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jpsdad - For all those not fully up to date on fishery jargon, would you please explain or describe your terms "forage running too hot" and "running the pond too hot"? Thank you.
Last edited by Bill Cody; 09/16/23 08:31 PM.
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Did you take issue with it? All I mean is that a there are limits. I meant so much fertility that the risks of mortality arise from something other than not having enough forage. Things like too much plant respiration, algal die-off, the aerator breaking down, the electric going out at the wrong time, a week of cloudy weather. Generally speaking, water quality parameters are more stressful in more fertile environments. It is just a risk that is different than not having enough forage that can also cause fish mortality.
RO40 originally asked whether pushing fish to grow would make them die faster. I think fast growing larger fish are no more susceptible to natural mortality when they are getting enough to eat and water quality is good.
Last edited by jpsdad; 09/16/23 10:53 PM.
It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers
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No issues with the wording. Just wanted novices and inexperienced to understand the terminology and meaning of "hot"..
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"Hot" is a rather vague word and to be vague about those other risks that can cause mortality was something I wanted to do. Mostly, because I don't know how much is too much. "Running hot" is how Snipe described conditions in his pond leading into the time where the crayfish were crawling onto the ice. Certainly some water can handle more of it than others. I am reminded of the Virginia Female Only pond Solitude is managing. They reported growing Northern LMB from 1.2 lb to a few ounces shy of 10 lbs in 3 years. They initially stocked the LMB at 67 females to the acre (and also 67 HSB to the acre). I presume the HSB were relying mostly on feed but I could be wrong about that. The LMB are fed supplemental forage. We can estimate the forage required each year to make that ultimate weight in 3 years which is in the SS below. The SS shows the initially stocking at each anniversary and year 3 is coincident with their report. Note how with no mortality the forage requirement grows exponentially. The 3rd year FCR is 13.43 to 1. They reported worse FCR (20-30) but this could be explained if they stocked more forage than was consumed ... or forage larger than optimum ... or if some of the forage wasn't consumed because of preference for feed by HSB. IOWs Some of the forage supplement wasn't eaten for one reason or another. The growth was amazing so it would seem that they were consuming as much as they cared to. For the 4th year the consumption to support maintenance and growth is 3666 llbs of BG per acre. So maybe this is hot? Of interest the consumption dry weight is ~ 733 lbs of dried BG. Imagine feeding a feed of 100% BG Meal to the LMB at this annual rate. This would be a feed of approximately 70% protein. This Virginia pond has the advantage of a good Spring to carry waste from additional forage consumption and the wastes of feeding resident BG down stream. Below I recreate the same initial stocking but also employ fishing mortality in order to keep the forage requirement stable and in the neighborhood of the first year's requirement. Is 850 lbs of forage per acre-year running too hot? In some ponds probably so, in others, probably not. Each person will have to be the judge of that for his own water. Anyways, given 850 lbs consumption per acre year one could grow some hefty female northern bass in 3 years. Is year 4 possible? I don't know but provided a person harvests 3 LMB by the middle of year 4 AND 821 lbs of BG forage are consumed ... it is in theory possible. The unknown is just how much forage will be consumed by survivors. It would require the consumption of 634 optimum length BG by each of the remaining 9 LMB (a little less than 2 per day)or on per acre basis the consumption of 5433 optimum length BG per acre ... plus ... whatever the 3 harvested LMB consumed. If the 3 LMB were harvested at the close of year 3, then just the 5433 optimum length BG would need to be consumed. At the start of year 4, an optimum length BG is ~4.53 inches at the end the optimum length is just under 5" in length. Can a pond produce this many optimum length BG for nine 9.2 lb bass to consume? Dang I don't know but if it can't produce a similar quantity that averages the weight of optimum length BG ... then they ain't going to be growing as much as modeled.
Last edited by jpsdad; 09/23/23 07:00 AM.
It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers
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Good analysis of the "hot" definition. My note regarding the VA Female LMB project. Keep in mind that not all the 67 female bass grew to a few ounces less than 10 lbs in 3 years. My guess would be smaller ones were 7lbs and most others were 7 to about 10 lbs. There are always jumpers as most aggressive individuals and a few slow growers in every stocking or year class. Regardless this all female project demonstrated excellent LMB growth that is possible when placed into a "hot" forage community. .
