Salmon Enhancement
Salmon enhancement, planting of (eggs/fry/smolt/ and brood stock), along with Habitat restoration and nutrient enhancement, are three elements that are necessary for salmon recovery.
Habitat restoration establishes places for salmon to spawn and rear. However, if salmon have not been spawning in that stream for years there is no "imprinting" so returning salmon will not use that stream until they have "imprinted" on that specific stream. Although salmon due stray, i.e. will spawn in a stream, they were not raised in, the stray rate is low, and with smaller salmon populations the probability of salmon straying to a newly restored stream becomes very low.
The purpose of "Salmon Enhancement" is to reestablish salmon in streams that have been restored so a naturally spawning will "imprint" in sustainable levels so salmon can once again populate that stream.
Salmon need to eat, so the eggs that we planted in the stream need nutrients to survive for up to 18 months before they go to the ocean were they mature for about four years before returning. The Link "Nutrient" in this web page discusses that element.
We plant about 1,080,000 eggs each year in 23 different sites. Volunteers accomplish much of this work. We use three types of incubators: Barrel, about 50 gallons which can raise up to 300,000 eggs, the culvert type which is used by the side of a stream which supports about 50,000, and a tray type which is placed in the stream and will raise about 6,000 salmon eggs.