,13 Numerous studies have focused on the need to expand production of ‘blue foods’, defined as aquatic foods captured or cultivated in marine and freshwater systems, to meet rising population- and income-driven demand. Here we analyze the roles of economic, demographic, and geographic factors and preferences in shaping blue food demand, using secondary data from FAO and The World Bank, parameters from published models, and case studies at national to sub-national scales. Our results show a weak cross-sectional relationship between per capita income and consumption globally when using an aggregate fish metric. Disaggregation by fish species group reveals distinct geographic patterns; for example, high consumption of freshwater fish in China and pelagic fish in Ghana and Peru where these fish are widely available, affordable, and traditionally eaten. We project a near doubling of global fish demand by mid-century assuming continued growth in aquaculture production and constant real prices for fish. Our study concludes that nutritional and environmental consequences of rising demand will depend on substitution among fish groups and other animal source foods in national diets. 1 Stanford University, Stanford, CA, USA. 2 International Food Policy Research Institute (IFPRI), New Delhi, India. 3 University of British Columbia, Vancouver, BC, Canada. 4 WorldFish, Bayan Lepas, Malaysia. 5 Michigan State University, East Lansing, MI, USA. 6 Wageningen University, Wageningen, The Netherlands. 7 Shanghai Jiao Tong University, Shanghai, China. 8 Pontificia Universidad Católica de Chile, Santiago, Chile. 9 American University, Washington, DC, USA. 10 Harvard T.H. Chan School of Public Health, Boston, MA, USA. 11 Beijer Institute of Ecological Economics, The Royal Swedish Academy of Sciences, Stockholm, Sweden. 12 Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden. 13 Royal Swedish Academy of Science, Stockholm, Sweden. 14 University of Stirling, Stirling, UK. ✉email: NATURE COMMUNICATIONS | (2021)12:5413 | https://doi.org/10.1038/s41467-021-25516-4 | www.nature.com/naturecommunications 1 ARTICLE U NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-021-25516-4 nderstanding the demand for aquatic foods is critical for assessing their current and future role in global food systems. A common view is that the production of aquatic foods, referred to here as “blue foods” captured from or cultivated in marine and freshwater systems, will need to expand in coming decades to meet population- and income-driven demand. The regional and species-specific aspects of demand are often obscured, however, raising questions about the alignment of demand and supply across a diverse array of aquatic food systems. This paper examines blue food demand for multiple species groups across regions over time. Unlike other papers that present comprehensive models of fish demand and supply1–5, this study provides a synthetic analysis based on secondary data from FAO and The World Bank, parameters from published models, and case studies at national to sub-national scales to characterize the diverse and changing nature of blue food consumption. It also compares consumption patterns for fish and terrestrial meat that are potential substitutes in demand. An assessment of blue food demand across geographies and time horizons provides insight into the nutritional and environmental outcomes of changing diets, as discussed in the “Results” section. The conceptual framework for this study aligns with consumer theory6,7 characterizing blue food demand as a function of population, income, relative prices, and preferences; other household characteristics such as employment and urban versus rural residence are embedded in preferences. Consumption is determined by a two-step budgeting process wherein consumers first allocate expenditures among separate groups of goods (for example, food versus non-food) and then allocate spending within each group (for example, different types of fish or fish versus terrestrial meat). Food typically comprises a large budget share for low-income consumers, making their food purchases more responsive to changes in prices and income than wealthy consumers. Accordingly, the income elasticity of demand for food in the aggregate, a metric of the responsiveness of demand to changes in income (see “Methods”), is higher for low-income populations than for high-income populations and declines with income growth (Engel’s Law)8,9. Consumers diversify food expenditures according to price and quality as their incomes increase, spending less of their budget on staple foods and more on luxury items10. Income elasticities of demand are thus greater for high market-valued foods, including aquatic and terrestrial animal products, than for low market-valued staple foods9–11. Since some wild fish are used for fishmeal and fish oil in animal feeds, demand for fish as a feed ingredient is expected to rise with per capita income growth5. These relationships provide a foundation for assessing both time series and cross-sectional trends in blue food demand within the global food system. The availability and affordability of blue foods also influence demand12. Small island nations with an abundance of wild fish in their ocean territories record especially high per capita fish consumption (Supplementary Table 1). In other regions, particularly throughout Asia, the expansion of aquaculture has driven down real prices for farmed fish produced in large volumes, making them increasingly accessible to low-income consumers13. Meanwhile, wild capture fish have become more expensive, both in real terms and relative to farmed fish, often restricting their accessibility to wealthier consumers14–16. Our projections of future demand assume that producers are able to supply the quantity of fish demanded at constant real prices (see “Methods”), a plausible assumption given the steady growth in global aquaculture production17–19. Climate change raises significant uncertainties surrounding this assumption, however, as described in the Discussion section. Given the geographic patchiness of wild fish and aquaculture production, trade is critical for meeting fish demand in many 2 parts of the world. Fish imports are especially important in countries where per capita fish demand is rising, aquaculture is limited, and wild fish capture for domestic consumption is stagnant or declining20. Seafood is among the most highly traded commodities in the global food system21,22 and has beco (...truncated)