So it's okay for her to press up against the glass, but not the visitors?

Steak said:

So it's okay for her to press up against the glass, but not the visitors?

I've not visited any Marine Aquarium, but why are you not allowed to do so?
Fear of breaking the glass or something / intimidate the animal

5pb said:

I've not visited an Marine Aquarium, but why are you not allowed to do so?
Fear of breaking the glass or something / intimidate the animal

It's the second reason, really. To break an aquarium glass you'd need something with piercing power akin to a bullet or such, since your action (impact from outside) will get dampened by the force of water pushing from inside, plus the shock-absorbant property of liquid and the specially-tempered glass.

However, it's a different matter when the force comes from the inside; the weight of water, momentum and other things can create stress that can easily crack glasses. Some creatures like dolphins, sharks and manta rays are known to be capable of breaking plexiglass dome in Sea World underwater walk, and let's not mention boxer crabs. These animals may pick up human shadows behind the glass as predator/prey and thus try to break their confinement-that is why you should not press your face against the glass.

Huge indeed.