using bedrock geology info to fish in acidrain areas

[k-bob]

sure, but good fishing itself is subjective: I like hiking & scenery, steep streams, dry flies, don't really care if fish are small. other guys pursue bigger fish, fish subsurface, whatever.

the idea in the OP is that studying bedrock geology from maps can help you fish in areas w/ acid rain issues. works for me. people might just adjust based on what they are looking for.

 

[troutbert]

k-bob wrote:
sure, but good fishing itself is subjective: I like hiking & scenery, steep streams, dry flies, don't really care if fish are small. other guys pursue bigger fish, fish subsurface, whatever.

I also like that type of fishing. You misunderstood what I wrote.

I was arguing that people SHOULD fish those types of streams, and not screen them out because they are flowing through infertile geologic layers.

 

[k-bob]

OK and maybe bedrock geology info can do the most for people who have fished but like trying new places. even ones not on the Nat repro list.

 

[troutbert]

k-bob wrote:
OK and maybe bedrock geology info can help people find trout in little streams not on the Nat repro list if they like trying new places.

I encourage learning about the geology. I haven't argued against that. I have studied it a lot myself.

It can help you. But I'm just pointing out that it can also throw you off.

It was posted earlier in the thread that Catskill is fertile and the overlying layers: Huntley Mtn, Burgoon, and Pottsville are infertile. That info is true.

But you have to be careful how you use that info. Many people would assume: fish the streams in the fertile Catskill layer. Don't fish those in the infertile layers.

That would be a mistake. Many of the streams where I've had great brookie fishing in NCPA never get down into the fertile Catskill layer. They run their whole length through the infertile layers above.

 

[k-bob]

I dont think anyone reading all the ideas in this thread will think there are simple statewide go/no-go categories of geology and that's all you need to think about?

I agree bedrock geo is only one factor along w drainage, gradient, elevation etc. And the Taylor books give different pH data for the same bedrock in different regions. Beyond regional differences, there's a range within any one region .. bottom line: yes I agree you certainly can't look at only bedrock geology.

still, many places in the NEPA mountains have Pocono burgoon Pottsville bedrock.. if I have no experience on a set of streams, and one has a higher buffering bedrock in its headwaters? if they otherwise seem equally interesting, I may go to the one with the higher buffering headwaters geology first.

and a few months experience suggests that adding geology to everything else I can think of has been a plus in stream selection

 

[k-bob]

TB, I look at it this way: In the Kirby study where you were one of the volunteer anglers, 6/6 of shawangunk bedrock streams had ST but only 9/28 Tuscarora ones did. That might make shawangunk streams more attractive in using maps -- without implying there are no good Tuscarora ones....

 

[troutbert]

Cool. I fished one of the Shawangunk streams with Chaz and it was pretty nice. Infertile, but with enough brookies to keep it interesting. And a scenic little stream, with some large woody debris creating pools and cover further down, and some "large rocky debris" further up.

I'll take the plateau infertile streams over the ridge-and-valley infertile streams, though.

 

[k-bob]

I have done more ridge-n-valley low fertility ST streams... what about the plateau ones?

 

[troutbert]

kbob, I think you've also fished a lot in the Pocono Plateau, which many consider an extension of the Allegheny Plateau. And I know you've also fished in the anthracite region, which is kind of its own separate thing.

I've done the majority of my freestone fishing in the Allegheny Plateau, mostly in what they call Big Woods Country. Roughly Sullivan County on the east going west through Lycoming, Tioga, Potter, Clinton, northern Centre, Cameron, Elk, Clearfield.

In this region you have fertile freestoners, most of which are influenced by the Catskill formation.

You also have much less fertile freestoners, in the geologies above the Catskill, in order going up: Huntley Mtn, Burgoon, Pottsville.

Some of these infertile freestoners flow for a long way, receive a lot of water from tributaries, and get pretty big, while still holding only brookies, not browns. Some have very good brookie fishing, if you do some exploring.

