Pond Boss Forums INTRO Questions & Observations Deliberate LMB spawn suppression strategy?

We know that excess BG can suppress LMB spawning, likely by physical harassment. So I'm wondering if it may be possible for ponds overloaded with LMB, which are the vast majority, could be improved by adding lots of BG just before & during LMB spawn.

Obviously this is more practical for small BOW, especially if the BG need to be purchased. An additional advantage is that it gives the LMB more to eat!

I have a small forage pond with CNBG which I intend to transfer into the main BOW next week. After restocking larger CNBG for spawning purposes, maybe I should feed up the forage population so I could stock them next February/March, when the LMB get romantic. Any thoughts on such a strategy? How many BG would it take to dampen LMB reproduction?

You could achieve this but it probably wouldn't work by stocking BG. You have too large a pond to do that cost effectively. I will add some thoughts.

Swingle found that it was an abundance of intermediate sized bluegill that prevented LMB reproduction. These are BG between 3" to 5". Interesting thing is ... this is the ideal size for growing monster bass! Swingle noted also that under these conditions LMB achieved maximum growth @2 lbs/year (northern strain). Swingle argued that the situation was unbalanced because the BG do not grow to sufficient size to be harvestable and because the situation is not self sustaining (no LMB reproduction). Predators are keystones in an ecosystem and so this situation is untenable without some plan for introducing predators on a periodic basis.

In order to achieve the condition, the biomass of BG in the intermediate sizes needs to be disproportionately weighted towards BG of the 3" to 6" size. There is only so much space for BG .... SOOOOOOOO ... it stands to reason and it is a sound hypothesis that when the standing weight of BG > 6" occupy a smaller proportion of the biomass, BG < 6" will occupy the remainder. But it is not just that simple. If there exists a preponderance of small LMB, as you do now, the predation of the very small BG YOY will short circuit the production of 3" to 5" BG below the ponds potential. So to manage for the situation requires management of both the BG and LMB population structure.

I think there are a number of things that are contributing to the over abundance of small LMB.

1. Feeding - something which favors large BG over smaller ones

2. Too many large BG - they are too big for even the largest LMB to eat. Eating BG > 25% their length - hardly ever happens - and it's dangerous for them. They can get one caught in their mouth being unable to expel it and die. Your BG are under harvested and this facet of managing for trophy bass has been overlooked.

3. Tilapia introductions early in the season. This takes space away from the smaller BG and removes the base of their food chain. The tilapia won't help inhibit LMB production and will not foster an abundance of 3" to 5" BG. It would be better to introduce latter in the season where they would not interfere with two or more BG hatches.

4. Finally, nothing succeeds like success and for the small LMB, being in high numbers favors small bass and few intermediate sized BG. It is self reinforcing mechanism.

OK, so you don't need to stop the LMB production all together to improve conditions. But you will need to greatly change the distribution of sizes and numbers of adult fish in order to get the results you want. On 8 acres, you have your work cut out for you. On another note. You mentioned delaying releasing the forage pond until doing a big culling with the survey. This is a very smart move I think.

My first hand experience with Bg suppressing lmb spawns for 3 years leads me to believe it can be done in an existing lmb pond. But it is going to require some bucks to do so. I would attempt it using the 2 to 3" bg. Why that size bg? Because they are cheaper and in a month or two survivors will be spawning. I also think it would require some thick vegetation around the pond to protect such a large stocking number of bg. You would also have to remove alot of the yoy lmb. And if the suppression of lmb spawn is not a 100% then I think you would see good RW numbers in the remaining lmb. The question I have is how many bg to add. Lets say you add a thousand per acre that's 8,000 bg @ .35 cents per bg. So, if you add transportation cost you might be looking at 3500 bucks for something that might not control a 100 % suppression of the lmb spawn. Hay, if it does not work I would still expect the lmb Rw's might look pretty good. And what about using Golden shiners to reduce lmb spawns? If you dumped in thousands would you think they might reduce lmb spawns?

Tracy,

The problem I see with stocking BG fingerlings is that the effect is rather temporary and that it fails to address the fundamental problem. The fundamental problem is that the pond produces insufficient BG fingerlings >3. I would argue that the 2-3 inch fingerlings will add little if any to the BG fingerling production. Indeed, I think they may actually inhibit the production of BG YOY until they are mostly consumed by LMB.

There are two approaches one may take. One can treat the symptom which would be like adding the BG that the pond cannot presently produce. Or one can treat the cause which would be like changing the population structure to produce more YOY than one could ever afford to buy.

If I were to spend $3,500 to improve my (hypothetical) bow, I would spend it on as many culling surveys as was needed, up to that amount, getting the population structure in line with the greatest production of 3" to 6" BG. I would do this because it would provide a longer lasting benefit and also produce more BG fingerlings even in the same year.

Many thanks, gentlemen! I've only had one year of adequate LMB harvest, and it shows. So far as I know, no CNBG or RES has ever been harvested.

In December I added 100 lb of forage RBT (around 4 -5 inches long) and 100 lb of catching size RBT (10 - 12 inches). Very few of the small RBT survived, but the larger ones grew like gangbusters on the feed. Went from under a pound to 2.5 pounds in 8 weeks! They stopped growing for a month or so -- Bob L think they were developing eggs -- but then resumed. Biggest caught now 3.5 pounds. They are nearing an end what with warmer weather.

The big RBK were a total blast to catch, but I wonder if maybe they took so much food, both natural & pelleted, that it hurt LMB growth. Next winter maybe I'll stock half as many.

In PB mag some time back I provided another partial method to interrupt LMB reproduction. Partial rotenone or nest interruption. You id the nest sites of LMB and disrupt them by seine or partial rotenone. It will take some effort and will have variable results but will reduce LMB offspring. You could also electroshock LMB nest sites during the spawn.

jpsdad, I agree with you when it comes to removing yoy lmb as I said in my last post. So if you remove lmb then there is less pressure on the 2 to 3" BG. The 3" bg should spawn as soon as water temps. moon phases etc allow. From my experience there should be a boom in bg numbers. And from my experience at my pond, if the number of bg are high they will reduce lmb spawn. At my pond I started with a thousand bg/res per acre and there were at least two spawns prior to adding the lmb fry. Now fast forward to today five and a half yrs later. I still have low spawning numbers or survival of lmb fry. I also added fhm's some years during the bg spawning times to reduce pressure on the bg fry. I will say that my pond experiences have been different from the norm. For years I have herd the stories of excess lmb but I have yet to see that in my pond. I am not sure any two ponds are alike. I also think the large lmb and hsb at my pond also help to control the numbers of lmb yoy survival.

No doubt that big LMB practice cannibalism !!!!!.

As a matter of fact so do small LMB on smaller kin folk.