(VIDEO) Bubbles, SeaWorld's Oldest Pilot Whale, Dies

The dearly loved "oldest" pilot whale in a zoological park, performing for three decades at the aquarium's San Diego spot, died recently while in her 50s.

Bubbles was one of the main attractions at the park's Dolphin Stadium, where she had been performing since the 1980s, said SeaWorld.

"She has inspired and amazed more than 100 million guests for nearly 50 years," it explained. "Loved by her trainers and veterinarians, Bubbles had been a member of the SeaWorld family for nearly 30 years."

Captured in 1966, according to WDC, Bubbles was at first owned by Marineland, another marine park in the Pacific. She was shifted to SeaWorld in 1987.

A necropsy will be undertaken to find out why she died. Usually, female, short-finned pilot whales can live upto 60 years.

The social media is seething with messages of remorse as well as appreciation.

In Twitter, Amber Noelle Morasse, 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."

Another user said: "RIP Bubbles. U were ripped away from your family & forced to do stupid tricks 4 stupid humans, you are finally free."

Friends of the WPZE said: "Just sad. Sad life. Sad death," while a fourth said: "Heart breaking news as yet another animal dies at SeaWorld :( CaptivityKills."

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 than 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!"

Meanwhile, the controversy over the treatment of captive marine mammals continues to rage. SeaWorld has been slammed by many for its treatment of animals, especially killer whales. The park's orcas will be its last generation, said the organization in March.

"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." It has been attempting to accept and change in accord with public perception on the ethics of "captive performing animals" as well as the rising wave of animal rights activism.