In the ridge-and-valley region the streams tend to have a shorter brookie zone, and not get as large within that zone.

Also, in the AP, the mileage of forested freestone streams on public land is just vast. Much more forested stream mileage to explore than in the ridge-and-valley.

 

[k-bob]

Sullivan and Lycoming I do fish... have fished a bit Tioga and potter. yeah amazing number of streams up there. Pocono plateau I have fished a lot. some good streams that start in Catskill. thought you might say something about less rhodo in north central. .

 

[Chaz]

pcray1231 wrote:
Here's one I've been pondering.

Over the last 30 years or so, the PH of the rainfall has improved. It's still not good by any stretch of the imagination, but the addition of scrubbers on a fairly high % of coal plants has helped.

Now, we're in the midst of a massive coal plant shutdown, in favor of gas. Many have already shut down, and I think around 30 more in PA and Ohio are planned to close shop in the next couple of years. I would assume the pH of the rain will rise further as a result.

Obviously, this is a good thing for streams. But how much effect it'll have, I'm not sure. As was mentioned, acid rain is a cumulative effect. You progressively use up the buffering capacity. Hence, rather than say it's a good effect, you might say it's "less bad", meaning streams will get worse at a slower rate?

That said, I have trouble believing that higher pH in the rainfall will not raise the pH of any streams. It's got to. And I think I've seen it in some streams in the NW PA. Acid rain affected streams getting a bit better over time, and in many cases, the appearance of browns where there were none or only a few. It's likely especially true during massive runoff events. The most acidic time in a stream is when you have surface runoff, for instance in the early spring when the ground is frozen, and unbuffered rainwater is pouring directly into the stream. Hence, your groundwater sources in freestoners may not be higher in pH, but your low pH spikes associated with these events should be less severe on account of the rainwater being higher in pH. No? And are not these events perhaps the true limiting factor of acid affected streams?

Thoughts?

I'm going to try to answer this, but I'm no expert. In many cases the buffering is gone, that's not good for streams if the rain is still under 5 PH. That's the threshold for fish and macros. The latest info I've seen says rainfall is as low as 4.5 or so.
Those marginal brookie streams will likely get better over time, but until buffering improves they won't make dramatic progress. As to browns moving in the same thing happens, nearly every stream below 6 PH has no browns and even at 6 PH there's are usually only a few. Then you have the 6.5 PH threshold, that's when browns start to expand their range, because they can tolerate 6.5 PH and above.
As the forest recover they will lay down more buffering, but the best buffering still comes from bedrock and that can't be replaced without intervention.


Further, another good question is that IF we were able to improve the acidity of the streams, would it really help the brookie?
IT may not help if the streams go over 7.0 PH at all, it may hurt. More trout is good but not at the expense of native fish, and that's not limited to brookies alone their are other native fish negatively impacted by browns.

 

[Chaz]

k-bob wrote:
Sullivan and Lycoming I do fish... have fished a bit Tioga and potter. yeah amazing number of streams up there. Pocono plateau I have fished a lot. some good streams that start in Catskill. thought you might say something about less rhodo in north central. .

Yeah Bob, TB doesn't like Rhodo, that being said compared to RV, the AP has very little Rhodo along the streams. There is more mt. laurel in the AP, but it's all at the higher elevations. Bob, you've fished that stream that TB mentioned in post 67.

 

[troutbert]

In NCPA Allegheny Plateau there are a lot less places where rhodo chokes a stream than in the ridge and valley.

There is some of that, though. There are some stretches in Sproul & Moshannon SFs where the stream is completely covered over by rhodo.

