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Author Topic: can a hatchery become a wild  (Read 10412 times)

Dave

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Re: can a hatchery become a wild
« Reply #15 on: February 05, 2012, 06:22:34 PM »

i was involved in hatchey steelhead programs for many years......its simple , take away the enhancement and they stop returning.

a good example would be the brunette and kanaka creek in the early 90's had upwards 300-400 fish....cut the program in the late 90's and 3 years later you get 6 fish back.

it just shows the hatchery band-aid is not the solution.
Jim, seriously?   400 fish in the Brunette and Kanaka Creek in the early 90’s?? 
Who did these enumerations?
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jetboatjim

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Re: can a hatchery become a wild
« Reply #16 on: February 05, 2012, 06:33:02 PM »

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firebird

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Re: can a hatchery become a wild
« Reply #17 on: February 05, 2012, 07:58:36 PM »

The pages at the links only show the results of the steelhead harvest analysis which is based on the mail-out questionnaire to anglers. The analysis does not provide estimates of run size, only estimates of angler effort and catch. The analysis is biased for various reasons that I'm not able to explain. There are a couple of papers that discuss the issues.

I think the analysis is able to illustrate trends in effort and catch but the actual numbers are not reliable. There is nothing preventing Average Steelheaderperson from fudging (or perhaps slightly exaggerating  ;)) their submission in whatever way they want.

The only enumeration attempts on Kanaka that I am aware of (through prov govt files) are a couple of fairly recent snorkel swims that counted a couple of fish.
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Dave

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Re: can a hatchery become a wild
« Reply #18 on: February 05, 2012, 08:00:06 PM »

Thanks for that link.  Wow, 13% smolt to adult survivals in the B ... wonder when that last happened ???  Whatever, and sadly, it was the best science of the day.
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jetboatjim

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Re: can a hatchery become a wild
« Reply #19 on: February 05, 2012, 08:04:39 PM »

The pages at the links only show the results of the steelhead harvest analysis which is based on the mail-out questionnaire to anglers. The analysis does not provide estimates of run size, only estimates of angler effort and catch. The analysis is biased for various reasons that I'm not able to explain. There are a couple of papers that discuss the issues.

I think the analysis is able to illustrate trends in effort and catch but the actual numbers are not reliable. There is nothing preventing Average Steelheaderperson from fudging (or perhaps slightly exaggerating  ;)) their submission in whatever way they want.

The only enumeration attempts on Kanaka that I am aware of (through prov govt files) are a couple of fairly recent snorkel swims that counted a couple of fish.

i still have some of the old log books to show the ammount of fish that was there pre/hatch and hatch and post hatch.....heck you could go there now and see how many there are.

in the early 90's it was not uncommon to catch 5-6 fish on a morning after a rain.
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firebird

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Re: can a hatchery become a wild
« Reply #20 on: February 05, 2012, 08:24:05 PM »

Thanks for that link.  Wow, 13% smolt to adult survivals in the B ... wonder when that last happened ???  Whatever, and sadly, it was the best science of the day.

The figures for adult capacities listed for all streams on the GGBSHRP site are based on 13% marine survival which may have been the case a decade or more ago when the figures were drawn up. I think the trend over the last few years has been something like 3 or 4% marine survival for streams in the Greater Georgia Basin.

I suppose with hatchery augmentation and 13% or higher marine survival, a few hundred fish in Kanaka and Brunette could have happened.

Oh, for those glory days of the mid-late 80's again ... sigh.
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silver ghost

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Re: can a hatchery become a wild
« Reply #21 on: February 06, 2012, 12:09:20 AM »

The figures for adult capacities listed for all streams on the GGBSHRP site are based on 13% marine survival which may have been the case a decade or more ago when the figures were drawn up. I think the trend over the last few years has been something like 3 or 4% marine survival for streams in the Greater Georgia Basin.

I suppose with hatchery augmentation and 13% or higher marine survival, a few hundred fish in Kanaka and Brunette could have happened.

Oh, for those glory days of the mid-late 80's again ... sigh.

yeah totally, I saw that and laughed. 13 percent is gold! for some species on some systems which I know of, less than 1% is the norm even with hatchery aug :(

But hey - THESE are the new good old days, so conserve your catches and enjoy!
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silver ghost

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Re: can a hatchery become a wild
« Reply #22 on: February 06, 2012, 12:12:35 AM »

Fish hunter your last post is an interesting thought, so how much does this behavior decrease survival chances do you think.

Honestly, your guess is as good as mine...

