UncleShorty
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http://www.post-gazette.com/sports/outdoors/2016/07/03/A-good-news-bad-news-story-The-Yough-is-getting-cleaner-but-its-tributaries-are-heating-up/stories/201607030112
PocketWater
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That sucks.
L
lestrout
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Yo Unc
Lot of material in that article about the Yough watershed. The Symposium covered a lot of ground. I wonder when the next surveys will be run? The ones cited were 2012.
Lot of material in that article about the Yough watershed. The Symposium covered a lot of ground. I wonder when the next surveys will be run? The ones cited were 2012.
afishinado
Moderator
Staff member
From the OP article:
Despite water chemistry improvements in some tributaries and in the river’s main stem, researchers from California University of Pennsylvania reported at the symposium that something is amiss in the Youghiogheny’s high-elevation headwater brook trout streams. William Kimmel and David Argent have studied headwater streams on Laurel Ridge since 1983. They note that water chemistry in studied streams has actually improved, and streamside vegetation remains unchanged since 1983, yet the abundance of native brook trout has declined by 58 percent. The only variable they could isolate to explain the decline is an increase in water temperature, possibly attributable to climate change.
“Our research indicates that brook trout in these mountain streams are now under thermal stress for several weeks every year,” Kimmel said. “It’s especially evident in the young-of-the-year trout, which we are finding in lower numbers.”
Cindy Dunn, Secretary of the Department of Conservation and Natural Resources and the symposium’s keynote speaker observed that this trend would likely grow worse if the invasive hemlock woolly adelgid decimates Laurel Highlands hemlock stands as it has in central and eastern Pennsylvania.
“The hemlock shades those streams and keeps them cool,” Dunn said. “We’re working on this. It’s our state tree but funds are limited.”
Not good, but still a mystery. I wonder if other ST streams in PA and neighboring states have seen the same thing? Short term weather trend, climate change or something else?
Despite water chemistry improvements in some tributaries and in the river’s main stem, researchers from California University of Pennsylvania reported at the symposium that something is amiss in the Youghiogheny’s high-elevation headwater brook trout streams. William Kimmel and David Argent have studied headwater streams on Laurel Ridge since 1983. They note that water chemistry in studied streams has actually improved, and streamside vegetation remains unchanged since 1983, yet the abundance of native brook trout has declined by 58 percent. The only variable they could isolate to explain the decline is an increase in water temperature, possibly attributable to climate change.
“Our research indicates that brook trout in these mountain streams are now under thermal stress for several weeks every year,” Kimmel said. “It’s especially evident in the young-of-the-year trout, which we are finding in lower numbers.”
Cindy Dunn, Secretary of the Department of Conservation and Natural Resources and the symposium’s keynote speaker observed that this trend would likely grow worse if the invasive hemlock woolly adelgid decimates Laurel Highlands hemlock stands as it has in central and eastern Pennsylvania.
“The hemlock shades those streams and keeps them cool,” Dunn said. “We’re working on this. It’s our state tree but funds are limited.”
Not good, but still a mystery. I wonder if other ST streams in PA and neighboring states have seen the same thing? Short term weather trend, climate change or something else?
JackM
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We've been through it before. If you like 6 inch trout, there are still plenty to be caught, if even 56% less.
afishinado
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evw659
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Afish,
It would be interesting to see what the decline curve in ST populations looks like in the headwater streams that calu apparently has been surveying for the last 30 years. Was it a steady decline or was there a couple poor spawning or low water years that the stream hasn't recovered from yet? The land use in those watersheds apparently hasn't changed at all, and I really doubt angler influence has had much of a negative effect. Climate change? Well, imo I think there's a greater probability that the cause of the St decline is because of some other factor. What else could it be? Acid rain shouldn't be ignored, as the frequency and severity of it can vary. Certainly an interesting problem to figure out.
