Challenge to all Trout Camps

Fish Sticks said:
Gradient and stream size does not uniformly predict species presence in this study because there are streams of the same size and gradient that are sympatric brook/brown and ones that just have brook trout so there must be another factor driving species composition in those streams besides gradient and stream size. Thats obviously is not proof of causation since neither group had a barrier but again it highlights something besides size and gradient are at work there.
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You're reading into the noise. The gray area where gradient and stream size predict you are on the boundary between brook trout and brown trout water. And some streams in this gray area are brook trout only, some are sympatric, and it's not in the table, but looking at the charts, some are brown trout only too. There must be some difference between these.

I agree with that. I will say that NONE in that category had barriers, so barriers are NOT the difference. There are other factors at play that are lost in the noise. There could be 1000 factors. When you get right on that gray area, small signals have big effect, you are in chaos theory territory. Butterfly effect. A stream right on that boundary that solidly favors neither species, the slightest push will push it one way or the other. 60 years ago a pair of browns and brookies spawned beside each other, and a racoon walked through one of the redds...

Regarding barriers, the only conclusion in this study is: If the physical characteristics of a stream solidly favor brook trout over brown trout, it will be a brook trout stream regardless of whether a barrier is present or not.

Anything beyond that on the question of barriers is neither supported or refuted by the data. Both sticks and I agree that barriers are probably sometimes beneficial. So do the authors. But that does not mean that the data collected in this study backs it up or can be used to justify it. I fully get that you have a position, and wish to find solid scientific evidence to support your position. An appeal to authority. I share your position based on gut feel and experience. But this particular batch of data is not evidence to back it up.
 
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I understood the environmental conditions (including the presence/absence of barriers) as justification for the conclusion and the types of streams that may theoretically benefit from isolation management. The only role barrier presence plays in the findings is that a barrier might negate the importance of other factors (gradient, temperature, etc.).

  • Smaller streams with higher gradient were brook trout exclusive. These also happen to have barriers.
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Exactly. Barriers weren't a driving factor in species presence.

  1. Smaller streams with high gradient favors brook trout. But I admit I already knew that. I grew up in NWPA.
  2. Slightly larger streams (but still small) with somewhat less gradient still favor brook trout, but does not exclude browns.
  3. Largest streams with low gradient favor browns.
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Exactly as well. So in building a case for where barriers might be useful, those criteria are key in differentiating between where one might or might not be useful.
 
What he said^
 
Just to reiterate.

I don't think the study is bad. I don't disagree with it's authors.

I don't disagree with the position I assume Fish Sticks holds on barriers either. I feel they are likely beneficial under certain scenarios.

I'm pushing back against using the data in this study to support a position on barriers being a positive thing. It neither supports nor refutes that position. The authors don't claim it does either. Silver is much more on point.

"We tried and failed to show an advantage to barriers using data. That doesn't mean there is no advantage, we just didn't have the right data, we still think it's likely there are situations where they are beneficial. The data does show situations where they are not beneficial. So, we should still consider and study other situations, which were not covered by this study. In those situations, barriers may prove to be beneficial."

More study is needed, etc. etc. etc.
 
But I'll also re-iterate what I took from it. I'm an optimist by nature!!!

1. If stream characteristics favor brook trout, it will remain a brook trout stream. Nomatter whether a barrier is present. Nomatter whether browns have access or not.

2. A point not made by the authors. I'm making it, because the data says it, and I find it noteworthy. We had small, high gradient streams that were fairly FERTILE. Alkalinities in the 40's and 50's, and as such, presumably good pH and resistant to spring runoff acid spikes. That's unusual. That brown trout have access to and/or are present in. And they were still primarily brook trout streams on account of size and gradient alone.

In a world where acid deposition from rainfall is abating, and mine acid drainage is being cleaned up, to me that's HUGELY encouraging that all the mountain streams are not on the verge of flipping to browns.
 
pcray1231 said:
But I'll also re-iterate what I took from it. I'm an optimist by nature!!!

1. If stream characteristics favor brook trout, it will remain a brook trout stream. Nomatter whether a barrier is present. Nomatter whether browns have access or not.

2. A point not made by the authors. I'm making it, because the data says it, and I find it noteworthy. We had small, high gradient streams that were fairly FERTILE. Alkalinities in the 40's and 50's, and as such, presumably good pH and resistant to spring runoff acid spikes. That's unusual. That brown trout have access to and/or are present in. And they were still primarily brook trout streams on account of size and gradient alone.

In a world where acid deposition from rainfall is abating, and mine acid drainage is being cleaned up, to me that's HUGELY encouraging that all the mountain streams are not on the verge of flipping to browns.
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I did find that interesting as well. Not just from the results in species composition but that the streams in that area had such relatively high alkalinity. I believe I've read another paper somewhere that more or less also suggested gradient is one of the most significant drivers.

This touches on one of the main reasons I've been coincidentally interested in that particular paper recently. In Moshannon, the mainstem upstream of Hale Rd. is a somewhat sizeable brook trout stream at roughly 30 ft wide in some areas. I believe I calculated gradient at 9.4m/km or roughly 50ft/mile which would put it below the low end of the recommended gradient where a barrier may be beneficial. It's very low gradient. That area is between 33 and 100 km2, depending on where you'd divide it up. It's currently allopatric.

Regardless, that entire upper population is currently isolated (or insulated), low gradient, and a medium size stream with a Class A allopatric brook trout population. It's exactly the kind of population I think we should look into protecting and exactly the kind of conditions identified in the paper we've been back and forth on as potentially appropriate for a species barrier. Considering the work planned there, I think it presents an important opportunity to at least discuss the possibility of employing isolation management.
 
silverfox said:
This touches on one of the main reasons I've been coincidentally interested in that particular paper recently. In Moshannon, the mainstem upstream of Hale Rd. is a somewhat sizeable brook trout stream at roughly 30 ft wide in some areas. I believe I calculated gradient at 9.4m/km or roughly 50ft/mile which would put it below the low end of the recommended gradient where a barrier may be beneficial. It's very low gradient. That area is between 33 and 100 km2, depending on where you'd divide it up. It's currently allopatric.

Regardless, that entire upper population is currently isolated (or insulated), low gradient, and a medium size stream with a Class A allopatric brook trout population. It's exactly the kind of population I think we should look into protecting and exactly the kind of conditions identified in the paper we've been back and forth on as potentially appropriate for a species barrier. Considering the work planned there, I think it presents an important opportunity to at least discuss the possibility of employing isolation management.
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What is the water chemistry there? There has been a lot of coal mining in the watershed above that point, and the geology is infertile.

I think the reason there aren't brown trout up there is because the pH is too low for browns, but OK for brookies.

There are many such streams. Some have mine drainage, many do not.
 
Anyone think the recent activity of volcanos will cool things down? Block sun light.
 
troutbert said:
What is the water chemistry there? There has been a lot of coal mining in the watershed above that point, and the geology is infertile.

I think the reason there aren't brown trout up there is because the pH is too low for browns, but OK for brookies.

There are many such streams. Some have mine drainage, many do not.
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Detailed answer: https://img1.wsimg.com/blobby/go/01...ConservationPlanSept28R.pdf?ver=1670173860439

I think around page 75 would be a good place to start.

The mainstem in that area is significantly impaired from AMD. Yes. I think one of the biggest issues is Aluminum. Bear Run contributes a lot of Aluminum. Though all the usual suspects (iron, manganese, etc.) are present as well. There is also pretty significant thermal impact from some existing treatment systems in that general area (my observation) closer to Beaver Run (first downstream tributary with brown trout). One of the biggest discharges in the watershed is just upstream of Beaver Run.

Pages 98 to 123 gives a pretty good overview of the upper end in terms of chemistry.
 
CRB said:
Anyone think the recent activity of volcanos will cool things down? Block sun light.
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Hawaii? No. Not an explosive eruption. To have significant cooling effects away from the eruption site, it has to go boom big enough to push sulfur dioxide through the troposphere and into the stratosphere. Stuff in the troposphere, down with the clouds, doesnt go far and washes out quickly. But in the stratosphere it aerosols and sticks around a few years.

Mauna Loa may be the biggest volcano on earth but it erupts effusively instead of explosively.

Hunga Tonga was easily boomy enough, but released mostly water vapor instead of SO2. That was a year ago now, will be interested to follow what effects it did have, but not gonna be anything real major. Very notable eruption though, super explosive, not just stratosphere but mesosphere and ionosphere too, the column touched space!
 
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The study linked defines barriers as 1) man made damn or 2) wetland (of at least 1km)/beaver damn.

In my experience, many high gradient (brookie) streams are full of natural barriers. Those barriers would slow the migration of brown trout to the high gradient sections of the stream where native brook trout have populated for a long time.

This study does not include time dimension which shows if brown trout are slowly making there way into higher gradient water.

I guess this is a long worded way for me to say the studies results were not surprising. It is not surprising that brown trout have a hard time setting populations in high gradient streams that most likely have many natural barriers which prevent migration except during extreme weather events.
 
Apparently multiple sympatric streams from Dr. Kirk’s study have only found browns in electro surveys over the last few years and are now considered allopatric brown

I do not know names
 
Here's a quote from a PFBC biologist's survey report from a small, unstocked obscure brookie stream in Big Woods Country in NC PA:

"section of stream examined is probably fished hard, as few legal size brook trout were encountered."
 
