Pond Boss Forums STOCKING A NEW POND Raising Forage and Bait Information on growth of CNBG in hatchery pond

Just had our 45 acer lake shocked and the results were very disappointing. Bass and bream stocked almost 4 yrs ago and bass not growing because CNBG apparently were eating up by an exiting small population of predators when the creek flooded into the lake before we bermed around it.
Here's the question: we have equipment and property to build a hatchery pond to grow BG. The plan is to dig/push about an acre or so in size hatchery pond. How fast do these fish grow with no predators and a strong feeding program. They have to be 3inch or better before we can transfer them. Since we live close to Pensacola fl ( the lake is located about 50 miles north of Pensacola) the amount of times they will spawn can be 7 to 8 times in a year. Second question how many fish can be a realistic expectation in a pond that size. Biologist said they would stock 2000/acer so that's 100000 BG to get the bass growing. We will make sure the water quality is as good as we can make it with lime and fertilizer in the hatchery pond. Thanks for any data and or suggestions.

scampbell,

Google "Guidelines for the Culture of Bluegill Sunfish". Everything you want to learn is in there. FWIW, BG do not handle well below 1" in length and in a culture pond that maximizes production of individual BG, they usually stop growing or grow very slowly at 1.5 to 2 in in length which occurs in about 45 to 60 days. IMO you will be better off stocking them between 1.5" and 2 " and allow them to attain 3" sizes in your much larger lake. Just stock them numerically strong enough to have the survival required to meet their recommendation.

One thing I didn't add, we will put the hatchety pond close enough to 45 acer lake to ditch them from the pond to the lake, the handling with be minimal.
According to article at first cursory read the pond has a chance to produce huge numbers of 1.5 to 2 inch BG every 2 months. Looks like up to 100000. If that's correct, we could put it 250000 bream over the course of the year with our warmer weather. Depending on how they do when the weather is close 95 to 100 degrees around July / August.

Yes. So even with 40% survival to 3" you could achieve the goal of 100,000 3" BG. Considering the biologist thought the >3" BG was what was in short supply, keep in mind that 1" to 3" BG are not being consumed by BG (but rather are being consumed by LMB up to about 18"). They can only eat so many so fast so the loss of your supplemental BG will only be the amount the <18" LMB were short relative to consuming ad libitum. It is possible that you will get more surviving than they recommended. You may want to talk with them about whether exceeding 100,000 3" BG per annum is something they would be concerned about. All things considered; I would prefer to have too many smaller BG than not enough 3" BG.

You will have to feed the CNBG in the hatchery pond, and since not all fish grow at the same rate AND you will have multiple spawns, you will be stocking a multitude of sizes, not just >3" BG. The only way to do that is to seine and grade the fish, returning the smaller ones to the hatchery pond to grow larger.

If the biologist recommended stocking the BG at >3", why are you recommending that the OP stock BG smaller than that size?

Unless you know something that I don't, how do you know that LMB <18: are eating the small BG? The OP said "Bass and bream stocked almost 4 yrs ago and bass not growing because CNBG apparently were eating up by an exiting small population of predators when the creek flooded into the lake before we bermed around it." There could be other predators that washed in besides the existing LMB population.

It's just that I have never known of <18" LMB refusing to eat <3" BG. Why wouldn't they eat them?.

Sure, thank you for the question esshup. Let's say the OP tries to grow them to a minimum of 3". To get most samples > 3" he will have grown them to an average length of 3.5 inches. Now if he crops them at 1.5 to 2 inches in length, 100,000 BG will weigh 332 lbs. But if he grows them to an average 3.5 inches, the 100,000 will weigh 332*(3.5/1.75)^3.43 = 3578 lbs. Personally, I wouldn't try growing such a high standing weight of BG in that pond ... especially considering he has opportunities to grow more crops. If he tries to grow the first crop to 3", he will lose one opportunity ... plus if he has a fish kill ... then he won't make the goal at all. To further complicate things, the BG need to gain ~ 3250 lbs over the next 60 days. Even if he has great feed and they convert at 1.1 to 1, it will require 3500 lbs of feed over a span of 60 days, that is over 58 lbs of high protein feed per day. That is a very high rate of feeding and he would need to be ultra careful with water quality and could easily lose a whole crop.

