Pond Boss Forums Thread Like Summary - In need of more predation

Hey guys, been a while
I've got a shallow 3/4 acre pond in WI, currently running a 4 diffuser aerator. I have established populations of YP, GSF, and LMB; theoretically there should still be PKS but I have not seen them in a while. GSF between 4 and 6 inches have dominated the catches and I have seen smaller in the water. YP are present, I have caught 3 this year 8-8.5 inches. The only LMB I have seen were less than 2 inches and a single 7in individual that was rather thin. So basically I am worried that I need a predator to cut down on the GSF numbers, normally I would suspect they are stunted but their body condition is rather good. The LMB recruitment I am seeing suggests a decent population of adult fish, but I have not seen one in a long time. The poor body condition of the one bass I have caught this year suggests that I need to make some changes.
The other problem I have is too much chara and duck weed, but I already have a possible solution in the works. Namely a KASCO Marine AquatiClear Water Circulator - 1hp, which I already have but the power is not yet wired so it is not installed yet. The idea here is to move a little water so the chara cannot grow to the surface and the duckweed can't sit on top of it. I also am hoping that it can help dig the pond out a little bit as I could use some more depth.
Here is where I want some input;
1. Should I stock say 20# of fatheads in fall to bump the growth/health of the bass?
2. Should I stock a new predator to temporarily deal with the small sunfish?
3. If I want to sample the fish in a more effective way than hook and line, should I get a seine or fyke net?
My brainstorming for a predator is to stock either WE or CC. I understand that WE working is a long shot but I like that they absolutely cannot reproduce and become a problem. Also I kinda hope that my artificial current could help them survive summer, although my pond does not heat up that much. I have had CC in the past before a recent fish kill so I know they would survive, but I am not sure they would help as much as they are not as big of piscivores as WE. I am not too fussed if the WE do not work, and I would really like to find a source of Saugeye but what do you guys think?

4Corners has good points. Abundant GSF can heavily reduce recruitment of LMB by eating eggs and fry. GSF have big mouths to eat big things for the fish's size. GSF are aggressive. I deal with GSF in a YP test feeding small pond. GSF like to hide in shallow shoreline habitats often making it hard for predators to capture them. GSF can be prolific and thrive living in rocky shoreline areas. For me GSF will readily enter unbaited minnow traps and fish traps with larger funnel openings. I can easily get 15-30 in each trap set. I'm trapping them daily now with lots of YOY GSF in the traps.. Strongly reduce GSF numbers before adding LMB unless you can add LMB big enough to right away eating GSF. But without strongly reducing the GSF the GSF will hinder reproduction success of LMB by eating eggs and fry. Walleye in my experience are not good predaors of GSF.

GSF population is predominantly between the sizes of 4" and 6". Maybe an average of 5".

So I think what is missing is enough forage at much smaller lengths. Keep this in mind. A 6" GSF is every bit as heavy as a poor conditioned 7" LMB. They are competing with little bass and have the advantage of being able to make better use of invertebrate prey as well. There are WAY TOO MANY 4"-6" GSF.

Sure the GSF are spawning but there aren't enough 1/2" to 3" GSF because there are WAY TOO MANY 4" to 6" GSF. They are cannibalizing their YOY.

IMHO, the OP needs to remove 4" to 6" GSF from the pond so that GSF YOY have better survival so the YOY can feed the LMB enough to grow well. Thinning some GSF will help the GSF grow better too.

This pond is forage locked in a sense. The populations are high and there is very little recruitment. Most of biomass is tied up in prey fish that are too big for the LMB to eat.

Ponddragon,

You earlier said the predominant size of GSF that you catch is 4 to 6". What percentage of the GSF biomass is in these sizes? How numerous are the smaller sizes relative to those you predominantly catch?

I can tell you, with little doubt in my mind, that the bulk of the GSF biomass will be comprised of those sizes that cannot be consumed by your LMB. They survive because they have outgrown the majority of LMB (if not all of them). After all, if you had LMB thinning the 4"-6" GSF, wouldn't you see examples of LMB large enough to consume them?

