"She was on the surface floating," Fischbeck said. "Her skin was turning yellow."
Ruby was moved to the back tank so guests couldn't see her, Fischbeck said. She died in 2014, after Fischbeck had left the park.
"You can't find Ruby's necropsy anywhere," she said. "I've asked my past coworkers and everyone's really hush-hush about it. No one wants to lose their jobs."
The whales are also drugged with Valium, several former workers have confirmed; Fischbeck said the whales were bored and frustrated with captivity, and would often become aggressive with workers.
And like orcas, belugas have shortened life spans in captivity, even though they're protected from predators and other natural threats.
"Given the known deleterious effect of chronic stress on immune function, it is plausible to argue that captive belugas lead less healthy lives than their wild counterparts, both psychologically and physically, which would explain why, despite protection from natural hazards, they do not live longer in captivity," a group of marine scientists with Whale and Dolphin Conservation wrote in 2012.