Hatchery Steelhead Found Inferior in yet Another Study [Archive] - Fly Fishing Forum

: Hatchery Steelhead Found Inferior in yet Another Study


Eric
10-05-2007, 02:00 PM
_The Oregon_ featured an article today summarizing a multi-generational study of the viability of hatchery versus wild stocks of steelhead in Oregon's Hood River.

As probably everyone reading this knows, hatchery steelhead do much more poorly in the wild than their stream-bred cousins. This multi-generational study finds the hatchery stocks continue to degenerate at an accelerated rate generation to generation. Because of the increasing load of inferior genes these hatchery stocks carry, the fish are virtually useless as rebuilders of wild runs and can cause serious harm to the wild stock gene pool if any of them actually succeed in breeding with a wild fish.

The full article can be found at:

http://www.oregonlive.com/oregonian/stories/index.ssf?/base/news/119155652355280.xml&coll=7

Cheers,

Eric

flytyer
10-05-2007, 04:16 PM
Now maybe all the federal judges will agree that wild fish ought to be treated differently than hatchery ones when they are presented with this evidence.

fredaevans
10-07-2007, 01:45 PM
Now maybe all the federal judges will agree that wild fish ought to be treated differently than hatchery ones when they are presented with this evidence.

We should get so lucky. That said, there are a couple of hatchery programs (Alsea -sp? and the Rogue where eggs etc., are taken from 'wild fish' for the Hatchery program.

Eric
10-09-2007, 12:38 AM
Fred reminded me of something.

Whatever happened to those Vibert boxes we were all playing with back in the 70's and 80's? The whole idea was to create stream-bred steelhead and salmon from fertilized eggs taken from either hatchery or stripped-wild stock.

Interesting idea --

Cheers,

Eric

Smalma
10-15-2007, 10:22 AM
Fred -
This latest hatchery survival study is on point regarding those wild brood stock programs. What the researchers did was compare the survival of the off spring of hatchery reared fish that spawned in the wild.

The hatchery fish were of two groups; one group where both parents were wild brood stock (WxW). The second where one parent was a fish that was first generation hatchery fish returning from wild brood stock fish and the other was a wild brood stock fish (HXW).

What they are reporting is that the survival of the mating that included one 2nd generation hatchery fish was significant less productive than those that included only 1st generation fish (wild brood stock).

Clearly these "integration hatchery" programs that include even 2nd generation hatchery fish from wild brood stocks can result in significant reduction in the productivity of the natural spawning populations. Given the reductions between the 1st and 2nd generation I have to wonder what productivity may be found in that 1st generation as well (not tested in this study).

In short these wild steelhead brood stock programs may not be the magic solution to the hatchery problems that some had hoped. In at least some cases those mal-adapted long term domesticed hatchery brood may be less damaging to wild populations than wild brood stocks.

Tight lines
Curt

teflon_jones
10-15-2007, 11:34 AM
All I know is that I can tell the difference between a naturally- and hatchery-bred salmon or trout within 15 seconds of hooking it. The naturally-bred fish are a whole nother animal than hatchery fish! That certainly translates into better survivabilty, better genes, and a just plain better all-around fish.

Case in point: I hooked a 17-18" salmon on Grand Lake Stream earlier this year that I still couldn't land after a 15 minute battle with many 3+ ft leaps and runs all over the stream. 3 of us finally corralled it so it would stop messing up other people's fishing, and even then we had trouble. I unhooked it and it took off like a shot throwing water all over the 3 of us. That's what a naturally-bred fish brings to the picture. :D

SSPey
10-16-2007, 02:45 AM
to my understanding, they did evaluate 1st generation hatchery fish, and the result was reproductive capacity averaging 85% of that in wild fish (but not significantly different, due to year-to-year variability in the data).

I'll revisit the study when I get a chance, stored on my office computer, and repost if I've got it wrong.

Smalma
10-16-2007, 09:07 PM
Steve -
In thsi months's Science the article that I read showed that the (hxw) fish (2 nd generation) were 40% less productive when spawning in the wild as the (WxW) fish. The researches also found difference in productivity was statistically significant.

Tight lines
Curt

SSPey
10-17-2007, 12:10 AM
Smalma, I read the paper quite closely, and will share what they found. Check out the Figure in the paper where they show both original data from a number of studies of captive bred salmonids (rainbows, Atlantics, browns) and the average trendline fit to that data. In the Figure, wild fish fitness is set at 100% (as a relative index). Compared to 100% wild fish, their Hood River steelhead data show a 15% decline in fitness in the first hatchery generation. The error bars of their first generation hatchery data overlap substantially with those of wild fish, for a change that is not statistically different from wild fish in one generation. Again, this is from looking at their own data. This result, interpreted literally, means "wild broodstock hatchery programs have a measurable but non-significant effect on fitness in one generation."

