Pond Boss Forums INTRO Questions & Observations pond carrying capacity

what is the total pounds per acre a non aerated pond can handle? the fish are being fed with an auto feeder heavily. bass and bluegill only.

Hey Scott,

My 2 cents...IMHO your pond can handle the number of pounds that will not exhaust your forage or negatively impact your water quality. Too many variables from pond to pond to give a definitive answer. I am not a pro though so just offering up an opinion. I tend to be conservative when the health of my fish is involved. Hopefully, a pro will provide a better answer.

Bill D.

Not a pro but I seem to remember in my warmwater fisheries class in college, high end CC for a body of water, that was not fed or aerated (extensive) was 300 lbs. per acre. At the other end of the spectrum I've heard of aquaculture ponds that were heavily surface aerated and fed (intensive) from 2000 to 5000 lbs. per acre.

In my semi-intensive ponds, where I hatch or grow out fish, and use bottom diffusers, I prefer not to go above 1000 lbs. per acre.

I once went above that in a small 1/10th acre pond, and although feed was not a limiting factor, my ammonia and nitrites spiked causing severe stress issues. The yellow perch exhibited similar symptoms to hypoxia (low D.O.), and were piping at the surface. That said, my Ph is high at 8.4 which means it doesn't take much for my unionized ammonia to get to dangerous levels.

Here's a link to a past discussion on carrying capacity in ponds right here on Pond Boss.

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92440

How do you know you have reached your carrying capacity? I remember reading after the first year your pond will be at its capacity.

Thanks Don.

Don, the only way I know that you can tell if you exceeded the carrying capacity is a fish kill.

Remember, the carrying capacity is for the worst conditions in the pond, not the best.

This is in the Pond Boss Archives....
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92440#Post92440

Hey that's the same link I posted!

I wanted Scott to read it twice to make sure he understood it.

Cecil, most CC farms run at least 11,000 pounds per acre foot now for open ponds, and 25,000 in raceways. automated Aeration and monitoring systems are really getting refined!!!
(and those weights are in ponds with waters exceeding 95* in the summer months)

Ok so this may be getting confusing. I have read over and over and over that 450# per acre is reasonable. Now is that 450# per acre foot or per acre of surface area.

I got the impression it is per acre of surface area because this is the limiting factor in allowing air to enter the water.

If one has aeration one could then expect 450# per acre foot as a conformable number?

All in all it is just a guess until you have a fish kill.

Cheers Don.

I think the concept of carrying capacity was developed for natural production systems. It was a concept to estimate how productive a system is at a natural balance. The more the carrying capacity becomes the more stressed the system becomes and more vulnerable it is to some sort of failure.

I see!

Sounds scary to me!

Fish go off feed. Could coincide with intense algae bloom under 12 inches visibility. Clinical signs of disease. Elevated ammonia, nitrites, and nitrates.

i have been busy, so i am just getting to read and comment. for some reason i had 400 lbs per acre in mind, from past reading. i think that was with feeding and fertilization, and maybe even aerating?

here's where i am confused. my new pond is about 1.75-2 acres. we will use 2 acres for easy math. i had 2500 bg and res(i think the res were supposed to make up about 15% of that mix) stocked in February. then in may i had had 150 lmb stocked. my goal is big bg. i am sure these fish are going to top a pound easily by spring 2016. right now i am catching them 8"s long and very healthy. they are getting fed 4-6 times a day aquamax 500. lets just suppose they only get to be 1/2 pound each. that is 1250 lbs of fish. then what about the bass, 2 lbs possibly within a couple of years, that's another 300 lbs. that's over 1500 lbs of fish.

here's another kicker. i do not have grass carp, and won't unless it is an absolute necessity. but the local pond management groups are recommending them for fa control at a rate of 10-15 per acre. they grow to 40 lbs right? if i did have them in my pond that would be another 1000 lbs of fish when they mature.

i know a few die, a few get caught to eat, but they are also spawning and producing more lbs. what am i missing here?

