Regarding Green Sunfish, mostly their status in a pond is in comparison to native bluegill or coppernose bluegill when BG and CNBG spawn more often each year than GSF thus providing more forage for other fish like LMB.
GSF also have a larger mouth that BG or CNBG. Thus the GSF can eat more smaller fish and this can impact the forage base for smaller LMB.
