Bringing
back
seasonality
into
coastal
aqua3c
agricultural
systems:
shi$ing
from
shrimp
monoculture
to
more
produc3ve,
diversified
and
resilient
systems

BANGLADESH
Salinity fluctuates from high in dry
season to medium in rainy season
Research site

Research Questions:
1.
Can
brackishwater
aquaculture
system
produc9vity
be
increased?
2.
What
species
combina9on
is
more
suitable
for
increased
produc9vity,
profitability
and
resilience
in
year-­‐round
brackishwater
areas?
3.
What
are
the
costs
and
benefits
of
monoculture
versus
polyculture?

4
Before
Construc3on
Ponds
Pond

Aquaculture Treatments in 2012
3 treatments with 4 replications:
1. Farmer’s mgt: Polyculture, shrimp+ different fish sp
2. Improved mgt1: Rotational Monoculture, shrimp-tilapia-prawn (Cycle 1, 2 & 3)
3. Improved mgt 2: Rotational Polyculture, shrimp+tilapia – tilapia+tengra -
prawn+tengra( Cycle 1, 2 & 3)
Tilapia
+
CaEish
Prawn
(fresh
water)
Shrimp
(brackish
water)

Aquaculture Treatments in 2013
3 treatments with 4 replications:
1. Farmers’ mgt : Polyculture
Shrimp+ several fish spp, multiple stockings & harvests
2. Improved mgt 1: Rotational monoculture
Dry season - shrimp (2 crops) (Cycle 1 & 2)
Wet season - tilapia (Cycle 3)
3. Improved mgt 2: Rotational polyculture
Dry season - shrimp+tilapia (2 crops) (Cycle 1 & 2)
Wet season - polyculture rohu + singh + magur (Cycle 3)
Carp
Singh
&
Magur
Shrimp
Nona
tengra
Tilapia
……………Dry
season……………………
……………….Wet
CaFish
(3
spp)

Aquaculture treatments (4 reps)
Treatments
Culture
paLerns
2012
2013
Cycle
1
Cycle
2
Cycle
3
Cycle
1
Cycle
2
Cycle
3
Farmer’s
prac3ce
Poly
Shrimp
+
different
sp
of
fish
(mul3ple
stocking
&
harves3ng)
Shrimp
+
different
sp
of
fish
(mul3ple
stocking
&
harves3ng)
Improved
prac3ce
1
Mono
Shrimp
Tilapia
Prawn
Shrimp
Shrimp
Tilapia
Improved
prac3ce
2
Poly
Shrimp
Tilapia
Tilapia
Tengra
Prawn
Tengra
Shrimp
Tilapia
Shrimp
Tilapia
Rohu
Singh
Magur
Managed
by
farmers

Management
Prac3ce
Farmer’s
Prac3ce
Improved
1
&
2
Liming
200
kg
ha-­‐1
200
kg
ha-­‐1
Water
filtering
Unfiltered
Filtered
Predatory
Fish
No
control
Controlled
Disinfec3on
No
disinfec9on
Disinfected
Fer3liza3on
No
fer9lizer
Fer9lizer
&
dolomite
Shrimp
seed
Not
PCR
tested
PCR
tested
Feed
No
feed
Feeding
Water
replenishment
When
needed
When
needed
Post
stocking
fer3liza3on
Very
insufficient
When
primary
produc9on
is
low
Fish
seed
Some
wild
All
from
hatcheries

Timeline 2012
Shrimp
& fish
Stocking 1 Shrimp
disease in
some ponds
Harvest 3
AprilMarch Aug. Dec.
Harvest 2
Sept.
Stocking 3Harvest 1 &
Stocking 2
June July Nov.May Oct.
Dry season Wet season

Timeline 2013
Shrimp
& fish
Stocking 1
Rice
harvest
AprilMarch Aug. Dec.
Harvest 2
Harvest 3
Sept.
Harvest 1
Stocking 2
May July Nov.
Stocking 3
Dry season Wet season

Water
Depth
(2012
versus
2013)
2012
2013
30
40
50
60
70
80
90
100
110
1
15
28
42
56
70
84
98
112
126
140
154
168
182
196
210
224
238
252
266
280
Depth
(cm)
7
March
Farmer's
prac3ce
Monoculture
Polyculture
20
30
40
50
60
70
80
90
100
1
14
28
42
56
70
84
98
112
126
140
154
168
182
196
210
224
238
252
Depth
(cm)
Days
of
culture
14
March
Farmer's
prac3ce
Monoculture
Polyculture
Cycle
1
Cycle
2
Cycle
3
Cycle
1
Cycle
2
Cycle
3

Water
Salinity
(2012
versus
2013)
2012
2013
Cycle
1
Cycle
2
Cycle
3
0
5
10
15
20
25
1
15
28
42
56
70
84
98
112
126
140
154
168
182
196
210
224
238
252
266
280
Salinity
(ppt)
7
March
Farmer's
prac3ce
Monoculture
Polyculture
0
5
10
15
20
25
1
14
28
42
56
70
84
98
112
126
140
154
168
182
196
210
224
238
252
Salinity
(ppt)
Days
of
Culture
14
March
Farmer's
prac3ce
Monoculture
Polyculture
Cycle
1
Cycle
2
Cycle
3

Results

0
500
1000
1500
2000
2500
3000
3500
4000
4500
Farmer's
prac3ce
Monoculture
Polyculture
Yield
(kg
ha-­‐1)
Shrimp
Fish
2012
a
b
c
a
b
c
0
500
1000
1500
2000
2500
3000
3500
4000
Farmer's
prac3ce
Monoculture
Polyculture
Yield
(kg
ha-­‐1)
Shrimp
Fish
2013
a
b
c
a
b
c
(1)
System
produc3vity
-­‐
annual
Produc3on
(kg/ha)
in
2012
&
2013