Recommending Grass Carp for FA control? There's a wire crossed somewhere.

Agree

Hey Scott,

Don't forget those LMB have probably been making bass snacks of some of those BG and RES, reducing their numbers.

Bill D is right, for every pound that is put on one LMB, they have to eat approx. 10# of fish.

GC aren't known for FA control. They should have said Tilapia. Tilapia can also help you grow large LMB, but I don't know if they are legal to stock in your state.

i agree about the grass carp, not from personal experience, just what i have read. but the the fish sellers don't make money if they don't sell fish. that's the only reason i can figure they are pushing them so hard, surely they know what the carp eat.

about tilapia. yes they are legal here and i stocked them twice in my old 3/4 acre pond. i am about as sold on them as i am carp. i had an auto feeder running there also, they seemed to have liked the pellets way more than the fa. also, pretty much never saw any young tilapia. they ones i did see were in a school about the size of a basketball or smaller. the fry looked less than 1/2". they also told me that when it got cold i could just go out there and scoop them up and have a great big fish fry. it didn't exactly work that way.

back to the pond carrying capacity. i understand the bass will whittle away at some of the bg, but my bg had several months jump on the bass when stocked. the bass were just fingerlings. they are 12"s now which i think is great growth since may, but the bg are 8"s so the bg are safe from bass predation for now i think. it just seems that a pond could get too heavy very quick without some type predation at the rates some of us are stocking.

I don't know what the stocking rate is there, but here if I don't stock 40# of Tilapia per surface acre and whack back any FA before stocking the Tilapia won't seem like they are working.

BUT, after not stocking them one year, I can see what the pond looks like when they aren't in there. They DO help. This year I didn't have to treat my pond once for FA - I was able to stock them before the FA became too prevalent.

I don't see many small Tilapia in my pond either, but I do see momma with schools of small ones near her. To me that means that the little ones are getting eaten, which is a good thing if I want to grow larger predators.

S69 says "i know a few die, a few get caught to eat, but they are also spawning and producing more lbs. what am i missing here?"
Several items need to be considered / remembered.

1. The carrying capacity and fishery balance changes as ponds age.

2. You are correct a few die, although the number is almost always more than a "few". Expect 10-35% maybe 40% early deaths depending on the source and handling. Often dead fish don't float.

3. Once the pond reaches carrying capacity natural annual mortality is high usually 20%-30% of the older/adult fish. These annual deaths are not always apparent and usually go unnoticed. This is why annual harvest is wise, efficient use of the resource.

4. In balanced communities or high predatory populations, few new fish survive long enough to be adult recruits.

5. Your 450lbs/ac figure may not be remembered correctly or the source of the info may not have been accurate or can not be applied to every situation. Rarely is one carrying capacity figure all inclusive. "It always depends."

6. In good poly culture, diverse communities where different species will utilize different niches, this allows less direct competition and ultimately higher carrying capacities.

7. Different ponds (situations) can have higher natural and artificial carrying capacities depending on habitat and soil type.

When ponds that are thought to have lots of fish are eventually drained / renovated, the owner asks "what happened to all the fish that were supposed to be in there?" Just because fish are stocked does not mean all or even lots are surviving. What should be in the pond and what poundage calculates on paper are not always the reality, especially in mature fisheries. Newly established fisheries always seem to be better in early 'life' than after that fishery and the pond becomes older and the types of productivity shift from "newer"(1-10 yrs) systems to "aged" (15-20+ yrs often eutrophic - hypertrophic ) systems.

Bill I really get excited when I see your posts. I read them word for word over and over then look at our pond and think of how that may apply.

Interesting enough this spring we were catching 1 6-8" for 5 10-12" stocked perch. This fits right into your statement of 20-30% loss or mortality's. Basically we are seeing recruitment currently equal to your 20%. Removing 20% annually for us I infer is a good management plan off our catch numbers this spring.

I do understand how invaluable records are if one is not going to drain a pond often.

You are a wealth of knowledge and experience well done.

Cheers Don.