It would be interesting to see what the decline curve in ST populations looks like in the headwater streams that calu apparently has been surveying for the last 30 years. Was it a steady decline or was there a couple poor spawning or low water years that the stream hasn't recovered from yet? The land use in those watersheds apparently hasn't changed at all, and I really doubt angler influence has had much of a negative effect. Climate change? Well, imo I think there's a greater probability that the cause of the St decline is because of some other factor. What else could it be? Acid rain shouldn't be ignored, as the frequency and severity of it can vary. Certainly an interesting problem to figure out.
T
troutbert
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If anyone knows how to find this study on the brookie populations, please let us know.
E
Eccles
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Possibly this...
Argent, D. G. & Kimmel, W. G. (2013). Potential impacts of climate change on brook trout (Salvelinus fontinalis) populations in streams draining the Laurel Hill in Pennsylvania. Journal of Freshwater Ecology, 28(4) 489-502.
It's behind a paywall but I can probably get it or you could just drop an email to one of the authors and ask for a .pdf.
T
troutbert
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Thanks Eccles!!
724flyfishing
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I was surprised to read rainbows do so much better in there. I know of more rainbows getting caught and see more pictures of bows versus browns, but I always figured it was just because they were easier to catch.
As far as the tribs I can't comment on a downward trend because I've only been fishing them as of the past couple years. They seem to fish ok for me. I will say on a temporary pattern, they're in bad shape right now. I just fished a Class A to the Yough Saturday and it was bad. Puddles with a trickle connecting them. It was enough to convince me to leave them alone for a while. We're not having a very trout friendly summer.
As far as the tribs I can't comment on a downward trend because I've only been fishing them as of the past couple years. They seem to fish ok for me. I will say on a temporary pattern, they're in bad shape right now. I just fished a Class A to the Yough Saturday and it was bad. Puddles with a trickle connecting them. It was enough to convince me to leave them alone for a while. We're not having a very trout friendly summer.
turkey
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I'm totally shooting from my memory's hip right here but the Pittsburgh region, I believe, still has considerably poor air quality which contributes to acid rain. I think I recall reading about Linn Run requiring liming stations to support trout populations and the Laurel Ridge "catching" a lot of acidic rain. If Linn Run has had problems sustaining trout I'd imagine a lot of the other not-to-be-named streams suffer the same effects.
Does any of this sound familiar to anyone? I'm too lazy to dig in to this right now.
Dave_W
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Staff member
Well said.
This study does indeed raise some very interesting questions.
Thirty years, it seems to me, is certainly long enough to account for the yearly swings in population that small, wild trout streams often exhibit. Water temps and declining hemlocks could certainly be a factor. . .but I wonder if in other areas in the state with declining pine cover are there similar declines?
Hhmmm. . .
ryansheehan
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Much of the yough has to be very tough to sample. I would think the big browns in those deep runs are not getting surveyed easily. They also put alot of "catchable" size fish in there as well, that could affect the results as well.
pcray1231
Well-known member
Depends on the stream. If acidity is the main threat, pine does not help. I can't say it hurts, but it could. Brookies are more tolerant of low pH than browns or rainbows because of the existence of various conifers here in the east, which, prior to logging, made up the majority of the forest, and even today often dominate the streambottoms. They acidify the soil. I've always tried to understand how that acidity plays with acid rain and, in places, AMD. They are different types of acid and can have different effects. And in terms of total pH, I'm not really sure. But I'd be interested in any real studies along these lines.
Any hunter knows that if you get a dense stand of hemlocks, there will be soft unfrozen soils and less snow underneath in winter. And when that snow does melt it'll go into a pine soil rather than runoff, which means it gets a chance for some buffering. In regards to acid rain, a major sudden snow melt running off of frozen ground is really when you get your damaging acid spikes. It could be that with pine, you could be more acidic on average. But being a type of acid that brookies are adapted to, combined with actually reducing the acid spikes associated with melt events, it's beneficial. I dunno. These are just musings, but one's I've held for some time.
