Register now on PaFlyFish.com! Login
HOME FORUM BLOG PHOTOS LINKS


Sponsors

Browsing this Thread:   1 Anonymous Users



(1) 2 »


On the Subject of Stockie Reproduction - Fingerlings

Joined:
2011/5/6 17:55
From Harrisburg
Posts: 460
Offline
Hey all. I know we just had a long and fairly fun to read conversation about the possibility of building reproducing trout populations on hatchery stock. While I respect and understand both sides of the argument, I've had to give my nod more toward what history has proven VS. what nature is capable of (tinges of Jeff Goldblum aside)-- that is to say that, in recent history, hatchery strains have not been adequately prepared for reproduction in the wild and have failed in almost all attempts.

However, if poor genetics are the reason being given for that failure, how can we explain the use of stocked fingerlings to (successfully!) repopulate streams?

For example, according to a recent article posted on the forum, Maryland fingerlings have gained a foothold in the N. Branch Potomac -
http://times-news.com/columns/x133376 ... -to-keep-trout-cool-alive

And, according to the CVTU website, the Letort also rebounded with a similar effort - http://cvtu.homestead.com/Letort.html


Does anyone have any information or insight as to why fingerlings might successfully reproduce while adult trout fail? Do hatcheries specifically raise wild-er strains for fingerlings?

While they probably release an unrelenting amount of fingerlings in these cases, it sounds as if the still-astronomical odds of successful reproduction and subsequent generations is still highly unlikely. Perhaps there's a variable with growing longer in a hatchery, the 'nurture' as it were, that hampers the fish moreso than their own selective genetics.

Posted on: 2013/7/2 15:39


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2009/6/5 14:47
From SW PA/Tioga
Posts: 196
Offline
Quote:

Gorosaurus wrote:
However, if poor genetics are the reason being given for that failure, how can we explain the use of stocked fingerlings to (successfully!) repopulate streams?

For example, according to a recent article posted on the forum, Maryland fingerlings have gained a foothold in the N. Branch Potomac -
http://times-news.com/columns/x133376 ... -to-keep-trout-cool-alive

And, according to the CVTU website, the Letort also rebounded with a similar effort - http://cvtu.homestead.com/Letort.html


Does anyone have any information or insight as to why fingerlings might successfully reproduce while adult trout fail? Do hatcheries specifically raise wild-er strains for fingerlings?


Likely repopulated from the existing upstream wild fish.

Posted on: 2013/7/2 15:52


Re: On the Subject of Stockie Reproduction - Fingerlings
Moderator
Joined:
2006/9/9 9:29
From Monessen, PA
Posts: 22413
Offline
Fingerlings are stocked in abundance-- hence a greater spread of genetics in the trout. Those planted with good genetics for survival in the environment into which they are introduced survive, thus enhancing the gene pool somewhat with specimens capable of surviving in the wild.

Posted on: 2013/7/2 16:03
_________________
Peace, Tony


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2008/1/31 17:19
From Pretty much everywhere at some point, Thorndale today.
Posts: 13556
Offline
Keep in mind that different states have different strains, which may be more or less suited than PA's strain. Also, yes, it's a fairly recent thing, but several states have started to raise "wild" strains in hatcheries, both to supplement truly wild populations as well as to try and seed new streams.

In the case of Maryland, there are multiple possibilities. I don't know enough about it. But my impression from the article isn't that the trout are reproducing at all. Rather, a normal fingerling situation where people are catching grown up fish that are there because they were stocked there, as fingerlings. There may well be some reproduction, but I see no indication that any population would sustain over the long haul should the fingerling stockings be stopped.

In the case of the Letort, it is likely the fingerlings had little, if any, influence on today's trout population. The article said a pre-existing "low density" population was there. When the water quality and habitat recovered, the trout population took off, which would have happened with or without the fingerlings. I'm not sure when the wild trout pop in the Letort was originally seeded, but the Letort strain is significantly different than both the modern PFBC fish AND the wild fish in most of the state. A rather unique population, genetically, I think. Would be interesting to find out how that population originally got there.

Posted on: 2013/7/2 16:26


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2006/11/10 8:32
Posts: 1760
Online
Pa's stocked brown trout adults reproduce if they survive the summer and the summer water temps have not been so warm as to destroy the viability of the gametes. The same would be true for the stocked fingerling browns if they survived long enough. Likewise to a much lesser extent for the rainbows (almost to the point that they should not be mentioned), although there is less evidence for this and the YOY RT produced rarely seem to survive to adult size.