Meanwhile, for past 60 days they could have been growing in the lake for free. And if BG are in short supply, then the rates of growth could be maximum rates of growth. But it isn't just this. There are other risks to growing past the 45 to 60 days. He will not know how many BG individuals he produced. So maybe 60,000 or maybe 180,000 BG. If the former, he would be feeding way more than they could eat and if the latter, they would not reach the 3" minimum anyway.

You may argue that the BG will all be eaten. This may be true. But I think that's the point. They need more forage to eat. What will happen is that predators that do well eating the smaller BG will get their fill and remaining BG will grow to larger sizes which can feed larger LMB. This is how the food chain works.

The white paper is a good resource and in it is the most cost effective way to culture BG. I recommend that he follow their protocol ... part of which is to harvest between 45 and 60 when they are anticipated to stop growing.

Go re-read the OP's posts. The biologist didn't specify that the LMB were eating the fish according to the OP. You could assume that they were, I am assuming that they are being eaten by another predator other than LMB. If predatory fish were washed in from the creek, what other predatory fish could be living in creeks 50 miles North of Pensacola, FL besides LMB that would eat <3" BG?

As for growing the fish in the pond to transport, I would recommend digging 2 ponds. One, one acre to grow the fingerlings and another that is 1/10 to 1/4 acre to hold the brood fish. After the first spawn, the week after fish abandon the nests post spawn, I would seine out the brood fish from the one acre pond and put them into the 1/10 acre pond to hold until they are needed in the 1 acre pond again. That will do two things. 1) Reduce the predation of the fingerlings by the brood fish and 2) Minimize the fingerling mortality when the fish are moved to the main pond by seining, or if the OP drains the pond via ditch to the main pond, he has to remove the brood fish to have for a 2nd crop that year anyway. He can use a seine with a big enough opening size to only catch the brood fish when removing them.

As for the growth of the BG, I think the OP has enough of a growing season to stock the main pond at least twice per year, each with approximately 50,000 >3" BG. By doing it that way, he doesn't run the risk of running into water quality issues by having too high of a biomass of fish in the pond, and he minimizes <3" fish predation upon stocking. 50,000 3" BG weigh around 950 pounds. He still has to monitor water quality and O2 levels, but he won't be putting all his eggs in one basket so to speak.

I think your idea of stocking enumerated fry into the 1 acre pond for grow-out will work. Caveat is whether 1/10 acre fry pond will produce 50,000 fry per cycle. IMO, the harvest should come out when the standing weight exceeds your estimate. Not all BG will be 3" but the average should be that. This approach will allow him to prep the grow out pond for another cycle at the soonest possible time.

I read the OPs post several times and I felt there were a lot of holes. I do think 10 people could have read it and come away with 10 impressions as to what the biologist was thinking and why that number was selected and to what purpose the supplement is for (eg food for a target sized fish or to strengthen very weak adult BG population). I thought there were several red flags that I will list below.

1. The water is 4 years from stocking. Dang, if I had a nickel for every lamentation posted here around that mark in time ... I would have a few dollars ... I think. So I did wonder if what is happening is just the effects of recruitment and the larger sizes of the original stocking.

2. It seemed to me that the biologist's explanation for lack of forage was that predators entered the pond and cleaned them all out and then exited (left) the pond. The OP didn't say there was a colonization of predators from the creek. Pretty handy "it depends" explanation for why the fish are so lean and not growing. The cost of such a supplement probably ranges between 30 and 40 thousand dollars if purchased (maybe more).

If the original LMB stocked in the OPs pond had grown by ad-libitum feeding, he would have examples of 10 lbs LMB presently. The number of the original stocking would now be diminished to have successfully reached that goal.

The prescribed supplement is for 2000 lbs of BG (in a 45 acre lake 44 lbs per acre). In a 45 acre lake with 60 lbs LMB/acre; the amount of consumption required for maintenance is 372 lbs per acre. The supplement is a minor fraction of that. There will be a benefit but probably less than the OP is anticipating.

The 1/10+ acre pond is for the adults to be placed, the 1 ac pond is to grow out the fry that were hatched there. So, depending on the depth of the 1 ac grow out pond that would determine the pounds per acre foot. But the 950# per surface acre should be pretty safe to grow assuming feeding and aeration.

