I don't know about elsewhere but in Alabama there are no special requirements but one does have to buy a commercial license which is $100 for fresh water, another separate license is needed to fish salt water.
A regular fishing license is $14, none is needed if you are over 65.
I worked with a commercial fisherman, his family had fished for generations. He worked on his equipment on midnight shifts if things were slow at the power plant. He tied trotlines and built fish traps and showed me every aspect of his fishing technique. He was a wealth of knowledge and fished the TN River year round for catfish as well as mussel diving in his spare time.
We tied me a set of trotlines, I put them out per his instructions and caught so many fish in one trip that I had trouble giving them away.
I fished my lines for a while but burned out on it, it is hard work getting bait, putting the lines out and dealing with the fish.
I sold most of my jump boxes but have a new one just for for SHTF situations, with it I know I can have something to eat when others are starving. The one I have is a 100 hook line that has never been in the water, I keep it "just in case", I live about 1/3 of a mile from a huge lake on the TN river (Wilson).
