The first known use of aquaponics was in Sixth Century China. Farmers at that time kept ducks in cages with partially open floors. These cages were placed above a pond of finfish. The farmers kept catfish in a separate pond into which drained water from the finfish pond. This arrangement automatically fed finfish from duck droppings and fed catfish from the waste of the finfish. Leftover "food" was distributed to rice fields to provide nutrients for these crops.
Peru's Inca's also practiced a form of aquaponics that operated similarly to the Chinese. But rather than using duck to feed fish, Inca farmers used geese. Their aquaponics system supplied food to more people in the Peruvian highlands than any other method of farming, even including present day agriculture.
Current Aquaponics Objectives
In present day agriculture, the purpose of using aquaponics is to preserve water and to reduce polluting lakes, rivers, and streams that receive chemicals and fertilizers. Current aquaponics methods helps reduce water pollution by recycling water and and wastes, and making recycled water available for other uses.
In today's aquaponic systems, fish and plants are grown in special above-ground environments where growers add heat and light. These systems reduce the need for pesticides and herbicides.