Ningyo Hime Marina no Boken

Adventures of the Little Mermaid (人魚姫 マリーナの冒険, Adventures of the Little Mermaid?) is an animated series produced by Fuji Television in the early 1990s, based on upon the Hans Christian Andersen fairy tale The Little Mermaid.

This 26-episode TV series was originally a Japanese/South Korean co-production directed by Takehiro Miyano and Yun Suk Hwa. The title of the series in Japan was Ningyo Hime Marina no Boken (The Adventures of Mermaid Princess Marina), and the series was broadcast on Japan's Fuji TV network from February to July 1991. As in the 1975 feature-length movie version produced by Toei (with which this series may be confused), the mermaid protagonist was drawn as a blonde in this version and given the name Marina. It also added a new ingredient to the story: a magical whistle given to Marina by the Sea Witch allowing her to shift back and forth between human and mermaid form when blowing it.

Released in America for Saturday-morning and weekday afternoon syndication by Saban Entertainment in the fall of 1991, the series wasn't nearly as popular as Disney's version and faded quickly.

Source: Wikipedia