biofloc technology
DESCRIPTION
Biofloc Technology in AquacultureTRANSCRIPT
-
Prepared By;
Gokhale Govinda Satish
M.F.Sc (Aquaculture)
-
As the human population continues to grow, food
production industries such as aquaculture will need to
expand as well.
Shrimp farming has become competitive and as such the
technology utilized needs to be efficient in all aspects
productivity, quality, sustainability, bio-security and to be
in line with market demand.
In order to preserve the environment and the natural
resources, this expansion will need to take place in a
sustainable way.
Introduction
-
The prime goal of aquaculture expansion must be to produce
more aquaculture products without significantly increasing the
usage of the basic natural resources of water and land.
The second goal is to develop sustainable aquaculture systems
that will not damage the environment.
The third goal is to build up systems providing an equitable
cost/benefit ratio to support economic and social sustainability.
All these three prerequisites for sustainable aquaculture
development can be met by biofloc technology
Three Goals.
-
Definition:-
The Biofloc is a protein rich macro aggregate of organic material and micro-organisms including diatoms, bacteria, protozoa,
algae, fecal pellets, remains of dead organisms and other
invertebrates.
-
Biofloc technology is a technique of enhancing water quality in
aquaculture through balancing carbon and nitrogen in the system.
The technology has recently gained attention as a sustainable
method to control water quality, with the added value of
producing protein rich feed in situ.
The basic technology was developed by Dr. Yoram Avnimelech
in Israel and initially implemented commercially in Belize by
Belize Aquaculture.
Biofloc technology has become a popular technology in the
farming of Pacific white shrimp, Litopenaeus vannamei
Biofloc Technology
-
It is possible that this microbial protein has a higher
availability than feed protein.
The basic requirements for biofloc system operation include
high stocking density, high aeration and lined ponds.
A crucial factor in the system is the control of biofloc in
ponds during operation. Fish /shrimp are fed with a lot of
feed
About 70-80% of it remains in the pond, in the water or the
sediment.
Ponds contain a high load of nutrients
Cont..
-
What are the outcomes?
-We waste Feed/Money (Quite a lot!)
- Toxic residues (Sulphides, Ammonia etc)
accumulate.
- Fish growth is affected.
- Intensification is limited (loose income, not being able to raise
production)
- Use industrial RAS (Recycling Aquaculture systems)
Quite expensive )
- use biofloc technology.
The outcome.
-
1. High stocking density - over 130 150 PL10/m2
2. High aeration 28 to 32 HP/ha/ PWAs
3. Paddle wheel position in ponds
4. HDPE / Concrete lined ponds
5. Grain (pellet)
6 Molasses
7. Expected production 2025 MT/ha/crop
Basic of BFT in Shrimp Farming
High density
High aeration
Bioflocs Grain pellet Dark Vannamei HDPE lined pond
Paddle Wheels position
-
Pond Operation High Aeration
Siphoning
-
FLOC Development stages (vol) in pond Stage 1 : Floc found but cannot measured (subjective)
Stage 2 : Floc found in small quantity, < 1.0 ml/litre
Stage 3 : Floc found abundance, 1.0 5.0 ml/litre
Stage 4 : Floc found abundance, 5.1 10.0 ml/litre
Stage 5 : Floc found abundance, > 10.1 ml/litre
STAGES
-
Sampling Method Measuring procedure
1 liter / 2 places/ 15 cm deep/ between 10-12 am
Let it settled for 15-20
minutes
Read density of flocs in
cone (ml/l)
-
Average Floc Development
0
2
4
6
8
10
12
14
20 30 40 50 60 70 80 90 100 110 120 130DOC (days)
Floc (ml/L)
Floc
Floc Development
-
Control Biofloc
Black gill
Black biofloc
Biofloc- general view at surface
Green biofloc Brown biofloc
-
We limit water exchange
Organic residues
accumulate
We mix and aerate.
Ideal conditions for
bacteria
Bacteria control water
quality.
Fish eat bacteria
Feed is recycled
What is BFT?
-
There is a lot of available food for bacteria. The pond is
loaded with organic residues.
The pond is fully aerated (needed for proper fish growth).
The pond is well mixed (typically 24 hours a day)
The number of bacteria in such ponds is 10 up to 10 Bacteria in one cm3!!!!
The pond becomes a biotechnological industry Biofloc
Technology
Conditions for bacteria
-
Normally, there is enough nitrogen in ponds for new cell production.
