Last time I was there (admittedly, this was like five years ago) they didn't have them, and I don't believe the aquarium was posted. Their website does not make any mention of a weapons policy, either.
"'Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost.' That is Alchemy's first law of Equivalent Exchange. In those days, we really believed that to be the world’s one, and only, truth." --Fullmetal Alchemist