Biofloc technology (BFT) is gaining popularity as an aquaculture strategy. The technology is applied to a variety of system types and is currently most commonly used for the culture of shrimp and tilapia, although other taxa such as catfish are being explored. The defining features of BFT systems include high animal stocking densities and restricted water exchange. As a result of high animal stocking densities a large amount of nutrients enters the water from feeds and because little water is exchanged those nutrients accumulate in the systems, contributing to the proliferation of a community of microscopic organisms. Organisms typically include bacteria, fungi, algae, protists, and zooplankton.
A substantial portion of these organisms are contained on and within biofloc particles which can reach a diameter of up to a few mm, and are primarily made up of microorganisms, feces, detritus, and exopolymeric substances. The microorganisms in BFT systems are responsible for detoxifying waste products; primarily nutrients excreted by culture animals, and have been shown to provide a repackaging of those nutrients that is available for consumption by animals, thereby lowering feed costs.
Utilizing BFT results in high levels of biosecurity, low feed conversion ratios, intensive animal culture, indoor operation potential, and the potential for the inland production of marine species. Research groups and industry stakeholders around the world are exploring a wide range of issues related to BFT. Some of these topics include unique diet formulations, the inclusion of biofloc material in diets, exclusion of pathogens by BFT microbes, energy input reduction, oxygenation strategies, using novel species in BFT systems, and water quality dynamics and impacts on animal performance. Research has shown that in order to appropriately manage BFT systems attention must be devoted to the management of the microbial communities on which the systems rely.
Every year interested practitioners, scientists, and others come together at various aquaculture conferences to present and discuss the most recent findings related to BFT. Look for a Biofloc Session at the next World Aquaculture Society (WAS) or Aquacultural Engineering Society (AES) meeting; anyone with any interest in BFT is encouraged to attend and the sessions are filled with discussions about current BFT issues. A Biofloc Steering Committee made up of members from around the world strives to ensure that the most relevant issues are addressed and the group welcomes feedback and questions from anyone interested in BFT.