Use of a gaff for removing a fish through an ice hole.

IDAPA rule 13.01.11 says, 05. Gaff Hook.   It is unlawful to land fish of any species with a gaff hook except through a hole cut or broken in the ice in waters which have no length restrictions or harvest closures for that species or when landing nongame fish species taken with archery equipment. So the answer to your question is, "yes, you can use a gaff hook to remove fish when ice fishing, as long as there are no length limit restrictions in-place or species closures for the fish you are catching.