Since Halifax is so close to the ocean it seems somewhat inhuman to capture sea animals and keep them in an enclosure. Instead Halifax could do something like in the image below. Have rooms built under the surface of the harbour so that people can see sea animals in their natural habitation. Especially now that the Halifax harbour has some waste-water treatment, it might be interesting.
(source:
http://www.allvoices.com/contributed...ea-resort-fiji )
Maybe something could be built at George's Island when it opens to the public in 2012(?) (just a few rooms below the water). Or, as you mentioned, if the HRM builds a stadium at Shannon Park that might be a good location.