I watched the documentary "Blackfish" a few months ago and it makes me furious! People who claims that we keep animals in zoo's for preservation are delusional, naive and straight up liars. Humans are the only species on earth to keep another living breathing thing in small containers for amusement and it's WRONG! If we want to preserve the endangered species of this planet, we have to give them plenty of space, acres upon acres, and not force them to perform for us! They're wild animals and they should be treated with respect and dignity. I will never for the rest of my life set foot at a zoo, because I will not support the horrible things we humans are doing to these magnificent creatures, I will never again go through the gates of any place where animals are kept inclosed and put on display. If we are to keep the zoo's around, they definitely have to get better at taking care of the animals, give them what they need and deserve, and stop exploiting them. Conservations is great, confinement is not.
Footnote: "Blackfish tells the story of Tilikum, a performing killer whale that killed several people while in captivity. Along the way, director-producer Gabriela Cowperthwaite compiles shocking footage and emotional interviews to explore the creature’s extraordinary nature, the species’ cruel treatment in captivity, the lives and losses of the trainers and the pressures brought to bear by the multi-billion dollar sea-park industry." - http://blackfishmovie.com.