In my "files" I came across an article called "Brook Trout Fishing in the Kettle Creek Country, by Charles Wetzel. He said from 1918 to 1921 he was engaged in a land survey of the area, and lived at Trout Run Hotel, 100 yards from Kettle Creek and he fished it a great deal. He writes:

"The brook trout was dominant at that time. Now and then a "foreign" brown trout would be caught only to be summarily dispatched."

So brown trout were already in Kettle Creek by 1918 to 1921.
 
More from my "files." An article by Max Greeley, who grew up near Wharton, which is at the confluence of First Fork and East Fork Sinnemahoning Creek. He said brown trout were first introduced there around 1915-1916, and he caught his first brown there a few years later. By the early 1930s 1 out of 3 trout caught in the lower East Branch was a brown. By the mid to late 1930s the brown trout had displaced the brookies in the lower East Branch. He described the lower East Branch as being from Jamison Run to the mouth.
 

That's the basics from the fish commission standpoint. The car was delivered to the commission in 1892 and started action then.

I've looked at other articles, and the way it was ran.

The brown trout were shipped here from European wild stock as eggs, which were easy to transport alive. Hatched here, and quickly shipped around the state as fry on this rail car (the PFBC was not yet successful in rearing them to adult size, as hatchery strains had not yet been developed). Anyone, including you, could make an order of fry. The commission would then set up a meeting point at a rail station, where they would deliver the fry to you, and it was your responsibility to stock the fish. In many cases horse and buggy would go to other meeting points, where people would receive them with buckets, backpacks, etc. and take them up their favorite waterways.

That is how the backbone of the wild brown trout in PA came to be. I'm not claiming there's been zero streams seeded by more modern stock, or that modern stock has zero DNA influence. But hatchery stock DNA has been shown, in other states, to be fairly unsuccessful in the wild, because hatcheries select based on growth rate, lack of "skittishness", willingness to feed from humans, etc. Traits which are helpful in a hatchery setting but detrimental in the wild. But very early on we were stocking fully wild DNA fish as fry into the headwaters of a huge number of streams. And as troutbert says, there are LOTS of anecdotal evidence which shows the brown trout took hold in the few decades that followed. 1890's-1930's time frame.
 
CRB said:
Anyone think the recent activity of volcanos will cool things down? Block sun light.
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Just returning to this, lol. Because I find it incredibly interesting!!!

It is believed the Hunga Tonga eruption a year or so prior is part of the reason for our WARM winter. It's tough to tell in a chaotic system how much small factors play a part, and there's natural and anthropogenic global warming, etc.

Small volcanos affect local weather. An especially explosive one that puts an eruption column through the troposphere and into the stratosphere can affect things globally. Things in the stratosphere spread out and create a whole earth blanket of sorts, and it's above the weather so they don't wash out quickly. The historically documented ones inject sulfur dioxide and ash into the stratosphere, which absorbs sunlight, heats the stratosphere and cools the troposphere (where we are). So such volcanoes cool our climate for a few years.

Hunga Tonga was a weird one. It was the highest eruption column EVER recorded, broke every record and even touched the mesosphere. But it injected very little sulfur dioxide and ash. Instead it was mostly water vapor, a steam plume, and it injected a whole lot of it into upper layers of the atmosphere. We have the strongest ever mesopheric clouds over our poles right now. And the stratosphere is cooler, and troposphere (ground) warmer than would otherwise be expected with global warming/El Nino, etc. taken into account. They're still arguing. But it appears that eruption had a temporary (couple year) but measurable warming effect on Earth.
 
I heard that about the volcano, but also think we would have had a warm winter anyway, as it was a somewhat rare 3rd straight La Niña which historically have been very warm winters in the mid Atlantic. Bracing for the inevitable late March snowstorm that happens just as we're all ready to dust off the dry fly rigs.
 
Actually La Nina generally corresponds to cold but dry around these parts. El Nino typically warm and wet.

That said, for us here on the east coast, and Europe as well, El Nino/La Nina has a relatively minor effect. The bigger effect is the NAO. It is positive right now and has been significantly positive throughout January. It hasn't been negative since early December. Positive NAO corresponds to a progressive pattern. Relatively flat jet stream, fairly stable temperatures, our weather comes from the west, lots of overrunning storms but not many blockbusters.

When it's negative is when you get blocking setup and get stable around Greenland. It's like sticking a potato in a pipe, makes make the jet stream go round and get wavy, and you get phased big systems coming from the south or full on nor-easters, huge temperature swings, etc.
 
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