The combination of aquaculture and hydroponics results in fish water being passed through the plant bedding material. This makes aquaponics a ‘closed system’ and one where water will not be wasted.
In traditional aquaculture and hydroponics systems water is constantly replaced. This practice is ultimately unsustainable. In a world of growing water shortages, water wastage is a major environmental and social issue that needs immediate critical attention.
Aquaponics has been around for a long, long time. The ancient Aztecs had agricultural islands which were known as ‘chinampas’. On these islands plants were raised on stationary (and sometimes movable) islands in lake shallows. Waste materials dredged from the Chinampa canals and surrounding cities were used to manually irrigate the plants.
In South China and Thailand, rice was (and still is) cultivated and farmed in paddy fields in combination with fish. This ‘polycultural’ type of farming is about using multiple crops in the same space, much in the same way as a natural ecosystem. These types of ecosystem farming practices existed in many Asian countries and used fish such as the oriental loach, swamp eel, common and crucian carp, as well as pond snails in the paddies.
The rice farmers in Southern China still use these kinds of eco-friendly systems to grow rice and fish today. According to research from Zhejiang University in China, the rice fish system requires 68% less pesticide use and 24% less chemical fertilizer than the regular monoculture rice system.