I know I'm very late on this, but, ill respond anyway. haha.
To crab, you dont need any sort of license.
To fish for migratory fish (such as striped bass), you need to register for a license online, but it is free)
To fish for fish that live in the river (catfish, carp, perch, etc, etc), you do need to have a "regular" inland fishing license.
hey speaking of perch, etc, we have no ice on the river as far as catskill and most likely higher up, quite a difference, and rare opportunity for some diehard, to fish off pier or land for yellow perch, bluegills etc , and whats a tommycod? before i venture further with this i like some feedback. the weather pattern does not seem to be changing much, and what i just read on ny dec about the fish that thrive during hudson winters, is getting me interested. even if its only once, as they say nothing ventured nothing gained. but would like to know if anybody has experience with this. sorry for the book i just wrote, but i fish, and so im fishing