Predicting wild trout presence

[afishinado]

I blundered upon this presentation when looking for some other info. It's some great info about predicting wild trout presence using geology and other factors for the DIY wild trout stream seekers.

http://www.coldwaterconference.com/uploads/5/0/9/0/50909909/ressler.pdf

 

[Swattie87]

Yeah, I've come across that one before. It's a good read. If I didn't know any better, I woulda thought our k-bob wrote it.

 

[afishinado]

Here's another good presentation on PA Unassessed Wild Trout Waters Program:

http://www.coldwaterheritage.org/docs/unassessed-waters/unassessed-waters-presentation.pdf?sfvrsn=0

 

[franklin]

afishinado wrote:
I blundered upon this presentation when looking for some other info. It's some great info about predicting wild trout presence using geology and other factors for the DIY wild trout stream seekers.

http://www.coldwaterconference.com/uploads/5/0/9/0/50909909/ressler.pdf

If they would have extended that area down about a mile they would have included my property. Would have been interesting to see their assessment of the stream flowing through. As it is I have explored a large number of the streams and tributaries they did cover and have found a lot of brookies in those waters. Small, yes, but healthy fish.

 

[k-bob]

I like these, but handle the "acid rain as buffered by bedrock" issue a little differently. Because I usually fish in NEPA, where the individual bedrock areas are larger than in the center of the state, I just try to fish in huntley, catskill, shawangunk, juniata, and mauch chunk bedrock areas, and avoid tuscarora, pottsville and burgoon ones. And if in doubt I have a dissolved aluminum test kit, if it is over .05 mg/ litre at low/ base flows, that is a bad sign because at high flow the alum may reach lethal levels. It is dissolved aluminum released from soils by acidity, not the acidity per se, that kills trout

For ex., upper devils hole in Monroe has a very high biomass of brookies on the Wilderness trout stream list, and it comes out of catskill bedrock and has a barrier waterfall that keeps the browns out of its upper levels. Some very steep streams in catskill bedrock may also have brookies not browns, perhaps because bookies handle steepness better.

I've learned the hard way that any significant underground stretch at lower levels is a bad sign of brookie presence in a very small stream. If there's an underground stretch down near the bigger body of water there's probably no way for the fish to repopulate after a drought.

 

[steveo27]

Neat. Ill have to give it a read

 

[TigerTrout4wt]

these were very great reads. i do have some questions on how to find waters like this. 1st question is how can I find the surveys on streams that have wild trout? some people have told me about public records of them but i cant seem to locate them when i search online. 2nd is is their any tips for location streams that are not on the lists? I have read the two power points but they use a lot of terms that i dont understand. I did understand the basics of it but is their a way to survey the stream geologically? I really dont know anything about this sort of thing and i would like to learn as much as i can. Any kind of information would be great. please excuse my ignorance to my terminology. Also steveo27 that is a beautiful tiger.

 

[troutbert]

The PFBC website has a very large list of streams supporting wild trout populations.

I recommend just starting with that, looking at the streams in your areas of interest.

 

[pcray1231]

Tiger,

They've kind of buried it on the website, unfortunately.

Streams with natural reproduction (list): http://www.fishandboat.com/Fish/PennsylvaniaFishes/Trout/Documents/trout_repro.pdf

Streams officially proposed for the above list (meaning wild trout were found and the PFBC has asked to have these added to the above list, but it has not been granted yet):

http://www.fishandboat.com/Fish/PennsylvaniaFishes/Trout/Pages/WildTroutStreamsOfficiallyProposed.aspx

And streams being "considered" for inclusion. Means they found wild fish but haven't officially proposed the addition of these streams yet:

http://www.fishandboat.com/Fish/PennsylvaniaFishes/Trout/Documents/WildTroutStreamsBeingConsidered.pdf

 

[TigerTrout4wt]

this is great information and has been very helpful. I was wondering though i have been looking at maybe testing other waters i have fished for the pH balance and i already had a thermometer. does anyone else try this? I was looking at collecting data to understand a trouts habitat and better understand the ecosystem to even see how it affects the hatches of the insects. I saw a few digital pH scales on amazon but was wondering how accurate they are?

 

[k-bob]

I found electronic pH gauges to be unreliable but have had good results with this:

http://www.hach.com/ph-test-kit-5-6-8-4-ph-model-17f/product-details?id=7640214952

also some data on streams under "water chemistry" here:

http://mdw.srbc.net/waterqualityportal

 

[TigerTrout4wt]

Wow that's a bit of coin to dish out to test the water pH... I was reading a lot of people say the digital scales are inaccurate. Thanks for the input k-bob I will look into this one more because I do want accurate readings. Lol.

 

[Chaz]

A quick easy way to predict wild trout presence is to walk along streams during the spawning season.

 

[FarmerDave]

TigerTrout4wt wrote:
Wow that's a bit of coin to dish out to test the water pH... I was reading a lot of people say the digital scales are inaccurate. Thanks for the input k-bob I will look into this one more because I do want accurate readings. Lol.

Tigertrout, there is no real need for big accuracy. You can buy Ph test strips for less than 10 bucks. Doing a very quick google search came up with this.

I never used them, so can't endorse them.

