Small fish such as sardinella are an affordable source of protein and essential nutrients for millions of people across West Africa.
Authors
- Wesley Malcorps
Research Fellow, Institute of Aquaculture, University of Stirling
- Richard Newton
Lecturer in Aquaculture, University of Stirling
- Umair Choksy
Senior Lecturer in Management, University of Stirling
Some of these fish are increasingly exported or processed into fishmeal and fish oil for aquaculture feeds used in high-income European countries and across East Asia, particularly China. As nutrient deficiencies are common in people living in parts of West Africa, retaining more fish for local consumption could help improve diets and address dietary health problems.
Aquaculture is one of the world’s fastest-growing food production sectors . Despite its growth in the last three decades, global wild fish catches for marine ingredients have declined overall. Production has increased in some regions, including West Africa, but the overall decline is mainly due to improved fishery management that allows recovery of fish stocks.
Globally, a quarter of wild-caught fish are processed into fishmeal and fish oil, and only a small share originates from West Africa. Most is used in animal feed, with aquaculture accounting for the largest share . These provide valuable nutrients , particularly in early-life-stage diets and for carnivorous species such as salmon and shrimp, while contributing to the relatively low carbon footprint of farmed seafood.
The supply of marine ingredients is highly regulated and fairly stable but should not be taken for granted. Climate change and warming periods such as El Niño can weaken the upwelling of nutrient-rich waters from the deep sea. This reduces the availability of plankton and fish and limits the supply of marine ingredients required for aquaculture.
This means we need to make the best use of the resources already available. Fish processing by-products (including heads, guts and skeletons) are playing an increasingly important role, accounting for 34% of global fishmeal production and 54% of fish oil supply in 2024.
A new era of supply chain risk
Marine ingredients from potentially unsustainable sources have slipped through the net despite responsible sourcing claims. One 2025 investigation found that certified Turkish-farmed seabass sold by major retailers in Europe was fed fishmeal sourced from three factories in Senegal that have been linked to food insecurity and job losses in local communities.
One way to reduce risk in aquaculture feed supply chains is to source ingredients domestically. But this is easier said than done. Aquafeed supply chains are dependent on the global trade in marine and terrestrial ingredients and thus face challenges related to scale, cost, nutritional quality and environmental sustainability .
While marine ingredients can be sustainably sourced and continue to be essential to the global food system, it’s important to use them in efficient ways that maximise their contribution to human nutrition. Certification programmes currently focus on ensuring that fish are caught or farmed responsibly. The environmental and social safeguards include stock status, environmental footprint and making sure workers are treated fairly.
The certification programmes pay less attention to food security and critics argue they favour export markets and corporations over local communities. As a result, calls are growing for broader measures of what constitutes truly sustainable and ethical seafood.
Use nutrients wisely
Some scientists argue that fish, such as anchovies and mackerel, provide more essential nutrients when eaten directly rather than used as feed. Most species used in the marine ingredients industry have low market appeal and limited consumer demand, meaning that diverting fish from feed to food does not automatically improve food security .
Peru’s anchoveta fishery is the world’s largest fish stock used to produce marine ingredients. Despite its scale and nutritional value, there has been low demand for anchoveta as a food fish within Peru. Factors such as low demand, short shelf life, limited logistics and strong economic incentives to process fish into fishmeal and fish oil have often hindered the development of markets for some fish as food . Strategic use of some fish as feed can help convert marine resources into nutritious and accessible seafood.
To make the most of limited marine resources, the aquaculture industry could improve how it tracks fish and nutrients as they are transformed into farmed seafood. We have developed a novel peer-reviewed performance tool that provides a common sustainability language . At the heart of the tool is the Fish In: Fish Out (Fifo) ratio, a measure of how efficiently fish, and the omega-3 fatty acids they contain , are converted into farmed fish.
Efficiency can be improved by increasing the use of fish processing by-products that are not normally eaten by people and by strategically replacing certain marine ingredients with alternatives such as algal oil and insect meal. The tool is currently being used by a variety of organisations like feed and ingredient companies, farmers, environmental charities, and researchers.
Applying the tool in our latest study already challenged conventional thinking about marine ingredient use in aquaculture. Although Faroese salmon is often viewed as a major consumer of marine ingredients, we found it was actually a net producer of edible omega-3 fatty acids. This was achieved by upcycling valuable nutrients from inedible sources (fishery by-products) into a nutritious farmed product, without increasing the need for fish that could be consumed directly by humans.
Making the most of limited marine resources is important, but decisions made in one country can affect food availability and affordability elsewhere. Therefore, harmonising nutrition-sensitive policies across local, national and regional levels is crucial to achieve meaningful outcomes . Traceability systems can play an important role, but they must do more than track supply chains.
They can only make a meaningful difference when they empower local communities through greater participation in decision-making and improved market access. They should support those closest to the resource, rather than treating them simply as sources of data for downstream companies. In West Africa, this could include retaining a proportion of the catch for local consumption and improving the cold chain to support its distribution.
These approaches would enable the marine ingredients and aquaculture industries to operate effectively. They would also contribute more to global food security, the economy and the supply of nutritious seafood to consumers.
