Stocking small streams (in the existing program) that support wild trout

[FarmerDave]

k-bob wrote:
OP simply states that "The impact of stocking a small stream, say 12-18 ft wide, that supports wild trout is not nearly what you may think it is, depending upon your line of thought." (italics added)

so Mike said that the effect of stocking a small stream with wilds may not be as great as is sometimes assumed or stated.

TB: "There is no biological justification for doing this. Anyone who studies fisheries in a decent university will be taught that this should not be done, because it harms wild trout populations."

OP doesn't say that there is no harm/effect of stocking on wilds. he simply said that the effect may not be as great as some people think it is. so, the effect may be a medium size effect on wilds when people expect a large effect. or, it may be a small effect when people expect a medium size effect.

he simply said that the effect may be overestimated, and as a biologist he's probably in a good position to consider this. he also pointed out that there are sometimes other issues involved, such as access.

thanks Mike for posting here, as always.

Very good summary there, k-bob.

Mike said the effect might not be as negative as we think (thought), which is likely true. But there is still some negative effect per his wording. Just not as much.

Troutbert said there is not biological reason for stocking over self sustaining populations, which I agree with 100% and I believe Mike would also agree. The decision to stock trout in such locations has nothing to do with science. We will hear all kinds of reasons such as maximizing the resource and such, but the bottom line is it all boils down to money.

 

[FarmerDave]

Maurice wrote:
Oh, and for Eccles... 20 years ago there were no wild trout so I am not sure the argument of breeding of wild and stocked has much merit since the population likely came from hatchery stock over the last 20 years.

Wait ... what?

Those little brookies I used to catch in the 70s were stocked? :roll:

Apparently you are being sarcastic.;-)

 

[FarmerDave]

Mike wrote:
Eccles,

Densities of wild fish do not factor into stocking rates in Pa streams. Biomass does, however. Class B streams that have been grandfathered in the stocking program (no B's may be added to the program) receive a relatively low stocking rate and are stocked one time per year. Biomass Class C and D streams are stocked independently of wild trout densities, with their stocking rates based largely on social factors and stream width.

There you go. Central PA rules applied to everywhere. Class C wild trout are completely disregarded even if Class C is a better stream for a given region.

That is what I was talking about when I said your York County example (I'm guessing brown trout) does not apply well everywhere. I wasn't picking nits.

Bring more buckets.

PFBC brown trout will reproduce in the wild and have done so repeatedly when and where conditions are favorable. I can't say that I have found any evidence of successful modern day stocked brook trout reproduction in Pa. There is certainly more awareness of brown trout impacts on brook trout populations than in the past and some species mixes involved in individual stream stockings have changed in part over the years with this in mind. For various reasons, more and more RT are being stocked instead of BT and ST, and rarely do RT that reproduce in Pa produce a fishable population. Densities are very, very low except in a few streams. Finally, with respect to genetic impacts of ST on ST, I recall having read paper(s) quite a while ago from studie(s) in Pa and other adjacent states that have, as I recall, found no genetic mixing, but I am waiting for another more recent study to be published.

And I have read where they do mix. I only had a paper copy of that particular study, and that was 15 years ago so I wouldn't know where it is. It did not go into negative effect. It only tested for presence of certain genes.

The hatchery strain no doubt has less genetic diversity and is a result of decades of hatchery evolution. I'm personally not convinced stocking of brook trout is a long term problem because they do not replace the existing genes. Stop stocking and mother nature will fairly quickly sort out what genes work best for a given environment through natural selection just like man has done through selective breeding in hatchery environment.

 

[k-bob]

FD "Troutbert said there is not biological reason for stocking over self sustaining populations, which I agree with 100% and I believe Mike would also agree."

true enough, but the Bio Just thing is really a straw man. I have never heard mike or anyone else say that stocking a small stream that has wilds has a biological justification, for ex., that it increases the wild trout population. Mike simply said the effect of stocking on the wilds is less than is sometimes expected.

apart from being a biologist with serious experience on pa streams, mike also writes clearly, why expect people to respond to things theydidn't say?

 

[FarmerDave]

FD: "Troutbert said there is not biological reason for stocking over self sustaining populations, which I agree with 100% and I believe Mike would also agree."

k-bob wrote:

true enough, but the Bio Just thing is really a straw man. I have never heard mike or anyone else say that stocking a small stream that has wilds has a biological justification, for ex., that it increases the wild trout population. Mike simply said the effect of stocking on the wilds is less than is sometimes expected.

apart from being a biologist with serious experience on pa streams, mike also writes clearly, why expect people to respond to things theydidn't say?

You know what? It is a straw man. How did I miss that? Shame on you troutbert. :lol:

 

[troutbert]

Biology is a strawman? Who knew?