Does a Stocked Trout Ever Become Wild?

silver creek

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An interesting article by Domenick Swentosky at Troutbitten.

Does a Stocked Trout Ever Become Wild? | Troutbitten
He defines "wild" by the genetic makeup of "stocked" trout and it is a proven fact that stocked trout are EPIgenetically different than wild trout. We think of genetics as the DNA but the DNA of trout DOES NOT change that fast in fish raised in hatcheries. What changes is the EPIgenetics which is how the DNA is manifested in the animal. Simple put, which genes are turned on and how these turned on genes are expressed phenotypically. This can happen in a single generation when a wild trout progeny is raised in a hatchery.

See this study which shows that a single generation of domestication heritably alters the expression of hundreds of genes

Wild Steelhead Trout from the Hood River

303 See Other

"“We find that there are hundreds of genes that are differentially expressed (DE) between the offspring of wild fish (W × W) and of the offspring of hatchery fish (H × H) reared in a common environment. By using reciprocal crosses, we further show that these differences in gene expression cannot be explained as maternal effects, sampling noise, or false discovery. Thus, our data suggest that the very first stages of domestication are characterized by massive, heritable changes to gene expression.”

“Remarkably, we found that there were 723 genes DE between the offspring of wild fish (W × W) and the offspring of first-generation hatchery fish (H × H)”



So what if the stocked trout then breed in the wild. Are they wild or are they stocked? The author NEVER addresses that issue and I believe that the this is more important that whether stocked fish are wild or not wild because crossbreeding allows the "stocked" genes to enter the "wild" gene pool. So how about that issue?

See how it gets more complex?

The fact is that when fish are hatched and bred in the wild, the EPIgenetic expression returns to the wild form. And it happens rapidly. So it boils down to this issue. Does the genome (the actual DNA sequence) of the stocked fish contain DNA that leads to weaker fish than the genome of the wild fish it has bred with. That is a maybe answer. We cannot know, except to say that it does decrease diversity of the DNA when there are a relative large number of stocked fish that can breed with a relatively small number of wild fish. Then it becomes a huge problem.

Human EPIgenetic expression changes with environmental changes as well as shown by the NASA Kelly identical twin astronaut experiment which showed that 7% of gene expression could have changed.

NASA Sent One Identical Twin Brother To Space For A Year - And It May Have Permanently Changed 7 Percent Of His DNA | IFLScience

Here are some references on epigenics

Epigenetics - Wikipedia

Selective expression of genes through epigenetics can regulate the social status of african cichlid fish

http://news.stanford.edu/news/2016/january/fish-fernald-genes-010516.html

I wrote about epigenetics before in this post

https://www.theflyfishingforum.com/...pigenetics-complex-science-2.html#post1047017
 
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sweetandsalt

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White Leghorn chickens put into a natural habitat fenced to protect from predation do not, in any number of generations, turn into grouse (or any wild form of chicken). All of our American brown trout were initially stocked producing the "wild" (never native) browns we fish for so avidly today. But our two originally introduced strains from Loch Levan, Scotland and the von Buhr Black Forest "German" browns arrived here via fish culturists in the mid 1880's from essentially wild forms of S. trutta. Browns have proven less generically malleable than have rainbows, the "Entirely Synthetic Fish". The "wild" rainbows I love in say, the upper Missouri watershed are wild, stream reproducing great fish but are the product of hatchery strain fish widely stocked by Montana Fish wildlife and Parks that were selectively bred for fast growth, early sexual maturity and resultant short lifespan (compared to native strains). If one wants to catch a Native rainbow in Montana, one must fish the Kootanai R. in the north western corner of the sate with three watersheds. These Oncorhynchus look different and get bigger than any other "junk strain" stream dwelling Montana rainbows. However, when zipping into my backing making cartwheels down the river, the last thing on my mind is the domesticated gene pool of rainbow trout.
 

dillon

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Although Montana trout streams are presently not stocked, there are first generation hatchery stockers in some tailwater rivers. For example, there are many hatchery fish in the Missouri. Fish stocked in the resrvoir above Holter Dam often wash over the top of the dam during high flows in the spring. These fish soon adapt to the river environemnt and will rise to duns, just like the wild, non native Rainbows born in the river. These fish are a big trophy sized sterile triploid strain. They are easily identified by deformed and/or missing fins. However, to the unknowlegeable angler they are assumed to be the same as any other Missouri Bow. Then they unknowingly go into their own record book as their personal best wild rainbow. Part of being a knowledgeable trout angler is having an understanding of the fish and their habitat.
 