If temperature and flow are the main threats, though, that's where the beneficial effects of conifers on our native brookies are pretty clear. The article mentions shade, which is true. But it goes well beyond that. They provide heat in the winter as well. Most hunters will recognize that a dense hemlock stand will be cooler in summer and warmer in winter than everywhere else, and again, the soil doesn't freeze easily and is the first to thaw if it does.
But the real benefit comes in those soft, spongy soils, with a high degree of water absorption, that are favored under conifers in general. As such, they vastly reduce variability in flow rate. Therefore, you don't get the scouring floods so easily, which not only kill fish but flush streams of cover, and knock out streamside trees whose root systems normally force all the undercuts and meanders that make good holding water. You also hold better flows through mid-summer when water temp is the biggest issue. And further, with less run-off and more groundwater, you don't get as much siltation issues. The water in streams which flow through primarily pine is absolutely crystal clear. It's filtered.
DaveS
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My .02 on this topic...
The Yough river is greatly influenced by the Casselman. AS the Casselman goes, so goes the Yough. Although a tailwater, that water is quickly met with the often times warm, and sometimes silt laden water of the Casselman river. This often results in temps into the 70 degree mark. Generally not for long periods of time, but enough that over time the stress builds. When the dam (almost always) runs out of cold water in late summer, the fish (and the fishing) suffer.
The rainbows are more tolerant of high temps so there are more of them. The browns, some are large enough to hold in a thermal refuge, likely eating the smaller fish. But there are fewer, and not generally easy to catch.
It not ideal, but it is improving...
No idea about the head water streams, but what Turkey said sounds familiar to me. All the industry in the region has over time diminished the buffering capacity of the soil. Normal weather patterns would predict where those effects are greatest. However the above mentioned study specifically named Thermal issues and how they may impact the streams.
The Yough river is greatly influenced by the Casselman. AS the Casselman goes, so goes the Yough. Although a tailwater, that water is quickly met with the often times warm, and sometimes silt laden water of the Casselman river. This often results in temps into the 70 degree mark. Generally not for long periods of time, but enough that over time the stress builds. When the dam (almost always) runs out of cold water in late summer, the fish (and the fishing) suffer.
The rainbows are more tolerant of high temps so there are more of them. The browns, some are large enough to hold in a thermal refuge, likely eating the smaller fish. But there are fewer, and not generally easy to catch.
It not ideal, but it is improving...
No idea about the head water streams, but what Turkey said sounds familiar to me. All the industry in the region has over time diminished the buffering capacity of the soil. Normal weather patterns would predict where those effects are greatest. However the above mentioned study specifically named Thermal issues and how they may impact the streams.
I
inthedrift
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I don't often weigh in here, but as someone who spends a considerable amount of time guiding and personally fishing the Middle Yough, I figured I would throw my 2 cents in.
While the Middle Yough is a markedly improved trout fishery over what it was even 5 years ago, there is certainly still room for improvement in the management of the fishery. Acid mine drainage remediation in the Indian Creek and Casselman drainages have done wonders for the Yough, and with a little help here and there, the fish have responded accordingly. Considering that the fishery more than likely relies on stockings (both state and private) to be what it is, I feel it is extremely important to gain an accurate understanding of what the fish populations look like to understand how to best manage the fishery. To date, the people that make the management decisions do not have that data.
As the PFBC has noted, the Middle Yough is an awfully hard section of river to sample with the gear available to them. Reading the recent PFBC biologist report reveals some flaws in the approach to surveying the river. They surveyed in August (when even the Yough is getting warm), presumably in the middle of the day, in predominantly pool habitat. Riffles were relatively inaccessible due to the gear. Considering this, it’s not surprising that they came away with the results that they did.
I'll leave you with some browns that are clearly struggling to earn a living in the Yough...
