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Climate Change in the Lower Mekong Basin: Impacts on Floods & Fisheries

Volume 17, No 3 December 2011ISSN 0859-290X
Fisheries Research and Development in the Mekong Region
Worst oods in fty years devastate Thai aquaculture
Rebuilding giant prawn stocks around the Tonle Sap
Scientists describe new species of walking cat sh
Climate change impacts on oods and sheries
CP sees Viet Nam acquisition as key growth driver
Cambodia’s potential for reservoir sheries
Training the gender trainers
Cover photo and photo above from Department of Fisheries, Thailand
Catch and Culture is published three times a year by the of ce of the Mekong River Commission Secretariat in Phnom
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© Mekong River Commission 2011
Editorial panel:
Xaypladeth Choulamany, Fisheries Programme Coordinator
Peter Degen, Chief Technical Advisor
Buoy Roitana, Fisheries Programme Of cer
Theerawat Samphawamana, Fisheries Programme Of cer
Nguyen Hai Son, Fisheries Programme Of cer
Malasri Khumsri, Fisheries Management and Governance Specialist
Ngor Peng Bun, Capture Fisheries Specialist
Kong Sovanara, Aquaculture Specialist
Editor: Peter Starr
Designer: Chhut Chheana
The opinions and interpretation expressed within are those of the authors and do not necessarily represent the views of the
Mekong River Commission.
4 Flood damage to aquatic resources
Worst oods in half a century devastate Thai aquaculture industry
8 Escapees
Catching escaped crocodiles
10 Stock enhancement
Rebuilding stocks of once-abundant freshwater prawns around the Tonle Sap
14 Taxonomy
Singapore, Vietnamese researchers describe new species of walking cat sh
16 Hydropower development
Further study on impact of Mekong mainstream development required
18 Aquaculture
Third edition of better management manual for Vietnamese cat sh farmers
19 Climate change in the Lower Mekong Basin
Impacts on oods and sheries
23 Management changes
New management at Department of Fisheries in Thailand
24 Investment
CP Hong Kong arm expects Viet Nam acquisition to be key growth driver
26 Interview
Cambodia’s potential for reservoir sheries
30 Development
Viet Nam to set up high-growth economic zone in four Mekong Delta provinces
32 Gender
Training the gender trainers
35 Staff
Recent changes
December 2011 Catch and Culture Volume 17, No. 3
4Catch and Culture Volume 17, No. 3 December 2011
Flood damage to aquatic resources
Worst oods in half a century
devastate Thai aquaculture industry
With more than 130,000 farmers affected,
damage to aquaculture and government
compensation is estimated
at almost $170 million
Thailand suffered its worst oods in half a century
in 2011. Between June and October, the country
was hit by four tropical depressions and a typhoon.
The government declared 65 of the country’s 77
provinces as disaster areas. More than 12.8 million
people were affected, with 693 deaths. According to
the Meteorological Department, cumulative rainfall
for the year rose to a record 1,674 millimetres,
which was 42 percent higher than the average for
the past 30 years.
Major ooding began in late June with heavy
precipitation from Tropical Depression Haima,
causing landslides in the north and the northeast as
well as ash oods in many provinces. In addition,
heavy rains from the annual southwest monsoon
continued for longer than usual.
Major storms between June and October
Storm Type Period
Haima Tropical depression Late June
Nok-Ten Tropical depression Late July-early August
Haitang Tropical depression Late September
Nesat Typhoon Early October
Nalgae Tropical depression Early October
Source: Thai Meteorological Department
The heavy rainfall continued for more than three
months, especially over the Mekong and Chao
Phraya River Basins. Most dams were forced to
increase discharge rates, resulting in rapid ooding of
residential, industrial and agricultural areas including
sh farms. The World Bank estimated damages at
THB 1,440 billion ($45 billion) with four million families
and six million hectares of land affected. The Of ce
of Agricultural Economics estimated that two million
hectares of farmland were damaged and more than
30 million heads of livestock lost.
The Department of Fisheries (DoF) warned sh
farmers, particularly in disaster areas, to harvest
sh or move them while strengthening defences
around ponds. Since the oods occurred so
quickly, however, losses were substantial. A DoF
survey found that 132,381 sh farmers in 70
provinces suffered damages. The area affected
was 43,510 hectares (34,890 hectares of sh
ponds, 8,590 hectares of shrimp/crab/mollusc
ponds and pens, and about 30 hectares of cages
and cement tanks). Total damage to aquaculture
was estimated at THB 3.64 billion ($122 million).
