Pond Boss Forums INTRO Questions & Observations Okay Ewest, you asked for it!

Related to your article "Key is Manageable Population Densities and Food Supply" I have the following questions:

First an easy one. In the article you mentioned "bioenergetic models" is this a computer simulation of some sort? Is there ever going to be a Ms. Bioenergetic USA Pagent? (ok you can ignore the second part, I just couldn't resist).

Second, in the article you wrote

"Bioenergetic models estimated the LMB population in these ponds consumed roughly 150 lbs per acre of bluegills in the first 300 days after stocking.

This study plus current recommendations of 2,000 stock size (5 inch average) BG per acre appear to be a remedy for the tendency of southern ponds to quickly (2 to 3 years) become bass crowded.

Ok, here's what I'm trying to come to terms with. Let say the bass are eating BG when they are 6" long and those BG weigh 4 ounces. If the bass are eating 150 pounds in 300 days or 2,400 ounces (150lbs x 16 oz) then they are only eating 600 bluegills (2,400 ounces divided by 4 ounce BG). Obviously the bigger the BG the less in numbers the bass need to eat. So that leaves 1,400 uneaten BG (2,000 stocked minus 600 eaten). How does this not lead to an over abundance of BG? I know there must be some basic thing I'm missing here. I know this is being done (heavy stocking of BG) and I know it is successful - Greg Grimes has posted some sucess stories. What am I missing here?

It seems like a very hands on management plan must be adhered to in order to sufficently feed the bass yet not become BG overcrowded.

You used the term biomass, is this the combined weight of the bass?

I'm thinking that the chance of an "average" pond meister to have a sustainable trophy bass pond would be very slim. It seems to me like a very active hands on management plan would have to be undertaken, one that I don't think the "average" pond meister can or will do. What are your thoughts on this?

It also makes me realize that the same "average" pond meister would have a much easier chance of achieving a trophy bass pond through pellet feeding. That way they wouldn't need to have such a large BG population to manage.

Do LMB eat at the same rate through out their lives (some multiple of their body weight per year)? In other words would the multiple remain relative constant or do they eat more initially and then taper off once they reach a certain size?

Dang JHAP that's a lot to explain. I will try to answer in parts.

JHAP - "First an easy one. In the article you mentioned "bioenergetic models" is this a computer simulation of some sort?"

Sort of. They are scientific formulas (equations) ( some take a page to write down) but they are run (calculated) on computers. There are still ongoing scientific debates on exactly which models are best and their pluses and minuses.

JHAP - "Do LMB eat at the same rate through out their lives (some multiple of their body weight per year)? In other words would the multiple remain relative constant or do they eat more initially and then taper off once they reach a certain size? "

No their energy requirements vary seasonally ,according to biologic process (spawning for example) and with age. YOY LMB have very high energy needs and fast growth rates to match. As they get out of the YOY size the rates slow down but the amounts increase due to there bigger size ( a 2 inch LMB may have a 6X growth and energy need but a 6 inch LMB may have only a 2X requirement but because it is many X bigger in mass it may eat 20X as much mass , #s for example purposes only). Once the LMB get to adult status the rate stabilizes (still changes just not as much) and is a function of size/mass of the LMB as effected by the factors in the first sentence of this paragraph. I will try to find a good published explanation.

More later.

And if you also have a large polpulation of Yellow Perch in your pond, that changes eveything.

JHAP - "You used the term biomass, is this the combined weight of the bass?"

Biomass, in pond systems, is the mass of living biological organisms in a given area or system at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms, plants or animals. So it depends on the context in which it is used. Often on the Forum it is used to mean the mass of all fish which a system can support.

JHAP -"It also makes me realize that the same "average" pond meister would have a much easier chance of achieving a trophy bass pond through pellet feeding. That way they wouldn't need to have such a large BG population to manage."

Any supplemental food source should help with LMB growth but watch water quality.

JHAP - "How does this not lead to an over abundance of BG? I know there must be some basic thing I'm missing here. I know this is being done (heavy stocking of BG) and I know it is successful ..."

Bioenergetic models estimated that the largemouth bass population in these ponds consumed between 132 and 171 kg ha (roughly 150 lbs per acre) of bluegills in the first 300 days after stocking to maintain the observed growth.

Each population of largemouth bass was predicted to have consumed 4.2 to 6.7 times their own biomass in bluegills in 300 days to maintain these growth rates and biomass.


Recent research has revealed consumption-dependent error in many bioenergetic models, including the one used in this study, which was particularly large when growth rates were fast . Thus, the percent of maximum consumption by largemouth bass estimated in this study were likely underestimated which probably indicates that the bluegill densities in the ponds used in this study may not be great enough to meet predator demand in the future, leading to slower growth, poorer condition, and a possibly lower production of trophy-sized fish.


A little confusion on the BG size. The catch rate BG were 5 inch average while the stock size (150% of normal in the study or the recommended 2000 at the convention) were small BG as were the LMB when stocked.


In this study LMB numbers were low and survival to age 1 was below normal. Even at those reduced rates the LMB were most likely to have over eaten the BG forage base which was 150% of normal if the study would have gone beyond 1 year. The moral is LMB eat a lot so you better put in plenty of forage if you want to maintain good growth rates. Then harvest to control LMB #s and size structure.



JHAP - "It seems like a very hands on management plan must be adhered to in order to sufficently feed the bass yet not become BG overcrowded."


I would not draw conclusions on longer term management from this study other than initial stocking rates (high for BG and low for LMB) and the need to take out LMB. Get the #s right survey to see what is happening then harvest to control. Sounds like standard mgt to me.

Thanks Eric I appreciate you taking the time to explain that. I know you're a busy guy.

JHAP I am not so busy I can't help friends.

If you are having doubts that you can manage your LMB because you are not there much - don't worry. In a few days you can make a big change in your pond.

I said before - if you have questions go ahead and ask.