After release, Keiko swam in the ocean, but never was able to survive without human feeding and he continued to seek human company. He never dove like wild whales, and didn't appear to reintegrate with wild whales.
A scientific paper offers an answer:
“A release program can be considered a success when the released animal is able to feed, maintain health and stress levels comparable to his wild conspecifics, show normal predator avoidance behaviour, and ultimately reproduce (unless unable for other reasons, such as reproductive senescence),” write the authors of this new paper.
“Under these criteria, Keiko’s release to the wild was not successful, since though physically unrestricted and free to leave, he kept returning to his caretakers for food and company.”
At the end of the day, while it might have been appealing for humans to free Keiko, it may not have been good for the whale.
Remember that upwards of $7 million was spent on this release program, and Keiko died of pneumonia a couple of years after reintroduction to the ocean.
I would not have chosen to spend this much money on an attempted reintroduction of Keiko. Tweet