A Flicker of Power — Sabrina Garie

Bara's powers are deteriorating. A daughter of the Norse sea gods, her magic is tied to the dying coral reefs.  When she catches Dylan, a human scuba diver, tampering with her coral, she attacks him only to discover he holds the key to the survival of the reefs and the pantheon gods, herself included. His passion recharges her magic.  But Bara has eight sisters and they all want a piece of the action. Bara must choose between her love for Dylan or saving the Norse Pantheon.