After nearly six months of rescue and dedicated care at the Sanya Haichang Animal Conservation Center in Hainan province, the stranded short-finned pilot whale named "Haitang" has recovered and returned to the sea on Sunday morning.

Under the watchful eyes of vets, volunteers and marine experts, the marine mammal can now eat 12 kilograms of squid and 2 kg of herring a day, served in four meals throughout the day, according to Cao Zheng, head of the conservation center. Its body length has grown from 3.6 meters to 3.7 meters, and its chest circumference has grown from 1.9 meters to 2 meters.

"Squid is the main staple of short-finned pilot whales. With the waters near Sanya teeming with an abundance of squid, the intelligent marine mammals have developed a knack for hunting and feasting on these slow-moving cephalopods," said Cao.

"Haitang has mastered the art of catching squid in the wild. Although it may need some time to readjust to the freedom of the open sea after being released, we'll monitor its movements through a specialized device," Cao added.

The release team has discussed and formulated every aspect of the release process, from transportation logistics to the precise location of entry into the sea, as the whale now weighs around 500kg.

Haitang's journey started as they went aboard the research ship on Saturday, destined for the designated release area, a journey of more than 10 hours at sea lied ahead. The team decided to release Haitang in a 500-meter-deep area, known for the activity of short-finned pilot whales. By choosing a location with a history of whale presence, the team aims to provide Haitang with the best possible chance of joining a population, finding companionship and establishing new connections within its natural habitat, said Cao.

Short-finned pilot whales are national second-class protected wild animals. On Jan 3, a short-finned pilot whale was found stranded in Haitang Bay, Sanya city, with obvious trauma in many parts of its body.