That is a turtle in the genus Elseya, the aquarium has white-throated snapping Turtle Elseya albagula and Irwin's turtle Elseya irwini. The white-throated snapping turtles there may be the only ones in a public facility while the Irwin's are the only ones outside of Australia. Judging by the species list by @Astrotom3000 , this should be an Irwin's turtle, named after the late Steve Irwin after he and his father discovered a female.