By adding carbohydrates( eg Starch, flour, molasses, cassawa etc) to the pond, heterotrophic bacterial growth is stimulated and nitrogen uptake through the production of microbial proteins takes place.
Then, there is a need for nitrogen.
If carbon and nitrogen are well balanced in the solution, ammonium in addition to organic nitrogenous waste will be converted into bacterial biomass.
The way to do it: Keep C/N ratio higher than 10
The bacteria now take the nitrogen from the water and control water quality
Manipulating bateria
-
This promoted nitrogen uptake by bacterial growth
decreases the ammonium concentration more rapidly than
nitrification.
Immobilization of ammonium by heterotrophic bacteria
occurs much more rapidly because the growth rate and
microbial biomass yield per unit substrate of heterotrophs
are a factor 10 higher than that of nitrifying bacteria.
Cont..
-
Bacteria are very small.
Luckily, when we have a dense
culture,
They tend to form bioflocs,
containing bacteria, other
organisms and organic particles.
Can we feed fish or shrimp with bacteria?
-
The flocculation of microbial communities is a complex
process.
Within the floc's matrix, a combination of physical, chemical
and biological phenomena is operating.
The exact mechanisms and the methods to engineer
microbiological flocs remain largely unknown.
The main constituents that can be found within the floc matrix
are the extracellular polymeric substances.
These structures form a matrix that encapsulates the microbial
cells, and play a major role in binding the floc components
together.
Mechanism of floc formation
-
They are typically made up out of polysaccharides,
protein, humic compounds, nucleic acids and lipids.
They are produced as slime or capsule layers under
various nutritional conditions but particularly in case of
limitation by nutrients like e.g. nitrogen.
Cont..
-
Mixing intensity
DO
Organic carbon source
Organic loading rate
Temperature
pH
Factors influencing floc formation and floc structure in
bio-flocs technology
-
APPLICATION OF BIOFLOC
TECHNOLOGY IN
AQUACULTURE
-
Nursery phase is defined as an intermediate step between
hatchery-reared early postlarvae and grow-out phase.
Such phase presents several benefits such as optimization of
farm land, increase in survival and enhanced growth
performance in grow-out ponds.
BFT has been applied successfully in nursery phase in different
shrimp species such as L.vannamei , P. monodon , F. paulensis ,
F. brasiliensis and F. setiferus.
-
Better nutrition by continuous consumption of biofloc
The growth enhancement of L. vannamei post larvae reared in
nursery BFT is related to a better nutrition by continuous
consumption of biofloc, which might positively influence grow-
out performance of L vannamei .
Enhance growth performance
-It was observed that presence of bioflocs resulted in increases of 50% in weight and almost 80% in final biomass in F.
paulensis early postlarval stage when compared to conventional
clear-water system.
Increased the survibility rate
reported survival rates of L vannamei in BFT nursery pond
range from 55.9% to 100% and 97% to100%, respectively.
-
Maintain favorable water quality and enhance production.
the addition of substrates in BFT systems increased growth and
further enhanced production, while also contributing to more
favourable water quality conditions. According to the same study,
growth and survival was not affected by stocking density (2500
vs 5000 PL/m2), therefore greater production outputs were
achieved at the higher density.
The F. brasiliensis postlarvae grow similarly with or without
pelletized feed in biofloc conditions during 30-d of nursery
phase, which was 40% more than conventional clear-water
continuous exchange system.
Decrease FCR and reducing cost in feed
-
In grow-out, BFT has been also shown nutritional and zoo
technical benefits.
It was estimated that more than 29% of the daily food intake
of L. vannamei consisted of microbial flocs, decreasing FCR
and reducing costs in feed.
The reference showed that juveniles of L. vannamei fed with
35% CP pelletized feed grew significantly better in biofloc
conditions as compared to clear-water conditions.
It was showed that controlling the concentration of particles
in super-intensive shrimp culture systems can significantly
improve shrimp production and water quality
Grow out
-
Also, the same authors demonstrated that environmentally
friendly plant-based diet can produce results comparable to a
fish-based feed in BFT conditions.
It was evaluated the stocking density in a 120d of L. vannamei
BFT culture, reporting consistent survival of 92, 81 and 75%
with 150, 300 and 450 shrimp/m2, respectively.
Moreover, the study performed in a heterotrophic-based
condition detected no significant difference in FCR when feeding
L. vannamei 30% and 45% CP diets and 39% and 43% CP diets,
respectively.
floc biomass might provide a complete source of cellular
nutrition as well as various bioactive compounds even at high
density.
