The head of Mendoza Zoo in Argentina has shot down any plans to move the zoo's only polar bear, 28 year-old Arturo, north of the Equator.

The Huffington Posts reports that the decision comes after a petition on Change.org, which aims to relocate the bear to Assiniboine Park Zoo in Canada, reached over 700,000 signatures.

Supporters as diverse as Greenpeace and U.S. House Speaker Newt Gingrich have supported moving Arturo, saying that he appears to suffer from depression and should no longer be kept in an open enclosure where temperatures can reach over 30 degrees Celsius.

He is the last remaining polar bear in the zoo - his partner Pelusa died of cancer in 2012 and another died in December of the same year during a heat wave.

However, zoo director Gustavo Pronotto claims that Arturo is too old, and that the move would be too risky. He says the bear will remain put, adding: "Arturo is close to his caretakers. We just want everyone to stop bothering the bear."