I was thinking you could just use pool test strips, but they only go down to something like 6.2 or 6.4 and most of the streams in NWPA wouldn't even register. On the upside, I think they do measure alkalinity, too.

I also have an old and cheap analog PH meter around the farm someplace. It probably would be accurate enough for measuring stream PH, but I can't see carrying a meter around for this.

 

[pcray1231]

Fd, I've used those. The problem is precision. Honestly, you dip it, and see right away it's under 7, but then, most streams are. But you try to compare, and it's like, I could call that 4, 5, or 6! When measuring stream ph, there's a HUGE difference between 4.0 and 6.6. And if it's truly 4.0, you didn't need a stream gauge to know it, lol.

I haven't tried Bob's kit but it looks good. I don't want to carry a full kit. I have, on occasion, taken a small bottle, then titrated it in the lab. But to go to that extreme, you gotta really wanna know. Not really a good way to screen a bunch of streams.

 

[k-bob]

yes, have to watch the scale range of test kits (weren't made for fishing)... that hach pH one has worked well (link in previous post).

test strips werent working well for me, not precise or reliable enough... I found electronic gauges to be wonky, give unstable readings on same water... I bought a hach kit after reading state biologist reports that gave small stream pH down to tenths, wondered how they did it for a lot of streams in the field... a colorwheel test like the hach one was the answer.

if I am only worried about acid rain/precip, not amd, I use a lovibond 0-.3 mg/l alum test kit. it is aluminum released by low pH, not the low pH itself, that kills trout in flood or snowmelt. this is a consequence of acid precip, moderated by bedrock (some less promising bedrocks: pottsville, llewelyn, tuscarora, burgoon, bald eagle, white quartz; better = catskill, huntley, shawangunk, mauch chunk, juniata). those bedrocks are in simpler NE PA, centre county alone 12,243 bedrock types

a low level of alum (for ex., < or = .05 mg/l) at very low "base" flows (I fish in summer a lot) is a good sign. but 2 days of .2 mg/l alum is lethal to trout.. if it's much above .05 in a low flow, it may hit those damaging levels in a precip event.

some streams in very low buffering bedrock are at .2 mg/l aluminum in a low summer flow, but over the mountain in another bedrock can sometimes be better.

either the pH or alum test kits cost $100, but they have worked for me. ... particularly the alum one, for acid precip/bedrock issues in headwater mountain streams... test a bunch of tribs where they cross a road, etc...

the alum one fits in a back vest pocket pretty well, weighs a lb

i am a laaaazy hiker, not carrying anything heavy

some bad bedrocks named and shamed in link below pottsville, llewelyn, tuscarora, burgoon, bald eagle

http://www.dcnr.state.pa.us/topogeo/publications/pgspub/openfile/acidmap/acidmaplayers/index.htm

note absence of bad stuff in say Potter.

note this is all mountain/headwater trib stuff, at lower elevations things are often better..

 

[k-bob]

http://www.lovibondwater.com/product/checkit-comparator-aluminium.aspx

 

[k-bob]

figure 4 here shows why .05 mg/l aluminum at low/base flows may be a good cutoff value when looking for brookies:

http://www.facstaff.bucknell.edu/kirby/KirbyEtAl2008STOTEN10392.pdf

(fig. 4 also shows that many streams in tuscarora bedrock were over the lethal aluminum level of .2 mg/l when these data were taken at low/base flows... heavy rains or snowmelts will increase the aluminum level)

 

[k-bob]

nice discussion of the effect of acid rain in quartz bedrock areas, such as the montalto bedrock area of the michaux state forest SE of carlisle. I have seen streams there with lethal aluminum levels at very low flows, similar to some of the tuscarora streams in fig 4 of kirby paper linked in previous post. (as is often the case w acid rain, nearby parts of michaux over other bedrocks have some nice trout)



"The ability to neutralize acid is called buffering capacity. Quartzites have a low-buffering capacity. This means they are extremely subject to becoming acidic, from the inability to buffer the carbonic acids supplied in acid rain. The type of soil and bedrock are very important to buffering capacity (thus, pH and life forms). The amount of carbonate minerals present is the most important factor. If the watershed contains a lot of limestone or dolomite bedrock, it will likely have enough buffering capacity to withstand even the most severe acid rain without any degradation of the environment. On the other hand, if the bedrock in the watershed is mostly quartzite or shale, there may not be enough buffering capacity and the pH will become acidic. The acidification of streams and lakes tends to get worse over time as the buffering capacity in the watershed is depleted. When the pH of the water gets lower, metals in the soil and stream bed become more soluble and dissolve into the water. These metals, especially aluminum, reach levels that are toxic to aquatic life, and this is how acid rain kills the fish."

http://www.bobpickett.org/08-08%20Tuscarora%20sandstone.htm

 

[k-bob]

imho, 2 reasons to test aluminum rather than pH when looking for mountain brookies in headwaters tribs that may have acid rain/precip issues: 1) aluminum, not pH, is the actual cause of fish mortality, and 2) on-stream measurement of alum may be easier in the first place.

see page 14 of below on issues they had w/ field pH measures on mountain tribs... not as easy as it sounds..

https://www.bucknell.edu/Documents/Biology/BMcInerny2006AcidPrecipThesis.pdf