What is your opinion of Sea World?

I am thinking about pursuing a career in marine biology, and people always ask if I would work at Sea World. I always say no because I do not think that whales and dolphins should be kept in captivity. They are just too big and too intelligent so I feel like they should not be confined to tiny pools and they should not have to do tricks for us. However, some of my family went to Sea World earlier this year, and they said that most of the whales are rescued, and that they usually only have the whales for a short time (a few years maybe?) and then they release them back into the wild. They also said that Sea World as a company donates large sums of money to ocean conservation effort. I am of course skeptical on this, since they heard it all while they were at Sea World, but I am curious on whether anyone else has heard this stuff, and if there is any truth to it. I would think that it would still be cruelty even if they were breeding the whales and helping preserve the species. I don't think we should make individual whales live in misery in captivity just because as a species we fail at being responsible enough to know to stop hunting them out in the wild.