James � Welcome to the Boss Forum. Your pond and fishery like many others are complicated with numerous variables. At least currently we do not need to be concerned with presence of LMB. They can always be easily added as an option of last resort before complete renovation of the fishery.
IMO your pond does have larger predators �the catfish - especially those that do not eat pellets. I think even the pellet eating CC at least occasionally prey on measurable numbers of fish especially at night. The larger CC could be eating at least some of the mid-sized BG (3�-5�).
I think your Option 2 is the better of the two listed Options.
IMO WE will survive in your pond at least initially. How well they grow will be the main point of interest, at least for me. Reports indicate that WE numbers and success are significantly reduced when WE are in eutrophic conditions and the fishery is dominated by sunfishes. In your case you have ample numbers of sunfishes of several different species (BG, GSF, RES, OSS, plus maybe natural hybrids). I think the WE will prey on GSF as much or more than BG, due to the more fusiform body shape of the GSF. The question is are WE adaptable enough to efficiently prey on the sunfishes in your pond habitat? With an abundance of smaller sunfishes the pond may need a higher standing crop of WE (numbers). High numbers IMO are in the 80-120/ac range. WE are put and take so if fewer or more are needed, they can fairly easily be added or removed.
Later an additional predator such as HSB or SMB may be needed to more efficiently reduce small sunfish. If higher numbers of WE do not significantly reduce then numbers of sunfishes, I would not hesitate stocking SMB into your pond before stocking LMB. When WE are added and grow to sizes of 12�-15� there should be a shift in the species composition of the percentages of sunfishes in the fishery. Look for one species to become more abundant, some species percentages to stay similar and one species to be significantly fewer. Shifts in percent composition will indicate WE feeding preference. You should do some sampling by trapping or seining before and after adding WE to monitor these percentages of the relative size classes of each species of sunfish.
I think the main concern for WE surviving in your pond is if there is always adequate DO. WE reportedly survive poorly when DO drops below 3 mg/L(ppm) whereas sunfishes and the LMB will tolerate 2.0mg/L for short periods. This occurs most frequently in eutrophic conditions which I think characterizes your 33 yr old pond. If you do not aerate your MO pond and the spring water inflow is relatively weak, the WE may have periodic die offs due to corresponding DO sags especially if the weed growth develops greater density than 30%. I think WE will tolerate higher water temperatures slightly above 90F providing the DO is above 3 mg/L and concentrations 4 to 5 mg/L are much better during the warmest periods. Your general water clarity of 3 to 5 ft is optimum for WE feeding efficiency. Spring water inflow into the pond should provide some cooler water areas and may minimize the degree of DO sags in your pond. Walleye are known to feed much better if water temperatures remain in the 70 to 76F range. Reported WE feedding rate slows noticably when water temps are above 80F.
The WE even the larger ones of 20�-26� IMO will not be eating the larger mid-sized BG (4.7�-6�). You may have to manually thin that size group with trapping or seining if their numbers are dense, body condition is thin and they don�t seem to be growing to the 7�-8� sizes.
On the topic of yellow perch for your pond, I think they will have the opposite habitat challenge of WE for surviving in your pond. The challenge for largest YP will be higher temperatures and not the lower DO concentrations. Younger YP tolerate 82-88F temperatures well. YP tolerate well lower DO than WE. Often the largest oldest YP become increasingly stressed to the point of death when water temperatures move from 84F to 90F. Again, the inflow of spring water into the pond may provide life-saving refuge areas for the oldest YP.
In summary,
1.Your pond currently has predators - the CC. Some predation of sunfishes is occurring on mid-sized sunfish but it may not be noticeable.
2. WE are IMO worth a try in your pond. WE should survive at last initially in your pond (1st 3-5yrs). Plan on them eating 1�-3� sunfish plus any minnows � shiners if available. Stock WE at higher densities of 80-120/ac to initially provide noticeable predation of the smaller sunfishes.
3. Bottom aeration would help WE survival and improve pond habitat esp in the deeper end.
4. YP should survive in your pond. You may want to first see what affect WE have on the sunfishes before adding YP. To diversify the forage base and panfish community you could add YP.
5. Spring water may improve long term survival of WE and YP.
6. You may see a need later to add HSB or SMB to increase predation of the small sunfishes because WE may selectively prey on one or two species.
7. Monitor sizes and species of sunfishes to check for shifts in species composition and predominant sizes of forage.
If you decide to stock WE keep us advised of the progress.
Last edited by Bill Cody; 08/06/11 08:04 PM.
