Eggs are selected from only the highest quality salmon and incubated in fresh water. Young salmon are allowed to develop in fresh water for about 1 year. They are then transferred to salt water cages. A typical cage holds 10 tons of salmon. A controlled diet of fish meal, processed from herring, is the main food for farm raised salmon.
Feed is regulated by body size and water temperature.
There is a 1 to 1 ratio of meal to product produced. In other words, a pound of feed will produce a pound of salmon. Salmon farming is a very efficient use of feed compared to land based farming. Harvesting of farm raised salmon is coordinated with market demand. A week before harvesting feeding stops, this produces a firmer meatier salmon.