Smalma may have had limited time this morning, but here's a copy & paste of his posts on the topic in another forum:

Yes it is indeed the case that male steelhead have a more protracted spawning time than the females. That said the period that those males actually remain viable spawners is shorter than many think may be the case. In the Saltonstall-Kennedy Skagit steelhead study that we all discussed some time ago the radio tagged wild steelhead had vacated the spawning areas on the average within 28 days of spawning. It probably is the case when those fish left the spawning area they were no longer viable spawners. However in keeping in trying to assure that we err on the side of the wild steelhead I will assume that some males (a small portion of the total population) remain potential viable spawner for 6 weeks after the last female has spawned. In the case of Chambers Creek males that would mean the latest there would be a viable spawer would be mid-March. A timing such that there would only be a fractional of a percent chance of a hatchery fish spawning with a wild fish.

Just for fun let's look at the real world and see if that 6 week period is a reasonable assumption. As we know in North Puget Sound rivers wild winter steelhead spawn into July. Using mid-July as the date of the last female spawner we would expect to see viable male spawners through August. If the males were viable longer than that as some to think that would mean those viable males would still be in the river looking for mates after labor day. Wonder how many of you have caught such a fish in September (remember in rivers like the Skagit the wild fish are much more abundant than hatchery fish) so those late spawning should be much more common than late spawning hatchery males. I suspect like me that answer to the number of viable male wild spawners that you have encountered in late August or September is zero!

Why would we assume that hatchery fish would be viable for longer periods than the wild fish?

There is no reason that those few residuals that survive that first year in the river that some would become smolts and migrate to the salt and some others that survive until maturity return to the hatchery rather than spawning in the wild. However in these kinds of discussions the tendency is to ignore such behaviors because by assuming that those survivors spawned in the rivers is consistent to be erring on the side of the wild resource.

an we be absolutely sure that there are no interactions; of course not. The real question are those frequency in which those interactions like to be producing significant interactions? Or if you will it becomes a risk assessment game. I argue that the very limited nature of those inactions do not represent a significant risk and attempted to show why I feel that way.

Not sure how much hatchery active/history you are looking for. There has been hatchery steelhead activities in basin like the Skagit for more than a century. I can certainly summarize that history though I'm not sure how relevant that would be. The evolution of the steelhead hatchery program has been of constant adaption and evolution with the critical factor being what has happened in recent years and is expected in the immediate future.

Let's take a closer look at what having 25,000 non-migrating smolts might be. First let's remain for more than 60 years in the Chambers Creek steelhead program any fish that mature early or did not migrate and return form the salt have been severely selected against - they are not included in the brood stock. This is much different than integrated programs like that of Little Sheep Creek where wild fish are incorporated annually into the brood stock. That alone may explain why frequency of male mature smolts in such programs are higher than in programs like Chambers. By any out of 25,000 fish that did migrate I would expect at least 90% would be gone within months of release (on water observations seem to support that). That would mean that going into the winter there might be 2,500 of those fish still left. For wild fish over winter mortalities are in the 50% range. Going into that second summer we would be looking at 1,250 hatchery parr. For the wild steelhead population where best guess puts the average number of wild smolts something in the 100,000 to 150,000 per year or about 200,000 to 300,000 parr per year.

That means only a 0.5% of the steelhead parr would be of hatchery origin. Is that excessive? That is each of our calls though that estimate is mostly likely on the high side. On continue that math exercise to the end point of any survivors interacting with wild spawners but that becomes such a low number to essentially be meaningless (though to be fair there could be a fish or two). I agree with your assessment that such impacts are a drop in the bucket compared to other potential hatchery/wild interactions.

In the video the second major Chambers Creek impacts discussed was the attraction of an artificial number predators to the system. Since both WW and TallFlyGuy have also mentioned this issue let's take a closer look at this issue. Again I will focus on the Skagit and will talk in rough round numbers for this year's smolt out migrations in the basin. As we all know the current Chambers Creek smolt release target is 239,000.

Every spring in the Skagit between the wild steelhead, sea-run cutthroat, and bull trout smolts leaving the river is roughly the same as the hatchery release.

