Officials know why, but not exactly how two beluga whales died at the Vancouver Aquarium.
A five-month investigation concluded that a toxin, which was found in the blooodstreams of Qila and her mother, Aurora in November, 2016, killed them.
“The investigation also determined that the toxin was likely introduced by food, water, or through human interference,” officials announced this week, after extensive investigation by veterinary pathologists, toxicologists and other experts.

Since their deaths, the aquarium has taken steps to cut the risk of toxins winding up in its marine mammals.
That includes better food screening, potentially problematic plants will be removed, mechanical water systems are being overhauled and new monitoring of the water.
“The loss of Qila and Aurora was devastating, Dr. Martin Haulena, Head Veterinarian at Vancouver Aquarium, said in a statement. “They were beloved members of our family and the community for more than two decades. Their loss is felt profoundly by our staff, members, supporters, and the public. The investigation has helped us understand what happened and, importantly, how we can best ensure the safety and welfare of marine mammals in our care.”
The facility is also heightening security to thwart any attempts of sabotage.
“We deeply appreciate the assistance of world-class experts during the investigation process, the outpouring of support from members and the local community, as well as the unwavering dedication of our staff and volunteers,” Dr. Haulena added. “The conclusion of the investigation helps bring closure to an extremely difficult situation.”

Qila was the first beluga whale to be conceived and born in a Canadian aquarium was born on July 23, 1995. Her mother, Aurora, was 30, when she died.
First, Qila fell ill and then, Aurora got sick. She died nine days after her daughter.

Photos Vancouver Aquarium