The best seven brookies of the year

[Mike]

Twelve years ago our crew conducted a survey of a stream (a trib to the Schuylkill R, Schuylkill Co) that was the recipient of substantial amounts of mine acid drainage. One tributary that I can recall even longer ago was brightly colored with iron precipitate. Twelve years ago the pH in the receiving stream was 4.2 and total alkalinity was 0. Rocks were only slightly iron colored on their undersides and had a natural coloration on top. Physical habitat was very good. With a pH of 4.2, searching for fish would have been fruitless. Somewhat better conditions existed toward the headwaters and no fish were found.

Last week we visited the stream again for the first time since the survey of 12 yrs ago. This time there was no iron precipitate on the undersides of the rocks and the pH was 4.8. There was still no alkalinity. A quick walk along the stream suggested that there were no fish present. Despite this and despite the marginal pH condidtions, the crew electrofished for 165 meters turning up two 8 inchers, 1 seven incher, 1 six incher, 1 five incher, and 2 four inchers (wild brookies).

With the improvement in the Schuylkill River and the wild brook trout present there, this stream now had a "feed stock" of wild brookies. As pH improved they most likely took advantage of the marginal situation, moving upstream in the trib for probably at least a quarter mile. There was no evidence of reproduction in the stream from last fall, but it did support a small wild brook trout population comprised of multiple year classes and the fish were very plump, apparently finding plenty of forage, most likely including the crayfish that were present as well as terrestrials and some aquatics. This was the apparent recolonization and perhaps the rebirth of still another wild brook trout stream in the Schuylkill R drainage basin.

 

[outsider]

Mike,

Several years ago I watched a local outdoor program on Berks TV. They were fishing an unnamed stream in Schuylkill County with all the characteristics of mine acid drainage - discolored rocks and the water had that yellow look. They suggested that the fish they caught were living on small bait fish. And the fish they were catching were native brook trout. Perhaps the same stream.

 

[Mike]

Outsider, the good news is that the video you saw was probably from another stream, meaning another stream was recovering as well.

 

[Fishidiot]

Interesting and promising observations.

Bet that - if you survey it again in a year or two - there will be YOY STs and a better population still.

Would make a good project to study annually for a few years to see if some solid correlation between population structure and changing PH can be graphed out for a recovering stream as it works it way up to a full population capacity or maybe even Class A. Wouldn't surprise me if this happens fairly fast, maybe 2-3 years(?). Worth keeping an eye on.

 

[Zak]

Nice Mike! Thanks for yet another encouraging report about improving trout waters.

 

[gulfgreyhound]

Why not introduce limestone in the stream bed to improve Ph ? GG

 

[pcray1231]

Generally speaking that's used for acid rain impacted streams, where the total acid load is lesser and a slight boost to alkalinity can mitigate the effects. Things are a little more tricky for AMD.

Well, maybe less tricky actually, if you have an obvious point source. Nonetheless, the strategy wouldn't be merely to lay some limestone in the creek bed. You'd need too much. Typically I think the discharge is deviated into a holding pond where there's a longer contact period with limestone as well as biologics.

Physical habitat was very good. With a pH of 4.2, searching for fish would have been fruitless. Somewhat better conditions existed toward the headwaters and no fish were found.

With the improvement in the Schuylkill River and the wild brook trout present there.

There was no evidence of reproduction in the stream from last fall, but it did support a small wild brook trout population comprised of multiple year classes and the fish were very plump, apparently finding plenty of forage.

Disclaimer: I'm not claiming no improvement and find it wonderful that we're finding this.

But, 12 years ago.... Was it actually surveyed, or they just didn't bother on account of the pH? What time of year was that?

And this time, I assume this was recently, as in late July or August?

Everything about this, to me, screams that this may not be a wild brookie stream, but rather, simply a seasonal cold water refuge. That's still pretty cool to find. But it doesn't guarantee an actual improvement in this stream, and if the brookie's presence is indeed new, it's more a reflection of the improvement in the Skuke than it is in this trib.

- pH at this time of year is going to be about as high as it'll get all year long. 4.8 now doesn't mean it's not still 4.2 at other times of the year.

- you found plump, well fed brookies in a still highly acidic environment. Suspect. Maybe they got plump somewhere else? Like a larger river just downstream or something.

- you were in the extreme bottom end (1/4 mile?) of a small, cold stream, that runs into a larger, richer stream with marginal temps and a known improving population of brookies. And you found only a handful of fish with no evidence of reproduction in this stream itself.

- You stated the headwaters had better pH's. Are fish still absent up there?

 

[geebee]

do brookies not like acidity ? - browns can and do adapt to it i know - Ireland and the Scottish Highlands are full of high acidity streams i know...

 

[Chaz]

Sounds like a stream that's coming back, though the ph is still marginal for trout.I'd love to see it monitored for ph throughout the year. Geology in Schuylkill County is such that the bedrock keeps ph and alkalinity low. Do you know Mike if it's being treated already? I'm guessing it isn't.
Monitoring the ph would tell you when the ph is worse and you could form a plan to treat the outflow of AMD. Different levels require different approaches. Many of the treat sites in Schuylkill County are treated with active and passive treatment working together.

 

[troutbert]

geebee wrote:
do brookies not like acidity ? - browns can and do adapt to it i know - Ireland and the Scottish Highlands are full of high acidity streams i know...

What is the ph of those streams?

 

[pcray1231]

brookies handle it better than browns do.

Numbers in Scotland/Ireland can get down to pH of 4.5 for brief periods, but they vary more than ours do, both seasonally as well as daily, and many of the fish are migratory, only in the streams during certain periods.

In their studies, they tend to focus on viability for breeding. A pH of 5.5 is often cited as a critical value. Different studies approach it different, some saying it's gotta be over 5.5 for X % of the time, and others stating it's gotta stay over 5.5 while eggs exist in the substrate, but doesn't matter as much at other times (that makes more sense to me).

Brown trout can enter more acidic streams, and be caught there, but they won't reproduce there. Not successfully, anyway, they may breed and lay eggs but the eggs die.

This is probably pretty similar for the critical value in the states for brown trout. I've always heard 5.0 for survival and 5.5 for eggs. I'm sure it's not a hard number, meaning it depends on the duration and realistically, there will be a range where % survival varies.

Brookies can handle more acidic environments than that. Generally about 0.5 below that of browns, for both eggs and survival.

 

[Chaz]

What is the cause of acidity in the Scottish and Irish Stream? If it's natural, i.e., caused by tannic acid from peat bogs that's very different from acid rain or AMD.

 

[troutbert]

Chaz wrote:
What is the cause of acidity in the Scottish and Irish Stream? If it's natural, i.e., caused by tannic acid from peat bogs that's very different from acid rain or AMD.

"Most of the UK sulphur dioxide comes from power stations (65% in 1999) and other industries (22% in 1999) whilst the largest source of nitrogen oxides is road transport (44% in 1999) and power stations (21% in 1999).

The UK experiences typical impacts from acid rain. Freshwater acidification is a serious problem in susceptible parts of the UK. These include central and southwest Scotland, the Pennines, parts of Cumbria, central and North Wales and parts of Northern Ireland."

 

[FarmerDave]

pcray1231 wrote:
brookies handle it better than browns do.

Numbers in Scotland/Ireland can get down to pH of 4.5 for brief periods, but they vary more than ours do, both seasonally as well as daily, and many of the fish are migratory, only in the streams during certain periods.

In their studies, they tend to focus on viability for breeding. A pH of 5.5 is often cited as a critical value. Different studies approach it different, some saying it's gotta be over 5.5 for X % of the time, and others stating it's gotta stay over 5.5 while eggs exist in the substrate, but doesn't matter as much at other times (that makes more sense to me).

Brown trout can enter more acidic streams, and be caught there, but they won't reproduce there. Not successfully, anyway, they may breed and lay eggs but the eggs die.

This is probably pretty similar for the critical value in the states for brown trout. I've always heard 5.0 for survival and 5.5 for eggs. I'm sure it's not a hard number, meaning it depends on the duration and realistically, there will be a range where % survival varies.

Brookies can handle more acidic environments than that. Generally about 0.5 below that of browns, for both eggs and survival.

