One animal rights group that has chosen to take a stand on this issue is PETA, or People for the Ethical Treatment of Animals. Interview with PETA PETA's Homepage Another group,the AVAR, or the Association of Veterinarians for Animal Rights takes a similar stand. Teri Bernato, National Director of the AVAR answered questions via email as well. The AVAR doesn't have an official position statement on aquariums. However, our position would be similar to the keeping of other nonhuman animals in confinement.
Confinement produces limitations to the kind of life anyone can have.
Therefore, aquariums limit the natural lifestyle of an animal. How detrimental this is to the individual animal would vary depending on circumstance. There could be unnatural food sources, space limitations, social deprivation, unnatural predation, etc. We prefer that nonhuman animals live in their natural environments and not be subject to any deprivation, manipulation, or exploitation for the purpose of entertaining people. I think that most animals would prefer this, too.