Wierd behavior?

[srfnsport]

Ive had a blue hippo tang for over three years, very healthy. And lately Ive noticed that she swims to the surface and seems to take a breath so that she swims back down releasing bubbles all the way. Ive watched her do this repeatedly recently but definately a new habit. Any advice?
And does anyone know why their face becomes speckled as they age?
Thanks