Wild Trout vs. Stocked

gaeronf

gaeronf

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There's no one that can answer a question like you guys. So, here it is. How would I be able to tell the difference between a stocked or a wild trout if i netted one and held it. How would I tell? I have fished places that have both but can't tell which is which. I heard something about a tail before...
 
You are correct about the right place to ask this question...the guys here are very qualified. I fish mostly for wild trout here in Maryland on the Gunpowder and tribs, but some a typical sign is that the fins and tails are often beat up on stockies. Wild trout will have pristine fins and tails. Another indication of a wild brown in particular is the adipose fin is often a bright reddis orange color, or sometimes has bright spots.
 
The longer I've studied trout and their physical characteristics, the more I've become skeptical when it comes to differentiating wild from stocked trout. I certainly have fished streams with both and could not tell some of them apart. As a general rule, the smaller, young fish are easier to tell. For one thing, most stockies are large (over 9") and many wild fish are smaller than this, including the majority of wild brooks. Brown trout in particular, I find, are tough to tell apart - esp the big fish. As BelAirSteve pointed out, bright colors and fin condition are good indicators. However, I've caught wild browns with no red coloration and worn, fleshy fins. With practice, as you catch and look at trout here in PA, you'll get pretty good at telling them apart and you'll know almost immediately if it's a wild fish. Then they'll be days when you're fishing a stream with both stocked and wild and you'll get a nice looking fish with nice fins.....when this happens, just admire the fish and accept that it could very well be wild.
 
Sort of agree.

I think myself, and many others on the board could differentiate wild vs. stocked 95% of the time. And in 4% of the other 5%, we're gonna say we don't know, i.e. we're not gonna get it wrong very often. But I am skeptical of someone who says they can always tell the difference.

Indicators:

Browns: red adipose, bluish blackish spot behind the eye, red spots are prominent (they are not absent nor are they orange), perfect clear fins. IMO, the easiest fish to tell, though the extremely large/old ones can be tough.

Brooks: The best physical characteristic is the white/black line on the anal fins. On stockies, it's rather rough. On wild fish, it's perfectly sharp and straight. That said, size is often a very good deliniator. Stocked fish are rarely stocked under 10", and wild fish rarely grow larger than 10" (both do happen on occasion, though).

 
What throws a wrench into the whole thing is the more "natural diet" they are feeding the stockies in some hatcheries; this makes them look prettier.

However, stockies are typically duller and little variation will appear in them. Wild fish are more vibrant and usually a little leaner/slimmer.
 
On browns, I've heard the area biologists say they use the blue spot behind the eye as a diagnostic. Usually the stocked fish aren't as colorful and have poor fin development and in some cases are missing fins altogether. However there are streams that have wild brown trout that are very silvery and have almost faded coloring, but otherwise have perfect fins, so they probably are wild.
Brook trout usually aren't tough at all, because mostly they don't survive the onslaught of opening day. When the stockies do survive the depth of color is far more faint in the stockies than in wild brookies. They look faded.
On both species the fins are very triagular, sometimes even coming to a distinct point rather than having a slightyly rounded tip. These days PFBC clips fins when they survey a stream, not always but often enough to differentiate by the novice. It's not easy and sometimes I'm not 100% sure. But I don't usually fish stocked streams so that makes it easier to tell the difference.
 
I'd caution against using the coloration (i.e. bright vs. faded), though. While what Chaz says is generally true, this is almost purely due to diet. And stockies color up after being in the stream a while, and some wild fish with certain diets can be rather pale. And "brightness" is NEVER going to differentiate wild vs. fingerling stocked. Plus, as was mentioned, the PFBC is experimenting with different feeds these days, and I've seen some pretty colored up fresh stockies in places.

I have caught many a holdover brookie. They're not all gone on opening day!

I agree with him that location is often important. On the tweeners, I make assumptions based on what should be there. The caveat is that fish move, sometimes big distances, so those assumptions won't be 100% correct, but they're probably right most of the time.
 
MKern wrote:
What throws a wrench into the whole thing is the more "natural diet" they are feeding the stockies in some hatcheries; this makes them look prettier.

Does anyone have information on changes in food fed PFBC hatchery fish? Have they posted something about this on their website.

Are they really getting more natural food? Or are they getting synthetic carotenoids (pigments)?

A Swiss chemical company sells these pigments to the aquaculture industry world-wide, for customers who wish to "color up" their fish.
 
I think people started seeing them, and PFBC Mike made the comment about a hatchery experimenting with foods.

Here is one such frankenfish, though not a very good example.

IMG_1330.jpg
 
I thought I was pretty good at identifying a wild trout until the survey was done at the LJ and it was determined that nearly all the brown trout surveyed were wild. I think we often assume things based on where we catch them rather than just evaluating strictly on the basis of the indicators.


Troubert wrote:
Does anyone have information on changes in food fed PFBC hatchery fish? Have they posted something about this on their website.

Are they really getting more natural food? Or are they getting synthetic carotenoids (pigments)?

A Swiss chemical company sells these pigments to the aquaculture industry world-wide, for customers who wish to "color up" their fish.



Pcray wrote:
I think people started seeing them, and PFBC Mike made the comment about a hatchery experimenting with foods.