Fish farmers affected by oods
Region Provinces affected Farmers affected
North 16 33,590
Northeast 20 58,702
Central 24 37,294
South 10 2,795
Total 70 132,381
Source: Department of Fisheries
Aquaculture affected by oods
Type of culture Area (ha)
Fish ponds 34,890
Shrimp/crab/ponds and mollusc pens 8,590
Cages/cement tanks 30
Damage estimate (THB) 3.64 billion
Source: Department of Fisheries
Flooded headquarters of Department of Fisheries in Bangkok
December 2011 Catch and Culture Volume 17, No. 3
Flood damage to aquatic resources
Damage to hatcheries and ponds at Ang Thong Fisheries Centre
Impact on marine life
Place Impact Period Source
Mahachai estuary, Samut Sakorn province Marine sh, mussels die Mid December Matichon, Dec 22
Bang Pa Kong,Cha Cherng Sao province Marine sh die Early December Manager, Dec 9
Kang Kao Island,Chon Buri province All coral bleached Late November Thai Post, Nov 27
Cha Um Beach, Phetch Buri province Marine sh and other fauna die Mid October Manager, Oct 14
The oods pushed a huge volume of water,
sediment, pollutants and waste into the mouths
of the Chao Phraya, Tha Chin, and Mae Klong
rivers and then into the Gulf of Thailand, where
the country’s most important sheries resources
are located. The degradation of water quality and
signi cant drop in salinity affected marine sh and
other animals, especially aquatic larvae and mud
organisms such as mussels, cockles and oysters.
Many smaller organisms sensitive to changes in
water quality and salinity were believed to have
died, affecting the food chain since they are eaten
by large sh. Along the coast, many sh were
found dead and it was reported that the quantity
of sh caught by marine shers fell sharply. How
much of the coastline was affected and how long it
will take to recover is unclear.
The oods also swept away many “temple sh”,
the large shes that congregate around temples
located along the banks of rivers, particularly
the Chao Phraya. These include shark cat shes,
barbs, gouramis and bagrid cat shes fed by
monks, local people and tourists who feed them
as a way to make merit. Since shing is banned at
such sh sanctuaries, many of these shes reach
a mature size. After being swept away by oods,
many were caught by shermen with various types
of shing gear such as hooks, cast nets and gill
nets. Some temples found that only a few shes
swam back after the ooding.
The oods also affected six Inland Fisheries
Centers in Nan, Nakhon Sawan, Lop Buri, Uthai
Thani, Ang Thong and Ayutthaya provinces as well
as the DoF of ce in Bangkok. Drainage control
systems were unable to prevent ood damage,
resulting in broodstock escaping into open waters.
Laboratory equipment, hatcheries, earthen ponds,
staff housing and personal property were also
Wimol Jantrarotai, the director general of the
6Catch and Culture Volume 17, No. 3 December 2011
Flood damage to aquatic resources
Department of Fisheries, said the oods resulted
in “impoverishment for many sh farmers and
damage to sheries resources.” The department’s
challenge was to “assist sh farmers and
rehabilitate the natural resources,” Dr Wimol said.
On August 25, the Thai cabinet decided to
compensate damaged sh farms at the rate of
THB 4,225 ($132) per rai (1,600 square metres)
up to ve rai per farmer. Compensation for prawn,
crab, or mollusc farms was set at THB 10,920
($341). Farmers with cages and cement tanks and
those raising other species such as ornamental
sh, frogs and soft-sell turtles were offered THB
315 ($10) per square metre with the maximum
set at 80 square metres per person. Budget
expenditure on compensation was estimated at
THB 1.5 billion ($47 million).
Payments to farmers
Culture Compensation Maximum
Fish/paddy- eld THB 4,225/rai 5 rai
Prawn/crab/molluscs THB 10,920/rai 5 rai
Cages/cement tanks THB/315 m280 m2
Source: Department of Fisheries
To create opportunities for affected sh farmers,
the DoF plans to provide training in aquaculture
techniques and seed for shes and other aquatic
animals such as tilapia, sea bass, white leg shrimp
and mussels. It also plans to provide feed and
technical knowledge.
To address food security and the livelihoods of
shers, the DoF plans to release about 67 million
individual marine animals in 2012 including sea
bass, shrimp, crabs and clams. Broodstock of
native molluscs, such as razor clams and angel
wings, were moved and will be returned when
water quality improves. Water and soil at the
mouths of rivers and coastal areas are being
monitored regularly for quality and treated with
“effective microorganisms” in blood cockle and
other farming areas. To rehabilitate marine
ecosystems, arti cial reefs are being established.
Rehabilitating sh sanctuaries
To rehabilitate sh sanctuaries set up by the
government’s Temple Fish Conservation Project
launched 2002, the DoF is cooperating with private
mills to provide feed to temples along rivers in
Overview of ood waters over central provinces of Thailand
Probable ood water on 13 Oct, 2011 (Envisat ASAR-WS)
December 2011 Catch and Culture Volume 17, No. 3
Flood damage to aquatic resources
Ang Thong, Ayutthaya, and Nontha Buri province.