Posted on: 2013/7/2 16:30


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2006/11/2 8:50
Posts: 6279
Offline
In the case of Letort, the sewage situation was remedied. Hatchery fingerlings were stocked. The wild brown trout population went way up.

Can you conclude from this that those wild brown trout are from the fingerling stockings? The answer is no. There is no way of knowing that.

They could have come from the small population that already existed in the lower stretch. And they could have come from the Class A wild brown trout population just upstream.

There have been cases where some sort of spill has devastated trout populations and aquatic insects too, but in a few years the trout populations were doing well again, and same for the insects.

Once the water quality returns to normal, things can bounce back very quickly if there are wild trout upstream or in tribs.



Posted on: 2013/7/2 17:19


Re: On the Subject of Stockie Reproduction - Fingerlings
Moderator
Joined:
2006/9/9 19:16
From Dallastown, PA
Posts: 7088
Offline
Blah, blah, blah...the sooner you get stocked trout into the stream the more likely they are to reproduce because they are less dependant on human interaction.

Stocked adult trout = least likely to reproduce

Stocked fingerlings = more likely to reproduce

stocked trout parented eggs =most likely to reproduce

Now the inverse is also evident in survival to adulthood.

Posted on: 2013/7/2 18:19
_________________
Don't hit me with them negative waves so early in the morning. Think the bridge will be there and it will be there. It's a mother, beautiful bridge, and it's gonna be there. Ok?


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2006/11/2 8:50
Posts: 6279
Offline
In the MD article the retired biologist made no claim that a self-sustaining wild trout population was created by stocking hatchery fingerlings.

They talk about the fingerlings growing fast.

And then in a particular section, somewhere downstream, the retired biologist talks about big browns, which he believes are coming from spawning in a tributary or the headwaters.

Posted on: 2013/7/2 19:22


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2011/5/26 10:12
From Dauphin PA
Posts: 2766
Offline
I just had a lengthy phone convo with DaveS on this very subject. Correct me if I'm wrong but any wild brown fishery is a direct result of stocking and then natural reproduction. I told Dave that 30 years of fingerling stocking in the Yough has had to result in some natural reproduction. Look at the Little J & Spring as 2 examples. Both were devastated by pollution yet each has a thriving population of naturally reproducing browns. Are those populations a direct result of fingerling programs, stocking or hatchery escapees? I know, not all of the wild fish died as a result of pollution but I find it hard to believe that 40 surviving fish populated 15 miles of river. The Delaware is another prime example.

I would assume the quality of fingerling stocked 20 years ago probably surpasses the current quality / genetics suited to live outside a raceway / genetic diversity.

Since the PFBC has toyed with the idea of making some lakes into cold water fisheries, I hope the do it right. If the Raystown outflow is managed correctly, I'd have to believe the cold water pool would support a 45-48 degree release all summer. If that's the case and they are serious, why not capture wild spawners and raise them to fingerlings for stocking in that river? If not that, import eggs from Germany, Ireland or somewhere out in Montana?

Posted on: 2013/7/2 20:42
_________________
"Excelling at making people angry since 1967"


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2008/1/31 17:19
From Pretty much everywhere at some point, Thorndale today.
Posts: 13556
Offline
Most of PA's wild brown trout pops stem from stocking, yes, but LONG ago. Tough to pinpoint an exact date, and it's probably a range of dates, but primarily pre 1950. The strains stocked back then were different, genetically, than the modern PFBC strains, thanks to 50+ more years of selective breeding (intentional or otherwise).

PFBC hatchery strains will reproduce on their own, but probably in limited numbers and unlikely to start a permanent, stable population. Yes, Maurice, that includes those released as fingerlings, it's genetic! Some states have figured this out and started harvesting eggs from wild trout and raising those. NY and Wisconsin are two I know for sure. They are much harder to raise, but they do better once stocked.

A better question is whether they interbreed with existing wild fish, and perhaps leave their genetic influence in that way. Research seems mixed based on that other thread. Which probably means, sometimes, but perhaps it's not the norm.

