The fact that nearly three quarters of the world´s fisheries are dangerously close to depletion makes aquaculture seem like our only chance at meeting the ever-growing demand for seafood. But it takes fish to grow fish: Most of the fish meal used in today´s aquaculture feed is made from small, oily specimens such as anchovies and sardines. A huge load of these â€forage†fish-roughly a third of the global catch-is turned into fish meal every year.