Animal rights groups are practicing some polar bear diplomacy.

In this case, their effort isn't the heady stuff of bilateral relations, but an attempt to set free an animal dubbed "the world's saddest polar bear" who glumly lays about in a shopping mall aquarium in South China's Guangdong province.

On Tuesday, the Washington-based Humane Society International (HSI) presented a letter signed by 50 Chinese animal rights groups calling for the Guangdong governor to close the city's Grandview Mall Ocean World, where "Pizza", as the bear is called, is among 500 animal species on exhibit.

The groups joined several other international organizations, such as the Born Free Foundation and the Hong Kong-based Animals Asia Foundation, which have gathered more than a million signatures on a petition calling for action.

"The Chinese groups are adding their voice to the international outrage at the polar bear's fate, as new video footage is released by Humane Society International and its Chinese partner group VShine, showing the polar bear exhibiting worrying stereotypical behaviours such as head swaying and repetitive pacing, evidence of frustration and mental decline," the letter said.

Last month, Yorkshire Wildlife Park in England offered to house the bear in a 10-acre enclosure, but the offer was declined.

The 3-year-old bear has been the mall's top draw it since it opened in January. A social media post about Pizza's apparently morose demeanor went viral, spurring the groups to action.

"Pizza is a superstar," Cao Jinwei, a representative from Beijing's Capital Animal Welfare Association, told the Los Angeles Times. "There was a large crowd around his enclosure, and children had their faces against the glass to get a good look at him. But he is a celebrity without freedom."

The mall responded to the criticism in an Oct 21 statement.

"Grandview Mall Ocean World has always operated with an 'animals first' philosophy, focusing from the outset on animal protection, scientific discovery and education," the statement said.

The statement also said that the aquarium welcomes feedback, but "some groups acting on ulterior motives and personal vendettas will be reported to the relevant government authorities, and [Grandview Mall Ocean World] reserves the right to take legal action."

Hongmei Yu, founder and president of Vshine Animal Protection Association, said "there is a worrying trend in China of wild animal exhibits in shopping centers, with another one reportedly being considered right now in Shijiazhuang, Hebei province".

"If the mall thinks foreign groups are not needed, let them meet with us Chinese groups instead, because we too care passionately about these animals and want to give them a better life," Yu said.

"Because [such recreational facilities including Grandview] aren't professional zoos, they often provide very poor living conditions [for animals in captivity]. Plus, they are often located in places where there are intense streams of visitors. So, from the aspect of animal welfare, that imposes a grave negative impact on the animals," Qin Xiaona, founder of Beijing-based Capital Animal Welfare Association (CAWA), told the Voice of America.

Grandview, in response to VOA, argued that Pizza is an artificially bred polar bear, which left its mother at the age of 2 and would be unable to survive in the wild.

"It is only objective to look at both animal welfare and their social function we also shoulder social responsibilities to popularize science and promote biodiversity," the curator wrote in an email.

Grandview said it has made the health of Pizza and other captive animals a priority, with 130 professionals tending to the animals' daily needs and performing regular checkups.

"Our star animal Pizza has been healthy, as all indicators from his recent physical exam fall with the normal range," the statement said.

The aquarium said that Pizza is well fed and that it has added more stimulating activities, such as hiding food in the snow, according to a Grandview promotional video.

Perhaps if Pizza knew how many people were pulling for him, that forlorn look might someday turn into a smile.

Contact the writer at williamhennelly@chinadailyusa.com