Smallmouth population declines quickly explained: Schuylkill R, Lwr Delaware R

[Mike]

Within the lower gradient portions of the Schuylkill R, starting at Gibralter, Berks Co and gradually getting worse downstream , sedimentation/habitat degradation have greatly reduced reproductive success in all but the best, isolated habitat areas. The last remaining good population heading in a downstream direction is just south of Pottstown until the river makes its way to the Bridgeport/Conshohocken area. We are not clear on whether the population is still good in the stretch within the mile below Flat Rock Dam.

In contrast, any perceived population decline in the segment from Gibralter to Port Clinton is likely the result of natural reproduction variations associated with untimely high and/or cold spring flows. Four of the six past years have yielded below average reproductive success indices, which was also the case on the lower Delaware. The other two years were average. Additionally, four of six below average year classes on the lower Delaware occurred in the the same years as they occurred in the upper (above Gibralter) Schuylkiill, further supporting the regional effects of precip and temperature.

As for larger fish now being caught in the Delaware, if that is the case it should not be a surprise if one recalls what happened on the lower Susky when the reproductive success declined. Reduce the competition in waters with good large fish habitat and adequate forage and you are likely to see a better population of larger fish. That's what occurred on the Susquehanna. The remaining SMB's bodies became quite fat and growth rates accelerated by the equivalent of a full year's growth in comparison to growth rates prior to the substantial disease caused mortalities that started in 2005.

 

[JerryC]

Interesting information, Mike. I always wondered about that stretch below Flat Rock. Always meant to try and get down there to fish because it shouted smallmouth at me. I remember years ago, mid-late 60's catching the occasional smallmouth just below the Falls Bridge.

 

[Susquehanna]

Not entirely true.
C&R, by regulation in the lower and voluntarily in the NB have contributed to an increase in SMB size abundance in the Susquehanna.
both played a role but not singular.

 

[Mike]

Susquehanna, the C&R regs went into effect in the 2012 Summary Booklet of Regulations. The abundance of 15 inch and larger SMB peaked in the lower Susquehanna the year prior to that (2011), when the fall electrofishing catch rate of those fish was about 14/hr. It was even 9/hr back in 2008. In 2012, when the C&R regs took effect in the Summary Booklet, it was 8/hr by fall, 2012, and dropped to around 4/hr from 2013 to 2016. Last fall it was 6/hr. These data support what I have said.

 

[Fredrick]

I cant speak for other areas but the area I fished was perfect smallie habitat and Afish fished it with me a few times it had a nice smallie population tons of forage and there was no siltation problems in the area was mostly rocks with some sand. This area also became a flathead hot spot there is even several videos on youtube with people catching monster flatheads right in this area. I have seen more then the occasional 5 gallon bucket filed with water and dead sunnies in this location as well . Mike you even surveyed this spot for shad and did not find one smallie.

 

[jacob]

This is definitely interesting. I live on the skuke in Conshohocken and rarely fish it, cuz well, the fishing for smallies pretty much sucks. 1-2 fish over 4 hours would be a good day. After numerous skunkings, I have deemed it not really worth it due to the lack of a good smallie population.

With that said, flatheads are abundant and large. I always attributed the lack of smallies to the presence of the flatheads. Honestly, smallmouth habitat above the matsonford bridge in Conshy looks pretty decent (in and around where the plymouth dam used to be especially) but like I said, a good day is a couple fish.

I keep telling myself one summer I am gonna dedicate some time to trying to pull a big ole nasty catfish up from the depths

 

[salvelinusfontinalis]

I wonder why C&R is producing larger fish on the upper river but not the lower river.
I'll have to call Mike's colleague and ask.

 

[jifigz]

I love cartfishing and I love catfish. That said, I'm really fond of smallies. I can understand a lack of smallie spawning habitat being lost to bad siltation and I can also understand what a few bad spawning years can do to a population. Combine both of those negative attributes of the Schuylkill and add in a ton of flatheads and it sounds like a recipe for disaster for bass.

 

[AndyP]

Have fished below Flat Rock Dam on many occasions.....always hoping for a better result than I get. Nice looking stretches of water but I don’t pick up many smallies.....