The number of sub-adult and adult sea-run cutthroat and bull trout leaving the system is roughly 1/3 to 1/2 of the hatchery steelhead release.

The number of hatchery Chinook and coho smolts leaving the system is 2 or 3 times of the numbers of hatchery steelhead releases.

The number of Baker sockeye smolts leaving the system is roughly 3 times the number of hatchery steelhead smolt #.

The number of wild coho leaving the system is typically 4 or 5 times the number of hatchery steelhead.

The number of wild Chinook migrants leaving the system is typically 8 to 10 times the number of hatchery steelhead.

The number of wild chum likely will be 4 times of the number of hatchery steelhead.

The number of wild pinks will be in the 40 to 80 times more numerous that hatchery steelhead.

In other words there will be pretty good numbers of salmonids (the majority of which are wild) migrating out the basin this spring.

In terms of attracting predators we probably should consider a couple of the other native species that can be fairly common in the basin. In the tidal section of the river there are surprising numbers of peamouth chubs and every year at this time there is a run of smelt spawning in the lower forks of the Skagit (some years the numbers of smelt are significant - most of which die after spawning and provide significant foraging opportunities). In addition there are quite few whitefish to be found through out the Skagit and Sauk.

Can any one say that whether the hatchery steelhead programs continues or not there would be significant difference in the forage base supporting potential predators?

Since yesterday I have been thinking a bit more about Cruik"s question of about whether we should expect mature residuals to return to the hatchery. While it is always dangerous when I start thinking about things and my thoughts often end up weirdly the more I thought about it the more I think he hit on a very important point. We know both anadromous and resident O. mykiss have demonstrated a strong tendency on reaching mature of returning to their "natal" home. We should expect maturing "residuals to do the same.

Any steelhead smolt residuals upon reaching maturity should be in that 14 to 18 size range or about the size of steelhead "jacks". Fortunately most of the hatcheries have both the ability to trap and keep track of the numbers of "jacks" returning (and captured) at various hatchery facilities. While the number of "jacks" returning to a steelhead hatchery would likely include true "jacks" and residuals the raw counts should provide us with the opportunity to look at the magnitude of the numbers of residuals surviving to maturity. Based on comments seen this and other discussions the range of residuals potentially reaching maturity ranges from 1,000s to 100s or if they survive at the rate of their anadromous siblings maybe dozens with the hatchery rack counts providing us insights into where in that range where the numbers might actually fall.

To explore those numbers I visited WDFW's hatchery escapement reports for the last 5 years at looked at the total adult returns as well as the "jack" numbers for both the Skagit and Snohomish systems (by far the two largest Chambers Creek programs in Puget Sound). What I found is that over the last 5 years 1,096 adults and zero "jacks" where trapped on the Skagit and 5,064 adults and 1 "jack" was trapped on the Snohomish system. I will leave it to the reader to decide what sort of survival to maturity rates those residuals are experiencing.

I have attempted to limit my comments in this thread to the issues raised in the McMillian Chambers Creek video. He specifically mentioned the potential hatchery/wild interactions off smolts that were sexually mature as smolts, residuals surviving to maturity, and the numbers of hatchery steelhead smolts attracting predators and used the Skagit as an example.

I think I have demonstrated:

1) With a early/mid-May release of the smolts any sexually mature smolt would be approximately 4 months past reaching maturity and are no longer viable spawner for the current spawning season.

2) Because of the general lack of fitness of the hatchery fish and the extreme hydrograph of the Skagit the long term survival of any residuals is very low approaching zero.

3) On the Skagit the total numbers of [potential prey in the spring on the Skagit dwarfs the contribution by hatchery steelhead. It is doubtful that those hatchery steelhead are attracting significant numbers of additional predators.
---------------------------------------------------------------------------------------------------

I'm acquainted with Bill McMillan and have much appreciation for his passion for and depth of knowledge about steelhead. That knowledge doesn't make him right about everything, and in that video he makes several gross over-generalizations relative to the effects of Chambers Creek hatchery fish on wild steelhead.

Sg