Decarbonizing Aquatic Food Production Through Circular Bioeconomy of Aquaponic Systems

Aquaponics is rapidly emerging as a sustainable aquatic food production system that addresses the many concerns associated with aquaculture, especially those related to environmental footprint. Depending on certain factors aquaponics can be graded as low-carbon, carbon neutral or carbon negative method. In aquaponics, water discharged from the fish production chamber feeds the plants and plants absorb the waste and filter the water which returns to the fish tank. This characterizes the circular bioeconomy of the system. Nitrifying bacteria play a vital role in biological filtration by way of transforming toxic waste into a form usable by plants. Grow-bed media filters are central in the nitrogen cycle in a closed-loop system. That is highly biodynamic, with the variables that tend to change the balance among the various components of the whole system. Optimization of biological processes allows the system-level changes within a specified range but because of self-renewal inherent in the operations, the system shows no overall change. Modulating the grow-bed media is the essential feature of this balancing mechanism. It includes selection of media filters according to their physical attributes. This paper seeks to advance the current understanding of the most critical aspects of aquaponics that could help in developing system designs for a truly aquatic carbon farming.