Some people believe we need 3, 5, 7 or even 10 kg of wild forage fish to produce one kg of farmed salmon. This is not correct.
©Skretting
Such assumptions and calculations are based on our dependency on fish oil, not our use of wild fish. That is a big difference.
Fish oil is a by-product from the production of fishmeal. Before we started salmon farming, this fish oil was used mainly for technical purposes like fuel and hardening of fat. We believe it is better to use fish oil for fish farming.
So how much do we actually use?
To produce one kg of salmon, we need around 180 g of fish oil. To extract 180 g of fish oil, we need 2.5 kg1) of forage fish. From these 2.5 kg, we also get approx. 560 g of fishmeal, of which 180 g goes into the fish feed.
To put it simply: From 2.5 kg of forage fish, of which as much as 90% may not be directly usable as human food, you get 1 kg of healthy and nutritious salmon. In addition to this, you get a surplus of around 380 g of fishmeal, which goes into the production of more seafood.2)
In comparison, wild salmon needs to eat 10 kg of wild fish to grow 1 kg!
You can dig deeper into the calculations of the usage of forage fish here.
1) 2.5 kg is the reference figure for the Norwegian salmon farming industry, representing about 70% of the global production of Atlantic salmon.
2) In 2008, 33% of the fishmeal produced in the EU and 25% globally, came from trimmings and offal from the fish food processing industry. This represents a further reduction of the amount of wild forage fish used to produce 1 kg of salmon, as presented above, but has not been included. For more facts and details on this matter, please check out IFFO's web site.