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Re: "wild" rainbows
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Well, here is what I put together over the course of yesterday. I worked on it here and there to try to respond to pcray, but I have since lost interest in trying to make it fool-proof, so I'll just lay it out there for what it is worth:


Quote:

pcray1231 wrote:
You argued that browns are not larger than brookies, that the larger size was solely due to the fertility of streams in which they inhabit. We said that wasn't true, browns indeed average larger regardless of water chemistry.

But does it matter whether it has to do with growth rates, age, year of sexual maturity? That wasn't your argument, you're argument was that brookies would average as large as browns in the same water! The bottom line is that, all else being equal, browns DO average larger than brookies.


I think what I stated was that given streams of equal fertility, I have not seen authoritative claims that brown trout grow large quicker than brook trout. ["Brookies I think are as capable of growing large quickly as are browns, stream fertility being equal. I have never read anything authoritative to the contrary."] I have just now noted that afishinado's link provides evidence that this is not true. It is still unclear whether the statement in the article he posted is a claim about growth rates generally or whether it is conditioned on the effect of spawning as I subsequently noted. I have provided one link to a study suggesting that the growth rates are similar, at least in Norway under those study conditions. In addition, I stumbled on this from a Northern European location as well:

The comparisons of sympatric* and allopatric** populations of brown trout indicated that brown trout life history was effected by brook trout presence in terms of lower growth rate, delayed maturation and increased apparent mortality. However, to definitely confirm these effects, more and larger samples are needed. Brook trout populations clearly had shorter life histories than those of brown trout, with higher growth rates, earlier maturation and higher fecundity and mortality. This gives brook trout a higher reproductive potential compared to brown trout, something that could have a high adaptive value in small, low-productive streams where population fecundity is low.


* Occupying the same or overlapping geographic areas without interbreeding.
**referring to organisms whose ranges are entirely separate, so that they do not occur in any one place together.

http://ex-epsilon.slu.se/archive/00001372/01/Ohlund.pdf

My argument was never "that brookies would average as large as browns in the same water***." As I just showed, that was a statement I made, duly qualified as a belief, based upon not having read anything to the contrary. My argument which led me to offer that statement of belief was that the reason we find more brown trout waters under special regulations is because brown trout waters, generally being our more fertile waters, produce large-sized trout more quickly than the less fertile waters where brook trout are more likely to dominate. ["Wild brown trout streams are generally more fertile than their brook trout counter-parts. Hence the consequential truth that wild brown trout tend to be larger or grow to large sizes sooner."] I thought you tendered your agreement to this argument, although you found explanation for larger trout in specially-regulated waters to be a function of factors other than fertility-- I think you placed primary emphasis on stream size.


***I didn't say "same water" either, just in waters of equal fertility. I wasn't clear, not having really thought about it, that I meant specifically "two different waterways," but I do think now that it makes a difference whether it is the shared water or water exclusively occupied by one or the other species. This is because where the two species co-exist, there is a greater impact on growth rate of the less-dominant brook trout in shared waters than on the brown trout.

In any case, I am still considering the growth rate issue. But the important point for what this discussion originally involved is whether the apparent favor bestowed upon brown trout by special regulations is a result of the species of trout involved or the growth characteristics of the trout which inhabit the regulated streams.

Posted on: 2009/7/2 7:10
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Re: "wild" rainbows

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It appears that the EBTJV has as part of its mission to catalog strains of eastern brook trout and look for heritage strains. Interstingly, I have found studies of many other states and all find a few to many streams with "heritage strains". I can find no postive or negative studies at all for PA on a brief search. Still an open question to me.

The point would be is to stock at least heritage streams with heritage trout, if stocked at all, and in all likelyhood EBTJV would argue for special protections on these streams. Having a unique "strain" seems to open doors for a lot more charitable and goverment dollars as well as broaden support for a given watershed amoungst envirnomental groups with limited resources.