 

[Susquehanna]

Susquehanna, the C&R regs went into effect in the 2012 Summary Booklet of Regulations. The abundance of 15 inch and larger SMB peaked in the lower Susquehanna the year prior to that (2011), when the fall electrofishing catch rate of those fish was about 14/hr. It was even 9/hr back in 2008. In 2012, when the C&R regs took effect in the Summary Booklet, it was 8/hr by fall, 2012, and dropped to around 4/hr from 2013 to 2016. Last fall it was 6/hr. These data support what I have said.

So let me see if I can understand you fully here.
C&R went into effect in 2012 and your 2013 survey didn't show a positive effect and dropped further from 2013-2016.
Well in doesn't sound like that is helping create any more bigger fish, I suppose if you are naive or gullible.

Smallmouth bass are very slow growers. It takes 6-7 years to grow a 15 inch bass and 8-10 to grow an 18" bass.

AREA 6 surveys in 12',13',14',15'& 16 were for YOY bass.
Why is that important?
from the 16' survey:
"Surveys were conducted using backpack electrofishing gear and targeted near -shore, gravel and cobble habitats favored by YOY
Smallmouth Bass that, for the most part, have been sampled
annually in the past."

or this tidbit from the 16' survey:
'Future boat electrofishing surveys targeting adult Smallmouth Bass will provide further insight into the survival and contribution of the 2016 year class to the catchable bass population
in the West Branch Susquehanna River and various reaches of the main-stem Susquehanna River"

So the 16' survey in area was not even targeting Adult SM Bass.
You can even take the above quoted paragraphs and just replace it with 15',14',13' & 12' for area 6.

Area 7's last SM BASS adult survey was done 13'. The rest were YOY bass studies.


SO...you dont think C&R regs have helped adult bass size, after only surveying the river for adult bass (in the middle section too) in 13' , one year after the regs went into effect? Then you dont think there are as many as in 10' (the peak) but have been surveying in YOY habitat? All the while, during a time when disease was running rampant in the population?
Fascinating.

Get your gear and go survey it for adult bass. Myself an anglers I talk to riverside see a difference. Most of them want the regs indefinitely. Its now been 6 years since the bass c&R you should start to see more 15" adult bass.
Then again the YOY was poor in some of those surveys.
I say keep the regs in effect another 10 years and then shocked it.
You will be surprised what you find.

 

[Susquehanna]

https://lancasteronline.com/sports/outdoors/concerns-remain-but-there-have-never-been-so-many-big/article_a2b544c6-8f38-11e7-80bf-93cf2cc6463a.html

Our surveys suggest that it’s a very good time to go bass fishing,” says Geoff Smith, the Pennsylvania Fish and Boat Commission’s Susquehanna River biologist.


“Not only do we have high catch rates of fish in general, but we also have high rates of large fish.”Put simply, your chance of catching multiple lunker bass on each outing has never been better.

On the Middle Susquehanna, from York Haven to Sunbury, large-bass catch rates weren’t quite as high, but still the second-highest since 1990.

The moratorium on keeping any bass, in place since 2011, is certainly a factor.

Yep, so the PFBC is seeing it too....
For a guy mentioned in the article you sure have a selective memory or i dunno what data you have. Clearly something different.
:lol:

 

[Dave_W]

Susquehanna wrote:

So let me see if I can understand you fully here.
C&R went into effect in 2012 and your 2013 survey didn't show a positive effect and dropped further from 2013-2016.
Well in doesn't sound like that is helping create any more bigger fish, I suppose if you are naive or gullible.

Smallmouth bass are very slow growers. It takes 6-7 years to grow a 15 inch bass and 8-10 to grow an 18" bass.

