THE IMPACT OF IRRIGATION SYSTEM ON THE LIVELIHOODS
OF FISHING COMMUNITIES OF THE TWO SUB-AREAS OF
IRRIGATION PROJECTS IN CA MAU PENINSULA, VIET NAM
Mai Viet Van, Tran Dac Dinh, Ngo Thuy Diem Trang, Huynh Van Hien
Dang Thi Phuong, Nguyen Thanh Toan, Nguyen Thi Kim Quyen
19-23/10/2015
Phnom Penh
Cambodia
Can Tho University, Vietnam (mvvan@ctu.edu.vn)

IMPACT OF IRRIGATION SYSTEM ON THE LIVELIHOODS OF FISHING COMMUNITIES
FISHERIES RESOURCES BETTER MANAGEMENT & LIVELIHOODS IMPROVEMENT

4-6: Brackish-water Ecosystem
2
3
1
4
5
6
1-3: Fresh-water Ecosystem

0
10
20
30
40
50
60
70
Inside Outside Inside Outside
Freshwater ecosystem Brackishwater ecosystem
Samplesize(households)
Dong Thang (1) Truong Long (2) Thoi Thanh (3)
An Trach (4) Phong Thanh Tay (5) Phong Thanh A (6)
The sample size

Diversi'es
of
income
sources
Livelihoods Freshwater
ecosystem
Brackishwater
ecosystem
Inside Outside Inside Outside
Mono rice 56,054.7 33,913.2 26.7 0.0
Upland crops 1,593.3 85 133.3 0.0
Orchard 3,168.3 200 0.0 0.0
Animal husbandry 7,246.3 14,271.2 6,004.0 3,090
Garden canal culture (fish) 788.3 24,182.2 1,400.0 2.4
Rice-Fish 0.0 1,783.3 19,966.7 12,132.5
Fishing 8,717.2
(11%)
17,983.4
(19%)
9,321.4
(25%)
26,097.8
(63%)
Other income 1,598.3 1,016.7 516.7 0.0
Total income (household
per year)
79,166.5 93,434.9 37,368.8 41,322.7
Unit: 1,000 VND

Impacts
of
irriga'on
system
on
fish
and
shrimp
community
composi'ons
§ A decrease of 3 economic fish species in the
FE (as compared to Sinh, 2007)
§ A decrease of 25 economic fish species in
the BW (as compared to Vo Thanh Toan,
2007)
Threatened species
Morulius chrysophekadionToxotes chatareus
Notopterus notopterus
Arius maculatus
Channa lucius
Clarias batrachus
Clarias macrocephalus
0
20
40
60
80
Inside Outside Inside Outside
Freshwater ecosystem Brackishwater ecosystem
No.ofspecies
Fish Shrimp
0
5
10
15
20
25
Inside Outside Inside Outside
Freshwater ecosystem Brackishwater ecosystem
No.ofeconomicspecies
Fish Shrimp

Impact
of
irriga'on
system
on
wildfish
produc'on
and
fishing
gears
Long trap net
Simple trap
net
Electricity traw net Electricity shock
Inshore stake trap netLong fence trap net
Destructive fishing gears
An increase of 6
fishing gears (as
compared to Sinh et al.,
2007)
0.0
5.0
10.0
15.0
20.0
Inside
Outside
FE
Inside
Outside
BE
Fresh water
ecosystem
Brackishwater
ecosystem
No.offishinggear
0.0
200.0
400.0
600.0
800.0
1000.0
1200.0
1400.0
2010 2014 2010 2014 2010 2014 2010 2014 2010 2014 2010 2014
Inside Outside FE Inside Outside BE
Freshwater ecosystem Brackishwater ecosystem
Wildfishproduction
(kg/year/household)

Impacts of irrigation system on society
Descriptions
Positive impacts
Houses are not submerged in flooding season
Easily transporting
Facilitating trading, improving living
Negative impacts
Reducing income from wildfish capture
Increasing food cost (due to natural resources
decline)
Health risks due to polluted water
Conflicts of interest between shrimp-rice
Recommendations of community
Appropriate operating sluice gates for water
transportation
Addressing properly the conflict between rice &
shrimp culture

