"Well I must some what disagree with you. I think sharks in captivity is very important. Not only does it give people (especially children) the oppurtunity to see them, but it also gives the science field time to do there thing. Especially with endangered species it could even possibly help the marine scientists help them. I do not think they should be cramed into small tanks, or mistreated. Adventure Aquarium does and has a big marine biology lab there. They do a lot of shark research. So it only made sense that they have a Great Hammerhead. I feel they should just keep them for a year or two, and then release them. But just my two cents."
I am afraid that a lot of the time, things done in the name of science only serve to bastardize the work of honest scientists by exploiting loopholes in the law and public opinion (for an example, look to the "Scientific" whaling efforts of the Japanese). The "rehabilitating" whale shark in Dubai serves to show that the same happens to sharks. This is unfortunate for the real scientists such as those at Mote Marine Lab, Hawaii Institute of Marine Biology, and Monterrey Bay Aquarium, who are working hard to figure out these mysterious creatures before they are too rare to find. Keeping endangered species in captivity can be a good idea if the animal is easy to keep, but in the case of great hammerheads, I'm afraid that a year or two survival in captivity is a little on the optimistic side.
There is another side to this. Many aquariums don't collect new sharks from the wild but instead serve as holding tanks for many smaller and home aquariums whose sharks have outgrown their exhibits. I work for an aquarium, and we just got in two juveniles from a private collector in California who couldn't keep the two new blacktips that were born in his aquarium. So I would argue that not all aquariums are the "bad guys," but it can be difficult to distinguish between the ones that are honestly trying to help and those that are in it for the business.