May I ask what your source is?
To me, that's a classic example of taking something very ordinary and making it sinister. ASPCA dog training classes tell you to bring your dog to class hungry. It's right there on the website. Are we reducing our dogs to "beggars" by training them with food?
I've read a lot of material about this, and one thing Pryor says over and over again is that you simply cannot train a dolphin through negative reinforcement. You cannot use a choke collar on a dolphin. They are much more powerful than humans, and can easily outmaneuver us in the water. And in fact, you canNOT force a dolphin to perform by withholding food, because dolphins get most of their water from their food. They dehydrate and die very quickly if not fed regularly.
As an aside, Pryor describes one dolphin who figured out how to "beach" itself on the pool rim - it would flop over to people and bang its beak on them when it wanted attention. In other words, working the system.
