Whale sharks and the ethics of aquariums

I was in Atlanta, Georgia, last week for a conference and had a few hours to do something for fun around town. I decided to go to the Georgia Aquarium. Besides the fact that it was highly recommended, I heard that there were whale sharks there, and when I knew that, I had to go. I had seen whale sharks once before in Osaka, Japan, when I was a teenager, and I had thought it was the only time in my life I would see one.