A short-finned pilot whale named "Haitang," which was found stranded earlier this year in south China's Hainan Province, was released off the coast of Sanya City on Sunday.

The short-finned pilot whale was released 70 nautical miles off the coast of Sanya in waters 500 meters deep after being nursed back to health over the course of 140 days, according to a staff member of the Blue Ribbon Ocean Conservation Association.

On January 3, the male short-finned pilot whale was found by tourists on a beach in Haitang District in Sanya. According to Xiong Chunlin, a veterinarian at the Sanya Haichang Animal Conservation Center, Haitang had multiple visible injuries and poor vital signs when it was found, and was unable to swim independently.

"Rescuing and releasing stranded short-finned pilot whales have previously been a rare success," said Xiong. "Whales float in the water. After getting stranded, the larger the whale, the greater the gravity it bears, and the more serious the injuries caused by compression. Therefore, it's very rare for Haitang to recover to a normal state from stranding to rescue."

After being treated and carefully cared for by technicians and volunteers, Haitang's condition gradually improved. Its body length increased from 3.6 meters to 3.96 meters. At the time of release, Haitang weighed 500 kilograms and demonstrated the ability to hunt independently and recognize its own species.

Pu Bingmei, the secretary-general of the Blue Ribbon Ocean Conservation Association said that the release area avoided shipping lanes and had previous records of short-finned pilot whale population activity, making it easier for Haitang to find other whales of its kind.