Effects of WSSV and bio-security on

shrimp farming in BangladeshPartho Pratim Debnath, Ben Belton, Manjurul Karim,

Hendrik Jan Keus, Chadag Vishnumurthy Mohan

Expanded rapidly since the 1980’s.

Main species cultured is black tiger shrimp (Penaeus monodon)

P. vannamei has not been introduced in Bangladesh.

Area expanded from 52,000 ha (1988) to 213,617 ha (2013).

History of Shrimp Farming in Bangladesh

4-5

ton/ha

600-

700

kg/ha

280-300

kg/ha

0.23

12

87.77

Semi intensive

Improve traditional

Traditional

History of Shrimp Hatchery In Bangladesh

PL nursing

1978

First hatching effort

1987 by DoF funded

by ADB

Successful hatching

1988 by DoF funded

by IDA

1st Private

Hatchery

1993

Presently

running

48 hatcheries

3.05

5.1

8

10

7

12

9.99

7.418.2

0

2

4

6

8

10

12

14

200520062007200820092010201120122013

PL

pro

du

ctio

n (

bill

ion

)

Year

2005

2006

2007

2008

2009

2010

2011

2012

2013

Fig: Year wise Shrimp PL

production by the hatcheries

0

5

10

15

20

25

0

10

20

30

40

50

60

70

19

93

19

94

19

95

19

96

19

97

19

98

19

99

20

00

20

01

20

02

20

03

20

04

20

05

20

06

20

07

20

08

20

09

20

10

20

11

20

12

20

13

Pro

du

ctio

n c

apac

ity

(bill

ion

)

No

s o

f h

atch

ery

Year

Large scale Medium scale Small scale Production Capacity

Fig: Year wise types of shrimp hatchery

establishment including estimated production

capacity in Cox’s Bazar area, Bangladesh.

Methodology

Study period: 2005 to 2013

Data collection:

Production data collected from Department of Fisheries.

Hatchery data from WorldFish projects, 2011 – 2013 data from

the AIN project. Samples of brood and nauplii collected from

20 shrimp hatcheries.

WSSV test: WSSV test done by nested PCR method (IQ2000)

Research findings

Fig : Year wise total shrimp production in Bangladesh

0

20000

40000

60000

80000

100000

120000

140000

160000

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

Pro

du

ctio

n (

MT)

Year

Year

Shrimp culture

area(ha)

1988 64000

1994 108280

1995 138000

1996 140000

2000 141353

2009 217877

2013 275232

In 1994, WSSV introduced in Bangladesh for the

first time and mainly affected semi-intensive farms

in Cox’s Bazar

Fig: Year wise average % of brood and nauplii found infected with WSSV

34.98

41.90 40.80

49.6845.43

38.72

33.38

49.41

55.47

23.14

28.82

35.76 36.04 36.1933.23 32.12

54.93

51.63

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

2005 2006 2007 2008 2009 2010 2011 2012 2013

Pe

rce

nta

ge

Year

WSSV positive percentage in brood WSSV positive percentage in nauplii

Research findings

Fig: Month wise WSSV occurrence in Brood

0.0010.0020.0030.0040.0050.0060.0070.0080.0090.00

January February March April May June July Aug

% W

SSV

po

siti

ve

Month

2005

2006

2007

2008

2009

2010

2011

2012

2013

Average

Research findings

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

January February March April May June July Aug

% W

SSV

po

siti

ve

Year

2005

2006

2007

2008

2009

2010

2011

2012

2013

Average

Fig: Month wise WSSV occurrence in Nauplii

April & May Peak

appearance of

WSSV in brood

and nauplii.

Appearance of

WSSV in January

for the last 2 years

was exceptionally

high.

Present Bio-security issues during capture

of brood stockBrood

Source Management

Bay of Bengal

WildIssu

es

Rec

om

men

dat

ions

Use of SPF

Stock

Issues

Brood tank in ship

Should not be mixed

Brood transportation (Ship to Hatchery)

One Per bagUse of PCR

tested WSSV

free brood

Present Bio-security issues at spawning stage

in hatchery

Hatching technique

Issues Recommendations

Maturation/Mother tank

– mass stocking system

Stocking of WSSV negative brood

Better single stocking system

Spawning tank – mass

spawning systemShould be single spawning system

Present Farm level Bio-security issues

Mostly

Traditional

Multiple stocking

Multiple harvesting

Po

or

wate

r d

ep

th

No

cra

b f

enci

ng

Wild/tested/non tested

PL mixed stocking

Po

or d

ike

No

ou

tlet

No

Bio

-se

cu

rity

main

ten

an

ce

No

bir

d f

en

cin

g

No water quality maintenance No health

assessment

Very serious bio-security

issues for farming system

is that there is no

management practice

applied for outbreak pond

Estimated survival of Post larvae

5.05

7.1

10

12

9

14

11.99

9.4110.2

1.74 1.80 1.82 1.98 2.16 1.852.62 2.88 2.95

0

2

4

6

8

10

12

14

16

2005 2006 2007 2008 2009 2010 2011 2012 2013

Bill

ion

Year

Total PL (billion) Total shrimp (billion)

Fig: Year wise nos. of PL stocked and nos. of shrimp produced34

25

18 16

24

13

22

31 29

0

10

20

30

40

2005 2006 2007 2008 2009 2010 2011 2012 2013

%

Year

Survival rate(%)

Fig: Year wise survival rate of stocked PL

For the purpose of this estimation

2 billion wild PL added to hatchery produced PL for arriving at total PL stocked

Freshwater prawn production (30%) reduced for estimating total shrimp production

shrimp numbers estimated assuming harvest weight of 30 pieces /1 kg

Potential production increase at higher

survival

Survival of

stocked PLSurvival @24%

Survival

@34%Survival @44% Survival @54%

Production(ton) 73277 80605 87932 95260

PL survival may increase by 30% by stocking only PCR tested PLs

combined with BMPs and farm level biosecurity, shrimp production may

increase proportionately.

Above estimates suggest a yearly average survival rate of 24%

WSSV is considered one of the key causes for low survival

Activities implemented by USAID-AIN

• Training of 50,000 shrimp farmers on BMP

• Different media awareness programs (leaflet, village theater show,

radio broadcasting, poster & billboard ) on using PCR tested PL

• Technical support to PCR laboratory of DoF and BFRI

• Promoting “single mother-single tank” system in hatchery

• Monitoring & tracing of PCR negative post larvae distribution from

hatchery through traders to farmers

• Technical advice to DOF in evaluation of SPF introductions

• Average production in 2013-2014 season increased from 270 kg to

402 kg/ha for farmers who received training from the AIN project.

• Average production of demonstration ponds with supplementary

feeding was 617 kg/ha.

Future plan of DoF with technical support by

USAID-AIN on reduction of WSSV prevalence

• Work with shrimp brood stock fishers to store brood

stock on board in individual containers.

• Hand over testing responsibility to private sector,

capacity building of lab staff.

• Capacity building of farmers on BMP: use of PCR

tested PLs, at least 3 feet depth of ponds, nursing of

PLs

• Evaluate pilot SPF imports for future policy development

Conclusion

WSSV free post-larvae supply combinedwith BMP at farm level will reduce diseaserisk, stimulate investment, leading toimproved shrimp production andimproved farmer livelihoods

Thank You