Conestoga River and Pequea Ck Smallmouth reproduction 2017

[Mike]

The Conestoga's SMB YOY index was very good this year for the second year in a row. It had been fairly poor for the 5 yrs prior to that. Just over the hill, so to speak, the Pequea's SMB YOY index was very poor this year, but generally ok for most of the years prior to this year. The Schuylkill and Delaware were also very poor this year and this was expected, given the flows and frequent rain events. The Conestoga was a puzzler, however, but I understand that the variability seen between the Conestoga and Pequea characterized other Susq R tribs as well this year. Tribs are important in their own right, but they also contribute fish to their receiving rivers, bolstering those populations and helping in particular in years when river reproductive success is poorer than usual.

 

[afishinado]

Mike wrote:
The Conestoga's SMB YOY index was very good this year for the second year in a row. It had been fairly poor for the 5 yrs prior to that. Just over the hill, so to speak, the Pequea's SMB YOY index was very poor this year, but generally ok for most of the years prior to this year. The Schuylkill and Delaware were also very poor this year and this was expected, given the flows and frequent rain events. The Conestoga was a puzzler, however, but I understand that the variability seen between the Conestoga and Pequea characterized other Susq R tribs as well this year. Tribs are important in their own right, but they also contribute fish to their receiving rivers, bolstering those populations and helping in particular in years when river reproductive success is poorer than usual.

^ Very interesting as well as puzzling given the close proximity of both rivers.

If you are confident in the accuracy of the surveys, one can only guess on the reason. Other than looking at them on a satellite map and driving along them once in a while, I have no real handle on the character of each or differences between the two rivers.

Is it possible that one river (the Conestoga) has more flat areas creating shallows for successful spawning during high water conditions, while the other stream (the Pequea) is more channelized and deep, offering less habitat for spawning at a higher flow?

Do you have any theories?

 

[Mike]

No theories. Sometimes the Conestoga is better; more often the Pequea is better. Both are agriculture streams. I'm just going with the flow on this one, no pun intended. The big picture is that this is one of nature's compensatory mechanisms for guaranteeing that drainage basins are receiving some YOY on an annual basis. The same can be said for protracted spawning periods, which are a good adaptation to variable environmental conditions during the spawning period.

 

[Dave_W]

Interesting - good stuff.

I frequent a few Susky tribs during the pre-spawn and have noted over the years that spawning starts very consistently (water levels permitting) at the same time and in the same spots. This would be the typical habitat: slack eddies with marl/pebble bottom and some woody debris. I see bass on these same spots every year.

What I have always found puzzling is that if I move up or downstream at spots that appear - at least to me - to be identical, bass don't spawn there. You can walk or wade miles up or downstream and you won't find spawning bass anywhere else. Whatever the reason, these fish are either creatures of habit or are far more discriminating about spawning sites than we can imagine.

Because of this tendency, I have long worried that a specific negative event - man made or natural - that impacts a single pool could really disrupt the entire YOY production for a significant length of a creek (we're talking about tributary creeks here, not wide rivers). This impacted section could be a considerable length, perhaps the distance of a standard survey section of 300M or so.

Anyway, I'm not convinced that I've got a reliable grip on this matter...but it is something I've noted for a long time and has had me thinking.

 

[afishinado]

Dave_W wrote:
Interesting - good stuff.

I frequent a few Susky tribs during the pre-spawn and have noted over the years that spawning starts very consistently (water levels permitting) at the same time and in the same spots. This would be the typical habitat: slack eddies with marl/pebble bottom and some woody debris. I see bass on these same spots every year.

What I have always found puzzling is that if I move up or downstream at spots that appear - at least to me - to be identical, bass don't spawn there. You can walk or wade miles up or downstream and you won't find spawning bass anywhere else. Whatever the reason, these fish are either creatures of habit or are far more discriminating about spawning sites than we can imagine.

Because of this tendency, I have long worried that a specific negative event - man made or natural - that impacts a single pool could really disrupt the entire YOY production for a significant length of a creek (we're talking about tributary creeks here, not wide rivers). This impacted section could be a considerable length, perhaps the distance of a standard survey section of 300M or so.

Anyway, I'm not convinced that I've got a reliable grip on this matter...but it is something I've noted for a long time and has had me thinking.

Agreed ^ I've noticed the same thing with trout. I often walk some local streams and see redds in the same area every fall, while other areas with habitat and flow that looks the same is devoid of any sign of spawning.

Also, I seen this when fishing for smallies. I know of many streams and rivers really with good looking habitat/ flow etc. but that section doesn't hold any or many fish. Yet some places, that look identical hold fish all the time. This is especially true when the population cycle is down and the fish are more scattered and tend to hang in specific places.

Smaller streams have more of a tendency to change because of storms and floods, but the bigger rivers are a lot more stable. Believe it or not, I can return to specific fishing spots that I've known since my youth on both the Susky and the Delaware Rivers, and they still produce.