Yes those fish are the infamous green sunfish. Your stocking plans are not ruined, however your fishery management will be significantly more challenging and the over all quality will be less successful. From now going forward most of your management should be focused on removing GSF. They are prolific bastards and are pretty darn good at being secretive and somewhat difficult for predators to easily locate and catch them in the near shore habitats. They are not an inhabitant of deeper water cover and habitats. They prefer near shore habitats away from most of the predators. As you now know that size of GSF will readily eat small minnows using their large mouth size and aggressive behavior.
Without strong predation pressure of lots of smaller bass and lots of annual trapping,,,,, the GSF can become abundant enough to significantly suppress minnow and YP recruitment. YP do not frequent the living areas preferred by GSF thus IMO YP eat few if any GSF. If GSF are common in the pond they will no doubt limit SMB reproduction to almost zero. If that happens of now new small YOY bass then you will need to ladder stock SMB every year or two to keep several year classes all putting pressure on and eating GSF. Numerous SMB will also significantly limit recruitment of YP. Abundant small 1 yr old GSF will gather around the spotfin spawning devices and eat all the fry swimming off the device. I have seen YOY perch also do this.
Moving forward I would get your SMB as soon as possible. Try to get stockers of this year's fingerlings and some of last year's hatch - 2023 and or 2022 year class/s. It will be best to stock some smallies that will eating eat this year's hatches of GSF. Nests are said to contain 15,000 - 50,000 eggs. This years GSF hatch could easily amount to 5000 - 15,000 fry from several GSF nests.
Start collecting minnow and fish traps. The Gee minnow traps even unbaited are best for catching small GSF. GSF like to enter secluded niche areas thus the Gee traps catch lots of small GSF. You can enlarge the funnel opening on some of the traps. Build yourself some larger traps using 1/4" and 1/2" hardware cloth mesh. I like cylinder traps especially for using traps on sloped banks. The Z Trap ( search YouTube for Z fish trap) is another good design to get and or build to try it for how well it catches GSF. I have a Z trap and it works well for catching sunfishes in shallow flat bottom areas . Cylinder traps are best to use on sloped banks. A very good cylinder trap to buy is from K Traps.
https://ktraps.com/I have a couple of the K Traps and I built some versions and sizes of them. They work very good for trapping GSF baited or unbaited with fish food or stale bread. I have often caught 15 to 30 GSF in one trap set. IMO you should have one or two traps working in the pond continuously all summer long.
Your work will be an up hill battle dealing with GSF in your YP - SMB pond. Keep us updated on the pond's progress and successes while dealing with GSF.
