Lyu Xueyi has been working as a guardian at the Dalian National Spotted Seal Nature Reserve in the northeastern province of Liaoning for more than three years.

The 39-year-old said he has rarely seen a seal in the wild, but believes that it's a good sign as it means the creatures, which prefer to stay away from humans, are safe.

Lyu and his fellow guardians carry out about three patrols along the reserve's 370-kilometer coastline every month.

The spotted seal, or phoca largha, is the only pinniped that breeds in China's coastal waters. Last year, the species was given national first-class protected animal status.

The spotted seals living in the Bohai Sea are ecologically isolated from those in other regions of the world, which is of great significance for the protection of biodiversity.

The sea's Liaodong Bay is the southernmost of the eight recognized spotted seal-breeding grounds in the world.

The animals usually return to the bay from the Pacific Ocean in November, give birth in January and swim back after May.

To better protect the seals, the Dalian government established a reserve area along the bay in 1992.The reserve, which covers 560,000 hectares and protects spotted seals and the ecological environment, was upgraded to a national-level nature reserve in 1997.

In January 2002, part of the reserve was named a wetland of international importance under the Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat.

The wetland of the spotted seal in the Dalian reserve boasts rich biological resources with 26 species of phytoplankton, 25 species of zooplankton and 35 species of aquatic animals, including spotted seals, fin whales and Minke whales.

"With years of efforts in promoting protection awareness and measures, the local people are highly conscious of such protection now," said Lyu, who became a guardian of the reclusive marine mammal in July 2019.

He said his fellow guardians once helped newborn pups that washed up on shore or strayed into aquaculture areas, but that he had never encountered such an occasion.

"I still have great enthusiasm to protect such precious mammals," Lyu said.

Every year from January to April, a series of special operations are carried out to protect the spotted seals in Dalian.

"When the administration bureau was established in 2005, there were less than 1,000 spotted seals in Liaodong Bay. The number is about 2,000 now," said Shi Xiaoming, director of the administrative bureau of the Dalian National Spotted Seal Nature Reserve.

"This year, we rescued three spotted seal pups. They were all being released into the sea after being given professional treatment and training for the wild."

In recent years, the bureau has continued to promote the protection of spotted seals, as well as monitor the ecological environment and conduct resource investigations.

"Some seals even give up migration and choose to settle down. At the two main landing sites on Mayi Island and Huping Island, spotted seals can be observed almost all year round," Shi said.