Marine Biology is different for different people, I suppose. I think of it as studying the food chain, diurnal cycles, the life cycle of copepods, that sort of thing. Tidal blooms of Gonyaulax, medicines from the sea, pelagic life versus benthic.
What you are describing- animal rescue and rehabilitation seems a world apart.
See if you can speak to someone at Sea World. I do not know what you would call this job or this major. But they certainly do it at Sea World. Maybe you could even get an employee discount on Budweiser?
Good luck!