Also, have you given any thought as to why your 7" LMB are so thin? If a 7" LMB is not getting enough to eat to have good condition. How could stocking 6" LMB immediately help? Wouldn't they have just as difficult a time finding enough forage to eat? That is what makes sense. Stocking 6" LMB will fail to help your situation unless you do something about your GSF population, IMHO.

I mean no disrespect to esshup. In his mind, your LMB are underrepresented. And here's the grub, he is right about that. What you need is around 75 or so LMB in small sizes preventing a high population of 4"-6" GSF from developing. This number is a very good recommendation for an initial stocking of LMB where large panfish are a goal. But then, in an initial stocking, the number of reproducing panfish is low. They produce a lot of YOY that can feed those 75 LMB and grow them. You have the opposite situation IMHO. I believe both the population and the Biomass of LMB is underrepresented. I also believe that both the population and biomass of adult GSF are overrepresented. A forage locked pond will not support a good biomass of LMB because prey is in short supply. So what has happened? Your LMB are in balance with the biomass that the forage locked pond can support.

So its more complicated than just a predator stocking. 4CP makes great point about being the predator of GSF. It may be difficult to source LMB that are large enough to consume optimally those 4"-6" GSF. Furthermore, the pond will not support very many LMB that large. Maybe 2 or three max and have acceptable balance (which still would not be ideal). So a population of LMB where the biomass is concentrated in large LMB would not work to grow larger panfish. They will reduce GSF in the 4-6" class, and by doing so, increase the number of GSF smaller than 4" (something counter to goals).

I am going to make a recommendation which is outlined below putting together the best advice you have thus far received.

1. Now is horrible time to stock additional predators. You need to prepare the pond for them. What you want at the time of remedial stocking of LMB is a thinned population of adult GSF producing large numbers of consumable YOY. We are probably looking at the June time frame next year for stocking LMB.

2. You need an adult GSF population that is similar to what would be ideal for an initial stocking with panfish goals. You need to remove all but around 300 of the GSF adult population. If you were to do that, you would have an adult population of 400 GSF per acre.

3. RIGHT NOW, is the time you need to be thinning GSF. Delaying would be contrary to the goal of restoring balance. Thinning now, will allow the remaining GSF to make winter in better condition. This will improve forage production next spring helping the remedial stocking of LMB to grow and control the number of GSF recruited.

4. Mark the first 150 GSF you catch in sizes > 4" and throw them back. Use whatever your preferred method of fishing is to do that. You can use a fin clip to mark them. Throw back marked fish when recaught.

5. After marking, from now until ice cover, remove all the unmarked GSF >4" you can until you are catching a 50/50 mix of marked and unmarked GSF. Use 4CPs method to leverage each cast for multiple GSF caught. If you are still catching more unmarked GSF than marked when the pond ices, then resume this removal of GSF next spring only stopping when there is a 50/50 balance in your catch of marked and unmarked GSF.

6. Watch for your first cohort of GSF YOY. When they reach sizes around 1", do your remedial stocking of LMB. I like 40 to 50 8-10" LMB. If you prefer, go with esshup's rec of 75 6" LMB. But if I were to do that, I would probably stock them before observing the GSF YOY.

I think there is pretty good chance you would see very good result by Fall of next year if you follow these recommendations. With numbers up, the LMB should more effectively control the number of GSF recruiting to the 4-6" sizes, this should be conducive to growing larger panfish. If control is sufficient, you next worry will be over recruitment of LMB. I have fished a lot of ponds with LMB/GSF combination, albeit much further south. All of these ponds had over representation of LMB. But your pond has the opposite condition in this moment.

