A new study has traced the development of the widely used Fish In: Fish Out (FIFO) metric—used to assess how much wild fish is required to produce farmed fish – that can now be used to assess the retention of essential omega-3 fatty acids from wild to farmed fish.
The research highlights the need to align FIFO with Life Cycle Assessment (LCA) approaches, the methodology used for carbon footprinting and other impacts, while also reflecting broader food system goals, including sustainable provision of essential nutrients to the global population.
Crucially, the study introduces a practical step forward for the industry: an accessible FIFO Performance Tool developed by Blue Food Performance, that allows stakeholders to calculate and optimise FIFO metrics in line with industry standards and Product Environmental Footprint Category Rules (PEFCR) compliant LCAs. Building on the published study, the tool now features a major update, enabling users to compare species diets, benchmark alternative ingredient scenarios, and evaluate FIFO performance.
Integration of these outputs into broader sustainability assessments and reporting frameworks supports more joined-up, consistent, transparent, and credible decision-making across the sector.
As such, the study, led by Dr Wesley Malcorps of Blue Food Performance and the University of Stirling’s internationally recognised Institute of Aquaculture, in collaboration with the Swedish Stockholm Resilience Centre, applied the FIFO Performance Tool to track the efficiency of several current and historical aquaculture diets. It was found that Atlantic salmon farmed in the Faroe Islands and tilapia farmed in China can act as net producers of edible EPA and DHA (neFIFO <1.0). This is largely due to the use of marine ingredients derived from by-products, which most likely would not be available for direct human consumption (Figure 1).
The research builds on existing literature on marine ingredient use in aquaculture, with a particular focus on fish conversion efficiency and nutrient retention. It compares different methodologies used to assess “fish as feed” dependency and efficiency, supported by case studies across species and feeding strategies.
The findings underline the importance of optimising marine resource use within global food systems. Aquatic food production operates along a continuum that spans both fisheries and aquaculture, rather than a strict divide between the two. Maximising the availability of essential nutrients for human populations remains a critical priority.
The FIFO Performance Tool is already experiencing strong industry uptake, with over 100 users to date. This includes leading feed companies with one publishing the outputs in their 2025 sustainability impact report, as well as emerging ingredient producers, NGOs, academics and others – enabling all users to model and quantify their impact on FIFO metrics.
Fish as Food or Feed? Aligning FIFO with LCA and Food System Objectives is published in the Journal Reviews in Fisheries Science & Aquaculture
Dr Wesley Malcorps is Study Lead, CEO of Blue Food Performance, and Research Fellow at the Institute of Aquaculture, University of Stirling.
“A unified “fish-as-feed” sustainability framework moves us from fragmented, unverified claims to credible impact—through consistent measurement, clear comparability, and shared transparency. It provides the foundation for a common language the industry can scale across other sustainability priorities.”
Dr Richard Newton is LCA Specialist at Blue Food Performance and Lecturer in Resilient Food Systems at the Institute of Aquaculture, University of Stirling.
“neFIFO was the culmination of years of evolution of metrics measuring the efficiency of using marine ingredients in aquaculture. We have to become much more efficient with our resources to deliver not just food, but quality nutrition. This study demonstrating the application of nutritionally sensitive metrics shows that it is possible.”
