using bedrock geology info to fish in acidrain areas

[k-bob]

interesting questions about the reduction in rainfall acidity over recent decades, and lately as well. one quick point: the data for the pH of well water in the table above was gathered about 25-30 years ago, so I don't assume things would be the just the same today. instead I think about relative buffering capacity of A vs B bedrock.

I sometimes find brookies in streams not on the natural repro list and wonder if the streams were never surveyed, or maybe if brookies came back to some just-below-threshold streams in recent decades. (we have lists where trout were found in surveys, but no lists of streams where trout were not found in a survey in some specific year). (yes I tell the state about the brookies)

mike are you out there? anyone know if brookies are sometimes found for the first time in previously assessed streams?

 

[k-bob]

another thought pat: at least in NE PA (eg sgl57, ricketts, sgl13, meehopany tribs), many of the mountain ridges seem to have low buffering bedrock (burgoon Pocono potsville). since brookies are good at living in tiny steep streams and better tolerate acid, it might be a long time before BT can live up there if BT spread further with less acidic rain, so may brookies, as some of these small steep streams are too acidic for ST now (sgl13 east branch fishing tribs)

 

[pcray1231]

Yeah, and I said as much.

Browns would likely take over some areas now inhabited by brookies. Brookies would likely take over some areas now inhabited by nothing. How it all balances out, I dunno.

Though, as I said, it was more an interesting thought than a call to action. Overall, more trout water = good. This would be a "good problem" to have, I suppose.

 

[pcray1231]

Here's a map of announced retirements. This is complete plant shutdowns between 2012 and 2016.

Many more individual units are being taken offline that aren't shown on the map. And it's projected that many more will shutdown that haven't been announced yet.

Note that many are upwind of us. And these are the remaining plants WITHOUT scrubbers, so by and large, the ones that affect our rainfall pH the most. Generally, when the Clean Air Act went into effect, the plants in which it was economical to install scrubbers, did. Now the EPA regs have been strengthened, and the remaining ones, where it was not economical to install scrubbers, are shutting their doors.

I'd also note, that in regards to the Marcellus debate, Marcellus shale is WHY these coal plants are shutting down. Gas got cheap. And the EPA is now able to increase it's requirements without making the price of energy skyrocket. So they did. I've never claimed that Marcellus doesn't have some environmental concerns. But the proper comparison isn't Marcellus vs. nothing. It's Marcellus vs. coal.

 

[k-bob]

think we were writing at same time, pat. by using > 2 fingers, I suspect, you type faster than I do

probably just aren't enough repeated surveys on the same streams to see gradual effects of less acidic rain?

yeah, interesting retirements map.. a step down in PA rain acidity may be coming our way, and its effects on ST BT etc may be fun to watch

 

[pcray1231]

Better map:

 

[k-bob]

upadated "pH of well water by bedrock" table

 

[k-bob]

pat: "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?"

this makes sense to me, as does a reduction in rainwater acidity w/ switches to gas and retirements of unscrubbed coal. I'd love to see ST spread out a bit... ongoing stream pH would still affect food supply and number/size of fish.

 

[duckfoot]

k-bob wrote:
pat: "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?"

Correct.

 

[k-bob]

article below: spring stream acidity spikes as acid discharged from snowpack; worse effect than just a heavy rainstorm. spring is a bad time, young fish more vulnerable. overall effect depends on speed of runoff entering streams and soil buffering capacity. soil buffering capacity derives from bedrock, depleted over time, recharge takes time.

http://hubbardbrookfoundation.org/wp-content/uploads/2010/12/spring_snowmelt.pdf

wish we had info on pfbc surveys where trout were not found, because brookies may spread out a bit with less acidic rain.

 

[troutbert]

Does anyone have a link to info on how the pH of rain in PA has changed over time?

And does anyone have good info on how pH of streamflow has changed in infertile streams?

I know that there are monitoring stations for both, but I couldn't find the info.

Preferably some summary report, not indecipherable raw data files.

 

[k-bob]

Dwight, not sure this is what you are looking for but try this link and hit "page down' key to advance years:

http://nadp.sws.uiuc.edu/maplib/ani/pH_ani.pdf

 

[troutbert]

Thanks kbob.

From what I've read the historical normal average of precip in PA was about pH 5.5.

According to a PSU researcher (Lynch), the average from 1982 to 1992 was pH 4.18.

From that graphic it looks like PA precip is now about pH 4.7 - 4.8?

It would be interesting to see what they are getting at the stream monitoring stations.

