The biologists list white perch as an aquatic problem right along with zebra mussels, which sooner is also full of, and tell you not to release them back into the lake. They also say white perch feed on fish eggs and will go into a nest and wipe out the entire nest of eggs. I understand they have been releasing a lot of walleye into the lake to try to control the white perch population. I would guess they caused the crappie decline over the years. Used to love fishing sooner but it has definitely changed over the years.