Keith,

"Same" was not the best choice of words. "Similar" would be better. A "good" return to a LCR tributary like the EFL will correspond to a "good" return on the WA coast, PS, Van. Is., and lower BC coast. Correspondence dissipates by geographical region when their respective steelhead populations migrate to differing ocean foraging areas.

Straying does happen. But there are two different kinds of straying, and their difference is important. The first is the one that concerns you, where a hatchery steelhead strays into some part of the natural environment and spawns with a wild steelhead, thereby diluting the reproductive fitness and productivity of the wild fish. Chambers Ck hatchery winter steelhead do this, and the effects vary. They vary depending on whether there are any wild steelhead in the same place at the same time as the ripe hatchery fish. The presence of early timed spawning wild steelhead is usually associated with tributary streams with lower elevation headwaters. These instances are reported to occur more in LCR tributaries, Willapa tributaries, and too a lesser degree, along some WA north coast streams. The remainder of the coastal and PS watersheds headwater at higher elevations and a later spawn timing that does not coincide with Chambers spawn timing.

This is not to say that there is no genetic introgression of Chambers DNA in these populations of wild steelhead. Rather, the amount of such introgression is exceedingly small. At first by coincidence, and later by design, Chambers steelhead DNA has remained mostly absent, that is, occurring at a very small percentage, in PS wild steelhead populations, even though Chambers Creek itself is a south PS tributary stream.

One of the best examples of the inability of Chambers Ck steelhead to successfully interbreed with wild steelhead is lower Cowlitz River tributaries. the old WDG deliberately stocked literally millions of these Chambers Ck hatchery steelhead fry into 3 or 4 lower Cowlitz tributaries for several years. If ever there was an opportunity for these hatchery fish to swamp a wild population and become the dominant genetic type present in a stream, these were it. Comes now the Cowlitz steelhead genetic study, dated about 2010, and low and behold, while Chambers Ck DNA was present in wild steelhead in these tributaries, it was present at a very low level, with typical lower Columbia wild steelhead DNA being the dominant genetic presence. I think that this tells us that the selective breeding of the Chambers Ck hatchery steelhead made them very unfit to reproduce naturally in natural stream environments. And while they may have compromised the fitness of any wild steelhead that they spawned with, their long-term damage to such populations appears to have been minimal.

I mentioned there are two types of straying. The second is very common, especially with summer steelhead like you have experienced on the N Lewis. Summer steelhead dip ins happen all over the lower Columbia. The Columbia River runs warm in the summer, and the tributaries are cooler. So summer steelhead dip into various tributaries, like the N Lewis, Cowlitz, Deschutes (until recent years, when the Pelton-Round Butte tower came on line) to avail themselves of the cooler water temperatures. You should know about the Kalama Falls hatchery, where summer runs were Floy tagged and passed upstream. Then, when the fall rains came, those tagged fish that were strays backed downstream to the Columbia and proceeded upstream to the tributary streams that were their natal waters.

I think the same thing happens on the coast, where summer steelhead have sometimes shunned the Columbia, only to temporarily ascend the Hoh or Queets - that have cooler water - and stay for a while and later disappear. My hypothesis is that they eventually enter the Columbia and migrate to whatever tributary they originally came from, but I don't have the data proving it. The upshot is that while summer steelhead do stray into and spawn in non-natal waters, most of them don't.

I think your hypothetical straying by steelhead into BC tributary streams falls into this second category, where they dip in but most don't stay to spawn. To reiterate, I completely agree that hatchery steelhead don't give any favors to wild steelhead. However, suggesting that hatchery steelhead are the proximate, i.e., the number one, cause of depressed wild steelhead populations is very badly misplaced.