Her Wolfish Groom by Rose Andrews

Lucille Dale, daughter of a wealthy businessman, marries Ira Winthrop, heir to a shipping company, in a long standing marriage agreement. She leaves behind the comfort and luxury of her Boston home for a coastal town steeped in magic, rumored to be roamed by werewolves. A cold and private man, she soon learns her new husband has a thirst for an unusual type of hunt.
Ira would rather spend his days pursuing prey instead of tending to a wife. He accepts the marriage as part of his duty to sire offspring and secure his company’s future. Yet the secret he harbors cannot be kept from his bride for long: he is leader of the Circle, a reclusive group of werewolves being hunted to extinction by the Silver Order of bloodthirsty werewolf hunters.
He offers to include her in on the fight to preserve all they know: remain human or become beast in order to join him in a bloody hunt that will change their lives forever.