Biofloc Production Systems for Aquaculture

Biofloc systems were developed to improve environmental control over production. In places where water is scarce or land is expensive, more intensive forms of aquaculture must be practiced for cost-effective production. There are strong economic incentives for an aquaculture business to be more efficient with production inputs, especially the most costly (feed) and most limiting (water or land). High-density rearing of fish typically requires some waste treatment infrastructure. At its core, biofloc is a waste treatment system. Biofloc systems were also developed to prevent the introduction of disease to a farm from incoming water. In the past, standard operation of shrimp ponds included water exchange (typically 10 percent per day) as a method to control water quality. In estuarine areas with many shrimp farms practicing water exchange, disease would spread among farms. Reducing water exchange is an obvious strategy for improving farm biosecurity. Shrimp farming began moving toward more closed and intensive production where waste treatment is more internalized. Biofloc systems use a counter-intuitive approach— allow or encourage solids and the associated microbial community to accumulate in water. As long as there is sufficient mixing and aeration to maintain an active floc in suspension, water quality can be controlled. Managing biofloc systems is not as straightforward as that, however, and some degree of technical sophistication is required for the system to be fully functional and most productive. Composition and nutritional value of bioflocs