1 EXECUTIVE SUMMARY 1. The report is based on a thorough review of the scientific literature on aquaponics; discussions with specialist aquaponics researchers and producers; analysis of web resources; an online survey of aquaponics initiatives; attendance at a technical consultation on aquaponics at Rarotonga (Cook Islands) organised by the Secretariat of the Pacific Community; and visits to operating aquaponics initiatives.
2. Aquaponics may be regarded as the integration of two relatively well established production technologies: recirculating aquaculture systems in which fish tank effluent is treated and cleaned before being returned to the fish tank; and hydroponic (or soil-less) nutrient solution based horticulture systems. Bringing the two together allows for the plants to utilize the waste nutrients produced by the fish. In principle it is very similar to a freshwater aquarium in which both plants and fish are grown.
3. Aquaponic systems come in a wide variety of forms, ranging from a simple fish tank set below a gravel filled vegetable bed (which also serves as a simple biofilter), with water from the fish tank pumped up and through the grow bed; to highly sophisticated systems incorporating multiple fish tanks, solid waste removal systems, aerobic and anaerobic biofilters, intensive aeration systems for both plants and fish, and sophisticated water quality monitoring and backup (i.e. fail-safe) systems.
4. Aquaponic systems are dominated by vegetable production in terms of area and quantity of product. This is biologically determined by the quantity of plant production required to absorb the waste nutrients generated by fish. In some of the more commercial systems, the fish are simply regarded as a source of high quality organic nutrients, rather than as marketable product in their own right.
5. The technology of aquaponics has been with us since the 1960’s, but interest has increased rapidly in recent years due to widespread interest in local sustainable food initiatives, and awareness amongst development agencies that aquaponics may allow for the production of both vegetables and fish in water-deficient or soil-deficient zones. The technology is also of particular interest to aquaculture scientists as a possible tool for the reduction/remediation of nutrient waste from intensive aquaculture production. Scientists, educators and community or development NGOs are, furthermore, particularly attracted to a technology that represents a small managed “ecosystem” comprising a highly productive balance of fish, bacteria and plants.