What are the stocking rates for LMB?
What are the stocking rates for walleye?
What are the stocking rates for HSB?
In all seriousness, it really does depend on what your goals are and a plethora of variables...
Ditto what CJ said.
Set defined goals for your pond, then the fish numbers can be calculated. Will the pond have aeration and supplemental feeding? That's just the tip of the iceberg.
Our pond is about 50 years old and has bluegill, channel catfish, LMB, a few common carp, green sunfish, freshwater drum, and gizzard shad. We want to control the gizzard shad by producing large LMB, HSB, and WE. We want to diversify the LMB gene by stocking new LMB. The pond doesn't need to be aerated because it is bed by a natural spring underneath the pond. Our pond is 4 acres. We want our LMB, HSB, and WE to be as big as possible so that they can control the gizzard shad.
to have more room for your target species remove the others like the CC and the drum.
Are the green sunfish out of control?
are the shad out of control?? and how do they do with your winters? How deep is the pond and is the water hot that comes in??
There are some good people in Nebraska that would love to help you!!
You can control the Gizzard Shad numbers by a selective Rotenone application. I doubt that LMB in your pond (or any northern pond for that matter) will get large enough to be able to eat adult mature Gizzard Shad.
GSD are more sensitive to Rotenone than the other fish species in your pond. So, what is a lethal dose to them will not be a lethal dose to your other fish.
Selective removal of g.shad can be done with low concentrations of rotenone but it should be done carefully, with very good planning, and proper methods or other fish will be impacted. If you have it done, expect at least a few of the most vulnerable other fish species to die. It is not widely used due to the high risk involved to other fish besides g.shad. Various species of fish have different tolerances to rotenone.
Cottonwood...having a spring under the water can be a problem...springs often become drains. It is also very unlikely your spring has any dissolved oxygen as most ground water is devoid of dissolved oxygen. At 50 years old, you may want to consider draining and renovating also.