It is told that Ariel isn't a superhero, other than saving Prince Eric. Ariel does have many abilities enabling her to do things most others can't. A few examples would be Atlantian strength, underwater breathing and Atlantian endurance. We know that Ariel has Atlantian strength because she was able to move a boulder blocking her underwater grotto with ease in which removing a boulder blocking an object or cave is virtually impossible to open. When saving Prince Eric, she is able to pull him to shore while holding him with just one arm. Nobody knows exactly how Ariel got her powers, but it is thought to have come from her father, King Triton, because she is a royal princess of the sea. As a mermaid, Ariel is able to breath underwater with out gills because she is able to metabolize oxygen from the water.
Every now and then, she has to go to the surface to breath oxygen from above the water.
She is able to breath underwater for massive amounts of time at once. Ariel is able to speak Epi-Fauna. She retains this ability even in human form. It is still debatable whether she has super strength or endurance abilities. Ariel also may have Atlantian endurance. During her final battle with Ursula, Ariel was then knocked into a whirlpool that was several miles deep and survived with little injuries. Such a feat would kill a normal human being if not crushed by the pressure of a whirlpool. It is also debatable whether she was able to retain her ability of Atlantian strength when she was transformed into a human.