# Pond Carrying Capacity (how many lbs. of bass?)



## RiparianRanger (Nov 18, 2015)

I have a small, naturally occurring pond that straddles my lot line. Using GIS overhead viewer it is calculated at approximately 7,800-8,000 sq. ft., or roughly one-fifth of an acre. The pond was recently vacuum dredged to remove the many years of silt and organic debris decomposing on the bottom and robbing aquatic life of valuable oxygen. The process required a pair of divers to enter the pond so we know the pond is approximately chest/shoulder deep on a six-foot man in the deepest location. The pond is aerated with a pump and 5/8" hose with a diffuser that keeps at least a 3x3 area clear of ice all year. There are loads, and I mean tons of bullfrog tadpoles in the pond. We've trapped golden shiners using minnow traps, though yields are down from a couple of years ago. Stunted bluegill are easily catchable on hook and worm or ultra light fly tackle. 

My question is, given we know the size, the approximate max depth, and the potential forage in addition to the fact it is healthy (recently cleaned + aerated), is there a formula for how many largemouth bass the pond could sustain? I'm assuming this answer would be in pounds as opposed to numbers since it stands to reason a three pounder is going to eat and respire generally as much as two 1.5-pounders. 

Any info is much appreciated. Thanks.


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## badducchio (Apr 21, 2015)

A starting point would be 50 lbs per acre but there are numerous factors that contribute to that number. Aeration, feeding, alkalinity, fertilization, structure, etc. Every pond will have a different maximum carrying capacity which is dictated by these factors and more. Carrying capacity is usually not discussed by a specific fish species but all the fish within the pond. The 50 lbs/acre would be for a balanced pond with no aeration, feeding, or fertilization. I would determine the average size of the stunted bluegill and add 8-10 LM that will target this average size. When the bluegill start balancing out I would add 8-10 more half the size of the original stocker LM. I would not add anymore LM than that being only 1/5th acre. At that point I would let natural reproduction take over. 

You could add Hybrid Striped Bass in lieu of the LM that way numbers can be controlled. However, at some point the bluegill size will exceed the mouth gape of the Hybrid potentially introducing another stunted population of bluegill several years down the road. Good luck.


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## RiparianRanger (Nov 18, 2015)

Good info. Thanks. We have no plans nor a desire to feed/fertilize but as mentioned previously it is aerated and we will do what we can to keep it free of oxygen robbing decomposing organic matter. 

Are the original 8-10 LMB “adult” size (of reproductive age) that will immediately prey on the bluegills, or are you suggesting fingerlings that grow into this role?

PS: there is good cover on the shallow end characterized by a 4 to 5 foot wide perimeter of a type of flowering reed grass. Minnow traps placed near here has yielded shiners historically and that seems to be where the heron frequents the most.


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## badducchio (Apr 21, 2015)

I have seen 8-12" LM reproduce in my pond but there were no advanced sizes at the time. Any LM you place in there will probably not reproduce this year but anything is possible. When determining the size to stock, multiply your average size bluegill by 3 and that is the size of LM you should stock. The numbers provided are slightly heavy so once your pond stabilizes you may pull 2-4 of the original stockers out if possible. The second stocking is to ensure you have a nice spread to keep the bluegill in check at all sizes going into the future.

For future management I would recommend reading https://appliedecology.cals.ncsu.edu/wp-content/uploads/ANR-1193.pdf. Anything I pull out that does not meet the standard weight for it's length does not get released back into the pond. It is not foolproof but does give a great idea of fish condition and is an extremely easy management strategy.

If you are not aware, there is a great pond management forum called Pond Boss. It has loads of information and gets into the nitty gritty of everything ponds. They also produce a magazine dedicated to pond management, amazing source for information.


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## RiparianRanger (Nov 18, 2015)

Interesting. If reproduction is a concern, would a better strategy be to stock the pond with smallmouth bass? My understanding is smallmouth are unlikely to reproduce in a mud bottom pond.


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## badducchio (Apr 21, 2015)

Smallmouth will reproduce in a pond even with a clay bottom. If LM are present, they will destroy a smallmouth population over time. The only safe bets would be walleye, hybrid striped bass, and trout. Channel cats are cavity spawners so ensuring a pond bottom is void of such structure can prevent reproduction. I have heard stories of some getting walleye to spawn but never successfully. Out of this list, only hybrids are genetically unable to spawn.


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