Off the coast of Zhejiang province, an unusual vessel plies the East China Sea. It could be mistaken for a cargo ship, but there are no containers on its deck. Its track is strange: instead of running between sequential ports of call, it bounces between points at sea for months at a time. However, its movements are anything but random.
The ship’s transponder identifies it as the Guoxin 2-1. It is moving with the tidal currents, seeking water at the right temperature for the cargo in its hull: vast tanks of large yellow croaker, raised from fry in the ship’s underbelly and destined for markets and restaurants from Shanghai to Suzhou.
Farther up the coast, off southern Shandong province, a crew in a small offshore boat works to sink a concrete block. Seagrass seeds have been tucked into nooks along its sides. These men are employed by a marine ranching initiative at Rongcheng, which is assembling artificial but productive coastal reefs from the seafloor up.
Some 200 kilometers northwest of Rongcheng, in the stretch of the Yellow Sea where Chinese and South Korean exclusive economic zone claims overlap, a South Korean research vessel and its coast guard escort approach a partly submerged steel cage as tall as a twenty-story building, along with a converted rig complete with a helipad. Two Chinese coast guard cutters and a rigid inflatable boat—ostensibly civilian, though the men aboard brandish knives—block their path. They are shielding the Deep Blue 2, a salmon farm China has parked in contested waters.
These are all stories about the same thing: aquaculture—the deliberate raising and farming of aquatic organisms—and its explosive growth in China. The Guoxin 2-1, the Rongcheng marine ranch, and the Deep Blue 2 are the products of a decades-long effort by the Chinese state and a legion of private entrepreneurs to build the world’s largest aquaculture industry—and, in doing so, to begin cultivating and terraforming the open ocean. A new frontier is opening, and its implications are as vast as the water it covers.
Aquatic Origins
Chinese aquaculture began in freshwater. China was among the first regions in the world to take up the practice, with farmers raising and harvesting fish in managed ponds by around 2500 BC. Writings from 2000 BC ascribed to Da Yu, the traditional founder of the Xia dynasty, describe picking “seeds”—common carp spawn—to “plant” in small ponds, along with laws specifying exactly when fish could be harvested. State involvement is nearly as old as the industry itself.
Modern aquaculture—artificial reproduction, hatchery-based farming, selective breeding—was developed mainly in Europe, but adopted in China toward the end of the twentieth century during the Reform and Opening Up period. China is now by far the largest producer of farmed aquatic animals in the world, accounting for roughly 55 percent of global output.
As of 2023, close to 60 percent of that output came from freshwater rather than marine environments. In recent years, the Chinese Communist Party (CCP) has pushed aquaculture investment into poorer interior regions like Xinjiang. More than just a form of economic stimulus, inland aquaculture is a source of domestic food security and, increasingly, of exports.
The caviar market shows what Chinese industry can do even to a gated, high-margin luxury good. After overfishing gutted the conventional, wild supply of sturgeon in Siberia during the mid-2000s, Chinese entrepreneurs, scientists, and fortune-seekers set their sights on the industry. Dozens of aquaculture operations sprang up around colder inland lakes to raise sturgeon and harvest their valuable eggs. Farmed sturgeon production grew roughly ninefold between 2003 and 2017, and Chinese cultured caviar output climbed from 0.7 to 135 metric tons between 2006 and 2018. Wholesale prices fell by roughly 50 percent between 2012 and 2018, turning caviar into an accessible luxury, while Chinese brands like Kaluga Queen became some of the world’s largest.
The remaining 40 percent of Chinese aquaculture occurs in marine environments: nearshore enclosure farms, net pens, and specialized aquaculture vessels. Particularly of note amongst these are China’s immense near-shore oyster rope-and-raft systems. The PRC accounts for nearly 85 percent of global oyster production, but they are more than just another protein source. Each oyster is capable of filtering 50 gallons of water a day, helping to remove pollutants from Chinese coastal waters. Partnerships in the Chinese Greater Bay Area–Hong Kong, Guangzhou, Shenzhen, and the surrounding cities–are working to restore the region’s old oyster beds. Recent measures by the party-state to protect and expand coastal fisheries have set off a boom in a related practice off Fujian, Shandong, and several other coastal provinces: sea ranching.
Sea ranches are built by seeding the seafloor with seagrass and kelp, sinking man-made reef structures, and stocking bottom-dwelling species such as the Dongke No. 1 sea cucumber, bred to grow faster and to survive the warming summer water off Hebei. These farms are designed like natural reefs, incorporating multiple trophic layers to act as multi-product farms and ranches.
As in other Chinese industries, sea ranching has generated a supporting technology stack: automated feeding systems, environmental monitoring networks, unmanned vessels of various stripes, and underwater inspection drones, all deployed so that coastal managers can watch a crop grow in the shallows. The goal is to turn the coastline into a set of established, controlled, production-oriented ranches, and to put the seafloor in service to man.
Modern Marvels
Moving away from the coastline into deeper waters, one comes across newer, larger, and more technologically advanced aquaculture facilities. Submersible cage facilities like the Deep Blue 1 & Deep Blue 2 in the Yellow Sea, or the Xinhuan No. 1 off the coast of Hainan, raise tons of fish in semi-permanent offshore installation bases. These structures can lower and raise their cages to accommodate different water temperatures, weather, and tidal conditions at different depths—increasing the quality and survival rate of farmed fish.
Of all the forms of advanced deep-sea aquaculture, it is the enclosed ship that most captures the public imagination. The Guoxin line is a series of three purpose-built vessels with onboard rearing tanks, specialized pumping systems, and circular “raceways” that serve as exercise zones and transition areas for juvenile fish.
