Two western Pacific harbor seals rest on the mudflat in Panjin, northeast China's Liaoning Province, March 23, 2024. [Photo/Xinhua]

Liaodong Bay in northeast China has reported steady growth in the harbor seal population over the past three years, said local authorities.

According to local observation statistics, the number of western Pacific harbor seals that visited Liaodong Bay in 2021 was 181, and the number reached 253 in 2022. In 2023, there were 302 such migratory seals recorded in the bay, showing an increasing momentum year by year. Furthermore, the seal population is expected to grow by about 20 percent this year compared with last year, according to the agriculture and rural affairs bureau of Panshan County, Panjin City, Liaoning Province.

Liaodong Bay is located in the northernmost frozen area of Chinese waters, and is the southernmost of the eight breeding areas of western Pacific harbor seals in the world. As the only pinniped marine mammal that can breed in China's waters, the western Pacific harbor seal is listed as a national first-class key protected wild animal in the country.

The harbor seals migrate to Liaodong Bay between November and December every year, and they give birth on the ice from January to February of the following year. The harbor seals gradually swim out of the Bohai Sea and begin their journey back to the Pacific Ocean between April and May, having replenished enough nutrition.

Over recent years, Panjin has carried out protection and restoration work on its wetlands, with nearly 86,000 mu (about 5,733 hectares) of coastal wetlands restored so far, which helps provide a suitable breeding and habitat environment for the annual migration of the harbor seals, said local authorities.