It is not known exactly how microbial flocs enhance growth.
-
Is well known that protein, peptides and amino acids
participate fully in synthesis of new membranes, somatic
growth and immune function and biofloc can potentially
provide such ingredients.
-
The BFT has been successfully applied for grow-out, but little
is known about biofloc benefits on breeding.
Biofloc in a form of rich-lipid-protein source could be utilized
for first stages of broodstock's gonads formation and ovary
development.
Furthermore, production of brood stock in BFT could be
located in small areas close to hatchery facilities, preventing
spread of diseases caused by shrimp transportation.
BFT could enhance spawning performance as compared to the
conventional pond and tank-reared system, respectively (i.e.
high number of eggs per spawn and high spawning activity
Application in Breeding
-
As an alternative for continuous in situ nutrition during the
whole life-cycle, breeders raised in BFT limited or zero water
exchange system are nutritional benefited by the natural
productivity (biofloc) available 24 hours per day.
better control of water quality parameters and continuous
availability of food (biofloc) in a form of fatty acids protected
against oxidation, vitamins, phospholipids and highly diverse
native protein, rather than conventional systems which
young breeders are often limited to pelletized feed.
The continuous availability of nutrients could promote high
nutrient storage in hepatopancreas, transferred to hemolymph
and directed to ovary, resulting in a better sexual tissue
formation and reproduction activity.
-
Excess of particulate organic matter covered breeders gills
and could limit oxygen exchange, might resulting in
mortalities
-
The cost of diets in several animal cultures is predominantly
due to the cost of protein component.
Fishmeal is prime raw material as a component of aquaculture
feed.
The quality attributed to fishmeal includes high palatability,
high content of digestible protein, highly unsaturated fatty
acids (HUFA) and minerals.
Recently the aquaculture industry has been facing some
important limitation i.e increasing price of fish meal
Application in animal food industry
-
pressure on natural
stock (overfishing)
Increasing price of fish meal
competition with animal cultures
(swine and poultry)
and differences in quality.
Aquaculture industry needs to investigate alternative source of
proteins to replace less sustainable ones
-
The microbial particles can provide important nutrients such as
protein , lipids , amino acids and fatty acids.
Biofloc act as raw material to produce biofloc meal.
Biofloc meal (also called single-celled protein), added to
compounded feed is currently focus of intensive research in
nutrition fields.
However, to produce this protein ingredient some processes are
required such as drying, milling and storage.
In this context, nutritional characteristics could be affected (by
i.e. temperature during drying)
Nutritional composition of biofloc differs according to
environmental condition, carbon source applied, TSS level,
salinity, stocking density, light intensity, phytoplankton and
bacterial communities and ratio, etc
-
Crude
protein (%)
Carbohydr
ates (%)
Lipids (%) Crude fiber
(%)
Ash (%) Reference
43.0 - 12.5 - 26.5 McIntosh D.
et all 2000
31.2 - 2.6 - 28.2 Tacon AGJ
et all 2002
12.0-42.0 - 2.0-2.8 - 22.0-46.0 Soares R et
all 2004
31.1 23.6 0.5 - 44.8 Wasielesky
W.et all
2006
26.0-41.9 - 1.2-2.3 - 18.3-40.7 Ju ZY et all
2008
30.4 - 1.9 12.4 38.9 Ju ZY et all
2008
49.0 36.4 1.13 12.6 13.4 Kuhn DD et
all 2009
38.8 25.3
-
Intensive aquaculture of crustaceans is one of the fastest-
growing sectors in aquaculture production.
Despite its huge success, shrimp culture is facing severel
outbreaks of infectious diseases, which have caused
significant economic losses.
Due to the haphazard mishandling of antibiotics in
aquaculture, pathogenic bacteria are now becoming resistant
to numerous antibiotics and as a result, antibiotics are no
longer effective in treating bacterial disease.
The use of bioflocs as a bio-control
measure
-
The disruption of quorum sensing, bacterial cell-to-cell
communication with small signal molecules has been proposed
as a new strategy to control bacterial infections in aquaculture
As this cell-to-cell communication mechanism regulates the
expression of virulence factors.
recently found that bioflocs grown on glycerol were able to
protect gnotobiotic brine shrimp (Artemia franciscana) against
pathogenic Vibrio harveyi, and that the beneficial effect was
likely due to interference with the pathogen's quorum sensing
system
-
Another interesting feature of bioflocs to further investigate
with respect to biocontrol effects is the capability to accumulate
the bacterial storage compound poly--hydroxybutyrate (PHB).