Like much of the Chinese aquaculture stack, the Guoxin ships were designed around automation to cut labor costs and raise efficiency. The enclosed nature and internal structure of the ships minimize the need for exhaustive manual moving of the fish. From an engineering standpoint, an enclosed hull also offers another advantage: it gives the operator far more control over the water the fish live in. More importantly, it can move—away from storms, toward better temperatures, and into port once the fish reach market weight.
The three ships have a combined expected output of over 10,000 tons of fish a year. Most of that is premium stock, such as salmon and large yellow croaker, though the operator Qingdao Conson Development Group plans to add more species. Survival rates aboard the first-generation vessel have exceeded 90 percent, with rearing cycles roughly three-fourths that of fish in conventional cages. Alongside vessels like the Suhai-1, an enclosed salmon ship that handles everything from breeding to processing onboard, the Guoxin line represents the current ceiling of Chinese aquaculture.
How has China achieved such immense strides in aquaculture? Start with the Chinese tertiary education system’s throughput of STEM graduates. Their sheer numbers depress wages and ensure that some highly capable workers take up unglamorous fields like fish farming. The same abundance feeds Chinese shipbuilding. China produces the concrete and steel that maritime infrastructure requires, and its yards—which turn out over 1,000 merchant vessels a year—accumulate skilled labor that iterates on design with every new hull. Any country hoping to compete in the ecological niches that China’s shipbuilding industry has filled must begin with an equivalent industrial eagerness.
With mass famine still in living memory, the party-state has a strategic interest in food sovereignty; China holds a sixth of the world’s population on less than a tenth of its arable land. This seems to be a significant driver of the Chinese state’s interest in aquaculture. Qingdao Conson, the operator of the Guoxin line, is a state-owned enterprise. It was the state that launched the Blue Granary Project that designated aquaculture a national priority in 2018. Continual state interest and investment has played a significant role in the industry’s expansion.
The coastal Chinese love of seafood could also play a significant role. This cultural quirk induces an immense quantity of demand; aquaculture is inherently a safer bet if consumer appetites for seafood are relentless, unlike in the West where they are far more fickle and prone to fluctuation. On top of this, while Western leaders have often promoted soft-handed social engineering designed to make common diets more sustainable—for example, through the adoption of plant milks or manufactured meat derivatives—the Chinese state has no problem with working to fill the nigh-endless Chinese appetite for seafood. Indeed, the state’s pursuit of expanded marine protein consumption is a perfect example of the way “engineering states” like China pursue legitimacy by meeting popular material desires.
The Deep Blue 2 incident illustrates the broader geopolitical advantages and implications of the Chinese aquaculture program. South Korean authorities claimed the right to inspect the structure under the 2001 Korea-China Fisheries Agreement, which established the Provisional Measures Zone within which Deep Blue 2 is stationed; when the Korean Coast Guard tried to investigate in early 2025, Chinese civilian and coast guard vessels blocked them. Seoul has protested that the installation encroaches on its maritime rights, violates the 2001 agreement, and attempts to illegally advance Chinese claims in the Yellow Sea. Like China’s controversial man-made islands in the South China Sea, semi-permanent floating aquaculture strongholds can be used to assert claims over ocean territory or to host signals intelligence.
Chinese investment and research in African and South American aquaculture projects form another vector of influence, and promise financial returns as China exports its world-class aquaculture stack. Chinese ventures like the Kajjansi Aquaculture Research and Development Centre in Uganda, or Joyvio’s acquisition of the Chilean firm Australis Seafoods, mark the emergence of a marine economic diplomacy.
There is a darker side to this maritime projection. Chinese distant-water fleets have produced one international scandal after another: large numbers of boats converge on a fishery—often just outside a country’s exclusive economic zone, sometimes illegally inside it—strip it with trawls and dredges, and move on once the fishery is exhausted. Not even the waters around the Galapagos have been spared. The ecological promise of some domestic aquaculture programs does not excuse the PRC’s role in destroying fisheries elsewhere.
The Call of The Deep
Like all ambitious projects of modernity, Chinese industrialization bears the two visages of Janus. The care now lavished on Chinese coasts and waterways was made necessary by the ecological damage of earlier phases of modernization. Efforts to restore fisheries, too, are necessary because of previous overfishing. Perhaps these earlier sacrifices were to the ultimate benefit of Chinese development, but the state’s willingness to now pursue ecological restoration at home while acting callously abroad displays a profoundly divergent worldview from Western universalist-multilateral ecology. “Environmentalism in one country” is different. It is a story of restoration, not conservation, and new Promethean heights rather than managed decline.
If sustainability is to be pursued state-by-state, as the recent decline of multilateral nation-state cooperation suggests, then it is no surprise that each country shall tend to its own garden. But tending to a garden and conscientiously exploiting it are the same act, and it is this mindset of exploitation that makes the Chinese vision of aquaculture possible. The distant-water fleets and the oyster rafts come from the same attitude of industrializing the ocean, maximizing its yield. Industrialized fish farming promises a future in which wild stocks cease to matter, in which we can produce as much fish as we care to eat without drawing down what remains in the sea. Under present conditions, such scenarios remain nothing more than a flight of fancy, but the scale and pace of Chinese advancements in aquaculture hold promise as a futurist vision simultaneously grounded in the here-and-now.
Man has always aimed to achieve mastery over his environment, so that he may eliminate the scarcity that has dominated his existence. Now that terra firma is all but tamed, his eyes are turning towards newer, further, more dangerous frontiers to master. Yet more men have passed into the reaches of space than have been to the extreme depths of the ocean—why should we seek to explore and master only the void above us when the ones below are just as compelling, lucrative, and stimulating to the imagination?