^^ Two things.
1. We can't actually access the full article to read it.
2. Based on the basic concept of the study, how is metabolic rate actually relevant to most of the issues raised with regard to killer whales in captivity? Short answer; it's not.
Sorry, but you've posted nothing in here that hasn't come directly from the mouths of Sea World. Your entire argument has been nothing more than a trainer's script, and now you're presenting this scientific article, carried out by Sea World, as if it actually means anything in relation to the main issues at hand, when all it will really do is show how much food and exercise a captive whale physically needs.
Using that article as a justification is nothing more than slight of hand. Most people either won't read it, or won't actually understand it. They'll just see lots of scientific words and references, and assume that it's a valid, scientific argument for keeping orcas in captivity. Based on what I can actually see, it isn't.