I have fished for Hickory Shad since the 80's, almost entirely in the Rappahannock.   As far as I knew, there was a ban on keeping all shad, in place at least in part to limit anyone keeping an American shad by mistake.  It seemed like a reasonable rule, as I and my fishing buds almost never saw or caught an American shad.  We did however have great fishing for hickories, returning all to the river.    I didn't realize that somewhere along the line it became legal to keep hickories,  but can say that in my experience the catch rate for hickories has declined in recent years.  Whether related to more people keeping them or other factors I cannot say, but I 100% support a limit on harvesting hickory shad.