I wont be adding HBC until I can verify their fecundity, or lack thereof.
Tagging would be cool...that's been on my list of considerations.
Yes we've harvested a dozen so far, mainly invertabrates [I think, black mush] and the minnows they were able to steal off our slip bobber rigs.
I keep cattails sprayed so muskrats haven't been too much of an issue, at least I don't think. I never see any swimming, but do see some holes from time to time.