Tilikum the Killer Whale Ailing Toward End of Captive Lifespan

Tilikum, SeaWorld's largest killer whale, is ailing and his condition is deteriorating as he reaches the high end of the mammals' average life expectancy, say the water parks' veterinarians.

Tilikum is infamous for the 2010 death of trainer Dawn Brancheau. the spark for the documentary "Blackfish."

The killer whale makes his home at SeaWorld's Orlando park, and SeaWorld said he had been "increasingly lethargic" over the past several weeks and veterinarians expressed concern about the animal's health, according to CNN.

"Since Tilikum became a part of SeaWorld's family 23 years ago, he has received the best in marine mammal health care and life enrichment available for killer whales – including a focus on his physical health, mental engagement and social activity with other whales," said a SeaWorld statement.

"Despite the best care available, like all aging animals, he battles chronic health issues that are taking a greater toll as he ages."

SeaWorld said vets are treating Tilikum for what they think is a bacterial infection in his lungs, but the ailment has been "very resistant to treatment and a cure for his illness has not been found."

Tilikum has a controversial history at SeaWorld. He has been connected with three human deaths during his 23 years in captivity, including that of Brancheau, noted the Washington Post. That death became one of the focuses of the 2013 documentary "Blackfish" and began a backlash against SeaWorld.

The Post said Tilikum has lived in captivity since November 1983 when he was captured with two female orcas near Iceland. Tilikum is estimated to be 35 years old, said SeaWorld.

The Post noted that male orcas tend to live from 50 to 60 years in the wild but the median survival rate for killer whales in U.S. marine parks is just 12 years.

"I wish I could say I was tremendously optimistic about Tilikum and his future," said SeaWorld veterinarian Scott Gearheart in a park video, per the Post. "But he has a disease which is chronic and progressive, and at some point might cause his death."

Related Stories:

• Whale, 'Gallon of Milk,' Spotted Off Mexico Coast for First Time in Years
  
• SeaWorld Killer Whale Dies in San Antonio, the Third Casualty in 6 Months