Drew have to completely disagree, I am really not convinced by that statement. Captive cetaceans arent a huge presence in much of Europe, which I would argue, doesn t impact the conservation movement there. (A stat I just pulled of bornfree.org suggests about 70% of all captive dolphins are in the North America and the Caribbean). I honestly think that most conservation minded people avoid these facilities and wildlife documentaries and photos are a far more important method of raising awareness.
Erol, while a major market for dolphins is in the US, there are quite a few dolphinariums within the EU even. It's a worldwide business and growing because of affluence. Dolphins come from the Pacific and Atlantic, many of them bottlenose because they are more trainable.
As for the dolphin safe tuna movement, many more people were motivated to boycott specific tuna sources unless it was considered "dolphin safe" in the 80s and 90s. Those dolphins weren't at risk of extinction but it was played up because of the public adoration brought about by Flipper and the other cetacean entertainment venues like Seaworld which are still very prevalent. I'm not referring to the methodology of making tuna "dolphin safe."
I think there must be declarations of shots with captive animals so people know what they are seeing and can decide whether to support it. I don't know if anyone remembers the skinny dipping Natalia and the Beluga shots, which were shot @ the White Sea enclosures but made to sound like the Belugas were wild. NO ONE mentions there are nets there, because that would diminish the shots marketability.
As Autopsea says, there are cetaceans which cannot be released into wild anymore. The Dolphin Tale star would be dead without the prosthetic tail and the required maintenance. Keiko the Orca (on which all those Free Willy movies was based on) died because it didn't want to go back to open sea or communicate with wild Orca. There are plenty of other cases of such nature.
Another point is that there are dolphins now being bred in captivity for the purpose of dolphinariums. Unfortunately, the growth of dolphinariums now outstrip the supply so many of them are still wild caught. I'm not disagreeing with the idea of banning cetaceanariums. However, most of the dolphin species captured aren't endangered (belugas I believe are) and due to the high demand of such venues as tourist traps, I don't see this trend disappearing anytime soon, unfortunately.