MaryJanice Davidson: Fred the Mermaid Series
I think I've mentioned before how much I LOVE Davidson's Betsy, the Vampire Queen series. I spent a whole winter pouring through her books. I can also recommend the Alaskan Royals series, although it isn't paranormal.
A stand-out series of hers is the Fred the Mermaid series, which starts with Sleeping With the Fishes. Fred (Fredrika), is the daughter of a human and a Mer-man. Raised by her single mom, she naturally drifted toward the ocean and ocean life. As an adult, she has become a noted marine biologist, who works at an Aquarium. Her job happens to be to take care of the big tanks and feeding the fish, which she always does after hours, when she can go into the tank and swim with her tail.
Fred is lucky in love, but has trouble deciding between her human boyfriend and the mysterious mer-man who has recently come into her life. Cute story, with lovable characters.
Fred the Mermaid
1. Sleeping with the Fishes
2. Swimming Without a Net
3. Fish Out of Water