Aquaculture efficiently farms fish species while hydroponics ensures controlled use of water and nutrients in plant cultivation.
In aquaponics, water saturated with nutrient-rich fish excreta from aquaculture tanks is used in plant breeding before being circulated back.
The technology produces fish and vegetables without the need for costly fertilisers, says Ram Bhujel, director of the World Aquaculture Society, a not-for-profit global network of aquaculture professionals affiliated to the Asian Institute of Technology, Thailand.
Aquaponics research and development has advanced over the last three decades, with several thousand household-level systems installed in the United States and Australia.
The Rotary Club of Patan, Nepal, and the Rotary Club of Brussels – with funding from Rotary International and technical support from the social enterprise, Aquaponics UK – already run an aquaponics unit that supports a rehabilitation home for 20 children and mothers affected by HIV/AIDS.
The system, operating since August, cost US$ 10,000 with annual production estimated to be worth US$ 8,000.
In 2013, the Nepal government will survey operating units in the country and also consider setting up an experimental site, Tek Bahadur Gurung, director of livestock and fisheries research at the Nepal Agricultural Research Council, told SciDev.Net.
In Nepal's mid-hills, "most water sources are 300 metres below human settlements, which makes access laborious," said Gurung. Reducing water demand through aquaponics could ease this.
The technology is suited to urban areas where land is scarce, said Bhujel. But, due to high capital investment, it "has not been a profitable business for lower income people," he said.
A major challenge in Nepal, which faces long power cuts during winter, is the cost of energy backup to keep the system running continuously, says Bill Ashwell, director of the Hope Bioponic Foods Company, which runs a research unit in Kathmandu.
There is potential for community-run systems that use local fish, and the flow from rainwater and streams to save on energy needed for recirculation, Ashwell told SciDev.Net.
The technology holds promise for rural communities, "especially for densely-populated countries like Bangladesh, Nepal and Vietnam, where farmers have limited land to provide their families food with protein, minerals and vitamins," Bhujel said.