PHB and PHB accumulating bacteria have been shown to
protect different aquaculture animals from bacterial infections.
PHB-accumulating bacteria that are present in bioflocs has
PHB levels of between 0.5 and 18% of the dry matter.
Bioflocs might also contain immunostimulatory compounds
since biofloc technology deals with bacteria and bacterial
products
-
Aquaponics is a sustainable food production system that
combines a traditional aquaculture with hydroponics in a
symbiotic environment.
Nowadays, BFT have been successfully applied in
aquaponics. The presence of rich-biota (microorganisms of
biofloc) and a variety of nutrients such as micro and
macronutrients originated from un-eaten or non-digested
feed seems to contribute in plant nutrition.
A well known example of biofloc and aquaponics interaction
was also developed by UVI. However, the application of
BFT in aquaponics needs particular attention, mainly on
management of solid levels in water.
Use of biofloc in aquaponics
-
High concentration of solids may cause excessive adhesion of
microorganism on plants roots (biofilm), causing its damage,
lowering oxygenation and poor growth. Filtering and settling
devices are often needed
Aquaponics system a t University of Virgin Islands
-
Commercial interest in biofloc technology is threefold,
for bioflocs provide high productivity, low feed-
conversion ratios (FCRs) and a stable culture
environment.
Also, with emerging viral problems and rising costs for
energy, biofloc technology appears to be an answer for
sustainable production at lower cost.
The technology has not only been applied at commercial
shrimp grow-out farms, but also in super-intensive
raceways to produce more than 9 kg shrimp/m3.
Commercial Interest
-
The raceway applications have supported nursery
and grow-out to shrimp broodstock rearing and
selection of family lines.
Presently, a number of studies by major universities
and private companies are using biofloc as a protein
source in shrimp and fish feeds
-
BIOFLOC TECHNOLOGY WORLD WIDE
-
Belize, Central America Biofloc system culture
Belize Aqua Ltd A view
Belize Aqua Ltd - ponds
BELIZE SHRIMP FARM (McIntosh, 2000b&c)
L. vannamei Mexican strain
Pond size 1.6 hectare
Pond type Fully HDPE lined
Aeration input 48 HP of PWA
System Heterotrophic zero water exchange
Production 13,500 kg/ha/crop
Carrying capacity 550 kg shrimp/HP of PWAs
-
Malaysia Biofloc System initiated on going
Seawater Intake 2.6 km offshore
Well designed farm layout
Biofloc
BAB Semi biofloc (8-9 MT /0.8ha
pond -Target)
-
Shrimp Farms in Indonesia &
Malaysia
Global Medan Indonesia
Bali, Indonesia
CPB Lampung, Indonesia Nyan Taw Shrimp Farming GAA 2005
Blue Archipelago Malaysia
-
Potential of BFT PERU Lined and covered
Piura - Intensive with freshwater covered
Tumbes-Extensive with SW
Piura Intensive FW Nursery
Piura -Inside covered pond
Grain
-
Potential for BFT GUATEMALA Lined with high energy input
Pasca Shrimp Farm 1
-
Potential for BFT CHINA Lined, covered & high energy input
Inside covered & lined ponds
Inside covered & lined ponds
Covered ponds
Covered ponds
-
Development of BFT (Productivity)
According to Shrimp News International (2006) No one knows how many shrimp farms are employing the bio-floc technology. The best examples of the of farms that have implemented the new technology are: 1. Belize Aquaculture, Ltd., in Belize. 2. OceanBoy Farms in Florida, USA, and 3. PT Central Pertiwi Bahari in Indonesia.
YA -Advised by email
NT Advised by short visits
NT- Advised by long visits
RM- Managed at site
NT Managed at site
-
Advantages 1. Bio-security very good (from water) to date WSSV negative
using the system. 2. Zero water exchange less than 100% exchange for whole culture
period. 3. Production (Carrying capacity): 5-10% better than normal system 4. Shrimp size bigger by about 2.0 g than normal system 5. FCR low between 1.0 to 1.3 (without GP) 6. Production cost lower by around 15-20 %. Disadvantages 1. High energy input paddlewheels 28HP/ha. 2. Power failure critical maximum one hour at any time (better zero
hour failure) 3. Full HDPE lined ponds minimum semi-HDPE lined 4. Technology similar but more advance need to train technicians
Advantages/ Disadvantages