Blue foods, derived from aquatic environments, play a significant role in the economies, livelihoods, nutritional security, and cultures of numerous nations. Often nutrient-dense and generating lower emissions and environmental impacts than many terrestrial meats, they contribute significantly to the well-being and livelihoods of rural communities. However, despite their importance, blue foods have been largely absent from many contemporary food system discussions and policies focused on both nature-positive and nutrition-positive outcomes. When included, their representation is often oversimplified, reducing them to a few fish types in dietary recommendations and demand projections. Ocean policy frequently neglects blue foods' contribution to human nutrition and the benefits to the communities that produce them. A deeper understanding of blue foods' roles is crucial for informing policy development that harnesses their unique capacity to address nutritional, social, and environmental food system challenges, while navigating the inherent trade-offs within and across countries. Blue foods encompass an immense diversity—over 2,200 wild species are caught and more than 600 are farmed, with wide variations in production and processing systems. National aquatic food consumption profiles also show remarkable diversity. This diversity influences blue foods' contributions to human health, nutrition, jobs, culture, and their environmental impacts. Social structures exacerbate existing inequalities across socioeconomic and geographic contexts, affecting the resilience of blue food systems. This paper integrates findings from the Blue Food Assessment, translating them into four policy objectives to leverage the positive contributions of blue foods to global food systems.

The paper draws upon the findings of the Blue Food Assessment, a comprehensive initiative involving over 100 scholars across various disciplines. This assessment investigated the nutritional contribution of blue foods, current and future demand, environmental impacts of blue food production, vulnerability to environmental stressors, the characteristics of small-scale fisheries and aquaculture (SSFA) actors, injustices within the blue food system, and climate risks to blue food systems. The assessment synthesized key dimensions characterizing small-scale fisheries and aquaculture (SSFA) actors—who produce two-thirds of aquatic foods—and evaluated injustices to identify policy attributes supporting equitable access to blue food benefits. Previous research on the nutritional content of blue foods, their environmental impacts, and the role of small-scale fisheries and aquaculture is also integrated into the analysis. The multi-perspective assessment, combined with existing literature, provides a unique and detailed understanding of the diverse functions of blue foods and how these can be leveraged for food system transformation.

The study employs a multi-faceted approach to analyze the role of blue foods in achieving global food system ambitions. It begins by identifying four key functions of blue foods: (1) sources of critical nutrients (vitamin B12 and omega-3 fatty acids), (2) healthy alternatives to terrestrial animal-source foods (particularly red meat), (3) nutrient sources with relatively low environmental footprints, and (4) cornerstones in cultures, diets, economies, and livelihoods. These functions are then translated into four corresponding policy objectives, aiming to leverage blue foods to address specific food system challenges. The relevance of each policy objective is assessed for individual countries using publicly available data. This involved developing a set of rules and cutoff points based on key literature and expert assessment. Data on nutrient insufficiency, blue food availability (through trade or domestic production), red meat consumption, cardiovascular disease incidence, ruminant meat intake, dietary GHG footprints, and the importance of blue foods for nutrition, livelihoods, or national revenue were used to map the relevance of each policy objective across nations. The degree of overlap between policy relevance for different objectives was also analyzed to identify potential synergies and trade-offs. An interactive website provides access to the data and allows users to adjust cutoff points to explore the sensitivity of the results. The study further explores potential co-benefits and trade-offs associated with pursuing the different policy objectives, such as the balance between domestic consumption and export revenue, and the trade-off between environmental sustainability and nutritional content of aquaculture products. Finally, the paper discusses the need for systemic food policies to address the complex interactions between different aspects of food systems and to navigate the trade-offs inherent in pursuing multiple objectives.

The study mapped the relevance of four blue food policy objectives across nations globally. Regarding the reduction of blue-food-sensitive nutrient deficiencies (vitamin B12 and omega-3 fatty acids), many African and South American nations showed high relevance, given high nutrient insufficiency and available blue foods. For reducing the cardiovascular disease burden associated with high red meat consumption, countries in the global North (with exceptions) showed high relevance, due to high red meat intake, cardiovascular disease incidence, and available blue food. A substantial number of countries displayed high relevance for reducing environmental footprints through lower-impact blue food consumption. Finally, a significant number of countries (especially in the global South), where blue foods play a crucial role in nutrition, livelihoods, or national revenue, showed high relevance for safeguarding their contributions under climate change. The analysis also revealed overlaps between policy objectives, suggesting potential win-win scenarios. For instance, reducing omega-3 deficiencies often overlapped with reducing environmental footprints. Similarly, addressing cardiovascular disease risk frequently coincided with environmental concerns. The study highlights potential co-benefits, such as simultaneously addressing malnutrition and environmental footprints through strategic choices in blue food species and production systems. The analysis also identifies trade-offs: prioritizing export revenue might negatively impact domestic consumption and nutritional security; focusing on efficient aquaculture production could compromise nutritional quality; and balancing efficiency and affordability against diversification and resilience is crucial. The interactive tool enables users to explore different scenarios and the impacts of varying cutoff points on policy relevance.

The study's findings demonstrate the diverse and context-specific contributions of blue foods to achieving global food system ambitions. The four policy objectives provide a framework for decision-makers to tailor strategies to their national contexts. The identified co-benefits and trade-offs emphasize the need for integrated and systemic food policies that consider the complex interactions between health, environmental sustainability, economic development, and social equity. The study highlights the potential of blue foods to contribute to more sustainable and healthy food systems, but also emphasizes that blue foods are not a panacea and their effectiveness depends on careful consideration of context-specific factors and the implementation of appropriate policies. The interactive tool provided allows for a dynamic assessment of policy options, enabling adaptation to changing circumstances and priorities.

This paper presents a comprehensive framework for integrating blue foods into national food system policies. The four proposed policy objectives – reducing nutrient deficiencies, offering healthier meat alternatives, lowering environmental footprints, and safeguarding climate resilience – offer a structured approach for decision-makers. The study highlights the significant potential of blue foods to contribute to healthier, more equitable, and environmentally sustainable food systems, but emphasizes the need for context-specific strategies and careful consideration of trade-offs. Further research should focus on refining the methodologies for assessing policy relevance at sub-national levels and developing more detailed, context-specific policy recommendations.

The study's analysis relies on publicly available data, which might have limitations in terms of accuracy and completeness, particularly at sub-national levels. The mapping of policy relevance is based on a set of rules and cutoff points, which, while informed by expert judgment, represent a simplification of complex realities. The assessment of trade-offs is largely hypothetical and could benefit from further empirical investigation. The focus is primarily on animal-sourced blue foods, and the contributions of plant-based aquatic foods (seaweeds, etc.) warrant further investigation.