Estuaries are tidewater, open to the ocean on one end, with fresh water entering near the headwaters.
As a result, you get a variety of critters adapted to one, the other, or even both environments (salt and fresh water), but more generally, best suited to the brackish water we fished in.
Those (yellow carp) are beautiful fish, and would be better than starvation, but generally those carp tasted like marsh mud.
I don't doubt what Guy Fieri was eating was good, I enjoy watching his show and have little doubt he likes good, basic, food.
I think the owner said he went through a thousand pounds a week. He got them from all over the country so I am thinking maybe farm raised - if anyone even does that.