You may ask why, if the most common condition is over representation of LMB, how did your particular pond develop the opposite condition. The best explanation I can proffer is that there may have been an event that drastically reduced the adult LMB population. The GSF population was not as affected. Once the imbalance was in place more GSF survived to be adults. This condition reduced the production of consumable forage production ... forage locking the pond. So a couple of possibilities. Possible overharvest of LMB, possibly poaching. OR a low DO event that affected the LMB more than the GSF.

I am the primary predator of our GSF. It seems to me that you, too, could be an effective reducer of the splendid GSF.

If I believe there's an imbalance between BG and GSF, I sit on the dock for and hour or two and haul them in. Some times it's GSF; other times it's BG. I chum a little to get them coming, then start with a double or triple hook rig on an ultralight spin or a 3 weight fly rod. Baits can be Berkeley Gulp or Powerbait grubs, crappie nibbles, earthworms, Creme trout worms, or nearly any other small rubber type baits. For me it's usual to hook 2 and often 3 sunfish on each cast. My water clarity is good, so I can sight fish for individuals that I'd like to remove.

At this rate you could pull 100, 200, 300 or more GSF out each week and reduce their population quickly.

Fyke nets are useful.

That scrawny bass actually indicates nothing except it hasn't been eating well or digesting its food. It seems there should be many many GSF fry and fingerlings for nearly all the bass in your pond. The opposite predation might also be occuring. The GSF may be gobbling up your young bass, limiting bass recruitment. A very good bait for big GSF in my pond is a 3" to 5" LMB.
I have no experience with WE nor CC in my pond. They both feed at night when YP and GSF tend to be motionless on the bottom so are easy targets.

Yes, more open water will allow for more predation.

I was going to reply that you would probably be the best predator on GSF, but 4Corners already put up a good post on that.

In ponds with abundant GSF, I find them to be both aggressive AND easy to catch. That is a perfect combination for you to make a dent.

Do you have any kids, grandkids, local Boy Scouts that can help you fish? Most kids love catching tons of 5-6" GSF.

When you say you only catch 1-2 at a time is that on artificial lures or live bait?

In Kansas, my solution would be put 8-10 cedars trees with a cinder block around the pond in 3-5' deep water. Have kids fish with worms on a small hook under a bobber. The cedars act a "fish concentrators". I have had kids catch over 20 from a single tree (plus a few BG), and then we move on to the next tree for more.

Do you have any "fluffy" cover in the pond to concentrate the smaller fish? Do you have any heavier cover with open spaces in between? LMB need the latter as "ambush cover" to dine happily. They use up much less energy if they can just hide behind a tree trunk and then suck up a clueless panfish as it wanders past.

Good luck improving your fish populations. That should be an enjoyable problem to undertake!

Alright we're back and we actually caught fish this time. Turns out all you need to do is use worms. We caught 72 total fish, 3 of which were recaptures. We'll need one or two more fishing excursions to get better recap data but this was a good start.

That's the reason why electroshocking surveys are done. Fish that don't bite the lure/bait are also sampled........

Couldn't catch enough to harvest today but I FINALLY caught an adult LMB, 13.25 in and 524g. Besides that it was 1 recap PKS, 3 recap YP and 1 new, 2 recap GSF and 1 new, and 1 other LMB at 125g 8.5in. I'll try again tomorrow if I get some time but I'm pretty pleased to finally see an adult bass. I will also mention that I lost another bass the same size 10 minutes earlier so there should at least be 2 of them (Adam and Eve?).

The standard reference (Wiley et.al 1984) for amount of plant cover in ponds for best or optimum (100%) all natural bass and sunfish production is to have 36%-40% maximum plant cover in the shallow areas aka littoral zone. The deep pond basin having no weeds. Weeds just around the shoreline areas maybe down to 5-6ft. . Fish production was still high with 80% fish production having plant cover percentages of 20% to 50% on ether side of the bell shaped curve. Regularly adding fish foods such as fish pellets to the system can enhance the fish production in ponds with low plant coverage.