Combine that with the fact that PFBC has only sampled the river THREE TIMES IN THE LAST 27 YEARS, and it’s pretty easy to say that they don’t have a clear picture of what exactly is going on in undoubtedly one of the best coldwater resources in Southwestern PA. Yet, management decisions are being made based upon an extremely limited supply of potentially flawed data. The question needs to be asked; why do we have such a small data set on such a unique resource? I have a feeling the sampling difficulty is only part of the equation.
Talk to any of the guides/anglers that spend a considerable amount of time on the river, and you will likely get the same story. Brown trout do just fine in the Middle and Lower Youghiogheny all the way to South Connellsville. On an average day, we certainly catch more rainbows than browns, but this is variable with the season, angler skill levels, weather, and our approach to the day. The bottom line is that those fish are doing very well in the river, and add a fairly unique trophy aspect to an already great fishery.
There are more variables at play here that I won’t go into detail about, but I think the bottom line is that it doesn’t seem that this is the right time to make management changes. The problem of collecting representative data has been acknowledged by PFBC, and efforts to supplement PFBC data with angler log books, creel surveys, etc. area gaining momentum. So why change the stocking policies now? It just seems like a shot in the dark.
Additionally, I’m not sure where the idea of rainbows doing better than browns in warmer water comes from, but I have heard it from several anglers fishing the Yough. Unless I’m missing something here, brown trout have always been noted for having a higher temperature tolerance than rainbows, and are found sharing sections of stream with smallmouth bass and other “warmwater” fish much more frequently than rainbows. Does anyone have any insight on where this line of thinking stems from?
I'll leave you with some browns that have clearly been struggling to get by in the Yough...
-Mike Engelhardt
Laurel Highlands Guide Services
While the Middle Yough is a markedly improved trout fishery over what it was even 5 years ago, there is certainly still room for improvement in the management of the fishery. Acid mine drainage remediation in the Indian Creek and Casselman drainages have done wonders for the Yough, and with a little help here and there, the fish have responded accordingly. Considering that the fishery more than likely relies on stockings (both state and private) to be what it is, I feel it is extremely important to gain an accurate understanding of what the fish populations look like to understand how to best manage the fishery. To date, the people that make the management decisions do not have that data.
As the PFBC has noted, the Middle Yough is an awfully hard section of river to sample with the gear available to them. Reading the recent PFBC biologist report reveals some flaws in the approach to surveying the river. They surveyed in August (when even the Yough is getting warm), presumably in the middle of the day, in predominantly pool habitat. Riffles were relatively inaccessible due to the gear. Considering this, it’s not surprising that they came away with the results that they did.
I'll leave you with some browns that are clearly struggling to earn a living in the Yough...
Combine that with the fact that PFBC has only sampled the river THREE TIMES IN THE LAST 27 YEARS, and it’s pretty easy to say that they don’t have a clear picture of what exactly is going on in undoubtedly one of the best coldwater resources in Southwestern PA. Yet, management decisions are being made based upon an extremely limited supply of potentially flawed data. The question needs to be asked; why do we have such a small data set on such a unique resource? I have a feeling the sampling difficulty is only part of the equation.
Talk to any of the guides/anglers that spend a considerable amount of time on the river, and you will likely get the same story. Brown trout do just fine in the Middle and Lower Youghiogheny all the way to South Connellsville. On an average day, we certainly catch more rainbows than browns, but this is variable with the season, angler skill levels, weather, and our approach to the day. The bottom line is that those fish are doing very well in the river, and add a fairly unique trophy aspect to an already great fishery.
There are more variables at play here that I won’t go into detail about, but I think the bottom line is that it doesn’t seem that this is the right time to make management changes. The problem of collecting representative data has been acknowledged by PFBC, and efforts to supplement PFBC data with angler log books, creel surveys, etc. area gaining momentum. So why change the stocking policies now? It just seems like a shot in the dark.