Posted on: 2009/7/2 7:14


Re: "wild" rainbows
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Jack,

From what I've read on the subject, the juvenile brook trout, at least the first year grow at a slightly faster rate than the brown trout the first year by a few mm. After that their growth rates are close to even. I think the real factor though in the size of both species as adult fish is not really growth rate but life span. The brooks have a short 3-4 year life span and rarely have a chance to grow very large.

How ‘bout this? I’ve fished in many waters, both fertile and infertile, that held both browns and brookies, and I have never seen the average brookie size equal or exceed the average brown trout size in those waters. I’m including all PA waters I fished, many streams and river in the northeast states, and also many of the waters I fished out-west. Has anyone on this board fished a stream where wild brookies and browns shared the stream, where the average size of the brookies were as big or bigger than the brownies?

Also, as many have posted, the records for the largest brook trout and brown trout caught everywhere I am aware back this up.

PS - I just read this about a new NY State record brook trout - 21" / 5lbs 4oz. Records in NY date back into the early 1800's according to the article.

http://www.pressconnects.com/article/ ... out+caught+in+Adirondacks

Just to give you a comparison, I have been fortunate enough to catch quite a few brown trout that size or bigger. A 21" brown caught on the Delaware River would hardly raise an eyebrow and just get a "nice fish" acknowledgment from a fellow fisherman while you released it. BTW, brookies are present in the great habitat of D River.

Posted on: 2009/7/2 7:32


Re: "wild" rainbows

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Jack,

Ok, I'm getting confused about where we agree and disagree now. :). Lets lay out a summary.

1. The wild brook trout in our state could be a. mostly heritage, natural strains. b. mostly a mix of different heritage natural strains (and perhaps some stockie blood) so that few if any of the original strains are still "pure", but they weren't totally eradicated and those genes still exist. c. Mostly descended from stockies, hence the PA strains are gone and we have VT fish or something or other. With the exception of TUPS, we all went with a or b. Thankfully, studies are underway at Mansfield, likely as part of the EBTJV, and we will all have more definitive answers soon. We all pretty much agreed the result has little effect on management decisions, unless only a small handful of isolated heritage strains are found, at which point we have a decision to make on whether to place special protections on them.

2. A much higher percentage of the total wild brown trout streams are under special regs than the percentage of wild brook trout streams.

3. It can be debated whether #2 is a bias for type of fish, or angler preference for a style of water (fertility, size, fish size, etc.). Most of us picked the latter but for various different reasons. My point was that it doesn't matter if the reasons are valid, it still shows brook trout are an undervalued resource that needs some promoting, IMO of course.

4. Brown trout average larger in every single stream where the two species co-populate. Browns do indeed tend to dominate in more fertile waters, but their size advantage over brookies has nothing to do with fertility. We are debating whether they grow more quickly overall, sexually mature a year later and thus grow more quickly for only one year, or simply live longer and thus have a higher average age. I hold that it doesn't matter, the end result is the same, but FWIW, I'll go with "all 3 factors are at play."

Posted on: 2009/7/2 8:34


Re: "wild" rainbows

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Quote:

pcray1231 wrote:


3. It can be debated whether #2 is a bias for type of fish, or angler preference for a style of water (fertility, size, fish size, etc.). Most of us picked the latter but for various different reasons. My point was that it doesn't matter if the reasons are valid, it still shows brook trout are an undervalued resource that needs some promoting, IMO of course.



That reminds me...

One of the points was that the PF&BC had favored browns over brook trout for a very long time.

I remember awhile back, someone pointed out that some in the PF&BC had argued that raising the legal size of trout to 7 inches would result in an underutilization of the wild brook trout resources.

Yea, it is hearsay, but we are not in court. This is another example of how the PF&BC has had no respect for brook trout for a very long time.

Here is another.

