Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Short term forage- how it affects on ponds

Back in March I was told, I would most likely be surprised on the number of fish in my pond. More fish than I thought I might have. I am not so sure because of things like cormorants, Eagles, Herons and otters but this brings up a plan and this question. Plans are to add some small 2 to 3" Tp to the pond this early fall and will most likely add recommended numbers at that time. This would increase the biomass in the pond. And also considering adding some RBT as the water cools down a little more. Would this cause a problem in the pond when it comes to higher biomass, even though it might be for just a short time of maybe a month or two with the tp because what does not get eaten will die off and I am guessing the same with the trout. I have seen Tp live till late December in my pond and I am guessing that would be about the time I would add the RBT. You guys see any problems with this? Would short term higher population be a problem in cooler water along with aeration?

I can't help you with your question...are trout cheaper than say BG or the other forages? Do they have a higher nutritional value? Just curious. How's the Texas heat affecting your pond this year?

Trout are or should be much higher in the food value over bg. Believe that is why California has large numbers of extra large lmb. And as far as the pond having hotter water right now, it seems to be doing fine right now. My goals are to grow some hefty lmb in a short time period and that is why I am looking into all I can do to speed things up and maintain high growth rates. And I don't have a problem spending some of the kids inheritance So why not feed those lmb I just was wondering how does one determine there is too much biomass (fish) in the pond. If it is at or near maximum now then how will pond act if adding additional forage for 60 to 90 days? Some here have said a pond will be full of fish in two years and this pond is now coming up on its 3rd year about the time I plan on adding 2 to 3" tp and 5" rainbows, so will how will this affect things when not growing out Tp or rainbows, can there be too much forage and how does one determine that? Is a fish kill due to too many the only way?

TGW - You have a very good question of ""I just was wondering how does one determine there is too much biomass (fish) in the pond. If it is at or near maximum now then how will pond act if adding additional forage for 60 to 90 days?""

Ideally a technical method of a fish survey would be the best way to estimate fish biomass. Mark and recapture would be one fairly simple method to estimate density. The method has pros & cons. Fish could be fin clipped to easily and reliably mark them for one year.
http://www.radford.edu/~jkell/mark_rec103.pdf

Generally as long as the fish are growing well or fast this indicates the community is not overly crowded. As crowding increased growth rates tend to decline. For your short term goals, if one adds too much forage biomass it should quickly trend toward decreasing due to predation. This will then put the standing crop somewhat back toward normalcy. Keep in mind that the largest fish will be become larger and their collective biomass will demand more food to keep their growth increasing. At that point it would be healthiest for the pond to have a harvest of some of the predators to minimize crowding and lack of food.

Thanks Bill, So the effects would be the lmb would add weight till there was a reduction of forage fish (rainbows and small Tp) then there would need to be replacement of forage to continue lmb growth rates. So, looking at a yearly calendar, Tp added in Oct the live till Dec, Rainbows added in Dec and they live to March and by that time there has been a spawn of Bg and Res. Bg continue spawning from Late Feb through November. And at some point there needs to be a reduction of lmb yoy? I understand this but now I am guessing lmb feed on Tp till dead or eaten and same with rainbows, and I am guessing as long as I aerate and feed all those I can have as many as I want? Hum, water quality due to poo and feed, then that is where the problem lies? Thanks for making me think it through.

You are correct to a point. That point is as you conclude is a combination of waste and water quality. Fish waste and water quality are at best levels when fish biomass is in the lower range. The higher the growing biomass the more chance of fish kill during stress periods.

Remember that the new year's crop of small BG do not actually feed the large bass efficiently. YOY BG are for YOY and year 1 bass. Big predators prefer and grow best utilizing larger prey items. Too small of prey items results in wasted energy and less growth of the predator. Keeping big predators growing optimally is done by providing larger prey items where the predator does not have to expend more energy catching food so a good surplus of digested food is available for growth and body maintenance.

Thank you Bill. Now if I could keep all those Heron of the shore line during the time my bg are in the 2 and 3" size and keep the otters out and the cormorants off the pond I would feel a lot better about growing out these lmb. Example from a month ago. They say the GBH is territorial but when the 2 to 3" forage bg are along the shoreline, I would have 8 to 9 GBH standing almost side by side along with 9 to 11 of the big white herons, all of them feeding on the small bg. I had a lot of that sized bg at that time. Discouraging Mother nature is not so easy I've learned.