Additionally, I’m not sure where the idea of rainbows doing better than browns in warmer water comes from, but I have heard it from several anglers fishing the Yough. Unless I’m missing something here, brown trout have always been noted for having a higher temperature tolerance than rainbows, and are found sharing sections of stream with smallmouth bass and other “warmwater” fish much more frequently than rainbows. Does anyone have any insight on where this line of thinking stems from?
I'll leave you with some browns that have clearly been struggling to get by in the Yough...
-Mike Engelhardt
Laurel Highlands Guide Services
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barbless
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Apparently, at least some strains of rainbow trout are as heat-tolerant as brown trout.
http://flickandflyjournal.com/2014/09/29/brown-and-rainbow-trout-how-hot-is-too-hot/
There are some studies on this, found in .pdf form- here's a keyword link to the pages https://www.google.com/search?q=rainbow+trout+heat+tolerant+brown+more&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US
fficial&client=firefox-a
That said, it's typically brown trout that are found in the reaches of a river where coldwater trout habitat merges into warmwater bass habitat. I think this may have something to do with the differences in habitat and current preferences for rainbows and browns- rainbows seem to like to have their noses in the bubbles, in fastwater runs and riffles, while browns more often favor lairs in water with slow-moving or moderate current, which is more like bass habitat.
To hazard a guess, while some strains of rainbows can tolerate temps over 70F degrees (and even up to 80F degrees, for short periods of time), they want the boost from the oxygenation found in churning currents. Brown trout seem to try to handle warmer temps by seeking out as much thermal refuge as they can find from deep water and shade. There may be other factors beyond the dissolved oxygen levels, too, like fungal and bacterial resistance, that might favor one species over another in thermally marginal habitat.
Neither species is at its best when under heat stress, of course. They do their best to slow their metabolic demands, which are most affected by the fact that warmer water holds less dissolved oxygen. 70F degrees is where things get borderline for rainbows and browns. But the optimum is more like 65F degrees. (Subtract 3-5 degrees for brookies.)
It's interesting to ponder the possible role of thermal stress in the natural selection of trout populations. It's undoubtedly the case that the rainbow/steelhead populations at the southernmost margin of their original native habitat- in southern California and Mexico- are adapted to be more relatively heat-tolerant than rainbows in colder climate zones. So it's possible that some trout populations will respond similarly to rising water temps. It may not be quite the same fish in all respects, though...?
I continue to find it hugely ironic that so much of our best sport fishing in the USA consists of exotic and introduced species. If you want to see healthy stream populations of good-size brookies, for instance, the best places I know to find them are in the Rockies. The entire Eastern seaboard owes its bass populations to introductions.
I don't want to encourage any more bucket biology- it can plainly cause big problems and ruin rare and valuable fisheries. Just noting the facts we've been handed.
http://flickandflyjournal.com/2014/09/29/brown-and-rainbow-trout-how-hot-is-too-hot/
There are some studies on this, found in .pdf form- here's a keyword link to the pages https://www.google.com/search?q=rainbow+trout+heat+tolerant+brown+more&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US
fficial&client=firefox-aThat said, it's typically brown trout that are found in the reaches of a river where coldwater trout habitat merges into warmwater bass habitat. I think this may have something to do with the differences in habitat and current preferences for rainbows and browns- rainbows seem to like to have their noses in the bubbles, in fastwater runs and riffles, while browns more often favor lairs in water with slow-moving or moderate current, which is more like bass habitat.
To hazard a guess, while some strains of rainbows can tolerate temps over 70F degrees (and even up to 80F degrees, for short periods of time), they want the boost from the oxygenation found in churning currents. Brown trout seem to try to handle warmer temps by seeking out as much thermal refuge as they can find from deep water and shade. There may be other factors beyond the dissolved oxygen levels, too, like fungal and bacterial resistance, that might favor one species over another in thermally marginal habitat.
