The Recirculating Aquaculture System (RAS) represents a sustainable and high-efficiency model for aquaculture in China’s aquatic production. In China, RAS technology has undergone four development stages since its introduction in 1985 : the technology importation phase (1985–1998), the exploratory development phase (1999–2006), the system integration phase (2007–2011), and the rapid growth phase (2012–present). With the continuous expansion of market demand, investments in water treatment technology R&D and theoretical RAS research have also increased significantly . At present, RAS technology has been successfully applied to the cultivation of several high-economic value aquatic species in China . By 2012, over 110 nationwide enterprises had established RAS infrastructure exceeding a total capacity of 1.4 million cubic meters (Fig. 1) . Consequently, R&D in related engineering technology have also become a strategic priority for China’s socioeconomic development.
In China, RAS systems can be categorized into three typical models based on production scale: automated precision systems for large-scale farms, semi-automated modular systems for medium-sized enterprises, and cost-effective basic systems for small-scale producers. While China has already achieved domestic production of core RAS equipments and reached internationally advanced levels in breeding technologies for certain marine species, in recent times, researchers are actively working to resolve key challenges with RAS, such as reducing production cost, technical optimization, and disease prevention.
Under the combined effects of policy support, improved environmental regulations, and market demand, currently, China’s RAS industry exhibits following developmental trends: transformation of technical systems toward high-tech, large-scale, and industrialized models; partial RAS units achieving international standards; progressive refinement of industry technical standards and manufacturing management systems; projected cultivation area exceeding 7 million square meters by 2027; industrial-scale application of RAS in fry production. Overall, through continuous technological innovation and industrial upgrading, China’s RAS sector is poised to attain global competitiveness and make substantial contributions to worldwide sustainable aquaculture development.