Originally Posted by Bill Cody
The main problem that I have experienced of having green sunfish with yellow perch is as the GSF population increases proportionally the YP population decreases because the GSF with their large mouth and aggressiveness heavily reduce recruitment of YP. GSF eat lots of tiny YP . . .

I wasn't aware of this effect Bill but it makes sense. It would be similar to the effect of a large number of very small LMB. They say knowledge only makes one ask more questions and this has me asking some. For example, can GSF qualify as a predator that can control YP sufficiently so as to prevent YP from overpopulating? It sounds a bit crazy but if there are sufficient number present when YP hatch they could potentially eliminate most all of the YP before they could outgrow predation by GSF. Provided GSF do not attain high standing weight and there remains sufficient food in the YP's niche to support a fair standing weight of YP ... the combination may be feasible for YP at least to attain good size and condition.

In the paper I referenced above, GSF occurrence was the highest frequency among species. So in OK where I was raised, GSF are in every creek and they tend to colonize most water that flows into them. What surprised me was how limited their standing weights were in the subject ponds. Please look at the tables below.

[Linked Image]
[Linked Image]

I am not aware of any research on what standing weights are achievable in single species environments with GSF. For a pond with identical fertilization, it would be very interesting to understand what such weights can be supported of different species. But all in all GSF had very low standing weights and E values (proportion of the species standing weight) in these samples Even where they achieved the maximum of 198 lbs/acre they comprised only 23% of a pond with a standing weight of 835 lbs/acre. This was also the largest E value as well. So long as they don't take up the lions share of a pond's carrying capacity they will still leave food for other species. I have a hunch this would also be the case with YP but with a couple of caveats. The YP might find it difficult to recruit and getting YP on the line where there is a good population of GSF might be much more difficult. I experience something similar with BG hitting bait before it gets to the RES' depth.

Anyways, just an aside, but may offer hope to Gpugh that they may leave something for the YP to eat. If so, perhaps a ladder of 6" YP each year could provide the needed recruitment.

Attached Images
Species interrelationships.jpg
Last edited by jpsdad; 09/24/21 06:10 PM.
It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers