#234572 - 03/02/04 12:46 AM
Re: broodstock programs
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Anonymous
Unregistered
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There is good and bad in it as everything else.
In a perfect world we wouldnt need any hatchery fish and that would be best.
But the world isnt perfect.
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#234573 - 03/02/04 01:37 AM
Re: broodstock programs
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Ornamental Rice Bowl
Registered: 11/24/03
Posts: 12616
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posted by Todd Supplementation programs are designed to help the wild runs by creating hatchery fish that are very similar to the wild fish, hoping that they will spawn in the wild with both the wild fish and their hatchery broodstock brothers and sisters. These fish are not created for harvest...they are created to help out ailing runs that do not have sufficient numbers to keep themselves going. The more I look into this issue the less inclined I am to believe that a wild broodstock program can be justifiably used for "supplementatiion" as Todd defined it. A wild run that is so depressed that it is just at or below escapement goals will produce relatively few juveniles that in turn hatch into a habitat of relative abundance. Egg to smolt survival is exceedingly high under such conditions. The fish really don't need the "help" of a hatchery during this lifestage. The data indicates that the number of returning adults will be maximized if the wild fish were just left alone in the first place. The only exception I could forsee is if the habitat is "rearing-limited" to the point that even the few naturally-produced juveniles can't be supported by the "limited" habitat. A broodstock program could buy a little time until the habitat conditions can be improved. To make it work, none of the broodstock progeny would be clipped (can that even be done legally now?)... the returning brood fish would be allowed to mix with the wild fish on the spawning gravel to help bolster numbers of "wild" fish. Clipping the juveniles would make no sense in this scenario since that would just render the returning adults vulnerable to harvest. You know, back to that scenario of mining eggs to support a harvest fishery.
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"Let every angler who loves to fish think what it would mean to him to find the fish were gone." (Zane Grey) "If you don't kill them, they will spawn." (Carcassman) The Keen Eye MDLong Live the Kings!
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#234574 - 03/02/04 02:26 AM
Re: broodstock programs
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Ornamental Rice Bowl
Registered: 11/24/03
Posts: 12616
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WRoutlaw When I first started this thread, I was not limiting this discussion to steelhead only... I was questioning the wisdom of broodstock programs for any anadramous salmonids. I would not be so quick to discount the Chilcote findings on the coho wild broodstock program I referenced. Similar observations have been made for hatchery steelhead from wild broodstock as well. hatchery:wild steelhead don\'t mix "These results confirm that hatchery fish are maladapted for reproductive survival in the natural environment. This confirmation is robust and applies to hatchery fish regardless of hatchery broodstock origin and various attempts to mimic the genetic and reproductive characteristics of wild fish. Further, it appears supplementation of depressed wild populations with hatchery spawners is an ineffective conservation strategy."
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"Let every angler who loves to fish think what it would mean to him to find the fish were gone." (Zane Grey) "If you don't kill them, they will spawn." (Carcassman) The Keen Eye MDLong Live the Kings!
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#234575 - 03/02/04 10:42 PM
Re: broodstock programs
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WINNER
Registered: 01/11/03
Posts: 10363
Loc: Olypen
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This is exhausting, but I'll try it once again (likely not the last time, however). Very simple question. Why are we not introducing Broodstock FRY back into our streams? Did I not read that the report says that the hatch rate is 20 to 30 times higher than when naturally spawned? The only response I have gotten previously was that fry do not do well upon release. OK, but we would have 20 to 30 times as many fish to introduce. Seems to me like the release could be screwed up and still be far ahead of natural spawn. Plus, I suspect that there has not been much effort put into finding out HOW to introduce fry with a low mortality rate. I have no idea WHY the State wouldn't want to find out a good way to release the tiny fellas. It appears that everything is geared for smolt stage transfers......and to me that methodology doesn't seem to work very well with it's hatcherized offspring. Fry do not seem to exhibit the same characteristics as the long held smolt, and it seems logical that they would more likely develop survival methods similar to naturally spawned fry. Fry would have the advantage of not being crippled by long term exposure to the unchanging, nonthreatening environment of hatcheries. There would be no need to clip them, as they would be truly WILD fish, only hatched by man. Not long ago I was wrangled into a long weekend in Leavenworth, and during my stay, visited the Chinook hatchery there. The salmon fry would "spook" as I walked by the raceways. Seems like a healthy survival instinct at that stage. Quite different from what I have observed at numerous hatcheries, once the fry reach par and then smolt stage. They swim up to passersby as a potential benefactor of food supply. I really, really think we are missing the boat here, guys. Ok, I'm done......again.
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Agendas kill truth. If it's a crop, plant it.
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#234576 - 03/02/04 10:56 PM
Re: broodstock programs
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Dick Nipples
Registered: 03/08/99
Posts: 27838
Loc: Seattle, Washington USA
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Fun5,
I think that it is a somewhat economic decision to not plant fry...though there would be a higher egg to fry survival, the fry to smolt survival AT BEST would be the same. The difference we're talking about here, since fry to smolt survival is a very, very low percentage even at the best conditions, is only a few fish.
