站在海工巨人肩上，读懂一条鱼Read a fish from the shoulder of the machine

English

When the morning fog skims Naozhou Island, the wind of the South China Sea crosses a vast green water and meets a steel whale that is changing what people imagine a fishery to be: Zhanjiang Bay No. 1.

One hundred and fifty-four metres long, forty-four wide, holding eighty thousand cubic metres of water, this heavy instrument of the sea is the world’s first floating, dynamically positioned farm in which ship and net are one body. It has the hull of a vessel, and another charge: out in the wide dark blue, to build a pasture that can move, and that can sense.

A large machine, and a fish’s small needs

This June, Zhanjiang Bay No. 1 brought in the first harvest of red-mouth croaker at a commercial scale. The waves watched the machine leave the drawing and enter the ocean, and watched Guangdong take a decisive step from the idea of deep-sea farming toward an industry.

The wind of the South China Sea keeps on toward the Southern Marine Science and Engineering Guangdong Laboratory in Zhanjiang, the Zhanjiang Bay Laboratory for short. There, Sun Mingyuan, deputy director of the equipment centre, and his team are still at work. He was deep in the structural design of Zhanjiang Bay No. 1, Bay Area Lingding, Hengyi No. 1, and other large farming platforms. A stretch of water, one bout of wind and wave, a change in how a fish grows: any of these may start the next drawing. What is written on paper has to go back to the sea, and be tested in real weather and in the growth of a living thing.

Cold industry, and a living fish

For Sun, meeting the South China Sea was not an accident.

He was born in Dalian, on the Bohai Gulf, and grew up in a port city. He studied ships and the sea, and then went into oil.

“My father and my grandfather were both seamen. When my father was young he sailed out of Dalian, mostly on the Northeast Asia run. Around the time he retired, Zhanjiang had become one of China’s important ports for energy and raw materials. Iron ore and crude oil come ashore here.” The change in what the ships carried told Sun early that the sea is not only water. It is tied to the direction a country’s industry takes.

As the Belt and Road went forward, China’s weight around the South China Sea grew, and the work of building a maritime power landed faster. “I could see how much room there was, and the laboratory happened to be there.” He came south and went straight into equipment for farming far offshore.

The move from oil equipment to farming equipment was his first failure to fit.

“Oil is a cold industry. Farming is not. The animal is complicated, and you cannot just calculate it.” Marine engineering, he says, is mostly a mechanical logic: meet the code, meet the strength. A fish is a life that does not move in a straight line. Much of it will not sit in a number. You get closer by counting, watching, and by what you have already seen.

To learn it from the water, he spent two summers in a row at sea, keeping the fish himself.

Once, some of the fish were doing badly. Water, oxygen, light, temperature: almost every measure they could think of came back fine, and still there was no cause. “The settings should have been enough. The fish were not.” They worked through it piece by piece. The trouble may have been a generator that had run too long, worn down, and grown louder and shakier. “The fish nearest the generator were clearly worse.”

A change that would barely register in an industrial system can decide whether a living one grows.

“A fish is very hard to satisfy.” The summer changed what he meant by equipment, and it gave him a respect for the trade he had not had. Before, he asked whether a machine could take a wave. After he had kept fish, he saw that a deep-sea farm is not only armour against the ocean. It is a room that has to hold a life, and fit it.

Teaching the steel whale to leave the storm

For him the real change in Zhanjiang Bay No. 1 is not that the machine is bigger. It throws out the old way of designing a deep-sea farm.

Older gear was built stronger and asked to carry more, and it met the weather head on. A larger machine also takes a larger load from the sea. The trade ended up with a machine that held and a school that did not. The team asked a different question: could the equipment leave the risk, instead of hitting it?

The answer is to move. The farm holds as much as sixteen to sixty-seven ordinary gravity cages, and it is not tied to the bottom in the old way. It holds its place with its own power, reads the weather and the sea ahead of time, and sails out of the dangerous water before a typhoon or a heavy sea arrives. It stops enduring the disaster and starts leaving it.

The idea changed the shape. Ship and net are one body. The ship supplies the movement. An open cage in the middle supplies the water the fish live in. The sea moves through it, and the deep water is used rather than shut out.

Joining a hull to a cage brought a new engineering problem. In a wave the hull bends and twists, and over time the structure tires. For the fish, too much motion also slows growth. “So we do not only ask whether it is strong enough. We ask how it moves in different seas.” The team shifted the weight in the hull so the platform answers a wave more quietly, and so fatigue and resonance stay down. They also read the forecast and change the route before the bad weather arrives.

A machine that works in a trial is only the first step. It still has to pass the market.

Cost was the second time the work did not fit what he already knew.

“Marine engineering is not farming.” In oil, the question is whether a large machine can run safely. In a farm it also has to pay. “If holding position depends on diesel every day, the fuel is heavy, and the cost lands on the fish. An industry like that may not last.”

That is why energy was in the design from the start. Solar and other clean sources cover more than 70 percent of ordinary power, so the platform can stay out and burn less of the old fuel, and the cost of farming far offshore comes down. A smart system feeds the fish on its own, watches water and fish around the clock, and uses AI in the daily management, so the work is steadier and wastes less.

The later boats in the series will keep being cut to what an industry can use: less material in a new shape, more fish from the same volume of water, more clean energy, a lower bill, and a flow of water that suits the fish and keeps the farm steady.

The force of believing it

He is in his sixth year at the laboratory, and he says his mind has changed.

“At the beginning, my confidence really was shaken.” In front of a row of models that have already left the page and reached the water, he sees more than equipment. He sees six years of crossing from industry into a fishery, of confidence broken and built again. “The more I know the trade, the more I think a marine ranch is a larger industry, one that faces forward. It is one of the hard industries of the time after heavy industry.”

The confidence comes from meeting the weather at sea, and from a path that is now visible: Guangdong’s modern marine ranches are taking shape and moving the right way. The province has the longest mainland coastline in the country, and its sea is about 2.3 times its land. In 2025 marine farming produced 3.8693 million tonnes, of which marine fish were 1.035 million tonnes, close to half the national figure. By 2 August 2026 Guangdong had added 920 gravity cages and 5 truss cages this year, concrete weight behind a new Guangdong at sea and a stronger maritime province.

The machines have kept moving the limit of the water: smart gravity cages near shore, jack-up truss cages, semi-submersible farms such as Penghu and Haiwei No. 2, then the floating, dynamically positioned Zhanjiang Bay No. 1, and the Lingding of the Bay Area, a farming ship. Large equipment keeps pushing Guangdong’s ranches off the coast and into deeper water.

While the farming itself is being made solid, Guangdong is also trying more than one use of the deep water. Zhuhai’s Gesheng No. 1 puts farming together with visits, recreational fishing, and teaching about the sea. Yangjiang’s Hailing No. 1 tries farming beside offshore wind, so the same water does more than one job.

In his mind the ranch still has a further shape: larger machines, and more of the power from clean sources. How much the deep-sea farms will finally return is not settled. He has an answer of his own. “Believe in the force of believing it. Believe that, in time, it will meet what the industry needs.”