Posted on: 2013/7/2 21:05


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2006/11/2 8:50
Posts: 6279
Offline
Brown trout have very likely been in the Little J watershed since 1900, and probably earlier.

The PFBC first got brown trout in 1886.

In the early years they transported hatchery trout by train.

The Little J had one of the busiest rail lines in the country running right along it, since the early days of the railroads. It was (and is) the major rail route that connects New York to Philly to Pittsburgh to Chicago and points west.

So, after the the PFBC received brown trout in 1886, and began propagating them and distributing them by train, how long do you think it would take them to get brown trout to the Little J watershed? Surely before 1900.

The Bellefonte hatchery opened in 1903. That is not that far way from the Little J.

They opened a hatchery on Spruce Creek, a trib to the Little J, in 1906 (later sold.)

Once the browns are introduced and take hold, then the population is maintained by natural reproduction, just as occurs with native species.

BTW, we've covered a lot of this territory in the previous thread. If you read over that, it will probably answer a lot of your questions.

Posted on: 2013/7/2 21:17

Edited by troutbert on 2013/7/2 21:35:56
Edited by troutbert on 2013/7/2 21:36:33


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2011/5/26 10:12
From Dauphin PA
Posts: 2766
Offline
No questions. I'm simply stating....if the wild population was decimated by pollution, you don't think any of the current population stemmed from reproduction of planted fingerlings over the last 30 years? I do.

Posted on: 2013/7/2 22:04
_________________
"Excelling at making people angry since 1967"


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2008/1/31 17:19
From Pretty much everywhere at some point, Thorndale today.
Posts: 13556
Offline
I never say none. But I think it's limited. In the case of the Letort, I think the strain that Vince and Charlie fished over is still going strong, and rather undisturbed by outside genetics. I do think various strains of stocked fish have reproduced at various times, including rainbows and fingerling browns. But I doubt that they've been interbreeding with the original stock, and I see their resulting populations as short lived. i.e. they'd die out in a few generations if no more stockies were added.

Although, I'm guessing that the main brownie population was seeded at a different time, or from different stock, than most of PA's wild brown populations. Maybe a private hatchery or something. They're very unique, in that if you show a picture, over half of this board would say "that's a Letort Brown" even if they've never fished the Letort.

Troutbert, yeah, I think browns were seeded slowly from the late 1800's right on through the first part of the 20th century. How late it goes I'm not sure. Likely the strain became less and less viable with each generation, so the genetic influence slowly faded from a lot to almost zero. Even today, I'd call it almost zero, not zero.

Posted on: 2013/7/2 22:29


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2006/11/2 8:50
Posts: 6279
Offline
Quote:

krayfish wrote:
No questions. I'm simply stating....if the wild population was decimated by pollution, you don't think any of the current population stemmed from reproduction of planted fingerlings over the last 30 years? I do.


Was the Little J's population ever decimated by pollution?

I don't think it ever was. During the time the papermill was discharging dirty effluent in the river, the trout were still there. I've talked to several guys who fished it during that period, and they said it had tremendous fishing for big browns. The color and smell of the effluent kept most people away, but it didn't kill the trout.


Posted on: 2013/7/2 22:48


Re: On the Subject of Stockie Reproduction - Fingerlings

Joined:
2006/9/9 17:18
From lancaster county
Posts: 6457
Offline
There is little doubt in my mind that the fingerlings stocked in the lower letort bred successfully. The variations of appearence in the fish down there is very widespread unlike the heritage arra. A purely personal observation but I think holds merit.

Posted on: 2013/7/3 4:29
_________________
http://cvtu.homestead.com/






(1) 2 »



You can view topic.
You cannot start a new topic.
You cannot reply to posts.
You cannot edit your posts.
You cannot delete your posts.
You cannot add new polls.
You cannot vote in polls.
You cannot attach files to posts.
You cannot post without approval.

[Advanced Search]





Site Content
Login
Username:

Password:

Remember me



Lost Password?

Register now!
Stay Connected

twitterfeed.com facebook instagram RSS Feed

Sponsors
Polls
Will you be fly fishing this autumn?
Yes
No
Thinking about it
_PL_TOTALVOTES
The poll will close at 2014/10/31 17:56
1 Comment





Copyright 2014 by PaFlyFish.com | Privacy Policy| Provided by Kile Media Group | Design by 7dana.com