I am thinking of going to visit DC but I always refused to visit any zoos at home (UK) I am not sure if DC is similar to Zoo....
Oooh mate that's an emotive subject here right now what with the recent news.
My personal opinion - and it will differ from others here - is...
Sea World keep animals in captivity yes. But a lot of those animals are threatened species in the wild due to human activity so that helps me a bit. Also Sea World do a heck of a lot behind the scenes for conservation globally so me paying my entrance dollars allows them to carry on this vital work.
So for me, keeping animals in captivity is not ethical, but Sea World do it far, far better than most.
That's not helped you at all has it.
DC isn't really a 'zoo' with exibits there is the area where you interact with the dolphin , a coral reef filled with tropical fish and rays where you snorkel and a ray pool to feed the rays and an aviary to feed the birds.
It isn't like a zoo at all, it feels like a luxury resort for the day and my family had probably one our best days ever there; and the best bit was snorkelling over the reef not the dolphin encounter.
Unlike some of the more 'theatrical' shows at SW the emphasis when you interact with the dolphins is all about teaching you about the animals, rather than getting them to do tricks.
If you go you will not be dissapointed and would make a wonderful follouw up to your other plans as the whole park is 'all inclusive' and they limit the numbers so it never feels crowded at all
I know lots of people have done the Discovery Cove thing and absolutely loved it. If you've got the money, then go for it!
My personal belief is that places like Sea World, Busch Gardens, Disney are doing everything in their power to treat the animals in their care with kindness and compassion while trying to show humans what these creatures are like so that we will help with conservation.
In a perfect world, they would all live free in the wild. It is not a perfect world :-(
One other thing to keep in mind is that a lot of the animals these places have would never be able to live in the wild again. The may be injured or have been separated from their Mother and never learned to hunt, and left in the wild, they would die.
Of course there are a million other factors to consider..