Bubbles was the oldest pilot whale in a zoological park, and performed at the aquarium's San Diego location for almost three decades, SeaWorld said. She was estimated to be in her 50s.
The whale was one of the star attractions at the park's Dolphin Stadium, where she had performed since the 1980s, SeaWorld said in a statement.
"She has inspired and amazed more than 100 million guests for nearly 50 years," it said. "Loved by her trainers and veterinarians, Bubbles had been a member of the SeaWorld family for nearly 30 years."
Bubbles was captured in 1966, according to WDC
, a marine-mammal advocacy group, and was originally owned by another marine park, Marineland of the Pacific. SeaWorld acquired her in 1987.
SeaWorld will perform a necropsy to determine the cause of death. Female short-finned pilot whales usually have a maximum lifespan of around 60 years
Captive life criticized
Some took to Twitter to express their distaste at Bubbles' life of captivity.
User Amber Noelle Morasse, whose account identifies her as an employee of the U.S. Humane Society, tweeted, "Bubbles was captured in US waters in 1966 & spent the rest of her life in a tank. She deserved better."
However, someone identified as one of her trainers took to Facebook to defend SeaWorld's animal programs.
"This whale was more loved than our own families, has brought more smiles to people then any pilot whale in the wild!" Jenny Thompson said in a post.
"We learned so much about this beautiful species and Bubbies (sic) lived a fantastic life, full of stimulation, comfort and beauty and was more loved and cared for than I can try to explain!"
SeaWorld has come under fire for its treatment of captive marine mammals, particularly its killer whales. Its orcas will be the last generation at its parks, the organization announced
"SeaWorld has been listening and we're changing. Society is changing and we're changing with it," the company said
. "SeaWorld is finding new ways to continue to deliver on our purpose to inspire all our guest(s) to take action to protect wild animals and wild places."
The company has come under fire for its treatment of killer whales since the 2013 CNN documentary "Blackfish
The organization has been trying to adapt to public perception on the ethics of captive performing animals and a growing tide of animal rights activism.