The marine star of the 1960s TV show, FLIPPER, a dolphin, committed suicide after battling depression.

Marine activist and dolphin trainer Ric O'Barry says he decided to devote his life to saving porpoises and whales after watching Flipper take her own life.

O'Barry had helped train dolphins for the beloved TV show, but stopped when the aquatic topliner  refused to breathe rather than live another moment in captivity.

"She was really depressed," O'Barry, the star of Oscar-winning documentary The Cove, revealed.

"You have to understand dolphins and whales are not air breathers like we are. Every breath they take is a conscious effort. They can end their life whenever.

"She swam into my arms and looked me right in the eye, took a breath and didn't take another one.

"I let her go and she sank straight down on her belly to the bottom of the tank.

"The next day I was in jail for trying to free the dolphin."

O'Barry then made a vow, "I was gonna free every captive dolphin I could."