Critics said that fish in: fish out (FIFO) ratios for aquaculture is wasteful of fish. For instance the FIFO for salmon is 3:1 which indicates that it takes 300 grams of feed fish to produce 100 gm of farmed salmon. Salmon is just one of many farmed species.
Looking at the whole of fed aquaculture the FIFO is 0.5:1, which means that global aquaculture used just 50g of wild fish in feed for each 100g of farmed fish and crustaceans produced. It is technically possible to grow high quality salmon using a feed that delivers a 1:1 ratio of wild fish to farmed, by substituting vegetable protein and oils for fish ingredients.
Fish farmers choose wild fish over vegetables because the resulting salmon is very high in the essential omega-3 fatty acids that we need for our health. Salmon is a very efficient converter of these essential nutrients from fishmeal and fish oil. If they are fed to land animals we do not reap the same human health benefits.
