Bismarck Dead: Denver Zoo's Physically-Challenged Seal Dies Under Anesthesia

It's been a sad couple of days at the Denver Zoo. Bismarck, a popular 5-year-old California sea lion passed away under anesthesia while being prepped for a neutering surgery Wednesday.

Bismarck was one of five other sea lions at the zoo but stood out because he had no back flippers. As a result, he'd carry all his weight on his two front flippers and became something of "an ambassador to the physically challenged," the zoo said in a statement Thursday.

"This was a very surprising loss and our hearts go out to the zookeepers that worked with Bismarck every day," says Vice President of Veterinary Medicine Scott Larsen. "It is always difficult to lose an animal, especially one as amazing as Bismarck, but to lose one during a medical procedure that was intended to help him is especially hard."

Male sea lions can grow to weigh 1,000 pounds, so to prevent him from growing to his full size and avoid future health complications from him carrying all that weight on his two front flippers, vets decided it'd be best to neuter him.

Unfortunately, KDVR reports that marine mammals can face a greater risk under anesthesia because of the way their bodies physically adapt underwater and process oxygen.

Under anesthesia, Bismarck quickly lapsed into a critical state and multiple efforts to resuscitate him were unsuccessful.

Bismarck came to the Denver Zoo in 2009 after being found as an pup alone by a pier in Newport Beach, California missing his back flippers. After being rescued by the Pacific Marine Mammal Center (PMMC), it was determined that he would not be released back into the wild because of his missing flippers.

"Bismarck taught us all something about overcoming challenges and adversity," said Vice President for Animal Collections Brian Aucone. "Many guests walked away inspired after watching him show how agile and limber he was, despite not having rear flippers. We will all miss him."



Bismarck The Denver Zoo Sea Lion