IMO the more sumerged weeds you can remove from the pond the better the LMB will find, catch and eat GSF. The opposite is true. For initial good GSF control, I think you should basically work each year to kill all the underwater vegetation. Then while you are manually removing every GSF you can, bass eating GSF plus you focus your bass angling on removing the LMB larger than 12"-13". Then after several years ,,when you see evidence of very few remaining GSF and those survivors are basically large individuals (7"-9") then you can allow submerged plants to naturally return or beneficial ones be planted to improve the size classes of panfish. When GSF have been significantly reduced to large individuals, then you can supplimentally stock large individuals of other species of panfish, YP, PSF, Crappie (hybrids), CC.

If you want this problematic fishery to be a quick fix get the entire shallow 3/4 ac pond chemically renovated. It depends on how fast you want this fishery to be revamped and restarted. Renovation costs money but your time and efforts spent for several years getting the fishery turned around also has $$$$ value unless you want to do all this effort as a hobby and your time and efforts have low value. Doing all this for the best outcome could take up to 4 to 5 years.

IMO the long term goal as capital appropriation is to get the pond drained and and properly rebuilt with good deep basin structure to endure northern winters without needed aeartion. Michigan State univ Extension pond managemetn booklet describes best pond basin structure for northern ponds.
https://archive.lib.msu.edu/DMC/extension_publications/e1554/e1554-1989-print2.pdf


Wiley, et.al 1984. The relationship between aquatic macrophytes and sport fish production in Ilinois ponds: a simple model. North Amer. J. Fish Management 4:111-119.

Ponddragon,

Thank you for sharing more about your pond. To be sure, how many GSF you should mark and how many LMB you should have, will depend on what weight of GSF your pond can support. To be clear, I didn't know what it would be and so the rec as a starting place assumes your pond would support 300 lbs of GSF without a predator fish. With a good balance of predators and prey, such a pond would support about half that weight in GSF > 3". A good predator balance will correspond with standing weights of GSF that are significantly below what pond foods would maintain. So in such a pond, 150 lbs of GSF could be maintained all the time even while producing 150 lbs of prey that are being consumed by the predators. What weight of predators could be supported on 150 lbs/acre of GSF consumption at your location? Around 37 lbs/acre.

But you voice concerns about having that much carry. To give you better rec on numbers that are appropriate for your pond's productivity, we need to have a better understanding of what your standing weight of GSF is. I would recommend marking what you can. You can always remove marked fish if we determine you don't have very many. So to start ... mark 40 or 50. Stop using minnows and go to earthworms and maybe try a multiple hook rig (as 4CP recommended) to improve catch numbers. Use size 10 hooks. After marking releasing 40 or 50 GSF, then let's use the mark and recapture method to estimate the total population. This entails recording catches and whether the fish was marked or not. From this, let's make an estimate of total population. Using that estimate of total population and your population structure metrics lets gain an understanding of your standing weight with your current mix of predators. With this discovery, we can make a better recommendation for GSF and LMB population numbers. Population numbers that are not only a good balance of BG and LMB but also a good balance of populations and pond productivity.

I assumed a population that fits 300 lbs of GSF biomass and your population metrics in the spreadsheet below. Conversely, we could use mark and recapture to estimate the population and combine it with your population metrics to make a better estimate of your standing weight of GSF. What we would want to do then is to goal a smaller standing weight of GSF. We can speak about that later, but for now, if your pond's standing weight is significantly below what I had earlier assumed, we need more discovery.

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Great work performing your survey and recording/sharing your data. To begin, lets discuss the population the surveys suggest and some other considerations regarding potential biases that can increase the uncertainty of the population estimate. In your first survey you marked 69 unique fish. In the second survey, you caught 61 fish of which 7 fish were recaptures. These values suggest that your total population of fish is 601. In a .73 acre pond, that is 823 total fish per acre. Of the 601 estimated, you identified 124 unique fish (roughly 20.6% of your estimated population).