Last edited by Bill Cody; 09/17/23 07:50 PM.
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My note regarding the VA Female LMB project. Keep in mind that not all the 67 female bass grew to a few ounces less than 10 lbs in 3 years. My guess would be smaller ones were 7lbs and most others were 7 to about 10 lbs. There are always jumpers as most aggressive individuals and a few slow growers in every stocking or year class. Good point Bill. I did adjust lower than the maximum but still wondered if I should have adjusted more. The SS is intended to be an average for a selection year class where some members of the class outperform while others underperform. I do want to also mention that in the examples I provided ... we have to consider them highly fertile environments. It's worth asking, "Do we need that much fertilty to grow big fish?" Consider a 1 acre swimming BOW where relatively clear water is desired. Could a person still grow trophy LMB? See the SS below where 112 lbs of BG consumption per acre is sufficient consumption to grow female LMB from 1.25 lbs to over 8 lbs in 4 years. The standing number of LMB in this scenario is only expected to be 4 per acre. 1 fish is harvested in its 4th year for each acre. Each Fall this 4th year LMB is replaced with one 1.25 lb female LMB. This is a very modest approach to growing trophy fish. Not many but an assembly line of one 8 lb LMB each year. There may occasionally be mortality of the 4th year class by natural means. When that happens, there will be no harvest in a 1 acre pond. Restricting harvest to 4th year fish ensures each gets their opportunity to complete the growout. In cases where the pond is unable to produce 112 lbs of lepomis forage ... supplemental forage like TP, RBT, or crayfish could fill the gap. Given the small numbers of LMB mouths to feed, a lepomis with less reproduction may be more ideal (eg RES). It would take around 2350 optimum length prey per acre to fill out the 112 lb forage requirement so the production number doesn't have to be large. I've even wondered if something like a BG-RES hybrid might work in combo with 3 lbs/AC of TP brooders. Still I think would prefer RES. Although RES couldn't support a trophy LMB fishery if the LMB were recruiting, where numbers of female LMB are restricted to balance RES forage production there could be balance for a handful of large LMB per acre. The expected standing weight fluctuates between 17 and 26 lbs of LMB per acre.
Last edited by jpsdad; 09/21/24 07:57 AM.
It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers
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IMO Good estimates of "normal" production of LMB. I like the examples. Examples do show that pond productivity as water clarity does definitely determine fish poundage.
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IMO Good estimates of "normal" production of LMB. I like the examples. Examples do show that pond productivity as water clarity does definitely determine fish poundage. Bill, I am not so sure any of the examples above were normal although it is very "kind" of you to say that. We "normally" have LMB recruitment to contend with and the standing weight of LMB less than 15" usually consume >50% of the yearly prey consumption by weight. Because each LMB consumes a comparable number of proportionately sized BG, the number of BG reaching the optimum sizes for >15" LMB are much fewer than being consumed by <15" bass. The struggle is growing enough 3" to 5" BG for the >15" LMB to eat. Willis thought 6 LMB >15" was a practical limit for most Midwestern ponds where trophy LMB were a goal. He of course meant working with the native fertility and so ponds can be made to support more by supplementing forage or feed. I think female only environments are out of reach for most pond owners. There is really no industry supporting it for the masses. All the same, understanding what a succession of growing females in memorable sizes need in terms of forage consumption is useful. Most BOW owners with an LMB trophy bent would be pleased to have 4 LMB per acre averaging over 5 lbs in their BOW. Regardless of whose pond, what its fertility is, or what forage is added, it still "only" takes 112 lbs of appropriate length forage consumed to maintain and grow 4 of them so long as 1 is harvested near the end of 4 years and 1 recruit replaces it. The SS examples are not so much examples of what a person can do ... they are examples of the forage consumption it takes for the LMB modeled in it. They are examples of the prey consumption that balances the maintenance and growth of a hypothetical population (or subset of one).
Last edited by jpsdad; 09/23/23 06:36 AM.
It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers
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