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scotty macfly

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White Leghorn chickens put into a natural habitat fenced to protect from predation do not, in any number of generations, turn into grouse (or any wild form of chicken). All of our American brown trout were initially stocked producing the "wild" (never native) browns we fish for so avidly today. But our two originally introduced strains from Loch Levan, Scotland and the von Buhr Black Forest "German" browns arrived here via fish culturists in the mid 1880's from essentially wild forms of S. trutta. Browns have proven less generically malleable than have rainbows, the "Entirely Synthetic Fish". The "wild" rainbows I love in say, the upper Missouri watershed are wild, stream reproducing great fish but are the product of hatchery strain fish widely stocked by Montana Fish wildlife and Parks that were selectively bred for fast growth, early sexual maturity and resultant short lifespan (compared to native strains). If one wants to catch a Native rainbow in Montana, one must fish the Kootanai R. in the north western corner of the sate with three watersheds. These Oncorhynchus look different and get bigger than any other "junk strain" stream dwelling Montana rainbows. However, when zipping into my backing making cartwheels down the river, the last thing on my mind is the domesticated gene pool of rainbow trout.
Is there a way to tell the difference between the Loch Leven and the Black Forest "German" browns apart?

I looked at both on the computer and the first thing I noticed is that you can't trust what it shows. But what I can see from Loch Leven and a Black Forest look the same to me.
 

sweetandsalt

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Is there a way to tell the difference between the Loch Leven and the Black Forest "German" browns apart?

I looked at both on the computer and the first thing I noticed is that you can't trust what it shows. But what I can see from Loch Leven and a Black Forest look the same to me.
Yes, while almost all our American browns are crosses between the two strains (they can't tell one another apart themselves) we still see fish that appear "pure" plus the full variation of mixtures between them. Loch Levens have no red spots and their black spots are larger while the German fish have smaller, sometimes more numerous black spots with red spots aplenty.

von Behr
W14 044 Missouri R. Brown Trout vs.jpg

Loch Leven
W13 097 Missouri R.Brown s.jpg
 

Unknownflyman

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I think our browns are mixed, every once and a while I`ll catch one with no red spots but its rare. I fished the Kootanai with my dad, seen some big fish in that river, my dad landed one 7 pounds. I kept catching Kokanee salmon and only small rainbows. :( Had some great follows though or should I say refusals. :)

This seems to come up a bit. I`m going to call our browns and steelhead for that matter, wild after 140 years of natural reproduction.

What I think is interesting is that they can see what brook trout are native heritage strain and which ones are mixed genes. The original genes are the fish that seem to reproduce the best, but in the case of our Kamloops, which were sterile and would never breed, after 50 years of stocking they were reproducing and with the wild steelhead as well and the Looper stocking program was terminated. Now the eggs and milt are taken from wild stock. So does nature eventually find a way? it looks like it to me.
 

scotty macfly

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Yes, while almost all our American browns are crosses between the two strains (they can't tell one another apart themselves) we still see fish that appear "pure" plus the full variation of mixtures between them. Loch Levens have no red spots and their black spots are larger while the German fish have smaller, sometimes more numerous black spots with red spots aplenty.

von Behr
View attachment 21133

Loch Leven
View attachment 21134
So then, is a Loch Leven a sea run brown?
 

sweetandsalt

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redietz is correct. Technically Loch Levens are a lacustrian brown. There are in their native range from Iceland in the west to the mountains of Afghanistan in the east numerous strains and subspecies of brown trout analogous to our western diversity of steelhead/rainbow/cutthroat. All trouts, given the geographic opportunity to go to sea will take the opportunity to have both sea run and resident populations. Also know that brown trout are closely related to the only other Salmo, salar the Atlantic salmon, itself with landlocked versions.
 

karstopo

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I wonder how rare are wild and native fish or watersheds that have never been influenced by any hatchery fish? Is there even such a thing in the lower 48? Even the native cutthroats get dumped out of airplanes into high alpine lakes. Where do the airborne cutthroats come from?

