Blue food

Food systems must be transformed to end hunger and malnutrition, tackle climate change and conserve biodiversity. This collection explores what aquatic foods can bring to the table.

A person carrying a box of fish overhead walking by a bay with many fishing boats and fishermen on the shore

Credit: Camilo Pareja/AFP/Getty

Credit: Camilo Pareja/AFP/Getty

There is widespread recognition that food systems need transforming. Nearly 700 million people go hungry, with 250 million potentially on the brink of starvation. Key drivers of food and nutrition insecurity, such as climate variability and extremes, conflict, and economic slowdowns and downturns, are increasing in frequency and intensity. At the same time, food systems are responsible for one-quarter of all greenhouse gas emissions and are a key driver of biodiversity loss. Charting a course to nutritious, sustainable and just food systems requires engagement with every aspect of their functioning.

Aquatic foods are an important component of many food systems, yet have received little attention in food policy discourse. This collection shines a light on the contribution that aquatic foods can make to future food systems and the challenges that need to be tackled if these contributions are to be realized.

Blue Food Assessment

Bangladeshi women hanging fish on overhead racks for drying

Credit: Mohammad Ponir Hossain/Reuters/Alamy

Credit: Mohammad Ponir Hossain/Reuters/Alamy

Blue foods — animals, plants and algae harvested from freshwater and marine environments — supply protein to over 3.2 billion people, are a key source of nutrients in many coastal, rural and indigenous communities, and support the livelihoods of over 800 million people, the majority of whom work in small-scale systems.  Despite their contribution to food systems globally, blue foods tend to be underrepresented in discussions about how to feed the world's population sustainably over the coming decades.

The Blue Food Assessment, a collaboration between the Stockholm Resilience Centre and Stanford University in partnership with EAT, brings together over 100 researchers to explore the role that aquatic foods can play in building healthy, sustainable and equitable food systems. In this collection Nature and the Nature journals present some of the findings, along with comment and opinion pieces on the project.

Nutrition and environment

A diver swims through rows of ropes covered with growing oysters covered in sea squirts

Credit: Boris Horvat/AFP/Getty

Credit: Boris Horvat/AFP/Getty

Blue foods comprise thousands of species of aquatic animals, plants and algae. This diversity is often given short shrift in food system policies, which tend to group aquatic foods under the banner of ‘seafood’ or ‘fish’. The following articles break down the nutritional value and environmental impacts of aquatic foods by taxa, paving the way to more informed assessments of the contributions that aquatic foods can make to food systems.

The nutritional diversity of aquatic foods is explored in a paper by Christopher Golden and colleagues. They compile data on the nutrient content of 3,753 aquatic animal food taxa and show that seven categories of aquatic food, including pelagic fish, shellfish and salmonid, are more nutritious than beef, lamb, goat, chicken or pork when averaging across the seven nutrients assessed (omega-3 long-chain polyunsaturated fatty acids, vitamins A and B12, calcium, iodine, iron and zinc).  By combining the nutrient data and a food systems model they show that a sharp increase in aquatic food production by 2030 could prevent undernutrition in 166 million people. Where differences between the sexes emerge, a greater number of countries see women benefiting more than men.

Jessica Gephart and colleagues chart the environmental performance of 23 species groups of aquatic food, representing three-quarters of global production. They provide standardized estimates of greenhouse gas emissions, nitrogen and phosphorus pollution, and freshwater and land use. Farmed bivalves and seaweeds perform best.  Capture fisheries vary widely in their greenhouse gas emissions but are low impact with respect to the other stressors. Unfed aquaculture performs well for most of the stressors considered. Stressors generated by the most common fed-aquaculture species — carp, trout, salmon, catfish and tilapia — are comparable to those of chicken, the most efficient land-based animal-sourced food. Reducing fuel use and improving the efficiency with which feed is converted into biomass may represent the greatest opportunities to improve the environmental performance of capture fisheries and fed aquaculture, respectively.

Cross-sector analyses such as these allow synergies and trade-offs to be explored.  For example, investment in small pelagic fish and shellfish aquaculture — which are rich sources of nutrients  and generate relatively low levels of stressors — could deliver benefits for human health and the environment.

