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 further 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.
This article was first published on SCMP
Source: CNA
