Not legal to camp as in set up camp (tent, chair, etc.), but legal to fish off. I've spent many a night fishing off those islands in my youth before I owned a boat - I still kayak out and fish all night on occasion. The island to the northwest of Goose island has a few concrete chairs with rod holders where the locals built them on the far north side. You'll likely have company out there as many people fish off of the islands on the weekends.
And no fires, but people do it anyway. Probably pretty unlikely to be busted at 2am on the island, but I've never done it personally.