China restores marine ecosystem for underwater wildlife

JINAN/HAIKOU, June 29 (Xinhua) -- Off the coast of east China's Shandong Province, where the Bohai Sea meets the Yellow Sea, lies the Changshan Islands, also known as Changdao, the largest island group in the area. Here, Pacific spotted seals lounge on sunlit reefs as the gentle sea breeze blows by them.

Beneath the sea surface, a "submerged grassland" is quietly making a comeback. Seagrass is a flowering plant that completes its entire life cycle -- pollination, seed formation, and germination underwater. A football-field-sized seagrass meadow can support 80,000 fish and 100 million small invertebrates.

In the past, intensive development without a well-thought-out plan, including aquaculture hatcheries and nearshore farming, rapidly whittled away these underwater habitats, leaving them a shadow of their former glory.

"The decline of seagrass is a global issue, but in Changdao we see an opportunity for restoration," said Wu Zhongxun, deputy director of the Changdao National Marine Park Management Center.

In 2018, the Shandong provincial government approved the establishment of the Marine Ecological Civilization Comprehensive Experimental Area of Changdao, marking an important shift in the area toward green development.

By tailoring their efforts to the unique marine ecosystem, the park management center has partnered with research institutes and universities to restore seagrass and seaweed beds, blending natural recovery with targeted human assistance to rebuild marine ecosystems and boost biodiversity.

"At present, we are using a restoration model developed jointly with Yantai University," Wu said. "First, we set up artificial seed banks to preserve germplasm. Then we sow the seeds onto biodegradable 'turf,' raise them indoors until they reach over 20 centimeters, and finally lay them out on the seabed like carpet."

Each year from March to May, more than 400 Pacific spotted seals migrate from Liaodong Bay to Changdao.

"As seagrass and seaweed increase in surrounding waters, they provide spawning grounds for fish and shrimp. With more fish and shrimp, the seals have sufficient food here," Wu said.

Xiao Shengzhi, a seagrass cultivation technician with the Marine Ecological Civilization Comprehensive Experimental Area of Changdao, has prepared materials for this year's planting season. "When seawater temperatures rise above 16 degrees Celsius in late May, we can begin seagrass planting," he said.

Further south in China, similar ecological changes are also unfolding underwater.

In the waters of Wuzhizhou Island, in Sanya, Hainan Province, a group of wild dolphins made an appearance in April -- their second sighting of the year.

"The frequent dolphin sightings are a clear sign that Sanya's marine ecology is improving," said Wang Fengguo, head of the marine department of Wuzhizhou Island tourism zone. He is known as a "subsea farmer" for his years of coral cultivation and protection work.

Since 2010, when Wuzhizhou Island and Hainan University launched China's first tropical marine ranch project, more than 80,000 cubic meters of artificial reefs and shipwreck reefs have been deployed, over 66,000 corals transplanted, and 61,000 square meters of seabed restored.

In recent years, the protection team has introduced a new cultivation technique that has boosted coral survival rates from 40 percent to over 70 percent. The area now records 116 species of corals and 265 fish species, with rare species such as hawksbill turtles becoming regular residents.

Wang Aimin, 65, is also one of the "underwater afforestation workers" in the Wuzhizhou Island waters. His team deploys artificial reefs on the seabed to provide habitats for fish, shellfish and corals.

"Marine ranching is a lot like grazing livestock on land," he said. "We're essentially farming marine life by creating habitats, which gradually restores the ecosystem and food chain."

Over the past decade, Wang's team has been constantly fine-tuning and enhancing the marine ranching program.

Since the first batch of artificial reefs was deployed in 2011, nearly 3,000 reef units and 21 shipwreck reefs have been installed in the area. Fish resources have increased five to ten-fold, and ecological benefits have gradually extended to nearly 10,000 mu (about 666.67 hectares) of surrounding waters.

"The real credit for restoration goes to nature itself. Its ability to recover is far greater than any human intervention. We should respect nature and strengthen ecological awareness," Wang said.