To work on some of the questions.
IMO Cecil's numbers are safe estimates for sport fish ponds which most here desire.
IMO A lot of this carrying capacity stuff is speculation (theory) since it is normally hard to measure.
Specific numbers in our normal ponds are variable at best due to "it all depends".
Since fishes rarely can be seen easily or observed how many are actually present, it is hard to determine total numbers or crop weight unless a draining and census occurs. Standardized sampling can provide just educated guesses/estimates.
1. Now how much would that carrying capacity change if there was no supplemental feeding? (again expressed in pounds per ac. ft.). Hard to say specificaly. "It all depends" and it depends primarily on fertility of the ecosystem. I think in general feeding pellets sensibly can easily boost capacity by 50-100 lbs per acre. Amount of food added and number of locations would also be factors. Fish will generally only travel a certain distance to the feeding area. Maybe 50-100ft? Others my have experience with this. Thus more feeding stations will increase carrying capacity.
For natural unfertilized ponds c.capacity could be as low as 80-100bs/ac or as high as 300-350lbs/ac. Type of species present would also be factors. Different species can utilize different niches and their numbers will add to the total capacity or fish weight. Natural carp/trash fish populations have been measured at 1000 or more pounds per acre.
2. How much would the carrying capacity change if both supplemental feeding and aeration were not present? Since carrying capacity has a fair amount of theory involved in it, exact numbers are hard to provide. How does one readily measure it? Estimates can give ball park ideas. IMO feeding will boost carrying capacity more than aeration. How much more??? Maybe 20%-35%? My guess is aeration alone will usually only boost carrying capacity by a maximum of 10%, usually 5%? or less. In some cases aeration will cause little increase in carrying capacity. Those cases are for ponds that do not stratify and those where there is only a small percentge of the benthic zone that is anoxic (without oxygen in summer).
However with feeding and without aeration the increased c.capacity may not be maintained for long periods due to deteriorated water quality at certain times -summer/winter kills.
Some species of fish could develop higher carrying capacities than other fish species. Generally fish that feed lower on the food chain and/or those species that tolerate crowding and lower water quality would develop the highest carrying capacities. One can grow more carp per acre compared to LMB or BG.
I would guess that regular feeding of a high protein fish food in a low fertility pond (100-200 lbs /ac) could just about double the carrying capacity for a "normal BG-LMB pond. This number might be less (15-30%) of an increase in c.capacity for the pond that was in fertile alkaline soil/watershed and more naturally fertile because the pond already had a higher standing crop to begin with due to an enhanced food chain (productivity). This concept may be debatable.
These of course are just my opinions. Others with experience or access to information may be able to provide more info.
Last edited by Bill Cody; 01/28/10 11:03 PM.