Here’s the post where Mike mentioned the change in diet to improve coloration:


Mike wrote:
Just a heads-up for those who plan to fish streams stocked by Benner Springs Hatchery. You will do a double-take if you catch their brown trout. I certainly did this spring before I learned of a diet experiment. The caudal fins told me that the fish were stocked trout because the colors did not (or at least not enough so that I had confidence in a coloration ID ). I had to check the fins because the yellows, reds, and oranges were so vivid. Not quite a good as wild trout, but close enough that color was not as reliable as fin wear. These fish will be difficult to ID as stocked trout when the fins of the fish in the best condition heal by late spring.

Posted on: 2009/4/2 21:06

 
Here's a link to an article that describes the use of artificial pigments to color the flesh of aquaculture raised salmon. The added pigments also create more vivid external colors on fish.

It's a few paragraphs down in the article.

Notice the SalmoFan produced by Hoffman-LaRoche, the company that produces the pigments, so that salmon growers can choose the salmon flesh color they want.

http://www.edwardtufte.com/files/salmofan.html

I'm not sure that the PFBC is using these. I hope not.

They could also improve pigmentation by using natural food additives with high quantities of carotenoids, such as ground up shrimp shells.
 
I thought I was pretty good at identifying a wild trout until the survey was done at the LJ and it was determined that nearly all the brown trout surveyed were wild. I think we often assume things based on where we catch them rather than just evaluating strictly on the basis of the indicators.

Yeah, the LJR humbled me a bit too. But to be fair, fingerlings are much tougher. You lose the color indicators, like the red adipose and the blue spot, because fingerlings often have that too. And very often the fin wear indicator too, contrary to popular belief, fins heal. And its at a rate roughly equivalent to fish growth. So a fingerling stocked fish, once it goes through a growth spurt, is likely to have very clean fins.

Which means I was identifying them as stocked basically based on location and genetics. And the wild stock in the LJR do indeed have genetics very similar to PFBC fish, which is not true everywhere. So that just leaves location. What can I say, I bought the PFBC story of staying cold but lacking appropriate breeding sites. I figured there were a few wilds mixed in, but thought the bulk of the fishery was fingerlings. Turned out I had it backwards.
 
There are farms out there that raise insects to be turned into fish food. A lot better for the environement than using bi-catch ground to a paste.
This is a little more eco-friendly and selfsustaining.
 
pcray1231 wrote:
I thought I was pretty good at identifying a wild trout until the survey was done at the LJ and it was determined that nearly all the brown trout surveyed were wild. I think we often assume things based on where we catch them rather than just evaluating strictly on the basis of the indicators.

Yeah, the LJR humbled me a bit too. But to be fair, fingerlings are much tougher. You lose the color indicators, like the red adipose and the blue spot, because fingerlings often have that too. And very often the fin wear indicator too, contrary to popular belief, fins heal. And its at a rate roughly equivalent to fish growth. So a fingerling stocked fish, once it goes through a growth spurt, is likely to have very clean fins.

Which means I was identifying them as stocked basically based on location and genetics. And the wild stock in the LJR do indeed have genetics very similar to PFBC fish, which is not true everywhere. So that just leaves location. What can I say, I bought the PFBC story of staying cold but lacking appropriate breeding sites. I figured there were a few wilds mixed in, but thought the bulk of the fishery was fingerlings. Turned out I had it backwards.

Told you so!! Nyeh, nyeh, nyeh, nyeh!! (Did I get the number of nyehs right?)

I thought those who supported the theory that a cool, limestone stream in central PA with good physical habitat and lined by trees does NOT support wild trout were being pretty brave. The odds are really against you.
 
How sure are we that the blue spot is an indicator? Or are we saying this is not a wild trout?
 

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First, the indicators aren't perfect. Thats why there's a bunch of them. Having none very likely means stocked, having all very likely means wild, but having some and not others is a judgement call.

Plus, your fish does have the eye spot. It's faint and gray, but its there. I've seen them range from gray to blue to black.

It's wild.
 
I think, I see what your talking about. It looks like an ash smug right behind the eye. When I read spot in the previous post I was thinking more of a defined spot like the others on the body.

Thanks for clarifying.
 
all of these fish are either fingerlings or wilds from the same stream... so hard to tell, but I would like to see someone take a crack at it. Some of the lings get the blue spot.

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March fish, pale... colored up quite nice by june... territorial fish

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way up towards the headwaters in the posted sections.. surely natural repro, but the bigger they get, the harder imo, as I guarantee some of these are wild but don't look so:

UnderWaterWildBrown2.jpg
 
The long, and short, of it; it is impossible to determine with any certainty without genealogical evaluation whether a fish is wild or stocked. As people have said before, there are some good indicators in determining a fishes origin, but none of them are airtight.

I think some of the indicators are bordering on junk science and people take a lot of liberty when they make evaluations.

Perhaps an easier question would be is there a god?
 
True statement.
As I am merely a fisherman, if a fish "sure looks wild", I'll call it wild and be satisfied with it. If it "kinda looks wild", I just dont call it wild. Im pretty confident with the amount of them that I've caught by now that I'm correct atleast in the 90 percentile.
And sometimes, that fish that "sure looks wild", can be a very satisfying catch.
 
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