Animal Cruelty? A red ear slider turtle is being kept in a tank set up for and with fish, without basking area?

I went to the nail salon and I saw the turtle desperately diving up for air every 5 seconds. I asked the lady about it and she he's okay, he's been in there for a year already so he's not going to die. I thought it was weird because I always heard turtles need a rock or something in their tank. I mean: a turtle is not a fish!