World Aquaculture - December 2014

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• WORLD AQUACULTURE • DECEMBER 2014 27
Biofloc and Shrimp Immunity
Kim et al. (2013) studied the effect of biofloc on growth and
immune activity of Pacific white shrimp post-larvae and found
dense microbial population associated with bioflocs induces a
trigger toward the development and maintenance of the shrimp
immune system. More than 2,000 bacterial species have been found
in well-developed biofloc water. Bioflocs enhance the non-specific
immune system of shrimp, based on mRNA expression of six
immune-related genes: ProPO1, proPO2, PPAE, ran, mas and SP1.
This mechanismmay be an important means to protect shrimp
against drastic disease outbreaks, which often lead to collapse of
shrimp production systems and huge losses.
A study at Bogor University, Indonesia and Ghent University,
Belgium revealed that the biofloc system contributes to the
enhancement of immune response and survival after IMNV
challenge, regardless of carbon source. The application of biofloc
technology brings about beneficial effect in disease control and
management in shrimp culture.1
A workshop on biofloc technology and shrimp diseases was
held in Ho Chi Minh City from December 9-10, 2013. Ekasari1
reported higher phenoloxidase activity (an immune indicator)
in response to carbon loading in a biofloc system. Avnimelech1
showed significantly lower infection of tilapia by Streptococcus in
biofloc compared to clear water system. Wasielesky1 showed that
biofloc can be successful in preventing WSSV in southern Brazil.
Taw1 presented on possible use of biofloc system as biosecurity in
preventing diseases in shrimp culture (Table 3).
In summary, the main attributes of biofloc systems that reduce
the risk of shrimp disease are:
• Low rates of water exchange improve pathogen exclusion
(biosecurity).
• Continuous aeration provides stable water quality (DO and
pH).
• A diverse and stable microbial community stimulates
the non-specific immune system and limits development of
opportunistic species like Vibrio.
• Regular removal of accumulated sludge controls biofloc
concentration to moderate levels.
Notes
Nyan Taw, Ph.D, Technical Consultant, Blue Archipelago Berhad,
Malaysia
Former Chief Technical Advisor (CTA) and Consultant for FAO of
the United Nations
1 Presentations at ‘Workshop on biofloc technology and shrimp
diseases’ held on 9-10 December 2013 in Ho Chi Min City,
Vietnam.
References
Avnimelech, Y., P. DeSchryver, M. Emerciano, D. Kuhn, A. Ray
and N. Taw. 2012. Biofloc Technology: A Practical Guidebook.
Technion Israel Institute of Technology, Second Edition. World
Aquaculture Society. Baton Rouge, LA, USA.
Cardona, E., B. Lorgeoux, L. Chim, and J. Goguenheim. 2014.
Effect of rearing systems, clear water vs biofloc, on reproductive
performances and quality of larvae of the shrimp Litopenaeus
stylitostris (Abstract) World Aquaculture 2014 Adelaide, Australia.
Kim, S.-K., I.-K. Jang, H.-C. Seo, Y.-R. Cho, T. Samocha and Z. Pang.
2013. Effect of biofloc on growth and immune activity of Pacific
white shrimp, Litopenaeus vannamei postlarvae. Aquaculture
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Kopot, R. and N. Taw. 2004. Efficiency of Pacific white shrimp
culture, current issues in Indonesia. Global Aquaculture Advocate,
April 2004.
Megahed, M.E. 2010. The effect of microbial biofloc on water quality,
survival and
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different crude protein levels, I: Sustainable solution to the
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McIntosh, R. 2001. Changing Paradigms in Shrimp Farming V.
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Samocha, T.M., R. Schveitzer, D. Krummenauer and T.C. Morris.
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Taw, N. 2005. Shrimp farming in Indonesia: evolving industry
responds to varied issues. Global Aquaculture Advocate, August
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Taw, N., H. Fuat and N. Tarigan. 2008. Partial harvest/biofloc system
promising for Pacific white shrimp. Global Aquaculture Advocate
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Taw, N. 2010. Biofloc technology expending at white shrimp farms;
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Taw, N., P.Y. Thoung, L.T. Ming, C. Thanabatra and K.Z. Salleh. 2011.
Malaysia shrimp farm redesign successfully; combines biosecurity,
biofloc technology. Global Aquaculture Advocate, March/April
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Taw, N., U. Saleh and M.S. Bujang Slamat. 2013. Malaysia Shrimp
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Taw, N. and S. Setio. 2014. Intensive farm in Bali, Indonesia produces
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Biofloc systems—a recent technology—offer a promise of stable and sustainable production,
inasmuch as the system is operated without water exchange and so has an enhanced capacity
for nitrification within the culture ponds.