Yes, that is how I understood it. You are recommending that the OP grow fry in a 1/10 acre fry production pond for grow out in the 1 acre pond to 3" in length. Two cycles of 50,000 3" fingerlings are the goal. To work, the 1/10 acre fry production pond must produce the amount fry needed to stock the grow out pond. With 100% survival the enumerated fry would have to be 50,000. With 70% survival to 3" the enumerated fry per cycle would need to be 71,500 fry. So a good estimate of survival and reliable enumeration is part of this recommendation. As I said before, I think this would work if the 1/10 acre fry production pond produces a sufficient number of fry per cycle. FWIW, I am totally OK with the OP following this path if that is what he wants to do.

I know next to nothing about this topic, but wouldn't "ladder stocking" of the grow-out BG perhaps work better?

As you move some 1.5-2" BG over to the main pond, then the population pressure on the food and space resources in the grow-out pond should be somewhat reduced. Would that help the remaining BG population more rapidly move to the 3-3.5" range?

You could even do several partial transfers.

That way you get lots of BG over to the main pond, and also get a significant number of larger BG over to the main pond.

(Just thinking out loud and reading what our experts say.)

I edited my post. The brood fish stay in the 1/10th acre pond most of the year they are placed in the 1 ac pond just to spawn and are removed so they don't consume their fry before they can grow to 3". They are seined and put in the 1 ac pond to spawn and are removed since they are in there solely to produce fry.

Every time you seine fish you stress them. The OP would have to run ALL the fish through a grader to transfer smaller fish. (seine, remove fish from seine, grade inside a holding tank, return larger fish to the grow-out pond) I'm lazy, why go through the extra work and stress the growing fish when there were no recommendations from the biologist to stock the smaller fish in the bigger pond? Also, I'd only put in 20 pair of brood fish in the 1 ac pond for the first hatch. Less fingerlings would equal faster growth, and not having the brood fish stay in the pond will reduce predation. The surviving >3" fingerlings can be counted upon 1st transfer to determine if more or less brood fish are needed for the next hatch. Using the ditch to transfer the fish is a good idea, but for the first few transfers, they need to be counted to see what quantity is actually getting produced and moved.

Hopefully the OP will come back and shed more light on his quandary.

The easy part. Habituate the BG in the big lake. Get a 150 ft seine and place it around where the BG from the ditch will enter the pond. Put it there just before you release the BG by seining from the land out to where you post the net. Then release the BG into the ditch. Keep them there at least 24 hours. You can even feed there for a bit. That will greatly increase survivability of the new BG as they will then recognize the predator danger and avoid being an easy meal.. Add some thick cover just outside of where the net will be. There are several threads here on the subject and the science is included.

https://forums.pondboss.com/ubbthre...ds=habituation&Search=true#Post26019

For those that are following, esshup's recommendation is to reduce the TPWD recommended brood stocking rate by 1/2. So this should, on average, yield 50,000 very close to 2" fingerlings in 60 days. At this point, feed is required for them to continue growing. The goal of 50,000 3" fingerlings could be met in as little as 90 to 100 days. There will be variation of fry production and the final harvest could be as many as 90,000 smaller than 3" fingerling or possibly fewer than 50,000 3". The results would not be as consistent as enumerated fry, however, it doesn't bother me if a more than necessary number of smaller BG are produced.

So we have had a lot of discussion around matching the biologist's recommendation of 100,000 >3" BG to a tee. My question to the OP is:

"What did the biologist say you would get for this investment?"

Was it just to say this would "Get them growing again?"

A good question for him is this: "OK Mr. Biologist, if I do this, where will I be in a year and what difference will it make in the metrics? What will the RWs be then? Give me a reference to understand whether it was successful or just a waste of money."

If you get an answer about improvements in the metrics. Ask him this. "Will you guarantee it?"

Ever see a crawfish evade a predator? You'll see a biologist back right up. LOL.

This much I can say. If after stocking 300,000 1.75" BG there isn't enough surviving to feed LMB needing >3" BG, there is something else wrong.