How did the original brown trout get to North America? I guess on a ship in a chilled tank or during a time of year it would be cold enough? There must have been more than two events with the two strains of browns. They didn’t get into every watershed at once, so there had to be secondary stockings. Were those secondary stockings from captured and wild American browns, hatchery raised American browns or from another shipment of wild, temporarily captive browns direct from Europe or Asia?

It would be cool to see an Atlas of watersheds with the type of fish labeled for each watershed.
 

trev

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Back in the 1800s they stocked trout every where that a train with milk cans of fry crossed a bridge and in every mountain stream or lake that a pack mule with cans of fry could reach. All across the USA, even in water totally unsuitable for them.
Some of those stockings worked to the extent that California rainbows still reproduce in Mo. streams said not to have been stocked since the 1880s.
And yes I have read of several efforts to establish the German trout and the German carp in USA waters in the 19th century. Even to the US government hiring and importing a German to run the hatchery. iirc, some importation was by private citizens or clubs but much of it was done by the US Fish Commission.
I seem to remember talk of eradicating native trout in some Idaho waters to better accommodate the stocked rainbows, early 1960s. I grew up and got to be past middle age believing that all trout are or have been stocked, eventually I found that there are a few instances of uncontaminated trout populations, but I still suspect they are very few.
In most of the world a "wild trout" is an invasive species. And that doesn't matter because in most of the world humans are also an invasive species. To quote a famous lady "at this point, what difference does it make?"
 

karstopo

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People have to constantly tinker and change things up. I live on a private lake and the residents are generally clambering for stocking this fish to help that fish or hurt some other fish, which causes another series of problems so something must be done and on it goes, ad nauseam, ad infinitum. It's all kind of ridiculous as no one relies on the lake for anything more than maybe some irrigation water. Meanwhile, whatever was native and true to the water is sacrificed for the whim of mankind without a second thought.
 

Bigfly

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I suspect farmed humans have won out over wild as well. I'm trying to at least hold down the feral category.
Sweet said he didn't think about the genetics of a fish on. I laughed, because that is exactly what I think about.
Will this fish be a butt kicker that makes me run a hundred yards, or just a faintly spotted faded wannabe, who comes to hand apologetically. I want fibrillations, not fun!! Our original McCloud strain bow has been here since 1903...Same year they started the 1st hatchery out here (See completely synthetic fish..). We can clearly tell them apart from recent stockers... wild bows also have a hint Lahontan cutthroat mixed in (An sm orange spot at jaw plate). Wild fish here have a very sharp wide tail (Steel heritage) as opposed to a smaller more rounded one, a sharper pointed face on bucks, masses of spots and an outrageous royal red band. I have fished the Sac for Steel and also fished the McCloud river, and they share a "look/attitude".
Those who have not felt the difference between stocked and wild, should come visit. It's a matter of taste/experience I guess....a fine home brew IPA, vs. a Coors light. A Buffalo vs a Hereford......etc

To answer the original question, after 117 years, a hatchery fish, one generation removed from Native fish, has been able to spawn and be managed for wild......as with all artificial populations, there is genetic variation, but when you see a fish retaining Steel style it is a treat. It's what keeps me here.


Jim
 
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karstopo

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Could hatcheries be run differently to select better strains and sort of tamp down the negative epigenetic influences. Are hatcheries all about the same or do some produce fish a little more wild?

Were the native and wild fish like the brook trout in the East such duds that the settlers just had to find something better? What about the wild and native cutthroats? Were they awful too so let’s bring in other fish?
 

Bigfly

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It may act like a wild trout but it will always be a stocked ie hatched in a hatchery trout so the answer is no .
So, after the hatchery fish spawn?
They aren't hatchery....that means wild. We are one generation from native...and not the 117 generations that are raised to look up for pellets that are likely elsewhere.
Born and raised in the river is wild.
But not native.
We are 300 miles from their natal waters, and no ocean access.
We do have some holdover stockers, but they never get the game of the wildies. Not the same challenge....
which is why the club guys put them in to start with. High density and dumb.

To address Karstopo's question...
Yes, there could be some attention to quality....in hatcheries.
But why start now?
CO. stocked whirling disease for example......
Mostly it's about keeping fish in the water so people can take them out.
Consumers run the show, not the connoissures....It's about Lic sales.
Fewer, harder fish don't appeal to most.....
where as, lots of easy ones do.

Jim
 
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