Wild fish are a precious resource—here's how aquaculture can bolster food security

Small fish like sardinella provide affordable protein and nutrients for millions in West Africa. However, these fish are often exported or processed into fishmeal and oil for aquaculture, primarily benefiting high-income countries like Europe and China. Despite aquaculture's rapid growth, global wild fish catches have declined due to better management of fish stocks.

Currently, a quarter of wild-caught fish are turned into fishmeal and oil, most used for animal feed, with aquaculture being the largest consumer. Global fish ingredient supply is stable but climate change and events like El Niño could disrupt plankton and fish populations, threatening aquaculture's marine ingredient supply. The industry relies heavily on by-products from fish processing for fishmeal and oil, comprising 34% and 54% of global supplies respectively in 2024.

However, not all marine ingredients are sustainably sourced. For instance, a 2025 investigation found Turkish-farmed sea bass fed fishmeal from Senegalese factories linked to food insecurity. To better utilize marine resources, the industry can improve tracking of fish and nutrients as they become farmed products. A new tool called Fish In: Fish Out (Fifo) ratio measures efficiency in converting fish into farmed seafood.

Applied in a study, the tool revealed that Faroese salmon is actually a net producer of omega-3 fatty acids, not a consumer, by upcycling nutrients from inedible sources. This approach challenges traditional views and could optimize marine resource use while improving food security and sustainability.