“Finding Dory” may be undergoing a sea change as Pixar is taking a page from a little-seen whale documentary.

The Walt Disney-owned animation studio is hard at work on “Finding Dory,” a follow-up to the 2003 oceanic blockbuster “Finding Nemo.” But this spring, after Pixar executives viewed “Blackfish,” a film that raises sharp questions about the health of whales kept in captivity, the studio decided to make substantial changes to the “Dory” script.

According to Louie Psihoyos, who directed 2009’s Oscar-winning dolphin slaughter documentary “The Cove,” Pixar chief creative officer John Lasseter and “Dory” director Andrew Stanton sat down with “Blackfish” director Gabriela Cowperthwaite in April after seeing her movie.

“At the end of the (Pixar) movie, some marine mammals are sent to an aquatic park/rehab facility — a SeaWorld-type environment,” explained Psihoyos, who heard about the meeting through a friend in the animal rights movement who lives near Pixar’s Emeryville, Calif., campus. “After seeing ‘Blackfish,’ they retooled the film so that the sea creatures now have the choice to leave that marine park.”

Pixar declined to comment. Cowperthwaite confirmed she screened the film on the studio’s Northern California campus, but would say only that employees there were deeply “impacted” by her movie.

“These are obviously people who are dedicated to researching every topic they cover,” the filmmaker said. “Whether ‘Blackfish’ affects their creative decisions, I can’t say.”

The plot for “Finding Dory,” set for release in November 2015, is not yet locked. At Pixar, as at many other animation studios, filmmakers often make changes to stories up until the final months before release.

However, the story will revolve around an amnesiac regal blue tang voiced by Ellen DeGeneres who doesn’t know who raised her. Dory was a key character in “Finding Nemo,” a box-office hit that grossed $921.7 million worldwide and won the Oscar for animated feature.

“Blackfish” is a look into what may have caused a killer whale to fatally attack SeaWorld trainer Dawn Brancheau in 2010. The movie began its limited theatrical release in mid-July and will likely be wider seen when it debuts on CNN on Oct. 24.