AREA 6 surveys in 12',13',14',15'& 16 were for YOY bass.
Why is that important?
from the 16' survey:
"Surveys were conducted using backpack electrofishing gear and targeted near -shore, gravel and cobble habitats favored by YOY
Smallmouth Bass that, for the most part, have been sampled
annually in the past."

or this tidbit from the 16' survey:
'Future boat electrofishing surveys targeting adult Smallmouth Bass will provide further insight into the survival and contribution of the 2016 year class to the catchable bass population
in the West Branch Susquehanna River and various reaches of the main-stem Susquehanna River"

So the 16' survey in area was not even targeting Adult SM Bass.
You can even take the above quoted paragraphs and just replace it with 15',14',13' & 12' for area 6.

Area 7's last SM BASS adult survey was done 13'. The rest were YOY bass studies.


SO...you dont think C&R regs have helped adult bass size, after only surveying the river for adult bass (in the middle section too) in 13' , one year after the regs went into effect? Then you dont think there are as many as in 10' (the peak) but have been surveying in YOY habitat? All the while, during a time when disease was running rampant in the population?
Fascinating.

Get your gear and go survey it for adult bass. Myself an anglers I talk to riverside see a difference. Most of them want the regs indefinitely. Its now been 6 years since the bass c&R you should start to see more 15" adult bass.
Then again the YOY was poor in some of those surveys.
I say keep the regs in effect another 10 years and then shocked it.
You will be surprised what you find.

I'm not following your point(s) here.

It seems that you're implying that no adult SMB surveys have been done since 2013 (only YOY)?
The lower and middle Susquehanna River are surveyed annually for both YOY and adult SMB.

While I support sustaining C&R regs on the river... Mike's point stands: the data of adult catch rate per hour of large bass did not rise after C&R, but rather declined.

 

[Susquehanna]

No.
What iam trying to say is using the data PROVIDED to the public, that is what it shows.
https://www.fishandboat.com/Fish/Fisheries/SmallmouthBassManagement/Pages/default.aspx

Then suddenly you see articles that dont jive with that or what Mike has said. Clearly Im missing something.
Of course the data will not show an increase in size on a slow growing fish immediately.
Somehow in 2016 they found more larger bass, probably because it was 4 years after the Regs and because the density of fish was down.

Look all im trying to say is I believe both had an effect and created larger fish, apparently the "missing" (viewable in the article) data supports this.

So you found more bigger bass from 13'-16'? right? or am I reading that wrong? I mean its higher than all medians on the chart.

to me it looks like 15" and bigger SM increased dramatically after the regs.
2011 looks like more like 9 per /hr
while 2016 looks more like the 14 per/hr

 

[FarmerDave]

salvelinusfontinalis wrote:
I wonder why C&R is producing larger fish on the upper river but not the lower river.
I'll have to call Mike's colleague and ask.

Are you sure that is what is causing it?

I am not a biologist, but I do know that with all other things being relatively stable, C&R does very little to improve the size quality of a population unless the waters were previously being SEVERELY over-fished/over-harvested. In fact, it can actually reduce the average size of the larger fish. More fish usually means lower average size. But neither of these are likely happening on a stream that size, at least not from C&R alone.

A body of water can only support so much biomass (by weight). The way to manage a body of water for larger fish is to remove many of the small to midsize which is exactly what happened in the scenarios that Mike described. Nobody likes how it happened, but it is what it is. Lower reproduction rate eventually means less competition for the adult fish, which results in bigger adult fish.

It also explains why when a new predator fish (e.g. flathead) is introduced, they grow faster than usual and will grow to extremely large size in just a handful of years until their population increases to the point of equilibrium. Other fish species can also see increase in size due to increased predation on the smaller members of their species.

 

[poopdeck]

I don't see C&R regs doing much of anything. Since most anglers practice C&R by choice, having a written regulation is not really doing anything more. Sure there are those who keep fish but I believe their numbers are decreasing to the point where they will have essentially no effect on the data curve.

I can't tell you the last time I saw a bass on a stringer or in a cooler. A majority of anglers have been practicing C&R long before 2012.

 

[Dave_W]

Well, the question here is Did C&R regs improve numbers of large bass after the implementation of C&R in 2012 (a claim about which I'm skeptical)?

