Ok, a native female heads up river, then sees a nice male hatchery fish and they decide to spawn. The hatchery ,male continues up to the hatchery while the native female goes back down river. Her babies swim out to the sea without being clipped. So are they native or not? Aren't they all mixed by now? I am just wondering how they tell a true native. Will they not spawn with hatchery fish? Is there truly a 100% strain of wildfish left? I am asking this in serious mode. I am wondering if there is an actual study of native fish only spawning with other natives, or is it a survival mode either way???

No they are wild fish but not native.
Fortunately in a lot of places this doesn't happen too often because of the earlier run/spawn timing of the hatchery fish.

In SW Washington you have both the early (type S) and late strain (type N) coho and the late strain coho probably overlap and spawn with the wild coho.
Then what you got is some screwed-up coho.

That is one of the concerns with the later spawning broodstock steelhead.

No, they aren't all mixed by now?
A good report to read is Kathyrn Kostow's "Naturally Spawning Hatchery Steelhead Contribute to Smolt
Production but Experience Low Reproductive Success" and you will see that the three species on the Clackamas River were all identified using DNA and it was concluded that cross-breeding was probably at a minium or non existant since the three species didn't share the same DNA.

You can pretty much tell if it is a native by the later run timing combined with an adipose fin.
As previously mentioned DNA can also answer that question.

They don't have DNA from fish 100 years ago or so, so it is impossible to compare DNA on wild fish back then to present fish.
But as I mentioned the DNA testing done on the Clackamas wild steelhead showed no DNA from the hatchery summers or hatchery winters.

Normally when a hatchery fish spawns with another hatchery fish or wild fish in the wild it's progeny don't survive very well.

Dano

BTBW hit the nail on the head with that one. They produce "viable" fry but exceedingly few of those juveniles survive to perpetuate their lack of genetic fitness. That in itself is what has helped to considerably slow down the genetic pollution of wild stocks by hatchery fish... the crappy genes just don't have a good mechanism to perpetuate themselves.

The only problem with the hatchery:wild cross that Angg described is it wastes the reproductive potential of that wild hen for that spawning cycle. If that is the only spawning run she would survive, then basically she made no more contribution to future returns than if she had been bonked.

Should she survive to make a return trip upriver for a second spawn, she may get another chance to successfully perpetuate her genetic fitness... that is if the spawning gravel isn't overrun by a bunch of hatchery males.

Yea physician, guess it is Mother Nature's way of cleaning up the garbage we put in there.

Dano

so are you two fish bios? Where do you think the "crappy" hatchery genes come from? These fish originated from wild stock.

One more thing. Hatchery fish return in greater numbers than wild fish so where do you get that they are inferior?

think by the total numbers of hatchery fry released = more return. also the hatchery fish are so interbred and that is not good.

Thats why mutts are worse then pure breads????I can never see how the mixing of the gene pool leads to a substandard spices....I think some people make sure stuff up and others believe it.....

Pimp'n,

Every credible study ever done on cross-breeding of hatchery and wild steelhead has shown that very few, if any, of the progeny return as adults.

The info that FishDoc posted is accurate.

Do a little research and you will find all the answers to your concerns. Start right here on this BB with the "search" function and you'll find citations to all the studies.

On your question regarding hatchery fish returns, they average about 3% return rate. That means if 100,000 fish are released from a hatchery, 3,000 fish will return, on average. If a wild run produced 100,000 smolts, it would return more like 9,000 to 14,000 adults.

The reason that there are more hatchery fish is that they don't plant 10,000...they plant 300,000, or 1,000,000. Even with very low return rates that adds up to a lot of fish.

Studies have shown that hatchery fish are inferior to wild fish in these ways:

1. percentage return rate
2. predator avoidance
3. reproductive fitness
4. genetic diversity
5. diversity among life history components
6. diversity among habitat utilization

And more...those are just the high points. All the research is out there, and most of it has been referenced on this BB at some point, so it should be pretty easy to find.

Fish on...

Todd

I edited your post Todd

Aunty......you caught that, did you?

Aunty & F5A,

Where Todd said 10,000 smolts, it should likely read 100,000 hatchery smolts, ergo, a 3% return yields 3,000 adults, etc.

The jist of it is correct; wild smolts generally survive at higher rates than hatchery smolts.

Sincerely,

Salmo g.

Todd can speak for himself (and I am sure he will) but I believe his typo was the number of smolt released... should have been 100K, not 10K. That makes his assertion is accurate.

I have all ways wondered how the offspring of an offspring of a hatchery wild mix survive. I know that this is almost an imossible study to undertake but still can't help but be curious. If the grandchildren of a wild, hatchery pair survived at a higher rate then their parents that would be good for the species and then hatchery wild interbreeding would not be such a large problem. Any way I just was curious.

Is your mom also your aunt? That would explain a lot...

Just kidding dude!

Many dogs that are purebred especially if they have been inbred at some point suffer more health problems than your so called Mutt...

I think the same is true for steelhead... just imagine mating with your sister or cousin.... same principal...

Um...yeah...10K smolts produce 14K fish.

As noted, it was a typo, should have been 100K. Thanks for catching it, everyone!

And thanks for fixing it, JG. See ya tonight.

Fish on...

Todd

JR32,

They're doing that study right now down on the Kalama...they count and DNA sample every fish that they pass over the falls at the upper hatchery, and they count the smolts coming back down.

Not only can they tell you what percentage of the pairs of spawners were WxW, HxW, or HxH, they can actually tell exactly which two parents produced a smolt.

The results are pretty consistent;

WxW, HxW, and HxH all spawn and all produce smolts at a fairly equal rate.

When those smolts return from the sea as adults, they are almost entirely adults from the WxW crosses, with some HxW crosses, and statistically zero HxH crosses.

There was a thread on this study with all the important information not too long ago, I'll see if I can find it.

Fish on...

Todd

There's lots of discussion about this topic in this thread...

Hatchery/Wild interaction thread

The folks in the thread cite to a lot of studies regarding this topic, and discuss the results.

Fish on...

Todd

Hey piper!!!

Do you believe in the Bible ?

Seems to me, that I read another story that said differnt

And just what does interbreeding dogs and steelhead have to do with whether or not I believe the Bible?

the Bible is replete with incidents of brother-sister, parent-child, etc. inbreeding... but Biblical interpretation is beyond the scope of this discussion thread...