 

[k-bob]

yeah, too much hiking under rhodo makes my back hurt! afraid we do have a higher rate of the stuff...

right, headwaters geology is just another useful stream variable along with drainage area, gradient, state list status, region, etc. you'd be better off with experience or good firsthand accounts, but we have so many tiny streams that even the best books (!) and the state's nat repro list can't cover 'em all:

http://www.coldwaterheritage.org/docs/2014-conference-/un-named-tributaries.pdf?sfvrsn=0

 

[Chaz]

k-bob wrote:
yeah, too much hiking under rhodo makes my back hurt! afraid we do have a higher rate of the stuff...

right, headwaters geology is just another useful stream variable along with drainage area, gradient, state list status, region, etc. you'd be better off with experience or good firsthand accounts, but we have so many tiny streams that even the best books (!) and the state's nat repro list can't cover 'em all:

http://www.coldwaterheritage.org/docs/2014-conference-/un-named-tributaries.pdf?sfvrsn=0

Here's a question, I noticed there was an un-tributary to Dry Run that had brook trout, the question is was Dry Run really dry or was it wet and did it have brook trout?
There are quite a few Dry Runs in PA, not all of them are dry all the time. Some of them have tribe, what happens to that water?

 

[troutbert]

pcray1231 wrote:
Further, another good question is that IF we were able to improve the acidity of the streams, would it really help the brookie?

I know that there are some very acidic streams with few or no brookies due to acid. And these streams would likely improve, to where they may hold relatively healthy brookie populations.

But alongside those, I think there are some streams with currently stable brookie populations that would switch over to primarily browns. Generally speaking, your brookie populations may merely get pushed even further to the headwaters, while browns take over the lower reaches of what are currently inhabited by brook trout. In some cases, slightly acidic streams could be regarded as the last bastion of brookie habitat, in that it holds off the onslaught of brown trout.

More trout is good, so I'm not suggesting we try to stop this from happening. Just musing out loud.

I think that both brookie and brown trout populations would improve.

 

[duckfoot]

^ Right. I'd say that you'd have an overall increase of fish populations.

However, pcray, your musings are legitimate. If there is a limited food supply, and given all things ideal for a marine environment, the brown is going to push the brook out and in some special cases you might have a "zoning" of brooks and browns along the same watershed.

I'd think that it'd have to hit the "magic" pH values for each species.

 

[troutbert]

I think that the brook trout and the brown trout would increase in roughly the same proportions.

And it's quite possible that the brook trout would improve at a higher proportion than the browns.

In the infertile watersheds, brook trout would re-inhabit the headwater stretches which presently hold no fish.

Below these headwater fishless stretches are commonly long stretches that hold brook trout but which are still very infertile. If pH of rainfall was returned to a normal 5.5, these stretches would still probably not support brown trout. The brook trout would improve here as a result of better food supply.

Further down, yes, there would be some increases in the range of brown trout in the upstream direction.

But I think the increases in brook trout would be as great or greater than increases in brown trout populations. In the infertile watersheds there would still be only brook trout for many miles down.

In the fertile watersheds, I'm not sure there would be much difference. Because the brown trout are not currently limited by pH in those watersheds. Often these streams have pH suitable for brown trout as far up as there is water. But the headwaters of these streams are still typically all brookies for a ways down. Then the brown trout appear, but they are still typically outnumbered by the brookies for a ways further downstream. Then you get to a zone where they run about 50/50, and the ratio continues to shift towards more browns / brookies as you continue down.

But this does not seem to be pH related. Because the pH is within the range for browns from right up where the streams originate the whole way down.

So, in fertile watersheds, why do the browns not totally displace the brookies in the upper ends? I don't know, but it's not about pH, IMHO.

It may be related to groundwater temps for spawning being more favorable for brookies than browns. Or it may be that brookies survive better in droughts in the small streams. Some PFBC survey reports during a severe drought stated that their data indicated that.

 

[duckfoot]

Came across this map while preparing a lecture for my environmental sciences class. I thought it would be relevant for this topic.

 

[k-bob]

"So, in fertile watersheds, why do the browns not totally displace the brookies in the upper ends? I don't know, but it's not about pH, IMHO."

my guess: brookies feed more throughout the day, while browns feed less consistently, so brookies can hang on in smaller headwater stream sections?