Neither species is at its best when under heat stress, of course. They do their best to slow their metabolic demands, which are most affected by the fact that warmer water holds less dissolved oxygen. 70F degrees is where things get borderline for rainbows and browns. But the optimum is more like 65F degrees. (Subtract 3-5 degrees for brookies.)
It's interesting to ponder the possible role of thermal stress in the natural selection of trout populations. It's undoubtedly the case that the rainbow/steelhead populations at the southernmost margin of their original native habitat- in southern California and Mexico- are adapted to be more relatively heat-tolerant than rainbows in colder climate zones. So it's possible that some trout populations will respond similarly to rising water temps. It may not be quite the same fish in all respects, though...?
I continue to find it hugely ironic that so much of our best sport fishing in the USA consists of exotic and introduced species. If you want to see healthy stream populations of good-size brookies, for instance, the best places I know to find them are in the Rockies. The entire Eastern seaboard owes its bass populations to introductions.
I don't want to encourage any more bucket biology- it can plainly cause big problems and ruin rare and valuable fisheries. Just noting the facts we've been handed.
ROVERT
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I become very skeptical when I see an ecological symptom based on a period of 20 to 30 years blamed on climate change. I would like to see the entire paper.
FWIW, I pulled some historical data for Seven Springs. I looked at the average July highs and lows from the first three years and the last three years of the time frame they looked at.
Here are the two sets of numbers:
High 80 deg, 78 deg, 80 deg
Low 65 deg, 60 deg, 63 deg
High 86 deg, 82 deg, 82 deg
Low 66 deg, 64 deg, 64 deg
Now, that second group is definitely warmer. The problem is those numbers are from 1983, 1984, and 1985, respectively. The "cooler" numbers are from 2013, 2014, and 2015. This is a result of weather patterns, not climate change. 30 years is nothing.
Warm water could easily be to blame. If they are blaming the lower trout populations on thermal issues I would hope that they have actual water temp data. The fraction of a degree that could be attributed to climate change is very unlikely to be the culprit. Climate change is a hot topic though and gets papers published. I suspect it is much more likely canopy related or there was a scorcher of a summer, a flood, etc... something that, while weather related, cannot be attributed to the constantly degrading thermal conditions that global warming would result in.
FWIW, I pulled some historical data for Seven Springs. I looked at the average July highs and lows from the first three years and the last three years of the time frame they looked at.
Here are the two sets of numbers:
High 80 deg, 78 deg, 80 deg
Low 65 deg, 60 deg, 63 deg
High 86 deg, 82 deg, 82 deg
Low 66 deg, 64 deg, 64 deg
Now, that second group is definitely warmer. The problem is those numbers are from 1983, 1984, and 1985, respectively. The "cooler" numbers are from 2013, 2014, and 2015. This is a result of weather patterns, not climate change. 30 years is nothing.
Warm water could easily be to blame. If they are blaming the lower trout populations on thermal issues I would hope that they have actual water temp data. The fraction of a degree that could be attributed to climate change is very unlikely to be the culprit. Climate change is a hot topic though and gets papers published. I suspect it is much more likely canopy related or there was a scorcher of a summer, a flood, etc... something that, while weather related, cannot be attributed to the constantly degrading thermal conditions that global warming would result in.
F
fayettenamese
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I really want to know which headwater streams they sampled and how they sampled them. Unless there was a stream gauge recording data for 20 years it would be tough to compare temperatures on a few days of sampling spaced a few decades apart. I wonder how they determined that the native brook trout populations were decreasing. I certainly catch many more brook trout in the yough's tributaries than I did 20 years ago by far. The only thing I can think of is them taking into account the streams where wild rainbows and wild browns have or are replacing native brook trout, which is happening a lot. I do agree that rainbows seem to more prevalent in the yough. I caught just shy of 900 trout from the yough last year between south connellsville and confluence and between 2/3 and 3/4 of them were rainbows. The browns that I caught all looked healthy though.
