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 20–25 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 10⁶ up to 10⁹ 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 breeder’s 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 <0.1 16.2 24.7 Kuhn DD et

all 2010

28.8-43.1 - 2.1-3.6 8.7-10.4 22.1-42.9 Maicá PF,et

all 2012

30.4 29.1 0.5 0.8 39.2 Emerencian

o M,etall

2012

18.2-29.3 22.8-29.9 0.4-0.7 1.5-3.5 43.7-51.8 Emerencian

o M,etall

2012

18.4-26.3 20.2-35.7

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-β-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