The death of Spinnaker the Pacific white-sided dolphin at the Vancouver Aquarium yesterday remains a mystery, says staff veterinarian Dr. Martin Haulena.
"At this point we don't have a real cause as to what happened," Dr. Haulena said Friday, citing stomach inflammation, pancreatic cancer and bone marrow problems as potential causes.
Spinnaker had been receiving treatment for a prolonged illness and showed signs of improvement in recent weeks, rejoining the aquarium's two other dolphins earlier this week after six weeks in a medical pool.
"When we left him on Wednesday he was very energetic. He was frolicking with the girls – a little too much sometimes – and had a full appetite, very much back to his normal schedule," Dr. Haulena said.
Security staff found Spinnaker floating at the bottom of his tank around 4:30 a.m. Thursday morning. He was thought to be at least 26-years-old.
Dr. Haulena also said several external wounds not seen the night before may have helped cause his death.
Further ancillary tests and an examination of microscopic tissue samples may help shed light on Spinnaker's condition following a necropsy conducted Thursday at the province's animal health centre in Abbotsford. Preliminary results could arrive Tuesday, with further lab results taking up to several weeks to come in.
"Surprise is the key word here," Dr. Haulena said. "So that makes it that much more devastating… On a personal level, Spin was one of my favourites. He was an athlete. He flew."
Aquarium employee Oona Prediger said Spinnaker's death was felt throughout the building.
"It affects everyone here," she said. "We're all saddened by it."
Ms. Prediger compared the loss of the marine mammal – found caught up fishing nets off the coast of Japan in 1991 – to that of a loyal pet.
"If you have a really faithful dog that you've had all your life… when he passes away you're really upset," she said. "And I think it's the same with these animals. You become really attached to them, so it's hard on people."
Spinnaker was brought to Vancouver on July 31, 2001, and achieved the average lifespan for a Pacific white-sided dolphin. The aquarium's two remaining dolphins, Hanna, 17, and Helen, 23, arrived at their new home in 2005.
The last dolphin to die at the aquarium was Laverne, a 31-year-old female who passed away in 2009.
Spinnaker's death follows the passing of Milo the sea otter from lymphoma in January. The 13-year-old grew to be adored worldwide after he was filmed holding paws with his companion at the Vancouver Aquarium, garnering over 17-million views online.
Tiqa, a three-year-old beluga whale, died of heart failure in September, 2011. Nola, a one-year-old beluga calf, died due to a blocked airway in June, 2010.