Aquaponics is the combination of fish production (aquaculture) with the soil-less production of plants (hydroponics). It operates within a closed-loop system and utilises minimal resources. Fish feed provides most of the nutrients required for healthy plant growth. These nutrients, excreted directly by the fish, or generated by the microbial breakdown of organic wastes, are absorbed by growing plants. Nutrient removal by the plants in turn treats the water by removing nitrogenous compounds, such as dissolved ammonia, which are harmful to fish. Water is then re-oxygenated and returned to the fish tanks. Fresh, potable water is added to the system, as necessary to replace evaporative loss.
The combined growing of fish and greenhouse crops has been tested successfully in Oman. In 2010 a report was published by a group of scientists from Sultan Qaboos University and the Ministry of Agriculture and Fisheries for the combined production of tomatoes and red hybrid tilapia. The trials were conducted at the Rumais Agricultural Station. This research is now being extended with support from the Agricultural and Fisheries Development Fund, which is operated by the Ministry of Agriculture and Fisheries. New varieties of salad crops and various fish species will be grown in a climate-controlled greenhouse and the results will be made available to growers. The unit in Rumais will also function as a demonstration facility. The main research objectives are to examine the production and uptake of minerals and their effects on the growth of plant crops, fish and plant crop productivity, the potential costs/benefits for farmers and quality and safety issues.
