If you haven't harvested a significant number of fish recently, your pond is at or very near carrying capacity which means several things. Two of them are: 1. your forage base of appropriate numbers of small fish is probably too low to feed extra walleye and perch. They do survive on mostly fish. The current fish are probably eating all excess small fish. Overstocking predators will result in skinny slow growing predators. Slow growing perch will get eaten by bass. Since perch and walleye are slender bodied expect the LMbass to eat perch and walleye 60% of the bass's length.
2. Adding new fish into a pond at carrying capacity results in fish being shorted on food items because the excess food is being eaten by the currrent fish community at capacity. Often what happens is the new fish become food for the current predators because the new fish behave differently and the predators find them very vulnerable and easy to catch since the new fish are strangers to the habitat. Book chapters are written about carrying capacity and standing crop. Carrying capacity is one of the things that determines who survives in a pond. Study and understand this short summary about carrying capacity:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92440#Post92440 IMO to get extra walleye and perch to survive you would have to first remove at least 50% of the bass starting with the largerst ones. A 16" bass will eat a 9" walleye and 8" perch. The fewer bass in the pond the better chances the new fish will survive. Also you will have to stock large sized stockers to keep them from becoming food for big mouth bass. If a bass can swallow it, it will likey soon be food. I have a local guy with largemouth in his pond and for him to get hatchling perch to survive to 8", he has to remove every bass he catches to keep the bass numbers low; thus predatory pressure low.