To put the money into collecting wild fish, spawning them, raising the eggs to fry, and then releasing them would be prohibitive when compared to the return on the investment, which would be literally a few fish.
FishDoc,
I think that the reason they would use that type of supplementation program on the Wenatchee River, and others that are similarly situated, is that the number of dams the fish have to traverse would mess up the usual high productivity that fish have at low densities.
In a normal river a run of ten wild fish might produce 20 or 30 adults, assuming that habitat is not the limiting factor.
In the Wenatchee a run of ten fish might all be killed by the first dam they reach, not to mention the other several they have to go by before they reach the river.
While the rule of higher productivity at lower densities is generally true, there comes a point where the density is so low that anything less than perfect can spell E-X-T-I-N-C-T-I-O-N.
Rivers like the Wenatchee and others in that part of the Columbia are using supplementation programs like that, and I believe that is the reason why. I don't think that they are using them to do that in any other situation, though some folks who operate or help out with broodstock programs think that they are, when they are actually just producing a higher quality hatchery fish to harvest. Not a value judgment on whether or not that is good, just a factual statement on what is actually going on.
Fish on...
Todd
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#234577 - 03/03/04 12:39 AM
Re: broodstock programs
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Fry
Registered: 03/02/04
Posts: 36
Loc: Longview, Washington
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#234578 - 03/03/04 02:41 AM
Re: broodstock programs
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Spawner
Registered: 10/26/02
Posts: 908
Loc: Idaho
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Originally posted by fishNphysician:
"These results confirm that hatchery fish are maladapted for reproductive survival in the natural environment. This confirmation is robust and applies to hatchery fish regardless of hatchery broodstock origin and various attempts to mimic the genetic and reproductive characteristics of wild fish. Further, it appears supplementation of depressed wild populations with hatchery spawners is an ineffective conservation strategy." [/QB] Some of the sources of potential error that need scrutiny include: reliability of detecting wire in returning adult fish with present technique (wanding of un-anesthetized fish), errors in estimating smolt migrants because of temporal variations in spill at NF dam and the associated reduction in gear efficiency, and wild adult recruitment from smolt production in areas other than above NF dam. I am sure there are other estimating problem areas; hopefully with the help of others we can complete and critique a full list of them. Wrong time over the dam and alot of the smolts die. And there are fish that spawn in the lower clackamas.. below all of the damns. Secondly that statement i quoted above of yours has nothing to do with the True Broodstock programs that they are trying right now on other rivers. He is refering to the standard "hatchery brat". If you have ever caught a True broodstock fish then you could instantly see the difference. its a whole different creature.
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Facts don't care about your feelings..
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#234579 - 03/03/04 04:34 AM
Re: broodstock programs
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Fry
Registered: 03/02/04
Posts: 36
Loc: Longview, Washington
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willametteriveroutlaw, I thought I read in there that one of the twelve rivers was the Umqua and they were using broodstock summer steelhead? The Clack never had broodstock until recently. Well I got Charlie Corrarino's phone# late this afternoon and will call him tomorrow/today and ask him if anything is being done regarding broodstock studies and if not I will plead my case with him for this very important study to take place ASAP. I'm confident that the same results will apply. Dano
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#234582 - 03/03/04 11:18 AM
Re: broodstock programs
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Fry
Registered: 03/02/04
Posts: 36
Loc: Longview, Washington
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willametteriveroutlaw,
Sounds like broodstock hatchery fish to me. Sure you were reading the correct report? I didn't remember the Clack being in that particular report.
Using the geographic groupings described earlier, each population was assigned a corresponding value for the variable (Gr). The value for this dummy variable was .-1. if the population belonged to the Snake region, .1. if the population belonged to the coastal region, and a value of .0. if the population belonged to either of the other two regions. A dummy variable was also used to represent the type of hatchery broodstock (Br). The value for Br was .1. if the hatchery fish returning to the basin were predominately from broodstocks developed from wild fish also from the same basin. All other populations (whether or not they had hatchery programs) were given a value of .0. for the Br variable. For both dummy variables, the number of values was purposely set to one less than number of possible categories in order to help avoid multicollinearity. Prior to regression analyses, those data points for which the value for Ln(R/S) deviated from the mean by more than 3 standard deviations were discarded.
Genetic differences may arise from the common situation that returning hatchery fish are the offspring of substantially fewer parents than is the case for wild fish returning to the same basin. For example, approximately 160 fish are used annually as broodstock for the North Umpqua summer steelhead hatchery program. In contrast, the number of wild fish that spawn naturally in the North Umpqua basin is typically greater than 3,000 fish (Appendix 1). Therefore, the genetic base for the hatchery return is approximately 80 families, whereas for the wild fish it is roughly 1,500 families.
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#234584 - 03/03/04 05:16 PM
Re: broodstock programs
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Spawner
Registered: 10/26/02
Posts: 908
Loc: Idaho
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Dan I responded to those on the other board.
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