Wild fish consumption can balance nutrient retention in farmed fish

Wild fish used as aquafeeds could be redirected towards human consumption to improve sustainable marine resource use. Using mass-balance fish-in/fish-out ratio approaches on Norwegian salmon farming data, the study quantified nutrient retention from edible, marketable feed fish (for example, anchovies, herring, mackerel) into farmed salmon fillets. Six of nine essential nutrients had higher yields in wild feed fish than in farmed salmon, indicating net nutrient losses through current feed use. Simulations show that reallocating one-third of food-grade wild feed fish to direct human consumption, while retaining processing by-products for aquafeeds, could increase seafood production and maximize nutrient utilization of marine resources.