A good friend was fishing with his buddies when they werekids over near DuBoise. They were catching tons of brook trout all just under the limit (6 inches at the time). They were measuring them all and throwing anything questionable back (which was pretty much all of them). soon they discovered they were being watched. The Fish cop (lets call him officer M. Jackson) who had been watching these yung boys then approached and as one of them was about to throw another back, the guy asked to see the fish. Deputy MJ proceded to pinch it right behind the head to beak the spine. "There, now it is legal size." I'm betting the deputy thought he was being a good guy to the kids.

Posted on: 2009/7/2 9:21
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There are certain pursuits which, if not wholly poetic and true, do at least suggest a nobler and finer relation to nature than we know. The keeping of bees, for instance." -Henry David Thoreau--


Re: "wild" rainbows
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Quote:

pcray1231 wrote:
Jack,

Ok, I'm getting confused about where we agree and disagree now....


Quote:
1. The wild brook trout in our state could be....

We all pretty much agreed the result has little effect on management decisions, unless only a small handful of isolated heritage strains are found, at which point we have a decision to make on whether to place special protections on them.


My belief is that while most wild brook trout are probably not a pure heritage strain, there are significant populations that are. This is a mere belief and I agree that the Mansfield U. studies may begin to answer this question definitively.

I do think it makes a difference in management decisions. If dealing with a population that is not heritage, it eliminates any justification for extraordinary efforts to preserve the non-indigenous brook trout strain at the expense of any other trout species that might thrive as well or better than the non-native brookie strain. On the other hand, if found to be indigenous, then it may provide a basis for extraordinary measure to preserve it, even to the extent of extirpation of non-natives by means of poisoning or attempt at species-selective harvest. The relative rarity of indigenoous strains should impact how far to go with any such extraordinary efforts, or how broad in scope such efforts should be. In other words, if all population of brookies are indigenous strains, then the justification for using extraordinary measures on any particular water become weaker.

Quote:
2. A much higher percentage of the total wild brown trout streams are under special regs than the percentage of wild brook trout streams.


I don't disagree, but we differ on why this is the case as noted below.

Quote:
3. It can be debated whether #2 is a bias for type of fish, or angler preference for a style of water (fertility, size, fish size, etc.). Most of us picked the latter but for various different reasons. My point was that it doesn't matter if the reasons are valid, it still shows brook trout are an undervalued resource that needs some promoting, IMO of course.


There are additional possible explanations here, and mine is missing. You mention a. bias for type of fish and b. angler preference for type of water. My position is that it has more to do with the extent to which special regulations can have a positive effect on the wild populations. To be sure, some special regs streams are that way only because of vocal angler desire, irrespective of whether from a resource management viewpoint the regs make sense. We had an example of this on another thread where FFOC&R remains on a stream where everyone agrees that few if any fish can hold over the summer.

What I think is at work is the understanding of whether harvest or tackle restriction can be effective on relatively infertile streams-- i.e. the majority of brook trout exclusive or brook trout dominated waters. On these types of waters, there is little or no evidence, except for anecdotal "cropping" claims occasional professed, that harvest or even incidental motality from angling constitutes a limiting factor. On the other hand, with fertile streams, including the typically most fertile limestoners, habitat and forage are NOT limiting factors, leaving only (primarily) mortality as a limiting factor. On such waters, harvest and IM can have an effect on populations. Though I don't believe that such stream can be devestated by these premature mortality issues, the catchable populations can be reduced in the short-term and negatively impact angler experience. Thus, in my opinion, the PFBC is more likely to impose special regulations. In my view, it is COINCIDENTAL that these types of water are predominantly brown trout waters.

In light of what I have stated is my view, I cannot accept the conclusion, which I do not believe really even follows from yours and other poster's view, that "brook trout are [treated by the PFBC as] an undervalued resource."

Quote:
4. Brown trout average larger in every single stream where the two species co-populate. Browns do indeed tend to dominate in more fertile waters, but their size advantage over brookies has nothing to do with fertility. We are debating whether they grow more quickly overall, sexually mature a year later and thus grow more quickly for only one year, or simply live longer and thus have a higher average age. I hold that it doesn't matter, the end result is the same, but FWIW, I'll go with "all 3 factors are at play."


