Where, when do Lehigh River wild browns spawn?

Underdog

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Thanks. Just curious. Do they spawn in the main stem? Or the tribs, but if the tribs - then why don't fishermen encounter hundreds of them? So they must spawn somewhere in the main river? Just very curious.
 
My theory: Lehigh River is very rocky which is not good spawning gravel for fish in general. They most likely will spawn in the tribs or the areas of the river with a more suitable gravel. Lower down on the river you get more fine gravel than the upper Lehigh, but I am sure there are spots where the gravel/silt builds up in the slower pools that could be suitable anywhere. There are numerous class A and natural reproduction tribs that help with the spawning.
 
It wouldn’t surprise me if Lehigh River BT that have spent the summer in the river not capable of spawning and do not attempt to spawn because of their extended exposure to warm temps in the summer.
 
I have never heard of this before. You must have some examples you have studied. I have often wondered what the breakdown of trout in Penn’s that spawn in the main stream versus tributaries. Penn’s must have similar summers though I don’t think it was that bad this year.
 
It wouldn’t surprise me if Lehigh River BT that have spent the summer in the river not capable of spawning and do not attempt to spawn because of their extended exposure to warm temps in the summer.
They still have to release the eggs n milt though regardless of its a succesful spawn or not
 
They still have to release the eggs n milt though regardless of its a succesful spawn or not
Fortunately for the fish, nature is all about conservation of energy.
If any eggs and sperm develop, but if conditions of these gametes or the environment are not or had not been suitable, they will be reabsorbed. The energy costs to develop gemetes are high; therefore, reabsorption conserves that energy. One frequently finds partially reabsorbed eggs in mature trout stocked for opening day that were not used as brood fish during the previous fall. Of course, if anglers are strictly C&R, they may never see this.

It would not surprise me if the wild trout in the Lehigh strictly come from the tribs.I don’t view that as a negative; it just may be that the
river system functions in that way.
 
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How many wild browns are in the Lehigh River? Have electrofishing surveys shed any light on that?
 
I used to think surveys weren’t being done because that could lead to calls to end stocking if healthy populations are found. But that doesn’t seem to matter anymore.
 
I wouldn't think any fish are spawning in the tribs this year or last as i'd think the extremely low water levels would keep them from being able to get in there
 
I wouldn't think any fish are spawning in the tribs this year or last as i'd think the extremely low water levels would keep them from being able to get in there
Put another way, that which I said in #8 above means that any low flow blockages might not matter anyway.

Speaking of trout ascending shallow riffles in fall, however, I have witnessed adult wild ST moving upstream through extremely low flow riffles in the Young Woman’s drainage by wiggling between rocks and at times barely powering over belly scraping rocks with bodies probably 90% out of the water.
 
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I have never heard of this before. You must have some examples you have studied. I have often wondered what the breakdown of trout in Penn’s that spawn in the main stream versus tributaries. Penn’s must have similar summers though I don’t think it was that bad this year.
During a study done by a PSU grad student and the Cooperative Fish and Wildlife Unit on Penns in the late 1970’s, part or perhaps all of the study was designed to measure movement of tagged wild browns in the system, specifically those that entered a distant (miles) downstream trib in fall where substantial numbers were then tagged. Many tag returns were recorded in the Coburn area. I’m not sure if electrofishing was also conducted to determine that fish were near Coburn. At any rate, come fall the tagged fish returned to the downstream trib where they, (perhaps not all that had entered the trib) entered a fish trap for capture, processing and release to continue up the trib. I include the “perhaps” portion because our PFBC Coldwater Unit crew assisted one day in recovering tagged fish farther up the trib via electrofishing.
 
Put another way, that which I said in #8 above means that any low flow blockages might not matter anyway.

Speaking of trout ascending shallow riffles in fall, however, I have witnessed adult wild ST moving upstream through extremely low flow riffles in the Young Woman’s drainage by wiggling between rocks and at times barely powering over belly scraping rocks with bodies probably 90% out of the water.
I've seen the same on tribs of the Little J. The drive to return is incredible.
But yet, people get breathless about the right way to cradle a trout during release
 
Even in extreme low water, when all the leaves are in the stream, they collect into piles on mid stream obstructions. This forces weak flows to narrow and deepen around the leaf cushions and I see trout take advantage of this to move upstream during this period. After today though, low flows shouldn't really be a problem anywhere. It has to be extremely bad to stop a 12" trout from being able to ascend a slight riffle.

I too am curious about the warm water potentially causing some trout not to spawn. It could explain why, on one of MD's most stressed wild trout streams, I saw about 40 adult trout last fall yet only documented two redds. The other explanation being that I am not an expert at spotting redds...
 
Even in extreme low water, when all the leaves are in the stream, they collect into piles on mid stream obstructions. This forces weak flows to narrow and deepen around the leaf cushions and I see trout take advantage of this to move upstream during this period. After today though, low flows shouldn't really be a problem anywhere. It has to be extremely bad to stop a 12" trout from being able to ascend a slight riffle.

I too am curious about the warm water potentially causing some trout not to spawn. It could explain why, on one of MD's most stressed wild trout streams, I saw about 40 adult trout last fall yet only documented two redds. The other explanation being that I am not an expert at spotting redds...
What it means is that it’s not always temperature problems killing off wild trout populations from the top down (killing adults); it can be somewhat frequent temperature excursions above a critical temp killing them off from the bottom up (no successful reproduction). It’s true with brook trout and I suspect that it’s one way that brown trout gain a selective advantage over brook trout because I’m betting that browns are more tolerant of the same temp excursions. If that’s the case, then browns aren’t directly out-competing brooks; they’re just more tolerant of temp excursions that limit the reproductive success of brooks.
 
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I've seen the same on tribs of the Little J. The drive to return is incredible.
But yet, people get breathless about the right way to cradle a trout during release
Agree 100 pct...the trout are waaay waaay tougher then you think....i just think the eletist fly fishing magazines and media folk got the newer to the sport of trout fishing that they need to be handled like a 8ft flouresent bulb lol
 
Personally I think that the browns in the small feeder streams are the source. Those fish continue to reproduce until they out grow the habitat (~12 ") they then drop down into the river.
Earlier this year I posted of the rarity of catching smaller browns in the river. Typical and most LR browns are 14 to 17 inches. (Obviously to prove me ignorant, a few days later I caught a small wild brown ~8 inches.)

The lack of smaller fish in the river itself, leads me to believe these fish spend the majority of their lives in the tribs, drop down when mature due to insufficient habitat, (ie cover, food etc) and live out their lives in the river.
 
Purely anecdotal but I remember catching way more small browns in Penn’s Creek back in the 80’s and 90’s. Maybe some of those caught back them were stocked fingerlings?
 
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