Descriptions
Positive impacts
Preventing flooding
Increasing number of crop, cultivation areas and yield
Reducing input costs (pumping and draining water)
Rice-fish co-culture (1 rice + 2 shrimp)
Preventing salt water intrusion (for rice cultivation in BE areas)
Negative impacts
Resulting in infield surface water pollution
Increasing pesticides/fertilizers accumulation
Reducing sediment causing soil infertile
Inappropriate operation of sluice gates causing salinization
Recommendations of community
Irrigation systems need to be constructed for production
Zoning areas for rice shrimp farming
Selecting salt-tolerant rice varieties
Having a suitable operation schedule of irrigation system for
rice and shrimp production
Impacts
of
irriga'on
system
on
rice
cul'va'on

Impacts
of
irriga'on
system
on
aquaculture
Descriptions
Positive impacts
Managing aquaculture ponds in flooding season
Supplying freshwater for aquaculture in brackish water
ecosystem areas
Easily controlling disease, preventing spreading to outside
irrigation systems
Negative impacts
Water pollution due to less circulating water
Lack of water in the dry season
Slow growth of fish, shrimp
Spreading disease between ponds
Increasing pumping cost
Less saline water for aquaculture in the rainy season
Recommendations of community
Operating sluice gates often to supply freshwater for
aquaculture

SOLUTIONS FOR BETTER MANAGEMENT OF FISHERIES RESOURCES &
IMPROVEMENT OF LIVELIHOODS FOR FISHER COMMUNITIES
Studied areas Solutions
Freshwater
ecosystems
1. Increasing communities awareness in protection of fisheries
resources
2. Diversifying careers/jobs to attract workers in local
unemployed
3. Reducing capture pressure by increasing aquaculture; and/or
compensating natural resources
4. Appropriate operating irrigation systems for rice, aquaculture
Brackishwater
ecosystems
1. Increasing communities awareness in protection of native
species, threatened species and endangered species
2. Vocational training for local unemployed to cope fisheries
resources decline
3. Zoning areas for rice shrimp farming (particularly in Ninh Quoi
– Bac Lieu need to have anti-salt dike for stable rice
production area).
4. Selecting salt-tolerant rice varieties to rotate with shrimp in
saline-soil.
5. Enhancing the role of the communities in planning, operating/
maintaining irrigation systems for production

Impact of irrigation system on wildfish capture production
Causes Freshwater ecosystem Brackishwater ecosystem
Inside Outside FE (aver.) Inside Outside BE (aver.)
Sample size n=57 n=54 n=111 n=49 n=51 n=100
Creating barrier to fish migration (IS) 56.1 28.8 51.0 25.0
Using of destructive fishing gears 29.8 40.7 35.1 63.3 64.7 64.0
Intensive rice crops negatively affected in
spawning grounds 35.1 25.9 30.6
Pesticides residues 36.8 14.8 26.1
Increasing number of fisherman 5.3 22.2 13.5 18.4 64.7 42.0
Capture fry and broodstock in the breeding
season 29.8 27.8 28.8 42.9 56.9 50.0
Capture of non-econ. fish species for
aquaculture feeding 68.5 33.3
0.0
200.0
400.0
600.0
800.0
1000.0
1200.0
1400.0
2010 2014 2010 2014 2010 2014 2010 2014 2010 2014 2010 2014
Inside Outside FE Inside Outside BE
Freshwater ecosystem Brackishwater ecosystem
Wildfishproduction
(kg/year/household)
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
Inside Outside FE Inside Outside BE
Freshwater ecosystem Brackishwater ecosystem
Ratioofwildfishproduction
decline(%)
Unit: %

Livelihood assets in the freshwater ecosystem
Livelihood assets in the brackishwater ecosystem
Livelihoods capital analysis of fisher households