Pond culture on farms of this kind often includes the culture of many fish species that feed on grasses, legumes, benthic invertebrates, detritus, zooplankton, and phytoplankton. Fish culture has been gaining application in rice fields where a second benefit is control of insect pests, reducing the need to apply toxic pesticides. These integrated systems, although somewhat more complex to manage, have the added advantage of reducing market risks to farmers from potential diseases or price fluctuations that affect any one product. Aquaculture also includes the production of freshwater and marine pearls. Fish monoculture systems have also been developed for a wide range of species that are most often grown on processed feed diets in ponds or raceways and irrigation canals with flowing water.
Fish wastes that enter irrigation canals become a supplementary fertilizer for crops.
The development objectives of the Sustainable Coastal Resources Development Project are to establish integrated coastal zone management plans that include zoning of mariculture, which involves the production of fish in cages and ponds, oysters, hard clams, several species of seaweed, and shrimp in four coastal provinces. Improved shrimp culture methods are being piloted to find methods to control the disease pandemic that devastated the shrimp culture industry in China in the early 1990s. The project also includes a component to provide training in seafood processing techniques and upgrade processing plants. The Southwest Poverty Reduction Project includes an aquaculture component to provide employment for people from desperately impoverished inland areas in Guangxi Autonomous Region while currently supporting the establishment of enterprises involved in the production of domestically consumed and exported seafood products, including fish, shellfish, and pearls. The Freshwater Fisheries Project developed integrated fish farming complexes around eight major Chinese cities, providing a source of fish close to markets.