Especially in the summer and/or when you catch a bunch, they'll start to die and the meat goes downhill quickly. Packing them in and on ice is the best. I've seen many dead crappie with cloudy eyes that died and sat in a livewell all day that I wouldn't eat... Meat rots in 80 degree weather... Same thing for dove hunters that don't put their kills on ice then wonder why they taste bad..