Maximising sustainable nutrient production from coupled fisheries-aquaculture systems

Aquaculture expansion is expected to meet growing demand for sustainable animal-source foods. Yet marine-fed species already require millions of tonnes wild-caught fish feed, over 90% which are nutritious food-grade species. Allocating feed human consumption could reduce pressure on marine resources while increasing seafood production. We examine micronutrient flows (the transfer micronutrients from fish) in Scotland’s farmed salmon industry, particularly reliant feeds, show that 1–49% essential dietary minerals and fatty acids available wild retained salmon. Using three alternative production scenarios we reducing feeds allocating produce more leave 66–82% the sea. global data aquaculture production, removing salmonid 3.7 Mt sea by 6.1 Mt.