It is not known why the adult male porpoise stranded, but officials said it could have been stuck by a boat, chased by a predator such as a killer whale or could be suffering from an unknown illness.
"The porpoise is a healthy weight, but is unable to swim on his own, so he is being supported in a specially-designed sling that helps him stay afloat while minimizing handling," said Vancouver Aquarium veterinarian Dr. Martin Haulena.
Historically, porpoises that have become stranded have a very poor chance of recovery — particularly adults, which often have underlying health issues.
However this porpoise, which has been named Levi, is in good condition, which suggests it is not suffering from cancer or some other long-term illness, Haulena said.
"The first 48 hours are critical and our team will continue to provide critical care in the hope that he improves and can be re-released," said Haulena.
The focus for the next 24 hours is to stabilize the porpoise with fluids, antibiotics and nutrition, while the team plans further diagnostic procedures.
"If the porpoise recovers and demonstrates that he can adequately forage for food, and we are confident that he can avoid predators and won't pose a threat to other marine life, the goal would be to eventually release him back to the wild," said Haulena.