I think the dominance of brown trout in certain waters has everything to do with fertility. Brown trout have their genetic origins in highly fertile, typically limestone waters. They are genetically programed to thrive in such waters. Ken Undercoffer makes an explanation in this PDF article of why, which I find persuasive. To an extent also, their preference for a higher pH chemistry keeps them from becoming dominant in the lower pH (and typically lesser fertile) waters.

Having addressed most of your points, it should, perhaps, be more clear to you where we agree and disagree.

Posted on: 2009/7/2 10:23
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I don't like spinach, and I'm glad I don't, because if I liked it I'd eat it, and I just hate it. --Clarence Darrow


Re: "wild" rainbows

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But, ... but, ... but ...

Ah, nevermind.

Seriously.

Quote:
I think the dominance of brown trout in certain waters has everything to do with fertility. Brown trout have their genetic origins in highly fertile, typically limestone waters. They are genetically programed to thrive in such waters. Ken Undercoffer makes an explanation in this PDF article of why, which I find persuasive. To an extent also, their preference for a higher pH chemistry keeps them from becoming dominant in the lower pH (and typically lesser fertile) waters.

Having addressed most of your points, it should, perhaps, be more clear to you where we agree and disagree.


I think that is a big part of it. However, I don't feel it is all of it.

For example. We know that brook trout can handle fairly low PH. However, Brown trout can survive at nearly as low PH, too. My personal experience has not shown this to be true, but a couple studies showed that the differences between tolerable PH levels between the two species are not that significant. Can we say that PH and fertility has a lot to do with it on the low end where the brook trout tend to dominate? Maybe to some degree, but I think there is a lot more to it.

Someone mentioned that Brown trout also dominate some larger and less fertile freestone streams. It's true. Why is that? Do we know of any larger freestone that are dominated by brook trout? I don't. Why is that?

Anyway, I feel that species size capability and several other factors are still considerable.

Larger and slower water favors the larger fish species (between competing species).

Higher gradient, fast moving ... favors the smaller.

Smaller water favors the faster to maturity and larger numbers of offspring...

The differences in temperature ranges really has more to do with amount of desolved O2. Brook trout require more. High gradient freestone (high O2) are dominated by he brook trout, while furter downstream (lower gradient), the same stream is dominated by browns.

Brook trout reproduce sooner in their life span and produce more offspring. that is a clear advantage in areas that see more environmental variation due to nature. Floods drought, predation, ... freeestone streams.

anyway, those are just some thoughts. there are more.

I don't see how anyone could say it is just one trate that determines ALL this (and I am not saying that either of you are saying that). With the amount of variation, it can't be just one thing.

Posted on: 2009/7/2 11:17
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There are certain pursuits which, if not wholly poetic and true, do at least suggest a nobler and finer relation to nature than we know. The keeping of bees, for instance." -Henry David Thoreau--


Re: "wild" rainbows

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Quote:
I do think it makes a difference in management decisions. If dealing with a population that is not heritage, it eliminates any justification for extraordinary efforts to preserve the non-indigenous brook trout strain at the expense of any other trout species that might thrive as well or better than the non-native brookie strain.


Agreed, but I know of no such extraordinary efforts to preserve brook trout at the expense of browns, nor do I foresee any such effort in the near future. I'm advocating greater efforts to highlight and preserve our brook trout resources, but not at any expense of browns whatsoever.

Quote:
There are additional possible explanations here, and mine is missing. You mention a. bias for type of fish and b. angler preference for type of water. My position is that it has more to do with the extent to which special regulations can have a positive effect on the wild populations.


I think this is the same as angler preference. I wasn't talking about vocal lobbying for special regs, though as you mention that plays a part as well. Special regulations are the PFBC's way of reducing angler impact in sections that are especially harmed by such impact. Angler impact is much greater in places where anglers prefer, i.e. that see a lot of pressure, hence special regs are more effective there, hence they are more often placed there.

I have no problem with that whatsoever. My point was that special regulations are in essence, advertisements for a fishery or type of fishery. The unintended side effect is beating a bunch of brown trout streams into fishermen's head, and they go out looking for more just like them. The brook trout fishery, as a whole, gets ignored. While having a stream be ignored is often good for the fishing in a particular stream, as was said, angler overuse isn't the biggest danger to such streams, they need more interest in order to validate allocating resources to them for preserving public access, preventing pollution, etc. I think this was the primary reason for the WBTEP; advertisement for a type of resource rather than advertising an individual stream or trying to protect an individual stream. It's a step in the right direction.

Quote:
I cannot accept the conclusion, which I do not believe really even follows from yours and other poster's view, that "brook trout are [treated by the PFBC as] an undervalued resource."


I didn't say they were treated by the PFBC as undervalued, I said they were undervalued by fishermen. Of course thats my opinion. You'd be shocked at how many people don't even know the brookies exist in their locales. I have people tell me all the time that they like fishing brookies and would do it more if there were more of them locally. When you ask where they live, you find out there's a dozen streams within a 20 minute drive that they didn't even know about. These aren't just truck chasers, they're so-called wild trout enthusiasts.

Quote:
I think the dominance of brown trout in certain waters has everything to do with fertility. Brown trout have their genetic origins in highly fertile, typically limestone waters. They are genetically programed to thrive in such waters.


I didn't say the dominance of browns in streams has nothing to do with fertility. I said the greater SIZE of browns over brookies has nothing to do with fertility, as they are bigger in every water I know of that holds both browns and brookies, and that holds for fertile or infertile waters.

Posted on: 2009/7/2 11:21


Re: "wild" rainbows

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2008/1/21 13:28
From South Central PA
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Genetics, migration, fertility, growth rates, policy-----complicated issues to be sure. Quite a bit of interest from a good cross section of the state. Would not be surprised if this board eventually became a key component on collecting data of this type.

Migration is a big problem. It happens far less than it should among brook trout in most of its historic range. Physical, thermal, and biological (exotics such as smallmouth bass, muskies, browns and rainbows) barriers have isolated many populations and this threatens their genetic diversity.

Posted on: 2009/7/2 12:41


Re: "wild" rainbows

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Quote:

DGC wrote:
Genetics, migration, fertility, growth rates, policy-----complicated issues to be sure. Quite a bit of interest from a good cross section of the state. Would not be surprised if this board eventually became a key component on collecting data of this type.

Migration is a big problem. It happens far less than it should among brook trout in most of its historic range. Physical, thermal, and biological (exotics such as smallmouth bass, muskies, browns and rainbows) barriers have isolated many populations and this threatens their genetic diversity.


Now leave my smallmouth out of this. They are not "exotic" in the west side of the state. Musky probably aren't either...

Posted on: 2009/7/2 13:49
_________________
There are certain pursuits which, if not wholly poetic and true, do at least suggest a nobler and finer relation to nature than we know. The keeping of bees, for instance." -Henry David Thoreau--


Re: "wild" rainbows

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2009/6/18 23:56
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This past year, I caught one rainbow on Dunbar Creek that appeared to streambred. I found this article in the Trib Review and thought it was interesting. In 2006, the PFBC found several rainbows in a survey that they conducted and they were not able to determine the origin.


http://www.pittsburghlive.com/x/pitts ... ts/outdoors/s_464981.html

Posted on: 2009/9/17 19:53


Re: "wild" rainbows

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2006/9/13 10:18
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I caught what looked like wild bows in Dunbar, but it was long ago, maybe 96, or 97.

Posted on: 2009/9/17 21:26
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It's time to stop stocking all wild trout streams no matter what Classification they are, and time to eradicate brown trout in some of our limestone streams and re-establish brookies in them.



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