The U.S. Soybean Export Council has reported installations of the in-pond raceway system (IPRS) for aquaculture have soared in China, with 7,000 installations since the system was introduced to the country’s aquaculture sector in 2013.
Promoted by the USSEC as a way to increase fish production while reducing environmental impact, its adoption accelerated after the system was embraced by Chinese government agencies seeking to reduce aquaculture-related pollution.
The first IPRS contained three cells and used to culture grass carp for demonstration purposes, recalled Jim Zhang, head of aquaculture programs at the USSEC’s China office.
“The demo was harvested after the fish were in the water for seven months,” he said. “The results of the demonstration, in terms of fish growth, yield, profit, drug/chemical use, and environment impact were so much better than traditional [methods of] production here in China [that] it was immediately accepted by the industry and supported by the government.”
Initial success and government backing meant many fish farmers, particularly in the Yangtze Delta area – encompassing Shanghai and surrounding provinces Anhui, Jiangsu, and Zhejiang – began construction of IPRS cells, Zhang told SeafoodSource. Today, over half of the 7,000 IPRS cells in China are based in the Yangtze River Delta.
IPRS systems concentrate fed fish in cells or “raceways” within a pond, providing them with constant water circulation to maintain optimal water quality and to improve feed management. IPRS systems sizes vary from three cells per unit to 54 cells per unit. More than 20 aquatic species have been successfully cultured in the system, according to Zhang, with the bulk of that cultivation comprised of grass carp, yellow catfish, largemouth bass, tilapia, and pangasius.
“Most of the farmers are very satisfied with the production performance of the IPRS,” Zhang said. “The main reasons for farmers claiming the IPRS doesn’t get them any better results are over-building the cells in a certain size of water space, as some farmers are too ‘greedy,’” Zhang said. “[Sometimes] not enough aerators are installed in the open water outside the cells to form up a ‘river’ flow to get the unused nutrients decomposed for cleaning the water. Over-stocking or under-stocking of facilities similarly leads to under-performance.”
Photo courtesy of U.S. Soybean Export Council