A harbor seal has been spotted for the first time off the coast of a small island in Hainan province, the most southerly point that the species has ever been seen
in China.
The seal was sighted in the waters of Wuzhizhou Island, 30 kilometers off the coast of the popular tourist resort of Sanya on Aug 23, in a marine conservation area where artificial reefs have been built in order to restore marine life.
Harbor seals are mainly found in the North Pacific Ocean, the Arctic Ocean and the Sea of Japan. They have a breeding area on the Changshan Islands off the coast of Shandong province in the Bohai Sea, but the previous most southerly sighting of the species was off the coast of Guangdong province.
At 1.48 square kilometers, Wuzhizhou Island is tiny, and its 5.7-km coastline is popular among surf and sun lovers. But since 2010, the waters of Wuzhizhou have been attracting a more diverse and thriving sea life because of a type of marine conservation known as sea ranching.
The sea ranching so far has involved the construction of 80,000 cubic meters of artificial reefs and the planting of 50,000 coral strains to breathe life into the ocean and attract marine species.
The seal was filmed swimming among the artificial reefs and resting on a float at night.
According to professor Wang Aimin, a marine expert from Hainan University, the marine ranch demonstration zone's more than 2,500 artificial cement reefs and 21 ship reefs have enabled coral, fish, shrimp and shellfish to flourish.
"Remarkable progress has been made in marine ecological restoration and conservation of fishery resources," he said.
"A recent survey shows the fishery resources around Wuzhizhou Island have doubled in the past decade, and in the artificial reef area they are five times higher than in the surrounding area. Live coral coverage on the artificial reefs has increased from 18 percent to 25 percent."
Wang said that due to overfishing in the past, the number and diversity of marine life have been damaged, and the artificial reefs are playing a restorative role on the ecosystem.
"Since 2016, we've been planting coral on artificial reefs made of concrete, steel mesh and volcanic rock, improving the ecological environment and attracting more species."
The over 100 species of coral have attracted some 300 species of marine life including giant clams, groupers and clownfish, he said.
Wang Hao, a staff member at Wuzhizhou Island's tourism zone, was excited about the seal sighting.
"This is the first time we've seen a harbor seal near Sanya, and we hope he can make his home here and become a new member of the Wuzhizhou Island family," he said, noting that the seal had been spotted a few more times after the original sighting on Aug 23.
Professor Wang said the arrival of the seal showed that the quality of water and the diversity of marine life were improving. As for where the seal came from and why, there is still no clear conclusion, and experts are carrying out further research.