 

[k-bob]

there are usgs sites with pH data, incl pine and kettle, but they only seem to make it available back a few years .... one usgs station with data for about last six years is in chester county (below) would like to see this kind of info for longer time of course :

 

[troutbert]

If anyone wants to check on trout moving up into areas previously too acidic, they could check at Swift Run, Snyder Cty.

The situation a few years ago was:
Brook trout could be found in decent numbers where the forest road parallels the stream.

As you continue upstream, you get to the last parking area, then the forest road turns away from Swift Run, and parallels a small trib.

Trout were found below that trib, and sometimes up to about 100 feet above it. But above that, continuing up into the backcountry headwaters of Swift Run, there were no trout.

 

[k-bob]

"If anyone wants to check on trout moving up into areas previously too acidic, they could check at Swift Run, Snyder Cty."

Swift run starts in low-buffering Tuscarora bedrock and stays in it for over 5 mi... a stream in that bedrock band probably would not be the first place for ST to recover from acid rain effects.

Coral run, just north of swift run, starts in higher buffering reedsville bedrock, and it does have brookies. I recently tried another stream round there not on nat repro list but starting in higher-buffering Juniata bedrock, it had brookies. I'd guess that many streams in the area in high-buffering bedrock probably have brookies now.

But when streams aren't on the nat repro list, you don't know if they were not surveyed or if they were but ST weren't found. I'd love to have info on streams where brookies were not found, incl year of survey? Given that info, I'd look for ST to return to streams with moderate buffering bedrocks before streams like Swift in low-buffering Tuscarora bedrock.

 

[troutbert]

In that region, the streams coming out of the Tuscarora are the ones with "issues."

The streams coming out of the Juniata have trout as far up as there is water. But that is not a new thing, it was that way all along. The streams coming out of the Juniata never lost their brook trout.

 

[pcray1231]

Bob,

Regarding the graph, probably not the best place to look. Typical pH looks to be above 7, and the lowest there is 6.1 or so. I doubt this is the type of place to look for streams that are helped when rainwater improves from 4.1 to 4.7 (and hopefully further in the future).

The historical streams without brook trout would be most useful. You could cherry pick a few streams most likely to show early results, and monitor them over time.

In the end, this is a long-term, slow, grudging improvement. And I would think any positive on stream results would be the same. The rod is probably not the best way to find minute differences. Electrofishing would find the differences, but proving WHY in the face of a myriad of other variables would still be difficult.

What you really need is pH data, like your Big Elk graph, but over a very long time period and specifically on acid rain affected streams. Lacking that, put it in perspective. Rainwater pH is improving, and set to take another jump in the positive direction over the next few years. That's a good thing, even if you can't prove it.

 

[k-bob]

pat I know six years isn't enough, but usgs only gives just 3-7 years of old pH data, so that's all I posted... I didn't draw conclusions from it. my point there was that I wish usgs gave us more data. probably not many little streams with ph data back 25 years to provide, I guess.

but see the link w/ animation in my post 52 for evidence of increased pH of PA rainfall.. makes the point clearly.

so Ok the pH of PA rainfall has increased a bit in the last 10-20 years. as you said, it will takes more years - for power plants to change, and soils to recharge - before streams will likely improve much from today's level.

and as for fishing, well we have limited stream survey data. no list of streams where nat repro not documented, and when.

one thought: there is the wilderness stream list, which unlike the nat repro list, gives biomass and the year the survey was done. some of these wilderness surveys are already 15 or more years old, and the rain pH has increased a bit since then. rainfall pH is likely to increase a bit more in next 6-12 years w/ new EPA regs and closure of unscrubbed coal in Ohio valley. so some of those wilderness streams that had low ST biomass 15+ years ago could have a higher level of ST biomass 5-10 years in the future.

 

[troutbert]

Going back to the original topic, there is an assumption being made that I think you have to be careful about.

The assumption that the fertile streams will have good fishing, and that the infertile streams will have poor fishing.

That SEEMS reasonable, but as usual with fisheries stuff, there are many confounding factors.

Some of the infertile streams have zero fish. But some of them do have fish, brook trout. And in some cases the brook trout fishing in these streams is very good.

One stream in the NC PA Allegheny Plateau that I've fished pretty regularly since the early 1990s has no trout at all in the headwaters. But once you get below that zone, I've had some very good brook trout fishing, including larger than average brookies.

And the section of stream where there are zero trout and where I've had very good brook trout fishing are less than 1 mile apart.