Ignore all the poor reviews, this is a great place to visit. Yes there are only 2 otters and 3 seals at the moment but the aqariums are superb, everyone is friendly and helpful, the signs around the place informative and the outside areas clean tidy and safe. We are going back again today (last there on wednesday) to see the things we missed the first time.
Good, reasonably priced cafe too.
Tip: there are plenty of offers around, from "book on the internet", 40% off vouchers on leaflets and 50% off with a Calmac ticket/receipt.