Recently, eight ministries jointly issued the country’s first national guidelines in developing deepwater aquaculture to seek new growth further offshore as inland and coastal resources are depleted.

The directive, issued in June, encourages the establishment of large fish farms in deep-sea areas – those more than 20 metres (65 feet) underwater or 10km (6.2 miles) away from the coast – with a breeding volume of at least 10,000 cubic metres.

Some experts say that such farms will become important sources of protein as Beijing pursues dietary diversity to meet growing food demand.

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Why is the Chinese government so concerned about food security?

Why is the Chinese government so concerned about food security?

As the world’s largest exporter of aquatic animal products, the country is aiming to build a full supply chain surrounding the sector, as part of a broad effort to upgrade the fishery industry, according to the directive.

Its owner, Qingdao Conson, a local state-owned conglomerate in Shandong province, has plans to operate a fleet of 50 vessels with varying dimensions and capacities with the same purpose – offshore fish farming, according to an article on its website in May.

China has also put into use a slew of smart, deep-sea mariculture platforms in the past couple of years, including the Haixia 1 and Genghai 1, as well as a large fully submersible fish cage called the Shenlan 1.

Ningde 1, a deep-sea semi-submersible farming platform that’s the largest of its type in the country so far, is said to be ready for operation after being towed to designated waters near Fujian province on June 27, according to the People’s Daily.

With a breeding volume of 65,000 cubic metres, the fully framed platform is expected to produce more than 100 million yuan (US$13.8 million) worth of large yellow croaker annually.

“Humans have developed from hunting to farming on the land. Now we have a dream that we can realise the same transition on the sea,” said Xu Hao, former head of the Fishery Machinery and Instrument Research Institute under the Chinese Academy of Fishery Sciences, which spearheaded the design of the Conson 1.

China needs to move aquaculture farther offshore as demand for high-quality animal protein rises while inland and coastal fishery has little room to grow, explained Xu, who is still active in fishery machinery research and was involved in the development of the vessel before retiring.

“It’s an issue of food security because sea fish provide good-quality protein, which is seeing increasing demand as people’s living standards improve,” he said.

As fishing resources get scarcer after decades of exploitation, farming is the only way to ensure production, but traditional aquaculture is under mounting pressure amid environmental concerns that induced tightened policies, he said.

“For coastal fish farms, our breeding density has been way higher than the global average. So, we have to seek new space for growth,” he said.

Chinese authorities have limited wild catching and have reduced vessel numbers on inland and coastal farms since 2017 amid growing ecological damage, including algal blooms and dead zones. They have issued tough policies including a 10-year fishing ban in all key waters of the Yangtse River from the start of 2021.

Though still ranked at the top globally, inland fishing volume in China dropped by a third from 2017 to 2020, and the number of vessels dropped by 47 per cent from 2013 to 2020, according to a 2022 report on the world’s fisheries by the UN’s Food and Agriculture Organisation.

Unlike deep-sea cages – a popular means of offshore aquaculture – large farming ships allow the fish farms to move around in pursuit of the best temperature for the fish in different seasons. They also allow for a greater degree of mobility, so the vessels can seek shelter in case of typhoons, which have long threatened China’s coastal fishery efforts, Xu said.

Calling them “a future protein-production base on the sea”, he said such floating farms can also better control fish pollutions and limit disease compared with the cage culture, because fish are bred in closed tanks.

“In general, we’re just starting out in distant-water aquaculture, as you can tell from the name of all those floating farms and cages, which often include the number one, meaning the first of the kind. So, we have a lot to improve in the future,” he said.

One major challenge is the high cost of building such vessels. Conson 1, which cost 450 million yuan, had farmed 1,200 tonnes of yellow croaker by its one-year anniversary in May, far from its designed capacity for 3,700 tonnes.

But it’s already a good start, according to Xu. “We expected the payback period to be 10 years, and judging from current circumstances, it might just take eight or nine years,” he said. “The survival rate of fish bred on the ship turns out to be better than expected – we originally aimed for 85 per cent, and it’s actually over 95 per cent.”

Since the ship is designed with a lifespan of more than 30 years, it should be commercially sustainable as long as there’s a steady, long-term production of aquatic animals and a solid supply chain, he added.

Professor Wang Yamin, from the Marine College of Shandong University, Weihai, noted that cost control is highly important for such giant offshore breeding facilities, as the sector is still in the early stages.

“It won’t work if they sell the aquatic products at a low price, and they must control labour costs and other operating costs via technological innovation,” he said.

High prices have also fuelled doubts over whether the growth of offshore aquaculture could help ensure food security.

The economics of operating in exposed offshore environments necessitates focusing on high-market-value fish species that low-income consumers cannot afford, even if significant technological advances are made, according to a research paper published in Nature in 2020.

Market participation is also a concern, as China’s water-farming endeavours are currently supported mostly by state capital.

“At this stage, the market often adopts a wait-and-see attitude. So, there should be more risk assessment and government incentives such as tax cuts and subsidies. Which species to breed also needs to be carefully studied,” Wang said.

Despite promising economic returns, private breeders are mostly reluctant to set foot in distant-water aquaculture, as it’s too risky, according to Lin Ming, a member of the Chinese Academy of Engineering.

A company might lose everything if there’s a strong thunderstorm, and commercial insurance comes with strict rules in compensation claims, he wrote in an article published in the official Journal of Management World in December, citing a meeting with local farmers in Guangdong province in the southern part of China’s 18,000km coastline.

“Many companies call the government ‘a coach on the river bank’ … local governments tend to talk more than they actually invest,” he said.

While some see deepwater mariculture as the next frontier for the sustainable production of highly nutritious fish, others are worried it will only bring pollution farther into the sea.

The Centre for Food Safety, a US non-profit organisation, called offshore aquaculture a “false solution to overfishing”.

“Just like factory farms on land, aquaculture operations are large sources of pollution with little regulation in place to keep their discharge in check,” it said on its website.

Pollutants – including nutrients, various pesticides and other toxic chemicals used to keep the fish healthy and enclosures clean – may escape into the surrounding water. Fuel consumed by boats transporting fish to and from offshore farms also leads to additional emissions.

But Chinese officials and industry watchers have vowed that the environmental impact would be limited.

Wang, the professor, defended the practice by saying that the self-restoring capacity among fish populations is greater in the open sea, and that it would be fine as long as farming activities are kept below certain levels.

“In fact, it’s not necessarily a bad thing to add some nutrients into the distant sea, because it lacks minerals like iodine and phosphorus there. What matters is we do things within the line of environmental capacity,” he said.

The latest government guidelines issued late last month called for healthy and eco-friendly farming, stressing that farmers should determine what and how to breed based on carrying capacity.

They were also ordered to use feed and veterinary medicine approved by state-level government agencies to ensure the safety of the aquatic animals produced.