On the other hand, they also fit a trendline to model the loss of fitness using a combination of their data, and data from other studies of other captive bred salmonids. They fit an exponential decline curve to all these studies. From this exponential trendline, it is correct to say that they model an average 40% (actually 37%) fitness loss across multiple successive generations of captive bred salmonids. However, it is not correct to use that model to conclude that there is an immediate 40% fitness loss in the first generation of hatchery steelhead. Why not? Because their own real data of hatchery steelhead show a fitness loss of only 15% in the first generation, even if the average loss over multiple successive generations is much higher (37%)

In contrast to the first hatchery generation, their original data of second hatchery generation steelhead show a huge fitness drop away from wild fish, statisically significant, and closer to the modeled trend line overall. This is highlighted by there own verbage in the abstract: "These results suggest that even a few generations of domestication may have negative effects on natural reproduction in the wild ...." note the use of "a few generations" instead of "one generation"

I am not trying to poke a hole in their work, nor advocate that "wild broodstock hatchery programs" have no effect on wild fish. I am pro-wild fish, the senior scientist on this paper does good work, and also happens to be a personal friend (though he is not the least bit interested in steelhead fishing!).

When I get beyond the abstract, and into the data as it will be interpreted by the pro-hatchery crowd, it becomes readily apparent that there is still some science remaining to be done on whether 1st generation "wild broodstock hatchery" programs are detrimental or not.

SSPey
10-17-2007, 12:14 AM
sorry for being so verbose ...

Mark Vegwert
10-17-2007, 12:39 AM
sorry for being so verbose ...

Don't be. That is good intel.

Smalma
10-17-2007, 02:21 AM
Steve -
Not verbose at all - in fact a very good summary of the article.

While this research doesn't answer all the questions it certianly provides so information for consideration and should cause managers at least a pause to consider how to proceed with various wild brood stock hatcheryprograms.

I agree that the earlier work on Hood River showed that the amount of domestication of a totally wild brood stock was relatively minor the first generation.

The new work here is what happens when a second generation is cultured and the impact on the productivity of natural spawning population.

The potential concerns from this work in large part depends on what type wild brood stock hatchery program is being considered/discussed. If one is looking at a "rescue" type brood stock program where the whole brood stock consists of wild fish collected annual the concerns would be entirely different than an integrated hatchery program as discribed by the Hatchry Scientific Review Group.

In such an integrated program only a portion of the annaul brood stock would be fish collected from the wild population. Typcially the recommendations was that the % of the brood stock that are of wild origin be greater than the % of the natural spawning population that is of hatchery orign. The result the portion of wild fish being introducted in the brood stock annauly is often less than 50%. This OSU research would seem to raise a red flag of concern for such programs if the concerns about the productivity of the natural spawning populations.

As always the case in the fish management world the issues are not simple and sound decisions can best be made with the best nformation available. This addition information should provide managers with some information to better tailor hatchery programs to fit specific needs.

Sorry but now I was really verbose

Tight lines
Curt

SSPey
10-17-2007, 05:09 PM
a picture is worth a thousand words ... for those interested, this is the figure that I attempted to describe


http://img.photobucket.com/albums/v45/wigspix/Slide1.gif

juro
10-17-2007, 06:23 PM
One has to wonder where mankind took such a wrong turn as to allow steelhead to become meat measurable in harvestable pounds.

The very idea of steelhead is miraculous, pure and not something that can be faked or manufactured although sadly, this is largely becoming the case.

Somewhere, somehow we lost sight of the fact that our mission as stewards is not just to ensure that a species survives, but to ensure that it thrives.

I would argue that hatchery steelhead are not steelhead. They are manufactured facsimiles unfit to survive, whose short terms in the places steelhead would otherwise thrive is welcomed only by the short-sightedness of selfish men.

To hell with hatcheries.

wrke
10-17-2007, 08:02 PM
I would argue that hatchery steelhead are not steelhead.

I know I'll get hammered for this but as far as I'm concerned it can't be a steelhead unless it's known saltwater. 30 years ago there were no steelhead in the eastern US there were plenty of lake run rainbows, large, beautiful fish that found a solid niche but now we have "steelhead" here. I occcasionally fish for those wonderful lake-run rainbows, but my steelhead come from the Pacific.

fredaevans
11-24-2007, 12:08 PM
Don't ask ....

SS, is the study on line somewhere?

Fred

SSPey
11-25-2007, 05:24 PM
no it is not available online, but check your email please.

fredaevans
11-26-2007, 10:30 AM
no it is not available online, but check your email please.

Many I ask you to resend; as I expected, the CP had an old e mail address. I've corrected same.

Fred

SSPey
11-29-2007, 12:41 AM
did the email go through this time?

millerbrown
11-29-2007, 09:37 PM
This is an interesting thread. I wonder, does this study have any relevance when it comes to the attempts to reintroduce Atlantic Salmon to New England Rivers, namely the Connecticut River Watershed. As I understand appox. 15% of fry introduced to these waters are from "current returnees" (previous year salmon). The rest are from brood stock captured and held through multiple spawning cycles.
Are we dealing with diminished viablity concerning the bulk of the fry?

Your thoughts.....

Millerbrown