Here I know of spots we call Gar holes with them rolling on the surface by the hundreds in hot weather. I figure they were eating same bait fish as Crappie and a few Crappie but we still catch Crappie right in same spot .
Gar are surface feeders and crappie typically stay in the middle of the water column. The only time I can see gar affecting the crappie is after ice-out when the crappie will be near the surface, just out of sight. Otherwise the two species are vertically separated in the water column.
beagle man, dfar LIKED above post