I have an idea. What if your having an over population problem and you throw in some Gar I know they'll help a great deal of lowering crappie population. I know in Texas we used to do that to lower are perch population because we didn't have any bass in it. It was a perch and crappie pond only and all we caught was perch and little crappie so I had that idea and threw in three gar I caught catfishin idk but a year after that we actually started catching more crappie but every now and then we caught one or two that were scared up but it didn't like any of the gar had messed with em. I'm jus throw in that out there and see if anyone wanted to throw in there input on that.