Well, in the past we used to just go there get a fishing license and it had provisions for bringing 5 live fish back. I have recently been told that may not be true, so go and check at any place where you can get a fishing license. If you are trying to bring back more fish you are not legally able to do so as they give the comercial license out only to natives.
There are also rules about bringing fish back into the U.S. if you are flying in, there are no restrictions as far as species, but you have to declare them and have both f&w and customs look at them. If you don't declare them you can get in lots of trouble if someone finds them. If you are on a cruise ship it isn't allowed and getting caught is a serious offence.
I don't know your schedule, but there are very few fish from the bahamas that are not found in FL and all you need to collect 20 animals per day here is a fishing license. You still have to follow the rules such as size and bag limits, and there are no stony corals allowed, but there are no restrictions as far as bringing your catch home. You can't touch corals in bahamas either, and with the exception of a few fish such as royal gramma and black cap basslets most anything you want can be caught in south FL.