Oh my gosh, that’s hilarious! They’re like those claw covers made for cats, except gator-sized. I had no idea such devices existed! 
I guess they serve the same purpose as the feline ones? Lets them keep their claws but minimizes how much damage they can do with them?
Don’t know, maybe. Or they might be covering clawtips that were injured rubbing on the enclosure scenery. It is, basically, a zoo enclosure and does use concrete and stuff.
In the wild. I bet they injure claws, and each other, all the time and just have to heal as best they can. At least here, they have caretakers.
Even if it does look like the girls had a manipedi day 
What a nice aquarium! I haven’t been to many in my day. The best one I’ve been to is probably the Denver Aquarium. It’s been forever since I’ve gone though.