
Barbie and her sisters go to visit Ken during his summer internship working at a coral reef where he is researching dolphins. When the sisters are diving, they see a rare, rainbow-colored dolphin during its annual visit to the reef. The exciting discovery makes them want to learn about preserving all the sea life in the area. In the process, they meet Isla who it working to save the coral and they become friends. Their adventure begins when they find out that Isla is actually a mermaid, and she needs the help of Barbie, her sisters and the gemstone dolphins.