Greenhouse gas emissions

Nitrogen emissions
(Values are negligible for wild-caught taxa)

Phosphorus emissions
(Values are negligible for wild-caught taxa)

Freshwater use
(Values are negligible for wild-caught taxa)

Land use
(Values are negligible for wild-caught taxa)

Percentage of recommended daily dose of fatty acids provided

Percentage of recommended daily dose of vitamin A provided

Percentage of recommended daily dose of vitamin B12 provided

Percentage of recommended daily dose of calcium provided

Percentage of recommended daily dose of iron provided

Percentage of recommended daily dose of zinc provided

Drivers of change

75-year-old fisherwoman sits on her boat as she pulls her fishing net

Credit: Jihed Abidellaoui/Reuters/Alamy

Credit: Jihed Abidellaoui/Reuters/Alamy

The blue food sector is changing fast.  Demand for aquatic foods continues to grow apace while pressures from climate change mount. The small-scale actors that lie at the heart of many aquatic food systems have to grapple with these and many other challenges, including environmental degradation, economic shocks, and limited gender and social inclusion. The following articles explore how some of these pressures are likely to play out over the coming decades, and how a better understanding of the diversity of small-scale actors can engender greater support for this vital sector.

The rising demand for blue food is explored in a paper by Rosamond Naylor and colleagues. Combining FAO and World Bank data, they estimate that the demand for fish has roughly doubled since the turn of the century and will likely double again by 2050. Focusing on the top two fish consuming countries in the five continents that make up the majority of demand, they estimate that Asia will continue to lead the way in freshwater fish consumption, with the highest demand for freshwater fish in 2050. Model projections suggest that China will consume a diverse range of species including crustaceans, demersal fish and cephalopods, Ghana and Peru will continue to dominate the consumption of small pelagic fish, and France, Spain, the US, Mexico and Brazil will continue to consume a wide variety of species. Per capita fish consumption in Nigeria is expected to remain low, at one-third of the level seen in Ghana. But given the large and growing size of the Nigerian population, country-level demand is expected to exceed that of Ghana by some margin in 2050.




Climate risks to aquatic food systems are explored in a paper by Michelle Tigchelaar and colleagues. They combine data on climate hazards, exposure and vulnerability for 219 countries, and show that aquatic food systems of Africa, South and Southeast Asia and the Indo-Pacific can be expected to face high climate risk by the middle of the century under a high-emissions scenario. Reducing societal vulnerabilities, for instance by strengthening governance, promoting gender equity and reducing poverty, can lower climate risk by margins similar to meeting the Paris Agreement’s mitigation targets.

Small-scale actors play a central role in global food and nutrition security, producing two-thirds of aquatic food for human consumption and much of the diversity in produce. Rebecca Short and colleagues present a framework for characterizing the diversity of actors in this sector based on 70 case profiles spanning a wide range of geographies and systems. Actors vary widely in terms of inputs and assets, degree of specialization, the markets they serve and the type of management they engage with. Despite this diversity, commonalities emerge. Activities are controlled at a local level by individuals or groups of households. Aquaculture producers often innovate and adapt. Fisher folk tend to engage in cooperative forms of management. The cultural importance of aquatic foods also comes to the fore. Opportunities to support small-scale actors in the face of climate, environmental, political and socioeconomic change are considered.

Breaking down boundaries

Women fish with nets and a small rowing in a creek in Nigeria

Credit: Akintunde Akinleye/Reuters/Alamy

Credit: Akintunde Akinleye/Reuters/Alamy

A nuanced understanding of the aquatic food sector, with its diverse produce and actors, production processes and impacts, demands and vulnerabilities, can yield benefits for people and the planet. In order to realize these benefits, blue foods must be bought into the fold in food systems discourse and managed as an integral part of these systems.

If managed appropriately, aquatic foods have the potential to make a meaningful contribution to the nutritious, sustainable and just food systems of the future, particularly in some of the most food-insecure parts of the world.

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