Going back and looking at the best data sets we have on this does not suggest increases of large bass at or greater than 15 inches. This can be seen here:

Bass Data

It's important to remember that these regs went into effect in 2012 (I think) on the middle Susky (Fig 2), the lower Susky (Fig 5) and the lower Juniata (Fig 8). I took some time to look over the graphs and averaged the annual CPUs for the years 2011 through 2016 (I used 2010 for the Middle Susky as it does not have an entry for 2011).

If I crunched the numbers correctly - always risky as my brain is no longer elastic - one gets the following average CPUs for the combined three river sections for big bass (15+"):

2011: 10.6 per hour
2012: 4.9
2013: 6
2014: 5.6
2015: 6.1
2016: 11

This suggests a slight drop in big bass after 2011 with a slight rebound by 2016. To be sure, these numbers have a lot of variability as the three river sections show ups and downs and variation by year. Again ,the numbers I've posted are averages for the three sections.

We all know there is a lot of big bass in the Susky and Juniata but the evidence does not correlate with this coming about as a result of C&R in 2012.

Speaking for myself, if we see a rise in bigger fish over the next decade, which is possible, and the control samples of the West Branch and North Branch (which lack C&R) remain the same, I would re-think my views on the impact of C&R.

In the meantime, I will continue to support these C&R regs as I support expanding C&R generally as a management tool that is beneficial for PA fisheries. And, of course, C&R certainly won't hurt the population structure and this, combined with the overalll strong support for this reg among bass fishermen on these rivers (I've never met anyone who wants these regs removed and harvest allowed again) means that the regs will almost certainly stay C&R.

EDIT: Correction - the data for 15" bass in the lower Juniata is Fig. 11. I have corrected the numbers above (trend is the same).
DW

 

[Susquehanna]

good post Dave
report

The PFBC press release of December 8th 2016 stated that “the implementation of mandatory catch-andrelease regulations enacted in 2011 have resulted in better recruitment of young bass to the adult populations.”

Which has lead to more YOY which has lead to more adult bass.
Honestly you have a slew of tournament anglers and guides licking their chops at fishing over beds and the spawn, they have been kept at bay by the regs.....
I dunno what else to say

 

[FarmerDave]

poopdeck wrote:
I don't see C&R regs doing much of anything. Since most anglers practice C&R by choice, having a written regulation is not really doing anything more. Sure there are those who keep fish but I believe their numbers are decreasing to the point where they will have essentially no effect on the data curve.

I can't tell you the last time I saw a bass on a stringer or in a cooler. A majority of anglers have been practicing C&R long before 2012.

True.

From what I have seen, those the creel smallmouth usually aren't catching the big ones, anyway. On occasions where I have seen smallmouth on stringers, they are either barely legal or even sub-legal.

Before anyone asks, of course I remind them of the minimum size limit.

 

[Dave_W]

Susquehanna wrote:

The PFBC press release of December 8th 2016 stated that “the implementation of mandatory catch-andrelease regulations enacted in 2011 have resulted in better recruitment of young bass to the adult populations.”

Which has lead to more YOY which has lead to more adult bass.
Honestly you have a slew of tournament anglers and guides licking their chops at fishing over beds and the spawn, they have been kept at bay by the regs.....
I dunno what else to say

We're in agreement on these matters.
And I see your point about the PFBC touting the C&R regs. I think they (PFBC) recognize how popular these regs are... and want the angling public to know that they they know.

Regarding guides and tournament folks fishing over the spawn, I also agree that this has abated.
However, I talk to a fair number of guides and I don't know any who favor fishing over spawners (they fish pre-spawn, as do I). I can't say with respect to tournament types as I don't talk to them much.

 

[Dave_W]

FarmerDave wrote:
I can't tell you the last time I saw a bass on a stringer or in a cooler. A majority of anglers have been practicing C&R long before 2012.

No doubt that creeled bass have largely disappeared on our rivers. It used to be common to see folks at boat ramps with stringers of bass (and often a 30" muskie). I do recall a case maybe four years ago when I saw an old fella with a couple very large bass on a stringer on Conodoguinet. I was tempted to tell him how long it takes to grow fish of that size...but decided not to. It was legal and ethical for him to posses those bass, it just made me cringe.

I do still see river anglers with catfish on stringers, but very rarely bass.