Biofloc technology (BFT) is a system of aquaculture that uses "microbial biotechnology to increase the efficacy and utilization of fish feeds, where toxic materials such as nitrogen components are treated and converted to a useful product, like a protein for use as supplementary feeds to the fish and crustaceans."

In high nitrogen environments, the beneficial heterotrophic bacteria are typically limited by carbon levels. Therefore, adding a readily available source of carbon allows the bacteria to simultaneously take up a greater portion of nitrogen (contributing to better water quality) and generate biomass that then serves as food for the cultured animals. The species of fish and crustaceans must be carefully chosen in order for the BFT system to realize its full potential.

The biofloc technology is a topic relevant to the UPSC context under General Studies Paper II and General Studies Paper III. It is a basic topic for aspirants to understand the dynamic aspect of biofloc technology. Biofloc technology is an important topic for UPSC Civil Services because it highlights the biofloc technology, which are frequently discussed in the exam. Join UPSC Coaching today to boost your preparation. 

Download the Daily Current Affairs for UPSC here!

Latest Update

Get Free Materials for UPSC Preparation by Testbook!

Biofloc technology is defined as 'the use of aggregates of bacteria, algae, or protozoa, held together in a matrix along with particulate organic matter for the purpose of improving water quality, waste treatment and disease prevention in intensive aquaculture systems'. In other words, bio floc is a symbiotic process that includes confined aquatic animals, heterotrophic bacteria and other microbial species in the water. Consumption of bioflocs also provides nutritional value to cultured marine species. This means that BT can be an ideal option for sustainable and environmentally friendly aquaculture (Crab et al., 2009, 2012). Generally speaking, BT can lead to many benefits, including the following:

• Prevention of the introduction of disease to fish farms from incoming water.
• Improvement of biosecurity.
• Improvement of feed conversion.
• Improvement of water quality.
• Improvement of water-use efficiency.
• Increasing land-use efficiency.
• Reduction of sensitivity to light fluctuations.

Background Of The Biofloc Technology

The first Biofloc Technology was developed in the 1970s at Ifremer-COP (French Research Institute for Exploitation of the Sea, Oceanic Center of Pacific). Israel and the USA (Waddell Mariculture Center) also started Research and Development in the late 1980s and 1990s.

Commercial application started in 1988 at a farm in Tahiti (French Polynesia) using 1000m2 concrete tanks with limited water exchange, achieving a record of 20–25 tons/ha/year in 2 crops. A farm located in Belize, Central America, also produced around 11-26 tons/ha/cycle using 1.6 ha poly-lined ponds. Another farm located in Maryland, USA, also produced 45-ton shrimp per year using ~570 m3 indoor greenhouse BFT raceways. 

BFT has been successfully practised in large-scale shrimp and finfish farms in Asia, Latin and Central America, the USA, South Korea, Brazil, Italy, China, India, and others. However, research on BFT by Universities and Research Centers is refining BFT for farm applications in grow-out culture, feeding technology, reproduction, microbiology, biotechnology, and economics.

The role of microorganisms

Microorganisms play a vital role in feeding and maintaining the overall health of cultured animals. The flocs of bacteria (biofloc) are a nutrient-rich source of proteins and lipids, providing food for the fish throughout the day. The water column shows a complex interaction between living microbes, planktons, organic matter, substrates, and grazers, such as rotifers, ciliates, protozoa and copepods, which serve as a secondary source of food. The combination of these particulate matters keeps the recycling of nutrients and maintains the water quality.

The consumption of floc by cultured organisms has proven to increase the immunity and growth rate, decrease the feed conversion ratio, and reduce the overall cost of production. The growth promotional factors have been attributed to both bacteria and plankton, where up to 30% of the total food is compensated in shrimp.

Species compatibility

In BFT, there is a species compatibility norm for culturing. To improve growth performance, the candidate species must be resistant to high stocking density and population density, adjust to fluctuations in dissolved oxygen (3–6 mg/L), settling solids (10–15 mL/L) and total ammonia compounds, and have omnivorous habits or the ability to consume microbial protein.

Study the Article No Till Farming for UPSC Exam.

Advantages Of The Biofloc Technology and Recirculating Aquaculture Systems

Biofloc Technology is a closed tank-based fish farming approach that cleans the water in fish tanks by using beneficial bacteria. Heterotrophic bacteria (commonly Bacillus, Pseudomonas, Nitrosomonas, Nitrobacter, Acinetobacter, and Alcaligenes) are used to convert organic waste (such as uneaten feed and fish waste) into microbial biomass, which the fish or shrimp can then consume.

Advantages

• This process keeps the water clean without needing to change it often and, at the same time, reduces the risk of disease as well in the fish. Water stays cleaner. Hence, farmers do not need to depend on the external use of chemicals or antibiotics.
• BFT also saves money on feed, as fish can get extra nutrients from the recycled waste, making it sustainable, cost-effective and environmentally friendly for fish farming.
• The inbuilt aeration system to maintain adequate dissolved oxygen levels to promote microbial activity, along with mechanical filtration, reduces the chances of infection.
• It is more suitable for small farmers with limited land as it can be established in a small area and even set up for backyard farming. However, it is associated with challenges, including high costs.

Also Read Dry Land Farming.

Challenges Of The Biofloc Technology and Recirculating Aquaculture Systems

Biofloc technology in aquaculture presents various advantages but also introduces several challenges. These include high initial and operational expenses, the demand for trained personnel, and probable disease outbreaks due to the complex microbial ecosystem. Additionally, managing water quality parameters like alkalinity and nitrite levels, along with the potential for biofloc to harbour pathogens, are key concerns. 

Challenges 

• High initial investment (₹4–5 lakh).
• Constant monitoring is required to maintain water quality and the carbon-to-nitrogen ratio, which is crucial for microbial growth.
• Limited species suitability→ Indian Major Carps like rohu & catla are difficult to rear in northern regions.
• Seasonal variations, such as cold winters, require additional investments like heating rods to maintain optimal conditions.

Learn about the Vertical Farming.

What is Recirculating Aquaculture Systems?

A recirculatory aquaculture system (RAS) is a technology that recycles water and reuses it after mechanical and biological filtration and removal of suspended matter and metabolites. This method is used for high-density cultures of various species of fish, utilizing minimum land area and water.

• It is also a closed-loop tank-based farming that recycles water after filtration.
• RAS filters and cleans the water in the tank, removing waste and keeping it safe for the fish to live in.
• It has an automated set-up of culture tanks with both mechanical and biological filtration units and effectively prevents the entry of pathogens from external sources.
• Minimal interventions are required to assess the culture, water, and disease monitoring, which allows for improved biosecurity. So, fish are less likely to get sick, and the need for disinfectants or antibiotics is reduced.
• The RAS approach also offers a controlled environment for factors like temperature, oxygen levels and cleanliness, ensuring optimal conditions for healthy fish growth.
• It can be set up indoors or in areas without natural water sources, allowing fish to be raised closer to cities and where demand is high.

Study the Article Zero Budget and Natural Farming here!

Download Biofloc Technology Key Takeaways PDF 

After reading this article, we hope all your doubts about the "biofloc technology" have been addressed. The textbook provides comprehensive notes on civil services and various other competitive examinations. It has always ensured the quality of its products, such as content pages, live tests, GK and current affairs, mocks, and so on. Ace your UPSC preparation with the Testbook. Download the Testbook App now!