Aquarium staff say Kavna had been displaying some behavioural changes recently, and a series of tests were being done to find out why.
At 46 years old, Kavna was the oldest beluga at the aquarium.
A veterinarian at the Aquarium says Kavna appears to have died of cancer associated with old age. Dr. Martin Haulena says the whale's health declined in the past week as fluid and other debris built up in its reproductive system.
He says the whale initially responded to hormone treatment, but the mammal died Monday afternoon.
The exact cause of death won’t be known until a full necropsy is done.
On Monday night, Canadian singer Raffi, who wrote “Baby Beluga” after meeting Kavna in 1979, tweeted about his sadness at learning of the whale’s death.
“Just heard the news, sad she's gone. Loved meeting her in ‘79 - gave me a kiss, inspired a song now known to millions!” he wrote.
Last September, three-year-old Tiqa died from heart failure that was induced by pneumonia.
She was the third beluga calf to die at the aquarium since 2005.
Haulena notes belugas have an average lifespan of 25 to 30 years in the wild and Kavna far outlived that.
Kavna arrived at the Vancouver Aquarium in 1976 after it was captured off Churchill, Man.