With mark and recapture, the larger the number of your samples (especially the second survey), the more reliable and less uncertain the estimate. I do consider this to be a good sampling but given the second survey comprises less than 11% of the population, it has a higher uncertainty than if the second sampling had been 22% of the population. In fact, the uncertainty would be halved by doubling the number of second survey samples. There will always be some level of uncertainty when the sample number of the second survey is less than the total population but the purpose of this statistical method is to make a good estimate of the population with acceptable levels of uncertainty WITHOUT having to count each one. By and large, mark and recapture does this so long as biases are not extreme in the sampling method(s).

It is especially important that the second survey be unbiased. Especially with respect to the first survey. Both of your surveys are by fishing with the same method (earthworms on a small hook). So there is little bias introduced by the method but it isn't bias free. Generally we agree that some fish after being caught are more difficult to catch again. This effect, would introduce a bias to overestimate a population. An electrosurvey eliminates this uncertainty because it ability to produce samples doesn't depend on vulnerability to angling. Even so, to be a good survey for mark and recapture, it must not introduce bias that affects the sampling of marked fish. Let's say the marked fish were caught at 25 ft depths but the electrosurvey only worked in water of 12 ft depths, then the electrosurvey would introduce a negative bias on recaptures (thus increasing population estimates).

Another important bias is geospatial bias. This would be especially important for fish that are not ranging considerably. If there is a equal chance that any fish in the population could be sampled in the sample areas then this would minimize bias. Also, if the second survey gives no preference to geospatial areas (being no more biased toward other areas than where the marked fish were captured) then this would minimize bias. If fish are territorial and not likely be impartial to location, then there is possible geospatial bias where the geospace of the samplings have been limited. For example, if your surveys occured in 1/3 of the geospatial extents of the BOW AND the fish are territorial, then you may have a great population survey that are limited to the extents of sampling area. In doing your sampling, these considerations should be given thought and decisions made regarding trust of the findings and adjustments if deemed prudent.

For now, I think we can move forward with estimate of the population that your surveys imply. While I do think they could underestimate your populations, I also know that careful future sampling will prove to make that evident. For example, if the proportion of unmarked fish is higher than anticipated, that would suggest the surveys underestimated the population. You describe the BOW as being fertile with much chara and (some duckweed). Chara favors water of good alkalinity. Duckweed favors high fertility. So I think there is a really good chance that your pond carries more than mark and recapture presently suggests. Also, you mentioned not having good access to all of the pond. Geospatial bias may have affected the population estimate. Presently, your survey suggests a standing weight of adult panfish of around 150 lbs per acre. Give some thought to geospatial bias and let me know if you are satisfied that all or most of the pond was sampled without geospatial bias.

For 3/4 acre pond and wanting a fyke net I would buy as small of one that is made. Fyke nets are usually fairly large compared to small fish and minnow traps. I built a small fyke net for a fish sampling study that I did for a pond boss conference. Basic box was around 2.5 ft on each side. Leads or wings can be as long as you want them. Instead of buying a fyke net consider buying or building a couple larger fish traps such as a Z Trap or from this company. Larger traps are easier to handle and use compared to a fyke net that is designed for use in larger bodies of water.
https://ktraps.com/

One can put leads or a wing or wings on a larger fish trap to have it catch more fish. A fyke net is just mainly a box type trap with wings.

Excellent! You've completed the "marking" phase of your mark and recapture. We will exclude the 3 recaptures from the count of 72. What you have are 69 marked fish in your population. All of the recaptures were GSF and there is definitely the potential if you were catching and releasing in the next phase to count a fish twice. You DON'T want to do that. The next survey needs to be comprised only of unique fish (none caught twice or more). Ideally your second survey would not be biased to catchability. An example would be an electrosurvey. Another example would be traps (though perhaps not as unbiased as an electro survey) In any event, even an electro survey might be biased to one species or another. Anyways, I recommend you give your fish a rest for a week or so and then try to collect another group of samples. If you can, try to collect around 70 if you can. Don't just throw them back. Either cull them, or hold them in a trap until the second survey is complete so that you are only counting unique catches. Your initial survey is biased to catchability on earthworms. That's probably a good trait to keep, so fish you have caught twice by that survey technique are probably good ones to keep from a fishability/population management perspective. Anyways, right now, I would be reluctant to cull fish I have caught twice.

