Before dolphin can be interacted with in any captive dolphin parks, dolphin encounters, swim the dolphin experiences, or dolphinariums, they must first be captured from their homes in the wild. At least one of the Cayman Islands dolphin parks claims that they purchased their stock from other parks. Does this make it okay? The simple answer is no, because it is exactly the same as taking them from the wild, because the park that supplied them must then replenish their dolphin from the wild. If any dolphin park claims to be self sustaining - let alone overage to sell, by birthing that is an outright lie. To verify this is easy and can be accomplished with a web search for "captive dolphin survival rate". The statistics speak for themselves. The life span and reproduction rate of captive dolphin is less than 20% that of wild dolphin. Another myth is that dolphin are "safer" in captivity. And why not? There are no predators in their little swimming pools. But unfortunately, to a highly evolved intelligent species such as dolphin, a life in prison is even less appealing than a death sentence so few dolphin breed in captivity, even fewer give birth, and even fewer yet ever survive.
There is a great new dolphin awareness site: