Cncfish,

Your question regarding the "not statistically different from zero" success of hatchery fish spawning in the natural environment has been covered here before, but a refresher may be helpful. The above quote applies more to some hatchery stocks than it does to others. Chambers Creek hatchery winter runs are the best fit to the quote because they are notorious for not producing NORs (Natural Origin Recruits). But even Chambers Ck have experienced some success since their genotype is found in varying degrees (from zero to fairly high) in some wild steelhead.

A major reason for their near "zero" success is because Chambers Ck steelhead have been specially selected for their early return timing and especially their early spawning timing. This places them out of synch with normal spawn timing of wild steelhead, which reduces the incidence of H x W matings. It also places them out of synch with normal steelhead fry emergence timing. Since spawn timing is very closely correlated with survival, being out of synchrony is not a good thing.

Hatchery fish in the Cowlitz have been transported to the upper basin upstream of the dams. Spring chinook, coho, and steelhead. Coho have been most successful, but most of us expected that because coho are the easiest of the salmonids to work with. They seem to adapt more easily than the others. Wild coho can be taken into hatchery environments and domesticated more readily than spring chinook or steelhead. On the flip side, hatchery coho can be stocked in the natural environment where they more readily re-adapt to natural conditions.

With regard to steelhead, the Cowlitz hatchery cultured both early-timed Chambers Ck steelhead and late timed steelhead that originated from native Cowlitz stock. Over the decades there was overlap and some mixing between the two, but the late timed steelhead still show a genetic difference from Chambers Ck fish. The late timed hatchery steelhead were chosen for re-introduction into the upper basin for this reason. They have reproduced successfully, and as generations go by, they should be as successful as normal wild steelhead that have no hatchery lineage.

The spring chinook, similar to steelhead, have been slower than coho to re-adapt to natural production, but wild springers are also regularly returning. Of course, getting the long-delayed juvenile fish passage facility installed will give natural production the biggest possible boost to the upper Cowlitz re-introductions.

Sg