On your second survey, at least measure and weigh unique catches (the unmarked fish). Decide if you will ultimately release the unmarked fish back to your population. If the decision is yes, mark it the same as you did those yesterday and put it in the holding pen for release later. For those unmarked that you will cull, chill them in ice until you can later clean them for cooking. I would keep the previously marked fish in the holding pen along with the newly marked fish you are keeping. The number caught in this second survey and the number of recaptures in this second survey (as they relate to the initial survey) will be used to estimate populations.


Your initial survey provides a lot of useful context. If it is reasonable that fishing with earthworms is not biased to the species, then we can use the proportions of species in the catch as reflective of the populations. Your initial survey suggests that PKS are your dominant species and comprise in the neighborhood of 50% of your adult prey fish population. The remaining 50% are split between GSF and YP where the GSF have only a modest numerical advantage in the survey. All of the fish in your initial survey are adult fish that are capable of reproduction. Up to now we don't have any information for potential recruits. My sense (right now) is that recruitment is low.

Of your existing prey fish species, the PKS have the best condition averaging 103 RW, where GSF follow with 86 RW, and YP with 78 RW. All of the different species have comparable average weights PKS (73.57 g), GSF (73.57 g), with YP (79.93 g) possessing the highest average weight. For PKS and YP, RW was negatively correlated with length (RW worsens at longer lengths). This is normal when food is limiting for the population. The GSF, however, have a positive correlation with length. If I had to venture a guess as to why, my guess would be that they have some advantage for consuming some of the prey in the pond. For example, perhaps longer GSF with larger gapes have an advantage with fish and crayfish prey items. The PKS having an overall species advantage for condition, perhaps this is a benefit of exploiting snails in their diet.

The good news. You do not have stunted populations of panfish (although they are admittedly growing slower than they could be growing). I base this on Swingle's definition of a harvest sized panfish. A panfish > 1/10 of pound is considered harvestable. In grams this is around 45.45 grams. >92% of your initial survey are comprised of harvest sized panfish (per Swingle). To be stable, there needs to be a good balance of predator and prey. Presently, the risks to this population structure are losses of the adult panfish population cocurring with an inadequate population of predators (both number and size). A reduced adult panfish population will result in reduced cannibalization of YOY and higher recruitment. This higher survival resulting from a lower adult panfish population needs to be balanced by the control of the right number and size of predators. To only reduce the number of adult panfish would probably result in fewer harvestable size panfish and more smaller panfish. I do think you will need to bump the number of LMB. I like 8"-10" LMB for this purpose. Probably fewer if we are able to pin a good number for your less than 8" LMB.

Did you happen to mark your LMB? Going forward, also do that and keep track of how many have been marked. Always release your LMB, at least for now. The single LMB has good RW (120). This fish is probably in its second year of life ... posssibly later. In population dynamics, LMB less than 8" are not counted. At least not in texts authored by Anderson and/or Willis. I think whether we should count them as part of your solution depends on how fast we can expect them to grow into the 8-12 class of fish. When you have good balance, there will need to be representation in this size.

PondDragon,

One of the things I noticed was that your recaptures did not match precisely fish in the list. So IF the recaptures were fish caught twice on the same day, there may have been variation in measurement(error introduced by the one taking measurements or problems with the measurement equipment). I questioned whether to say anything but now that you voice concern ... I would just say ... continue to practice with your measurements and isolate the cause if there is noticed variation measuring the same thing multiple times. Also, they make weights of a specific mass that you can use to calibrate with. Use your best judgment and experiment until you are satisfied that your measurements are consistent.

