Lingshui Li Autonomous County in south China's Hainan Province is home to the country's first, and so far only, offshore tuna farming base. Above the shimmering waves of the South China Sea, yellow-fin tuna leap through the water in net-cages to compete for food, splashing silvery water droplets.

Feng Yitao, general manager of a marine company under the Lingshui Agricultural Investment Group, said proudly: "Look! Those are the 'gold of the sea' we are raising!"

In August 2023, carefully selected wild yellow-fin tuna fry from the South China Sea were transferred to China's first offshore tuna farming base, located 3.6 kilometers off the coast of Xincun town of Lingshui. After 30 months of dedicated effort, yellow-fin tuna exceeding 50 kilograms were successfully cultivated, marking a historic breakthrough in artificial cultivation of tuna in China.

Photo shows tuna cutting at the 27th China (Hainan) International Winter Trade Fair for Tropical Agricultural Products in south China's Hainan Province in 2024. (Photo courtesy of a marine company of Lingshui Agricultural Investment Group)

From August to the following February each year, large schools of fish, mainly yellow-fin tuna, gather in the central and northern parts of the South China Sea basin. Lingshui, the closest land to this natural fishing ground, offers a tropical climate and water quality ideal for yellow-fin tuna. Currently, the base is home to four gravity-type cages, each 90 meters in circumference. The total number of tuna being farmed in Lingshui exceeds 4,000.

Tuna farming has been a truly arduous journey. "Catching live wild juveniles was the first hurdle we had to cross," said Feng. During transportation, it was not easy to keep the fragile fry alive. In the early stages of net-cage rearing, disease prevention and emergency response were critical. The tuna's famously picky palate posed yet another obstacle—only the most precise bait would do. And then came the challenge of safely replacing massive deep-sea nets.

A worker feeds tuna in the offshore tuna farming base in Lingshui Li Autonomous County of south China's Hainan Province. (People's Daily Online/Fu Wuping)

"Tuna, rich in unsaturated fatty acids, are a prime example of red-meat fish, and have extremely demanding requirements for both feed type and quality. Only with good feed can we raise good fish," said a worker tossing high-quality and fresh baitfish into the water.

Even more exciting is the breakthrough in artificial spawning technology, achieved by the farming base in collaboration with the South China Sea Fisheries Research Institute under the Chinese Academy of Fishery Sciences. In just a single spawning trial, 196,800 fertilized eggs were obtained, with a hatching rate as high as 83.1 percent. This breakthrough has ignited new hope for China's independent breeding of tuna fry.

According to Feng, the yellow-fin tuna raised here boast a remarkable increase in unsaturated fatty acid content, which give the meat a fuller, more pronounced aroma. The flavor and texture of the meat have already surpassed that of wild-caught populations.

To bring tuna, a premium delicacy, to the tables of ordinary households, Lingshui is striving to establish a complete industrial chain. In Lingshui Bay, the construction of a deep-sea fishery complex is in full swing. A truss-structured intelligent net-cage, engineered to withstand Category 17 typhoons and hold 60,000 cubic meters of water, is scheduled for completion in 2025.

As breeding is the "core chip" of the whole industry, Lingshui has planned the construction of a county-level aquaculture seed industry base to gather world-class researchers, establish an international tuna research center, and focus on introducing high-quality seed resources such as Pacific bluefin tuna to overcome bottlenecks in the seed industry.

In addition, inside the Wenluo logistics industrial park, ultra-low temperature cold storage and modern processing lines operate efficiently, ensuring that "Lingshui Tuna" can reach dining tables across the country within 24 hours, preserving its exceptional freshness every step of the way.

“We're going to make tuna affordable for the people of Hainan first, and then help people across the country enjoy tuna," Feng said confidently.

(Source: People's Daily)