The costliest factors in aquaculture are high-quality feeds, filtration systems and the investment needed for ample space to grow target species. With continuously rising production costs, farmers and researchers are looking for alternative ways to produce more seafood while utilising fewer resources.
Originally conceived as a natural way to clean water, biofloc systems are becoming increasingly popular as a low-cost means of cleaning the culture water of fish and shrimp farms while simultaneously providing an additional source of feed. Best of all, implementing biofloc principles requires little investment – as only sunlight, a carbohydrate source and plenty of aeration are needed.
Biofloc Fish Farming systems bank on photosynthesis to convert uneaten feeds, faeces and excess nutrients into food. While breaking down toxic ammonia and nitrates, both primary-producing autotrophic and heterotrophic bacteria multiply to attract an ever-growing host of organisms – including diatoms, fungi, algae, protozoans and various types of plankton. Loosely bound by bacterial mucous, most of these floating clumps or “flocs” are microscopic. Larger aggregations can be seen by the human eye, resembling brown or green sludge. Though not too appealing for humans, this is a scrumptious smorgasbord for fish and shrimp.
By recycling proteins, biofloc systems overcome concerns associated with high animal-stocking densities and low filtration capacity – like decreased water quality and increased risk of disease outbreaks. In traditional farming systems, only about 25 percent of the protein content of feeds are actually utilised by farmed species. By converting ammonium into microbial proteins that can be consumed by filter feeders, biofloc systems are able to double this figure, saving farmers big money. Biofloc systems reduce the spread and effectiveness of pathogens while simultaneously improving fish health through better water quality and bolstered feed availability. As such, biofloc systems can give us a natural way of producing more seafood sustainably, while concurrently improving farm profitability.
