Pond Boss Forums MANAGING AN EXISTING POND Corrective stocking Overcrowded bass

No one invests in so many 3-5" BG without the expectation of growing large LMB. So my sense is, you were advised that the action of stocking 8000 3-5" BG would help you to do that.

I am doubtful because you added so many 3-5" bluegill. These are too large for your current contingent of LMB to eat AND you don't need them to produce sufficient consumable forage. How do I know you don't need them? Because ... you produced a whole lot of YOY (1"-3") without them. I think you will agree that Early November last year that there weren't nearly so many of them present. So what has changed? First, you culled over 300 LMB. Second, you limed and fertilized early in the season and maintained a bloom this year. This expanded your forage potential. How much depends on the age of your pond and whether there were problems with excessive weeds ... but these two efforts were very successful where culling bass increased survival of BG YOY and fertilization increased production of YOY. This is also reflected in the improvement of LMB condition over the same period. The 8000 BG you stocked in October don't get any credit for this at all.

So you were on a really good path until you added the 2133 ~4" BG/Acre (8000 Total). I think this action is going to reduce YOY production next year. So for me, a bluegill has to reach 33 mm (1.3") or so before it becomes relevant to >8" bass. This is the size where they reach a high probability of evading cannibalistic predation by other BG. This action added thousands of hungry mouths and may have as much a quintupled the predatory influence on YOY BG by their own kind. Furthermore, the action dedicated a large percentage of your forage potential to the maintenance of BG that are not consumable by your current population of LMB. IMO, this action will work against the goal of growing big bass. Only ongoing culling, maintenance of fertilization will be contributing to YOY recruitment to >33 mm lengths next year.

I want to be clear that I am not against stocking 3-5" BG. I believe there are circumstance where this would be a very good remedy. Here is an example:

Let's say a pond is overrun with LMB and the population of BG is very limited. So in such a pond the biomass of LMB may be very nearly the biomass of BG, it may even exceed the biomass of BG in some cases. The population may consist of few individual BG/acre that are large in size, may primarily be male BG of advanced age. Circumstances like these can benefit from a stocking of BG in 3-5" sizes. Also, let's say there are no BG but Green Sunfish are the dominant forage. In these cases addition of this size class of BG can be very beneficial. 3-5" BG are large enough that one can expect high survival ... also they are large enough to begin spawning right away. Chances are good around 50% of them will be female. I personally would never stock more than 150-300 or so of them in a pond where an existing population of BG exists and fertility is restricted to fertilization (800 lbs forage potential with no feeding) ... that is ... if I had a big bass focus. I would want LOTS of forage in consumable sizes available to my LMB ... that is again ... if I had a big bass focus.

Below is an example of the consumable forage outlay per acre with a trophy bass focus. In it, it is assumed that all BG under the length of 6" are consumable by LMB. You will notice that there is a greater number of ~4" BG than you stocked. You may ask "what gives"? The difference is that the scenario outlined below assumes one has LMB averaging 4-5 lbs already. IOWs its not a "Field of Dreams". One can't just put 4200 4" BG/acre "out there" and expect LMB averaging >4 lbs to come. They have to be grown first and in the beginning they need much smaller prey. When you look at this outlay, what I want you take from it are these things ...

1. Most of the population of BG are less than 1 year old

2. Intermediate BG are 1 to 4 years of age and dominate the biomass (as well as the consumed forage)

3. Only a few BG grow beyond 6" and their biomass is only a small percentage of the forage biomass.

4. To feed BIG LMB year round requires maintaining multiple year classes of BG in sizes that LMB can successfully consume.



It is interesting to note that this scenario actually does fit Swingle's definition of balance except for Y/C (which still falls very close to the limits of balance):

F/C = 6.02 Ratio of Forage Biomass to LMB Biomass
E_LMB = 14 Percentage of Total Standing occupied by LMB
Y/C = 5.56 Ratio of consumable prey to LMB biomass
A_F = 47 Percentage biomass that is harvestable

Other interesting points. The forage potential required to support the standing weight and mortality biomass could be supplied by fertilization. The supported biomass of LMB meets Lusk's referenced carry of a well managed pond. The Y/C is only just a little higher than what Lusk and Willis report as most desired for trophy LMB (Y/C=5). In computing Y/C, I am using BG between 5" and 6" and if I omit these (which are also harvestable by Swingle's Definition) then the Y/C is 3.13 which lies almost within the range of ideal per Swingle. Anyways, I include BG of this size in the consumables because I think they are important to >20" LMB as forage and this scenario supports trophy LMB.

So what will go wrong with this scenario?

Recruitment and mortality. This scenario depends on consistent and stable recruitment and mortality of both BG and LMB. For LMB, an adult population averaging 16 LMB/acre where recruitment of 12-14" female LMB is offset by the mortality of >12" LMB each year keeping the population stable at 16 LMB/acre. The scenario also requires the recruitment of 14000 BG to a minimum length of 1.5" each year. I think this is a tall order and I do think a population of BG like this ... would probably fail to recruit that many BG YOY in most years. Also, it probably unlikely to recruit LMB naturally and consistently under this scenario in most years. So here is what else I want you take from it ...

5. It is really helpful to have a forage pond that can supplement shortfalls on YOY recruitment. In this scenario it takes recruitment of 24 lbs of 1.5" BG for each acre. An appropriately sized forage pond could supply all of them.

6. Female LMB may need to be purchased to supplement what the pond did not recruit in a year.

7. One needs to understand that to maintain a limited number of LMB >12", one will have to remove some large LMB each year to balance mortality with recruitment. If he doesn't, the group >12" will experience slow or negative growth and the conveyor belt comes to a screeching halt. To consistently grow Big LMB ... one has the GROW THEM ... NEW ONES each year. It is just not possible to maintain a population. Mortality must balance recruitment. This is best achieved by exploitation mortality but if one has enough water, the recruitment rate could be restricted enough so that natural mortality does all the mortality. Advantage of planned end of life? Faster interim growth and more rapid replacement of the adult population. Disadvantages, recruitment rate has to be higher and this might involve more expense.

8. Finally, the scenario assumes nothing but selected female LMB >12". In your pond, there are still lots of little LMB. You've improved LMB condition and you can make additional progress but the path to big bass will be a challenge starting from where you began. I sweated over expressing my doubts about the results of the advisors actions meeting your anticipated outcome. I do believe the BG stocking will work against your other efforts for the purpose of growing big bass. In as much as I do, I also believe that your advisor believes that action will help your goals. He has experienced results after such stockings that improved things in very noticeable ways in the first year. But here is the rub. Other actions were taken. Liming, Fertilization, Feeding, Culling LMB. These are the actions that are making the difference. The advisor has no foggy notion what the contribution of 2133/acre additional ~4" BG will be ... especially 1 to 3 years down the road.