From the paper: "With a broodfish
stocking rate of 100 pairs/ha (40 pairs/acre) and assuming a 50% hatch rate, approximately
774,074 advanced fry/ha (313,500/acre) can be produced from a well-managed pond. However,
Huner and Dupree (1984) reported that under normal circumstances about 300,000 fingerlings/ha
(120,000 fingerlings/acre) are produced."

That's with leaving the broodfish in the pond. What would the survival rate be if the broodfish are removed? As for feeding, I'd start feeding at 8 days like the paper says, not waiting until they get to an advanced growth stage.

That's a good question. The answer is that it will variable. One should expect an average in the neighborhood of 120,000 according to Huner and Dupree. The white paper assumes 311,000/acre of 25 mm (1") BG can be produced. Upon reaching this milestone the standing weight of fingerlings is 139 lbs/acre. Not all that high a standing weight. The paper, if you notice, is not a historical account of production at TWPD. It seems to be more of a set of guidelines seeking to standardize production at the various hatcheries.

They are assuming a 50% hatch rate so I guess the question is really this, how many eggs are they assuming? So at 40 pairs per acre there are 40 females. Earlier they say a female can lay up between 2,000 and 63,000 eggs. Taking an average (32,500) and multiplying that by 40 females ... I get 1,300,000 eggs. At 50% hatch it would seem there are 650,000 fry swimming up. So if a well managed pond produces 313,500 advanced fry per acre then they must be assuming only around 51.8 % mortality. Seems pretty rosy and so I am interpreting that as a lofty goal rather than it being a normal (or average) production number.


I didn't read the paper that way. In it they talk about monitoring the zooplankton population and feeding as needed. When necessary, food is supplemented to fingerlings. They are using two metrics to determine feed rates. One is the growth of samples, the other is the zooplankton population analysis. I don't however think it will hurt to feed the rates in the table as a precaution against problems with the zooplankton populations. I do think taking zooplankton counts is beyond the scope of myself and the OP. I don't want to get that deep in the weeds, LOL.

It is questionable how much the fingerlings are benefitting from feed when the standing weights are below 250 lbs/acre. A fertilized pond can support as much as 550 lbs of BG. Plenty of BG fingerlings have been produced using a combination of organic and inorganic fertilization. The white paper discussed the recipe for a spawning pond to ensure food is available for fry when they hatch. This fertilization and the follow up treatments are absolutely essential for success. There are enough nutrients in the regimen to grow 100,000 BG fingerlings to at least 1.5" in 60 days. The only thing that would prevent that is if the nutrients didn't find their way into zooplankton that the BG could graze on.

The other reason why I would feed is that all of the commercial fish farms where I buy fish, feed their fish, starting with fry powder even though they have green water with a secchi reading around 18". I have to assume that if it wasn't cost effective to feed the fish, then they wouldn't. Why spend the money on equipment, labor and food if there wasn't a ROI?

I don't see the cost of feed being an impediment at all. For example, consider the wholesale value of a 1" BG at 10 cents each FOB the commercial distributor. Growing 311,000 BG where feed provides all the sustenance to grow them will be 369 lbs of feed fed from day 7 to day 33. So even at a buck fifty for the feed, there is only 554 dollars in feed to grow 31,000 dollars of wholesale fish. So even if they didn't need the feed during the first 33 days ... they could flush all that feed down a toilet instead without affecting the bottom line much. I am a very reasonable man and there is no way I wouldn't feed if the conditions warranted feeding. I also wouldn't try to fix something that wasn't broken. I would apply good reason and do what is necessary when it is necessary.

So look, all I tried to do is point the OP to a paper with a recipe for fertilization and a recommended stocking rate for brooders. Trying to keep things simple, I would still recommend doing only this and taking the results (whatever they are) in 45 to 60 days, rinsing and repeating, to get as many small BG recruits as I could into the lake during spawning season. So, I get that this doesn't suit you primarily because it doesn't match the biologist's recommendation. But you have deviated significantly from the paper. You are only trying to grow 50,000 BG per cycle. They are trying to grow 250,000 BG from 1" to 2" or 311,000 BG from swim up to 1". You are trying to grow the BG from swim up to 3". So I will defer to you for this effort but the white paper will be no help for him to accomplish what you are demanding.

