Daisy, the Vancouver Aquarium’s nine-year-old harbour porpoise, died Thursday.
How she died isn’t yet known.
In a statement the Aquarium says a change in her behaviour earlier this month was concerning, leading to increased monitoring, which turned into around-the-clock care earlier this week after her health deteriorated.
Head veterinarian Dr. Martin Haulena says “Daisy helped change the way the scientific community approaches the rescue and care of harbour porpoises and other cetaceans in distress.”
She was first rescued by the Aquarium in August, 2008.
The aquarium says rehabilitation work with Daisy lead to the creation of its cetacean rescue protocol.
Two cetaceans remain at the aquarium: Helen, a Pacific white-sided dolphin, and Chester, a false Killer Whale.
WATCH: June 15, Vancouver Aquarium sues Vancouver Park Board: