[b]Telepathy[/b]
 Orin, as a memeber of the Atlantean Royal Family is a practiced telepath. Though not as powerful as beings like the Martian Manhunter, he is able to communicate telepathically, and defend himself to a degree against psychic assaults. Control over sea-life is a facet of this ability.

Something like that. It is canon that He's a telepath, and I made sure he couldn't read minds or use it as a weapon.