2012
Culture
patterns
Cycle-1
(91 days)
Cycle-2
(71days)
Cycle-3
(100 days)
Total
Shrimp Tilapia Tilapia Tengra Prawn Tengra Shrimp Fish
Farmer’s
practice
278 days *209.84a 728.14a
Mono 197.77 -­‐
2367.4
8
-­‐
363.63
-­‐
556.40b 2367.48b
Poly 172.64 1163.41
1519.78
352.34
231.74 286.50
404.38c 3322.04c
2013
Culture
patterns
Cycle-1
(70 days)
Cycle-2
(50 days)
Cycle-3
(99 days)
Total
Shrimp Tilapia Shrimp Tilapia
Magur+
singh
Tilapia/
rohu
Shrimp Fish
Farmer’s
practice
259 days 390.05a 659.41a
Mono 565.62 -­‐
291.77
- - *3307.71 857.39b 3307.71b
Poly 373.64 1744.45
193.19
777.90
557.63
**480.05 566.83c 3560.02c
Cycle-­‐wise
produc3on
(kg/ha)
in
2012
&
2013

Fish
Category
2012**
2013**
Remarks
Tengra-­‐Tilapia
41654.38a
-­‐
Risk
free;
Less
profit
-­‐
Tengra
may
escape
if
dikes
are
not
good
Tengra
-­‐Prawn
116000b
-­‐
Depends
on
availability
of
prawn
Juvenile;
-­‐
Tengra
may
escape
if
the
dikes
are
not
good
Carp-­‐Singh-­‐Magur
147816.11c
-­‐
Singh
&
Magur
culture
depends
on
rainfall
-­‐
Singh
&
Magur
may
escape
if
the
dikes
are
not
good
Shrimp-­‐Tilapia
101450.71b
128000b
-­‐Shrimp
risky
but
9lapia
provides
the
back
up
(2)
Species
combina3ons
-­‐
gross
margin
(BDT/per
cycle/ha)
from
different
polyculture
species
composi3on

(3)
Polyculture
vs
monoculture
-­‐100
0
100
200
300
400
500
600
700
Farmer's
prac3ce
Monoculture
Polyculture
BDT
1000
ha-­‐1
Variable
cost
Total
return
Gross
margin
2012
a
b
c
-­‐100
0
100
200
300
400
500
600
700
800
Farmer's
prac3ce
Monoculture
Polyculture
BDT1000
ha-­‐1
Variable
cost
Total
return
Gross
margin
2013
a
b
b
Cost,
return,
gross
margin
(including
farmer’s
labor
&
land
leasing
value)

Ponds Species
Total
cost
(BDT/ha)
Produc3on
(kg/ha)
Sale
(BDT/ha)
Gross
return
(BDT/ha)
3
Shrimp
212240
515.97
257985
297985
Tilapia 2557.58
281333.8
281356
8
Shrimp
182147
349.26
174630
174630
Tilapia 2079.62
228758.2
228758
6
Shrimp
157900
0
0
0
Tilapia 1930.79
193079
193079
11
Shrimp
157137
0
0
0
Tilapia 1920.71
192071
192078
Impact
of
crop
diversifica3on
in
shrimp
ghers
(Shrimp
–
3/m2
&
3lapia
2/m2,
culture
period
–
91
DOC)

Promising
opportuni3es
for
scaling
! 275,000
ha
of
all
year-­‐round
saline
aquaculture
area
! G2
extension
farmers
involved
par9cipatory
adop9on
trial
and
sharing
with
other
farmers
! Implemen9ng
community
water
management
for
brackishwater
aquaculture
with
BRAC
! Extension
materials
prepared
and
disseminated

Key
implementa3on
challenges
Markets
systems
• Access
to
quality
shrimp
and
fish
seed
• Access
to
quality
feed
in
local
market
Aquaculture
management
• Maintaining
water
depth
• Preven3on
of
escaping
cat
fish
through
dikes
• Aqua3c
weed
control
Community
• Poor
feeder
canal
for
gravita3onal
water
exchange
(need
community
level
management
–
common
theme!)
• Poaching
risk

Conclusion
q Significant
improvements
in
produc3vity
and
income
through
a
diversified
culture
system
under
beLer
management
prac3ces.
q Shrimp-­‐3lapia
polyculture
system
profitable
with
greater
resilience
compared
to
other
species
combina3ons.
Risks
of
shrimp
can
be
recovered
by
return
from
Nile
3lapia
q Polyculture
and
alternate
cropping
monoculture
more
profitable
than
current
prac3ces.
Gross
margin
from
polyculture
higher
than
monoculture

Lesson
learned
q Considerable
opportuni3es
exist
for
improving
aquaculture
in
the
coastal
“year-­‐round”
saline
zone.
q Technologies
appear
to
be
very
“adoptable”
by
farmers
q Community
water
management
can
further
improve
op3ons
for
aquaculture
and
risk
management
q Possible
to
integrate
vegetable
produc3on
from
dikes
in
wet
season
and
support
livestock
food
by
growing
saline
tolerant
grass
on
the
dikes
q Saline
water
represents
an
asset….

Aquaculture production must more than
double by 2050 to satisfy projected fish
demand
Million tons
Sources:
Produc9on
data
1961–2010:
FAO
(2014a),
FAO
(2014b).
Aquaculture
produc9on
projec9ons
2011–2050:
Authors’
calcula9ons
assuming
a
linear
growth
rate
of
2
Mt
per
year.

Project aquaculture production
…. South Asia is a hotspot for future
fish demand
• S.
Asia
–
from
2.2
to
4.4
mt
• India
–
from
3.9
to
8.6
mt