Recently trialled by Shan Dong Min Sheng Group Co and Global Fishery Emporium (Shandong) Industry Development Co, under the supervision of researchers from the Yellow Sea Fisheries Research Institute (YSFRI) and Deakin University – these air-supported structures aim to outperform traditional shrimp greenhouses in terms of growth rates, animal welfare, worker safety, energy efficiency and year-round stability.
Early results suggest they may succeed. And according to project partners, the concept is scalable, commercially available and attracting international interest.
“We think maybe it is the first one in the world,” says Dr Weifang Wang, a researcher at YSFRI in Qingdao. “We have good results now… I think in the near future it will be common in China, maybe in the world.”
From tennis courts to shrimp tanks
The idea for air-domed aquaculture came not from agriculture, but from the sports and construction sectors.
“They use this kind of shelter for gyms and for indoor swimming pools and also for some protection where they have construction with dusty environments,” explains Dr Wang.
Recognising the potential advantages – durability, environmental stability and a clean interior environment – a group of company managers (Qiang Zhang, Zhihong Yuan, Ke Zhang) and researchers at YSFRI (Qingwen Zhang and Weifang Wang) began exploring whether this architecture could be applied to intensive shrimp farming, as an alternative to the greenhouse system that currently accounts for around 30 percent of Chinese shrimp production.
After approaching dome construction specialists and months of technical discussions, the first prototypes were ready, and the first trial started in July.
How the system works
Unlike the greenhouse system, which essentially consists of tanks within polytunnels that rely on rigid frames and plastic covers that degrade after two or three years, the inflatable domes use a double-layer membrane strengthened with polyester fibre, PVC and PVDF. Blowers provide the airflow required to support the structure without the need for solid beams, while also allowing it to withstand extreme conditions – including heavy snow and strong winds, according to Dr Wang.
“The material is really strong,” she says. “It can last for at least 20 or 25 years.”
The membrane effectively insulates the tank within – ensuring that conditions can be regulated much more efficiently than in the greenhouse systems, which are prone to temperature spikes and troughs, depending on the season, the weather and the time of day.
Inside the air domes, by comparison the environment can be regulated through automated fans and AI-enabled monitoring tools via a mobile app, greatly reducing labour requirements, according to Dr Wang.
“You can control the airflow, the temperature, everything… It is only 0.3 or 0.4 kilowatt-hours to run the fans. It’s really cheap,” she explains.
© Dr Weifang Wang
Industry trials
The results of the first trial using the air domes at Global Fishery Emporium (Shandong) Industry Development Co’s farm suggest they have huge potential, although more assessments are required to see how the system fares outside the summer months, as Dr Wang observes.
Taking place for six weeks in the summer, the trial showed that the temperature was more stable in the dome, providing better growing conditions compared to the adjacent greenhouses, with shrimp growth rates in the air dome system 13.41 percent higher.
This is likely to be explained by the superior stability of the temperatures in the dome system. Indeed, according the results compiled by the YSFRI researchers, the daily air temperature fluctuation was upwards of 24 ℃ in the greenhouses, while only a 2.9 ℃ fluctuation was typically observed in the air dome. Meanwhile the greenhouse had a 1.1 ℃ daily fluctuation of water temperature, compared to 0.2 ℃ in the dome.
As Dr Wang explains, in traditional greenhouses, if the outside air temperature is 40 °C – as can be the case in the summer in Shandong – temperatures inside the polytunnels can reach up to 60 °C, making for extremely testing working conditions, as well as causing the water in the tanks to warm up, thereby stressing the shrimp, increasing mortality levels and reducing growth rates.
By contrast, the air domes maintain a much narrower temperature band – both in summer and winter.
“In summer the inside air temperature is around 28 to 30 degrees,” Dr Wang explains. “Righ now, in December it is about 15 degrees inside, even when the outside temperatures are close to zero.”
This reduces the need for energy intensive heating and cooling systems.
Economic impacts
Although the capital cost of setting up an air dome is higher (~2000RMB/m2) than a traditional greenhouse(~1300RMB/m2), Dr Wang emphasises that this will pay for itself fairly swiftly, as the dome’s structure should last ten times longer.
“Conventional shrimp greenhouses generally need their roof plastic membrane replaced every 2-3 years and steel support structures every 5-6 years. These replacements are not only costly but also disrupt farming schedules. By contrast, air-supported structures should last for at least 25 years. The original Beijing Chaoyang Park air-supported gymnasium, for instance, has remained in pristine condition for 35 years now,” she notes.
Worker welfare – and their ability to fulfil their roles as effectively as possible – is another major advantage, according to Dr Wang – as in the summer the lower internal temperatures reduce heat stress.
“The people can stay a long time inside the system and keep their eyes on the animal,” Dr Wang says. “They do not need to work under the sunshine… the environment is better.”
Diversification of species and geographies
Since the successful first trial, the YSFRI researchers have begun exploring the system’s suitability for other species.
“In winter we can do some cold-water fish like salmon and turbot,” says Dr Wang.
They are also testing Japanese shrimp production, as well as polyculture options, including mushroom cultivation in the warm, humid air above the tanks – potentially adding a new dimension to the domes.
“The moisture is high and the temperature is good,” she explains. “We can use the whole space.”
Minsheng Aquaculture Group currently operates two domes at its initial trial site, with a third being built elsewhere in Qingdao. By next year, according to Dr Wang, three locations in the region will be using the system and she fully expects the number to expand, not least as the domes can be retrofitted to existing shrimp farms, as the membranes can be deflated, moved and re-inflated at other locations.
“It can move to anywhere with the same base. That’s a big advantage as you don’t need a new farm,” Dr Wang explains.
What’s more, Global Fishery Emporium (Shandong) Industry Development Co and YSFRI recently secured a Chinese patent, awarded on 1 December.
The concept is also gaining attention outside Shandong. “The company has some business with Hubei province,” Dr Wang says. “They will build up the new system.”
Interest is not limited to China. “Last month some visitors from Saudi Arabia and Canada… visited our system,” Dr Wang notes. “They are really interested and want to have it in their countries.”
© Dr Weifang Wang
A cross-border collaboration
The project has also benefited from international scientific cooperation. Dr Michael Salini, formerly of Deakin University in Australia and now with the Pacific Community (SPC), began collaborating with Dr Wang after she spent a year at the NuSea [MS1] nutrition and seafood laboratory, in Geelong.
“From that point we entered into a collaborative agreement between the institutions,” Dr Salini explains. “We sent one of my PhD students, Chethana Tissera, to work with Weifang in China, and she spent some time in this inflatable system. It’s been a good collaboration.”
He believes the transnational approach strengthens both research relevance and scientific impact.
“In terms of progressing the research collaborations between Australia and China, I think it’s a fantastic opportunity,” Dr Salini reflects.
Challenges and future outlook
Despite the huge potential of the system barriers to adoption remain – not least the comparatively high level of upfront investment required.
“It is better suited to big companies, not independent farmers,” Dr Wang says.
However, she adds that local and provincial governments are supporting early deployment, and interest from buyers abroad may accelerate economies of scale.
As a result, Dr Wang anticipates – and fully supports – the rapid growth of air dome aquaculture.
“In two or three years it will be in many areas,” she predicts.
“We want to make progress for this system… We want to develop it in the world and give a big progress in aquaculture. A really good one – especially for the animals and for the working people,” she adds.
© Dr Weifang Wang