Pat has that about right based on what i have read. Although it is at about 6.0 that survivability of the eggs starts to decline, some will survive at 5.5.

As far as PH survivability of adult trout, Brook handle lower PH than Browns, and Browns handle it better than rainbows.

Even some anecdotal info I have supports this. IN a tank fed by a spring in NWPA, we placed some legally caught trout so we could eat them later, fresh. Brook trout did fine, but browns turned belly up within a half hour. We didn't measure the PH, but now that springs tend to be acidic in that area. No other pollutants either. It was quite remote in that respect. We had brown trout for dinner that night.;-)

I think Pat made some good points about the steam in the OP.

 

[pcray1231]

Yeah, they have acid rain.

That said, the most acidic of their streams are very clearly in coniferous dominated forests.

I'm not sure I agree that it's very different if it comes from peat. pH is pH. Though it may be that peat is acidic, but not enough to cause real issues, while also virtually eliminating more acidic spikes because of it's water absorption characteristics which increase groundwater flow and decrease runoff.

 

[Mike]

Two or three years ago we discussed the possibility of a treatment system for this stream with the Schuylkill Co Conservation District. Some investigation occurred and the appropriate individual is aware of the potential. Finding brookies now will certainly not hurt the cause.

As for the Schuylkill River itself, there are no known thermal problems from the SGL below Schuylkill Haven to the headwaters so it is unclear why this particular technicality surfaced in this discussion. The trib falls within that stretch.

As for plump trout in acidified streams or those with few aquatic macro invertebrates due to heavy iron precipitate, that is the norm in Schuylkill Co. Ask Chaz. That question was answered for summer and fall periods via stomach analyses about a decade ago...terrestrials, including large caterpillars at one end and tiny aphids at the other end of the size spectrum. This particular trib also has some macros as well as crayfish, but no forage fish.

 

[pcray1231]

Fair enough. And finding brookies there is a good thing regardless of source/cause, so in no way was my post meant to be a criticism. Just trying to understand the why, so that we can apply the info to other situations.

I didn't know exactly where it flowed into the Skuke, as you didn't state the stream or exact location (for obvious reasons). But while I was wrong, it wasn't exactly a stretch to wonder if the Skuke had thermal issues in that area.

It came up because you surveyed the extreme lower end of a still acidic trib of a larger waterway known to hold brookies, did this survey in mid-late summer, and found a handful of fish with no evidence of actual reproduction, while also commenting on how well fed those fish appeared to be. I was trying to connect the dots, that's all. Given those facts, thermally induced migration seemed to fit, rather than assuming an improvement in this stream itself.

It resulted in getting more useful info, including that the larger waterway below does not have thermal issues and that brookies in similar streams nearby have been shown to be well fed despite the water chemistry, thanks to an abundance of terrestrials. So thank you for the follow up and adding additional pieces to the puzzle.

 

[Smike]

I didn't know exactly where it flowed into the Skuke, as you didn't state the stream or exact location (for obvious reasons).

Unless I'm missing something, this stream is either currently publically listed as having natural trout reproduction, or it will, and the overall intent by PAFB is to publically list it. Now unless the obvious reason is they can not disclose it until the paperwork is filed, I can't see one. I think it would help to say this stream is either currently listed or is being considered to be listed.

 

[Zak]

Mike's got a proven track record of not dumping stream names and I'm particularly happy he does that. With only 10 trout being found, and half of them being legal, what would stop someone from catching and keeping those f5-6 fish? I know, thats super unlikely. But lets say 2 people get he stream name and decide to fish it, deep hooking 1-2 of the 10 trout and killing them. That's a 20% reduction in trout numbers. When a stream is good enough to support a recreational fishery it's stated as such. The rest should be left for us to discover on our own.

 

[Smike]

It would be incredible if a fish survey was an absolute number of actual fish in a given stream section. I’m sure Mike can comment on what a survey # is considered to be of what % of actual fish numbers that may ultimately exist.

Anyway the point there is a process which the PAFB goes through to document (yes publically) streams found to have natural reproduction. Which I’m in favor of, as its help TU and others with working with various stakeholders in protecting said streams. If this stream were to qualify, I hope it gets listed is my point.