The sudden transition from the sea to the cage is traumatic for dolphins. Here are the most common signs of stress in captive dolphins.
Imagine how you would feel if you were suddenly taken away from your friends and family to another place. No prior information. No warning. Nothing.
Worst of all, on getting there you are forced to remain in confinement against your will!
This is the plight of dolphins in captivity though their captors would want to convince you otherwise. The signs that a dolphin or other cetacean is undergoing stress are noticeable, some more noticeable than others.