Coho – Hatchery production of coho usually involves incubation in stacked trays and rearing in concrete or earthen channels to the smolt stage of 15-25 g for release in the spring. This requires incubation and rearing for 1.5 years in fresh water, as is the normal condition for most naturally-produced coho.
Chinook – Chinook culture uses the same basic techniques as coho production but, because some chinook projects handle very large numbers of fish, there is more use of bigger containers (bulk incubators, large raceways). Smolt size is much smaller for chinook (3-8 g) than coho, so incubation and rearing can be completed for spring release the year following spawning, as is common for coastal and southern chinook stocks. Most non-coastal stocks are reared for a year (to 15-20 g) in freshwater, as is the condition for naturally- produced inland chinook (Healey 1991).
Chum – The Japanese hatchery technique for enhancing chum salmon involves bulk incubation to the eyed stage, placement in gravel-lined channels until swim-up, then rearing in concrete raceways to the 1-3 g size for release in the spring. Naturally-spawned chum salmon normally migrate to estuarine areas immediately upon emergence from the gravel, but a short term of feeding in freshwater has been shown to give a substantial increase in marine survival.
Pink – Because pink salmon migrate to the ocean immediately upon emergence from the gravel, SEP enhancement of pinks has usually involved only provision of 9 incubation assistance; either in a spawning channel or in bulk incubation boxes in hatcheries, with no feeding prior to release. Some short-term sea-pen rearing has improved survival of some stocks.
Sockeye – Most SEP sockeye come from spawning channels, where only the physical conditions for natural spawning and incubation are controlled to increase spawning and incubation success. Sockeye hatchery projects have used bulk and tray incubators, rearing raceways and (freshwater) net pens, usually releasing at 1-2 g size.