After several years of public scrutiny and criticism, SeaWorld announced that it is ending its orca breeding program. Because the theme park operator long ago stopped capturing orcas from the wild, the orcas currently at the parks will be the last generation to live at SeaWorld.

It has not been an easy few years for SeaWorld. After a series of high-profile protests following the 2013 premier of the documentary Blackfish, SeaWorld has fought against allegations of inhumane conditions and abusive treatment of its 23 captive orcas. Last November, the company announced that it will phase out its once-popular “Shamu Shows” by 2017—the same month that legislators in the California House of Representatives proposed a bill banning orca breeding throughout the state.

“Times have changed, and we are changing with them,” SeaWorld wrote in a statement. “We love our whales and so do many of our visitors and this is about doing the best thing for our whales, our guests, our employees and SeaWorld.”

While SeaWorld has denounced Blackfish as inaccurate and exploitative, since the documentary debuted the company has seen a dramatic drop in visitors to its flagship theme parks and watched as its value on the stock exchange was halved, BBC News reports. At one point, SeaWorld launched a multimillion dollar ad campaign to try and save its image, but eventually decided that phasing out its orca programs would be the best path.

But even though SeaWorld says the current generation of orcas housed at its parks will be its last, these whales will also spend the remainder of their lives in captivity, which could last as long as 50 years. Although some animal rights activists have pushed for SeaWorld to release its remaining orcas into sea pens or coastal sanctuaries, SeaWorld president and chief executive officer Joel Manby writes in an Op-Ed for the Los Angeles Times that releasing the orcas into the wild would be disastrous.

“Most of our orcas were born at SeaWorld, and those that were born in the wild have been in our parks for the majority of their lives,” Manby writes. “If we release them into the ocean, they will likely die. In fact, no orca or dolphin born under human care has ever survived release into the wild.”

Over the last 50 years, few captive orcas have been released into the wild, but most that were released have indeed met unfortunate endings. Whales and dolphins have very complex social and familial networks and do not readily accept new members into the pod without knowing a captive whale’s background. Because of this, it can be incredibly difficult for them to transition from captivity to the wild, particularly if they were reared in captivity.

One infamous and particularly tragic example is the 2002 attempt to rewild Keiko, the orca who starred in Free Willy. Keiko was captured from his native waters near Norway as a youth, and even though he spent several years in a sea pen before he was released into the wild, he never joined a new pod and died a year later, Kaleigh Rogers reports for Motherboard.

While SeaWorld’s remaining orcas may be there to stay, this is still a step forward for animal rights groups and orca lovers alike.