Project Statement

In recent decades, the market demand for aquaculture has driven the transformation of the traditional dike-pond system in Pearl River Delta, China from multifunctional aquaculture systems to intensive system of monoculture. This has led to decreased biodiversity and landscape heterogeneity, resulting in landscape simplification and ultimately increasing livelihood risks for farmers.

To address the economic and environmental unsustainability caused by landscape simplification, the main goal is to establish a circular economy at the community level. It includes increasing the land use diversity, rebuilding material circulation system, while maintaining the current production levels, thereby enhancing the overall value of ecosystem services.

Project Narrative

Project Context

Aquaculture landscapes are expanding due to the demand for fish products, especially in Asia. In the past decades, multifunctional aquaculture systems have been replaced by the monoculture modes to increase yields. As a result, landscape simplification has been the main issue threating the sustainable development of the traditional aquaculture areas.

Project Issues

Ruxi Village in the Pearl River Deltain South China, with an area of 9.6 km², was once famous for its integrated dike-pond systems, has undergone landscape simplification. Firstly, extensive farmlands and dikes have been converted into water bodies, reducing the proportion of arable dikes and altering the original landscape patterns. Secondly, crop cultivation activities on the dikes have been abandoned, causing the decline in the landscape elements.

We believe the key site issue is the disruption of the previous cycle model, leading to a linear production model characterized by high input, unstable yields, inadequate waste utilization, and water eutrophication. The intensive aquaculture system relies heavily on feed and drugs, which generates about 5 million tons of wastewater and 680,000 m³ of pond mud annually. Due to the lack of community regulation, pond mud accumulates on the dikes without decomposition, and wastewater discharge deteriorates the water quality of public rivers, resulting in water eutrophication and sediment accumulation, increasing the risk of fish diseases, which ultimately poses a growing livelihood risk for farmers.

Design Strategies

The core goal of this project is to build circular economy at the community level through 4 stages, namely input, production, use, and post-use. It is realized by establishing 3 diverse areas and constructing their connections through material flow with an assessment of the site’s production suitability based on 4 key environmental factors.

Intensive Aquaculture Area: The most suitable area for aquaculture (382 hectares) is reserved for intensive fish farming. By improving the production environment (e.g. infrastructure and water quality) and establishing community management regulations (e.g. scientific feeding methods and pond management), the quality of aquaculture can be ensured, thereby maintaining farmers' livelihoods.

Arable cultivation Area: Abandoned farmland within the community (115.8 hectares) are planned for agricultural planting to enrich the community livelihoods. By planting flowers, fruits and vegetables that can be used for fish feed, the nutrients in the pond mud can be consumed. Moreover, the organs of these plants can be processed to partially replace the proteins and carbohydrates in the artificial feed, reducing the overall input of the system.

Artificial Wetland Area: An area of 71.8 hectares, equivalent to 1/6 of the site, unsuitable for aquaculture, is converted into artificial wetlands. Within controllable economic costs, 6 wetlands are planned based on pond drainage needs and water flow direction, with a purification cycle of 7 days, providing fresh water for the system. The wetlands can provide natural habitats for insects, fish, and birds, enhancing the ecological service value of the ecosystem.

Project Benefits

By establishing a community-based circulation system, the program not only increases farmers' incomes, but also significantly enhance the ecological service value in the traditional dike-pond landscape, thus achieving the goal of a circular economy.