First question - How long does it take for a pond to reach carrying capacity? Research agrees with ewests answer for more southern ponds: abt 2 yrs. The cooler the climate the longer it takes - usually 2.5-3 yrs in zones 6, 5, 4, etc. It has to due with length of growing season. To get even more specific/academic the species composition and the time it takes for them to become mature and reproduce can influence when a pond reaches carrying capacity. A FHM pond would probably reach capacity quicker than a pond with just predators that do not become mature until ages of 2-4 yrs based on growing zone an species.
To answer the blue question: "So, given those facts/figures, and using the esteemed Mr. Cody's definitions, what carrying capacity should I shoot for, with the answer expressed in % of standing crop figuring on 0% CC in the standing crop in an aerated, 9 ac/ft, supplementally fed BOW in Zone 5? (HSB, LMB, BG, RES, GSH) To make it easier, shoot for 100% standing crop and I'll reduce the numbers by 20% to make room for the tilapia and RBT."
I tend to agree with Eric and Cecil - around 400 lbs per acre.
Then my question is, How you gonna measure it? And determine where you're at pound wise?
Even though I often do it, estimating based on visual factors - guessing the total weight and total numbers of fish in my pond is not very accurate and is just a WAG without some methodical and standardized sampling. Those methods consist of electroshocking, nettings, trappings, anglings and possibly mark and recaptures, each with recorded data.
The WAGs or casual observations are always notably too high. And when the pond is actually drained, one invariably says "what happened to all my fish?". Our recent good example of this was Cecil's 2009 brook trout pond draining and census.
Thus, I am saying it is IMO it is basically academic and fruitless to spend time trying to estimate the amount of fish in the pond because IMO It is too difficult for the average Joe to do it without professional help. Professionals with standard methodologies can get pretty good ball park estimates of standing stocks and carrying capacities.
IMO the Best plan is to use some good common sense methods of stocking, provide some reasonable supplimental pellet feedings, and if you feed pellets - aerate. Then don't worry a lot about carrying capacity. Then the next IMPORTANT thing to do is harvest to maintain a good BALANCED fishery to achieve your REALISTIC goals based on pond size, available habitat and location. Knowing and better understanding those are important.
GOALS can be to skew the fishery toward certain size groups or aspects of balance of sport fish i.e. stocker, quality, memorable or trophy sizes or some blend of those sizes.
As I get older, I am learning and realizing that as Bob always suggests, HARVEST is a very important part of pond management especially if one incorporates supplimental feedings or fertilizations. Or when the pond is close to carrying capacity. But close to or at carrying capacity is hard to determine correct? At least as I see it. Then what is a person to do?
Realise harvest helps maintain or insures a more healthy balance where the fish are not crowded and all are adequately growing. Think about it and do it. Not crowded fish and adequately growing are very Important features of healthy balanced fish communities. Not crowded is a key item here. Learn how to determine when they are crowded and if your fish are adequately growing. Look and check for those features / characters.
Where most people get into eventual trouble is season after season, they feed - fertilize; feed - fertilize; feed - fertilize; feed - fertilize and do not harvest. Fish become crowded and then problems start to arise. Intensity of problems gradually increase as fish grow. Crowding intensifies due primarily to reproduciton, recruitment, and growth. Feeding and fertilizings stimulate reproduciton, growth, and recruitment until an environmenal stressor/s (disease, low DO or water quality) steps in and puts the pond a few steps or poundages back ward - fish kills.
As fish poundages and crowdings build up or increase, water quality increasingly declines to where fish often die or the community becomes out of balance based on the original goal. PROPER harvest is very important to maintain "healthy carrying capacities i.e. balance and room for added growth. Knowing what and how many to harvest based on the goals are important. Based on how important Bob considers harvest to be, harvest and its guidelines are probably not discussed enough here for all the species involved in the various communities involved.
I think it is much better for the fishery to be several "degrees" under capacity than at or near capacity. At least better in terms of overall fish health and less chance of a fish kill and the majority of remaining fishes being able to maintain good or optimum growth. One asks "what is a degree"? Who knows? I made up the term. Someone else may be able to help with this or similar ideas.
PS: "The esteemed Mr. Cody" is very much a matter of opinion. Believe me, I've been called much worse. Thanks for the complement.
Last edited by Bill Cody; 01/29/10 11:36 PM.
