Aquaculture is the production of fish, either in containment nets or in a recirculating system. Aquaponics is the combination of fish culture and hydroponic vegetable production.
Aquaponics systems are more economically and environmentally feasible than typical recirculating aquaculture systems. By growing a secondary crop, such as vegetables or herbs, costs associated with construction, operation and maintenance can be distributed across both fish and vegetable production and make both more viable in cost return. Plants/vegetables via the nitrogen cycle help break down ammonia and nitrates and remove them from the culture water. This is mutually beneficial for both plant propagation and fish culture.
It is expensive and relatively difficult to filter, and sanitize culture water from fish propagation before disposal. When water is introduced to the environment before concentrated wastes are removed it can cause huge environmental impacts. Current aquaculture can devastate the surrounding environment, especially in open water systems that have no filtration or waste removal. In these systems waste disposal is left to the surrounding environment. Unable to handle such concentrated waste the ocean floor becomes covered in fish bi-product suffocating the floor life. In other systems cleaning and filtering fish effluent is costly and difficult, typically what is left is then let into the municipal waste stream, which then the water is left to be handled by the sewage treatment systems. This cost is not figured into aquaculture systems but this is also a problem with current aquaculture.
In aquaponics the fish effluent and the nutrients left by leftover decomposing fish food can be utilized by plants and other aquatic life as food. Rather than just throwing away these nutrients food can be produced. Creating a closed loop is not only economically more viable but is also more environmentally sustainable.
Water use is also a concern. In typical aquaculture water has to be moved out of the system consistently to maintain proper PH and ammonia levels. To high of either in fish culture water is toxic. This water not only has to be cleaned but replaced. This cost of water can be expensive especially in arid areas as well as have drastic environmental impacts. Aquaponics has a much lower water exchange rate typically 5%. This is due mostly to evaporation and plant uptake. This allows aquaponics to be more viable where water shortage is a problem. Aquaponics also consumes much less water than typical soil farming, about 90% less. Most irrigation water in farming is lost to the soil and into the water table than used by the plants.
Aquaponics could be used in areas where normal farming practices are impossible due to contaminated or otherwise unusable soil, as well as in areas with water scarcity. Aquaponics systems could also be utilized in areas after natural disasters, such as Hati, as part of relief efforts. Food production could be introduced on site rather than continuously imported. Teaching locals how to operate these systems could provide new jobs in a damaged economy.
Looking at these factors aquaponics is a much more viable option than aquaculture alone. Economically aquaponics produces much more than aquaculture without a lot of extra costs involved. The plants and bacteria take care of a lot of the waste treatment actually alleviating a lot of costs associated with water purification and eliminates the need for extra bio filters. From the environmental impact perspective aquaculture is not a viable option; in aquaponics the manmade ecosystem can handle the toxicity and turn it into food rather than a burden on the environment. Aquaponics could be a viable, profitable, sustainably sound addition to our food production system.