The OP must rely on your expert advice in order produce the 100,000 3" BG that you say your advice will yield. You need to lay it out for him or he will fail. He needs to understand how to do it, how much to feed and when to feed it particularly because green water alone will not get him there. If you don't do this, then your comments don't matter much and they just come across as urinating in his tea. So lay it out for him and help him succeed at meeting your expectations.

So then if the OP constructs his 1 acre hatchery pond, after following your protocol we can say he was successful if he has produced 100,000 3" BG in two cycles.

esshup (and others),

I was asking about much simpler process than that.

I was wondering if you partially seined after X days with no sorting, and moved over SOME BG presumably containing the bell curve of fish sizes at that age.

And then you later seined again after X plus Y days, and subsequently moved over some more BG that were presumably larger at that age.


Answers I don't know:

Does stocking a main pond in a single iteration increase the survival rate of the stocked fish, in the case where you are worried about "immediate" predation? Presumably by the predator fish becoming sated?

Does removing a significant number of fish from a grow-out pond (with a population below the carrying capacity) substantially increase the growth rate of the remaining fish?

We really need the OP to come back on here and clarify a few things. Did the biologist recommend stocking that quantity of 3" fish to take predation of stocked fish into account? Why did they specify 3" fish and not 2" fish? Too many unanswered questions to keep making assumptions.

If the goal is to stock 3" fish, AND you had 50K fish in the pond from the first hatch, then seining and stocking fish less than 3" would be detrimental to the plan that was laid out, no matter how fast the remaining fish in the pond grew. Remember, when someone says 3" fish, usually they will be roughly 2.5"-3.5" in size.

Like ewest said, using a blocking net would increase chance of survival. Stocking all at once will increase chances of survival because of the sheer number of fish stocked at once. The predators will get full tummies and stop eating allowing the rest to escape, but the blocking net will help.

Growing 100,000 3" BG would be risky for a one time stocking in a 1 ac pond. Carrying capacity is the problem. Remember all fish don't grow at the same pace, so you will have bigger and smaller ones in the pond too.

Would be great if the OP could shed more light on the history of the lake and everything the biologist told him. When I hear of skinny LMB, my mind goes immediately to the notion that there is too much competition for the forage that isn't recruiting sufficiently. In my mind, forage recruited for consumption by LMB are forage that BG are not able to consume. One author I have read said this size is 30 mm or about 1.2" in length. Now definitely a 6" LMB will go to town on such sized BG but if you are not recruiting sufficient numbers to this size ... there is no chance there will be sufficient forage to satiate the appetites of all the LMB. If we understood the average proportionate length that LMB consume, we would understand the proportionate weight consumed on average and from that we could calculate its satiation needs for a year in terms individual BG consumed. I consider satiation to be the quantity required to attain its full potential for growth.

The OP is in a warm climate where LMB can gain 2.6 lbs annually. It's warm and a lot of what they eat goes to maintenance so they are going to have to eat alot of BG to reach their potential. I can say for sure that not enough 1.2" BG are being recruited for the number of LMB that are in the lake. If there were enough, there wouldn't be disappointment, plain and simple. So what is enough? All they need to reach their potential. So the average 1.5 lb female LMB in his location will try to consume 22.7 lbs of LMB to fulfill her potential of growth. How many BG is normal for that consumption? If we know the average proportionate size of fish she is eating, we could use that for to estimate the number. A 1.5 lb LMB takes more BG to reach her potential for the year than a heavier one does. So each size class requires a diminishing number of BG. But a 1.5 lb LMB would eat 840 BG per annum to grow 2.6 lbs if the average BG was 1% of its weight (in the OP's climate).

Here's the gig. The average 1.5 lb LMB will not stop trying to consume that weight of BG. This is the weight required to fulfill all its metabolic needs and fuel its full potential for growth. The will to grow is there ... what may or may not be missing is the means. For larger LMB, their growth depends on what filters through smaller size classes. If the BG forage recruits are sufficient in number, there is potential for ad libitum feeding and maximized growth.

My question is two-fold. Since there are not enough BG being recruited for forage, is this because the BG are not recruiting efficiently? Or is it because the LMB are too numerous? Could both be a problem?