Population decline?

[SlingerFlyRods]

there is a class A trout water that runs through our camp property near sinnemahoning and it is bone dry nearly every summer.. after this rain this weekend, i bet sunday i can catch brookies where there was not only no water, but no saturated rocks..

life finds a way

 

[troutbert]

SlingerFlyRods wrote:
there is a class A trout water that runs through our camp property near sinnemahoning and it is bone dry nearly every summer.. after this rain this weekend, i bet sunday i can catch brookies where there was not only no water, but no saturated rocks..

Is the whole stream dry, or just parts of it?

And if it's all dry, how do you think that happens that you can catch brookies when rain brings back water?

Where are those brook trout coming from? Where were they surviving the dry period?

 

[troutbert]

salmonoid wrote:

troutbert wrote:
Salmonid's photos show the importance of pool habitat.

On small freestone streams, during bad droughts, the pools are the places that have water.

The rest of the streambed is dry (or nearly so.)

And trout being AQUATIC creatures...

I'm curious to know what the depth to bedrock is in some of the small freestone valleys. In some places, bedrock is exposed. But in others, there could be several or dozens of feet of small rounded stones that have eroded over many thousands of years. And while the exposed streambed is dry, there's clearly flow occurring at some level. For instance, I have seen fish stack up a few yards downstream of cold tributaries, where there is zero surface flow, but clearly something cool and inviting is moving underground.

On many freestone streams (most?) you will see bedrock exposures here and there as you walk up the stream. In those cases I think bedrock is probably generally not very far down, even in the stretches where all you see is cobble and gravel on the streambed.

On freestone streams in unglaciated areas in PA, I think bedrock is usually not far down.

In some of the glaciated areas, though, the glaciers dug the valleys both wide and deep, then large amounts of glacial material was deposited.

I read that in some places (maybe Bradford County?) that the floodplains are 60 feet deep.

 

[pcray1231]

Trout burrowing through the stream bed, wow. Wouldn't the water get warm from the exposed rocks acting as heat conductors? How far down are we talking about when they burrow?

No. I mean, normal freestone springs are the result of shallow underground flows, and they come out at around 55 degrees year round (ok, they do vary a few degrees, but not much). You don't have to get very deep to hit stabilized temperatures.

This is why streams stay cool in summertime! Small freestoners are largely spring fed and have portions of their flow underground throughout most of their length, and in steeper areas, pick up new springs more frequently. That's how it can be 75-90 degrees day after day in July and that little freestone stream is at 60-65 degrees. But as they get lower and larger and flatten out, it's usually on or nearly on bedrock, so there's more water above ground and less % below ground. The springs also come less frequently (they blew their load on the hillsides). So the streams warm. In any given area with freestoners, there's a semi-consistent "max size" for trout, where when a stream gets too big it also gets too warm.

The same thought process applies to limestoners, but there's no max size. Because the underground water doesn't have to be over the bedrock, it can be through the bedrock. Thus instead of hundreds of small springs spread out over a large area you can have 1 large one, where a sizable stream emerges all at once. Further, in the lowlands, flowing on bedrock does not mean water can't go down. The bedrock is permeable. So even largish streams can have large portions of their flow disappear underground and flow there long enough to cool down, re-emerging far away and rejuvenated.

So the difference is over bedrock for freestoners vs. under bedrock for limestoners. But even over bedrock is indeed deep enough to hit stabilized temps. Only need a foot or two for that.

Think of it this way. If temperatures don't become an issue in water that is above ground, it certainly isn't going to be an issue for water that is below ground. There are other, obvious issues they'd face. But temperature isn't one of them.

 

[Jessed]

Could it be possible that the fish swim into the spring ? I've seen holes in the ground maybe a foot round of water coming out of the ground.

 

[steveo27]

Neat.

Are there any articles or studies on this subject. Im interested in reading more

 

[Hook_Jaw]

I've never seen Penns this low in my lifetime.

 

[Jessed]

Hopefully this few days of rain helps the streams

 

[SlingerFlyRods]

troutbert wrote:

SlingerFlyRods wrote:
there is a class A trout water that runs through our camp property near sinnemahoning and it is bone dry nearly every summer.. after this rain this weekend, i bet sunday i can catch brookies where there was not only no water, but no saturated rocks..

Is the whole stream dry, or just parts of it?

And if it's all dry, how do you think that happens that you can catch brookies when rain brings back water?

Where are those brook trout coming from? Where were they surviving the dry period?

the entire stream from as far up the hollow i can see is dry.. all the way 200 yards downstream to the mouth.

i would guess they are in spring seeps literally under the ground, i cant imagine they all run down into the sinnemahoning.

very good question i never really thought of the science behind it but year in and year out. They are there all year round with water

 

[BrooksAndHooks]

I know a few unnamed around here were dried up, but fish were surviving well in the few large pools and puddles around. I would not be shocked at fish burrowing and also sitting in water under the rock that is visible as well. Have only seen one dead fish in the last few weeks, and it was on a limestoner and probably normal mortality.

That said, one of my favorite brown streams appeared almost devoid of fish, and it has actually fished pretty sadly the past two years or so, a combination of factors, which includes dry summers and deterioration of structure/holding water for them to survive these drought event.

It's definitely tough on the fish, but they survive. It's what they do.

 

[BradFromPotter]

A problem no one is talking about is anchor ice. With this low flow of water & a very cold early winter this could kill many trout.

 

[wildtrout2]

BradFromPotter wrote:
A problem no one is talking about is anchor ice. With this low flow of water & a very cold early winter this could kill many trout.

That's a real good point you bring up. I hope that scenario doesn't play out.

 

[TJones]

Are you guys serious? Trout borrowing holes and traveling underground... ? Ummm let's have a few more beers... This sounds a little far fetched.

 

[Hook_Jaw]

Alot of the trout I've caught In penns the last 2 weeks have been really slender was a long hard summer on them.

 

[Zak]

Also to consider is that not all parts of PA were hit like NC PA. SWPA and the entire Eastern half of PA, streams were low but nothing that we're going to notice from a trout recruitment standpoint. I really think that the huge impact area is isolatied to Central and NC PA....which unfortunately is the hot bed for our trout angling.
Now, lots of time to be had in this drought possibly. You never know how long this could last for. If this goes into winter then hardly anything is going to survive is those little dried up streams.

 

[Swattie87]

The cooler temps are a plus for now, and the other positive thing is that after the first good frost the vegetation doesn’t suck up near as much water and a much higher % of a given rain event makes it into the watershed. After the last couple nights in southern Berks Co., I’d have to imagine they’ve had a good frost up there in the NC by now. If we can get some rain, base flows should start to improve.

Keep in mind we're at the lowest flow point of the year anyway, and in terms of median flow, we're not all that far off on many streams. Things are low, but the fish are alive up there. I can attest to that being up that way a couple weeks ago. Things should improve through Spring at this point. Even an average, or slightly below average, precipitation period from now til then should have things back to normal.