SeaWorld announced Thursday an end to an orca breeding program that has lasted for more than 50 years.

In a letter to the Los Angeles Times, SeaWorld President & CEO Joel Manby said the current orcas in SeaWorld’s care will be the last generation of killer whales at SeaWorld. The company is also phasing out theatrical orca whale shows.

Americans’ attitudes about orcas have changed dramatically. When the first SeaWorld Park opened in 1964, orcas, or killer whales, were not universally loved, to put it mildly. Instead, they were feared, hated and even hunted. Half a century later, orcas are among the most popular marine mammals on the planet. One reason: People came to SeaWorld and learned about orcas up close.

SeaWorld says the Orcas they currently have will live out their lives at SeaWorld parks. Manby said in the letter, “no orca or dolphin born under human care has ever survived release into the wild. Even the attempt to return the whale from ‘Free Willy,’ Keiko, who was born in the wild, was a failure.”

In addition, SeaWorld announced new a new partnership with the Humane Society of the United States.What others are clicking on: