"She was on the surface floating," Fischbeck said. "Her skin was turning yellow."
Ruby passed away in 2014, after Fischbeck left, and she doesn't know what happened to her.
"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."
As with the other animals, the divers had to be wary when swimming with the belugas as the stress of captivity would exhibit itself as aggression. Pearl lost the fear that wild belugas have and would roughly try to play with the divers. "She'd come and pull us off walls and grab us on the bottom of the tank," Fischbeck said.
Her father, Nanuq, was also "extremely aggressive." He ended up breaking his jaw in a fight with other whales. It became infected, and he died in February.
And like the other animals, the belugas exhibit stereotypic behavior, mindless repetitive patterns that are often a symptom of captive stress. One male, Ferdinand, will compulsively perform spy hops, little jumps out of the water that wild belugas use to spot predators.