Don't get me wrong, fish feed on the surface regardless - even truly wild adults, but hatcheries encourage this behaviour during every feeding event... surface-dwelling is positively reinforced by pellet feeding :/ I sometimes wonder with the hatchery only rivers if each year it takes more fish to bring back the same number of adults as the year prior because of this...but we will never know exactly, as the ocean stage remains such a mystery as to what goes on out there...
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Geff_t

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Re: can a hatchery become a wild
« Reply #23 on: February 06, 2012, 09:03:34 AM »

i was involved in hatchey steelhead programs for many years......its simple , take away the enhancement and they stop returning.

a good example would be the brunette and kanaka creek in the early 90's had upwards 300-400 fish....cut the program in the late 90's and 3 years later you get 6 fish back.

it just shows the hatchery band-aid is not the solution.


 And the government always promised us that if the fish returning fell below 20 then we would get a return in funding to start with steelhead again. Well the steelhead counts are now below 6 in the Kanaka creek and still no funding. I guess this will be another stream where steelhead are gone. On a side note the cutthroat have faired a little better.
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RalphH

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Re: can a hatchery become a wild
« Reply #24 on: February 06, 2012, 10:40:41 AM »

Yes they can become wild. Wild self sustaining populations of rainbow trout and steelhead have been established from hatchery plants in many parts of the world.

However there is evidence that hatchery fish are not as genetically able to reporduce as wild fish:

http://www.sciencedaily.com/releases/2009/...90610091224.htm

http://rsbl.royalsocietypublishing.org/con...1.full.pdf+html

which suggests such interactions can be a negative thing.

I'd be careful about the loss of steelhead in a river like Burnette creek as the stream has very poor habitat. Steelhead were extripated from the river in the middle of the 20th century. Water quality is not great and there isn't much spawning gravel. Hatchery plants can't re-jeuvinate such a stream Kanaka doesn't have great habitat either.
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fisher man

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Re: can a hatchery become a wild
« Reply #25 on: February 06, 2012, 03:34:32 PM »

lol, thanks guys, i was just wondering if a if hatchery had offspring that it would be a wild. oops didn't know the sensitivity!.
Thanks Sandman and Fishunter your earlier replies were perfect, lets not blame who or who, it is what it is, safe to say a river with a hatchery is hard to tell if the wild are
"true" or "hatchery wild", but without the hatchery there probably would be no fish
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silver ghost

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Re: can a hatchery become a wild
« Reply #26 on: February 06, 2012, 05:14:49 PM »

but without the hatchery there probably would be no fish


I'm all for wild fish, but amen to that in most LML flows.
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RalphH

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Re: can a hatchery become a wild
« Reply #27 on: February 06, 2012, 05:24:50 PM »

I think people need to exercise a little care when talking about wild vs hatchery and also about genetics, particularly when most of us are not 'experts'
Each steelhead will be genetically unique from each other though steelhead within a given river system likely have more genetic similarities than from another system.

Is a steelhead, the offspring of 2 hatchery fish that spawned in the river wild? Yes it is.

Has the interaction between hatchery fish that spawn in the river and wild fish changed the genetic character of the steelhead population of a river like the Chilliwack. Possibly.
There is good evidence from the US that this has taken place. But that's largely in rivers with a long (over 50 years) history of heavy hatchery augumentation where the wild and hatchery fish were also mixed in the hatchery and the wild fish had no protection from harvest and were basically fished to near extinction leaving mostly surplus hatchery fish to utilize the available spawning gravel.

This is completely different from how hatchery enhancement of steelhead has been managed in BC from the get go. There is not much evidence if any the fish in the Chilliwack have been genetically much affected by the hatchery program. There is also no evidence the Chilliwack needs that hatchery to sustain any of it's native wild salmonids. It just needs appropriate management.

Perhaps hatchery fish has changed the genetics of the wild fish but does anyone think the genetics weren't altered over decades of merely angling for them before the hatchery?
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firebird

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Re: can a hatchery become a wild
« Reply #28 on: February 06, 2012, 06:38:41 PM »

Perhaps hatchery fish has changed the genetics of the wild fish but does anyone think the genetics weren't altered over decades of merely angling for them before the hatchery?

Based on the assumption that larger fish are killed at a higher rate, it's conceivable that angling could eventually remove the genes for large size from a population resulting in a lower average size  :(
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firebird

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Re: can a hatchery become a wild
« Reply #29 on: February 06, 2012, 06:56:24 PM »

Oops ... the above would only apply to a wild kill fishery so our great, great, great grandchildren probably have nothing to worry about  ;)
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