The problem I've seen with too many adult shiners in my 1/4 acre pond was zero recruitment of new SMB. I've removed a lot of adult GSH since restocking SMB in my pond as they were competing with the both my newly stocked SMB and and similar sized RES for food. I consider large GSH a competitors for food with similar sized or smaller fish.
2019 110 3-4" SMB stocked
2020 308 5-1/2" to 7" GSH were removed (1232 GSH per acre, mostly in the 6" to 6 1/2" size range)
2021 363 5 1/2" to 7" GSH were removed (1452 GSH per acre, mostly in the 7" size range)
2022 101 6-8" GSH were removed (404 GSH per acre, mostly in the 8" size range)
I have caught a few 6 1/2" to 9" SMB this summer which makes me believe I have had some recruitment. I had huge GSH hatch again in June, lots of 2-1/2 to to 3" shiners going into winter and good numbers of 4" to 5 1/2" from last years huge GSH hatch.
For some odd reason RES recruitment hasn't been an issue with GSH present but SMB recruitment has.
