Definitely a Great Blue Heron!
Hi Thomas,
Your thief was definitely a great blue heron. They are usually very respective of humans and tend to keep their distance. Your experience makes me think that this guy has been fed by other fishermen who gave him a standard, nine-inch stocker or two. He may have also come from a broken family, had a crack-wh*** for a mother and just drifted into the gang life to commit such a desperate act. Was he wearing a colored bandanna?
I've never had a fish taken directly off my line but I've had a bald eagle snatch a big fish out of a large group of surface feeding fish that I was casting to (I know, prepositions should never be the last word in a sentence but what the heck). It was a major thrill to see that eagle; they are still spotty in SC, though coming back well. Needless to say, the fish stopped feeding and I stopped fishing. There's just something about the unexpected appearance of huge, air-born objects that tends to put feeding fish down. 8T :)