Were it me, I would focus on the PKS and manage around them. I don't think you need the GSF at all (with the addition of the right number and size of LMB), but that said, they are playing a predator's role in helping to control some of the recruitment of your desired panfish. Be mindful of that, If you have 30 lbs of GSF in your pond, they are consuming a non-neglible weight of small panfish. Try to gain an understanding (using minnow traps) of how many YOY you have presently in the pond (and their distributions of lengths). Is there a need for GSF predation of YOY over winter? If not, then I would still track the weight and number of the GSF that you remove.

As to the question can you remove only GSF?

IMHO, no. First, I wouldn't add nutrients to your pond to push growth. You've had winterkill before and I would opt to stimulate growth by reducing populations. Removing GSF will free some pond foods for the desired species. It's not going to add the small fish that GSF were consuming (that were too big for PKS gapes). But everything else is, in theory, freed for consumption by your desired species. Based on your initial survey, GSF may comprise around 25% of your adult panfish biomass. This adjustment of increasing foods (per PKS and YP mouth) by less than 25% will be TOO SMALL to get really good growth (if you don't cull PKS and YP too). It will likely also be insuffient to stimulate enough production of YOY for your newly stocked LMB. You need between 35%-45% annual mortalitly of the adult biomass to support superior growth. So the PKS and the YP should undergo that kind of mortality. You want this mortality focused in near quality or quality sizes (5 to 8" for PKS). Fish that are big enough to harvest but that will thereafter grow slow if they are not thinned. Each year, you get a new crop of harvestable fish in those sizes. Reserve some of them for grow out to larger sizes. Invariably, they will recruit more than what would be ideal for growth ... If you don't harvest some.

IMHO, you need to remove 60% of your adult panfish biomass to initiate good growth and good YOY production. So up to 25% of that biomass could be GSF but you also need to take 35% of the existing biomass of PKS and YP. Additionally, You need to add around 10% of your existing adult panfish biomass with LMB that will be large enough by next season's end to consume YOY that have grown all season. Ideally, some of your earlier stocked LMB will have approached 12" in length by season's end. By season's end, perhaps as much as half or more of the adult panfish biomass will be recovered. The pond will still be below its maintenance carry and fish will be growing. You wan't to maintain it in this condition where they have not maxed the carry. This will be done by your predators and yourself through thinning (which might also involve trapping given your weeds). In this state, your pond is more like a new pond (remember when growth was good?) After more discovery, lets discuss how you can manage for the population structure you desire most.

With regard to the species of predator, IMHO it doesn't matter so long as they are stocked at sizes that get you the growth you need this first summer. It may be difficult to source other species in the sizes you need. But whatever size they are going in, if it is working, they should be large enough that 3" PKS are still occasionally on the menu at the end of the growing season. So what I am saying is that there is no magic bullet species that works miracles. Any large gape predator stocking could work and it could fail to produce optimum results if their number and their lengths are not right or if they are ill timed. If your YOY get ahead of your predators, then I would consider that a failure for YOUR goals. You want your predators to stay ahead of your YOY until the predators reach around 11-12" in length. Ideally, they are balanced about there. There should be enough of them so that YOY that ultimately grow to survive predators of this length are not so numerous as to be manageable by harvesting quality panfish. That is probably the definition of balance. Where predators only allow enough recruitment to support a harvestable weight of panfish while restricting the population such that the growth of survivors is sufficient to meet goals and balance with the mortality (both harvest and natural mortality). This may seem overwhelmingly difficult, but balance is painted with a pretty broad brush in terms of acceptable. Good fishing doesn't necessarily mean that growth rates are maximumized. Good fishing can fall within a broad range population structures and harvestable fish sizes.

Let's at least see your second survey before discussing potential stocking rates of LMB. From my perspective, in my own pond, I wouldn't worry about LMB genetics where I am focused on growing panfish. I would go the path of least resistance and do what is the right balance of convenience and cost.