It is also advising monks and volunteers to
continue feeding sh to bring about aggregations
that can be naturally propagated to increase sh
production in natural habitats.
“Promoting the conservation of temple sh is one
of our tasks,” Dr Wimol said. “It will enable a new
generation to know native sh from nature rather
than books. Fish productivity will increase in the
water as fertility returns to past levels.”
Plankton, insect larvae and plant seedlings are
plentiful in the Mekong and Chao Phraya basins
during the wet season and support the grow of
sh larvae. In oodplain areas, the DoF plans
to collect from the wild broodstock of at least six
freshwater species including silver and red-tail
barbs. After being reared and reaching a mature
size, the best will be selected for breeding and the
fry will be released into ooded areas. To improve
awareness of conservation, this will be done in
cooperation with local communities.
Damage to Ang Thong Fisheries Centre
Aquaculture area ooded in Ang Thong province
During the oods, the DoF mobilised 272 staff,
66 speed boats and 49 trucks to provide food,
water and transport for victims, especially those in
Nontha Buri, Ayutthaya, Pathumb Thani, Nakhon
Sawan, Lop Buri, Uthai Thani, Sing Buri, Chainat,
Samut Prakarn and Bangkok.
Special thanks to Naruenart Phakphongyothin, Phitan
Nongnuon and Pratheep Sriphoca
* Mr Theerawat is an MRC Fisheries Programme Of cer
8Catch and Culture Volume 17, No. 3 December 2011
Catching escaped crocodiles
Crocodile trivia
When crocodiles sit on river banks with their
mouths opens, it’s not aggression. They’re trying
to cool off as they sweat through their mouths.
Crocodiles display increased aggressiveness
during the mating season, which is linked to the
Each crocodile jaw has 24 teeth that are meant to
grasp and crush, not chew. They swallow stones
that grind food inside their stomachs, and also act
as ballast.
Department of Fisheries teams up with a
private crocodile farmer to ally public fears
In past centuries, crocodiles were so plentiful in
Thailand that they could be found throughout the
country. People grew accustomed to living side
by side with the reptiles. Due to the changing
environment and hunting for meat and skins,
however, the reptiles disappeared from the wild
many decades ago.
Today, Thailand is among the world’s main
exporters of crocodile products, farming roughly
200,000 heads at more than 30 farms and
900 small breeding operations, mostly around
During this year’s oods, news of escaped
crocodiles in many provinces appeared, having
a big impact on people’s fear of the reptiles.
In response, the Thai Department of Fisheries
Receiving training on how to catch a crocodile
(DoF) set up a hot line for people to report
escaped crocodiles in ooded areas. It also set
up a crocodile catch team comprising 15 staff
from the department and three experts from
Golden Crocodile Agriculture (Thailand) Co
based in Nakhon Pathom in central Thailand. The
December 2011 Catch and Culture Volume 17, No. 3
team learned how to catch crocodiles by using
long, electric cattle prods until the reptile fell
unconscious. The technique then involved snaring
it and dragging the animal on board, covering the
eyes and jaws with thick rope.
“It’s important to use this opportunity
to show people that they have nothing
to fear about crocodiles”
Due to the similarities between crocodiles and
water monitors, the DoF provided the public with
information on the two species. Whereas water
monitors are found both during the day and at
night, crocodiles are usually found only at night.
Swimming behaviour also differs between the two
species. While the entire body of a water monitor
moves in an S-shape, only the tail moves in the
case of crocodiles. And unlike water monitors,
parts of the nose and eyes appear above water
when crocodiles are swimming.
“There have been no reports of people injured
by crocodiles,” said Wimol Jantrarotai, the new
director general of the DoF as he waded through
water to see one of the crocodiles caught by his
team. “It’s important to use this opportunity to
The catch team swings into action in Nontha Buri
Mr Praipan, a crocodile catcher, relaxing after work
show people that they have nothing to fear about
crocodiles,” Dr Wimol told the Asian Wall Street
Journal. “We’ve lived alongside them in all kinds of
habitats in the past. Now, we just have to learn to
do so again.”
During October and November, the department
caught nine crocodiles including four in Bangkok.
Another four were caught in nearby Nontha Buri
and one in Nakhon Pathom. All were taken to
Suphan Buri Fisheries Centre for research.
* Mr Theerawat is an MRC Fisheries Programme Of cer
and Mr Charoenchai is Fisheries Officer with the Thai
Department of Fisheries
10 Catch and Culture Volume 17, No. 3 December 2011
Stock enhancement
Rebuilding stocks of once-abundant
freshwater prawns around the Tonle Sap
Cambodia’s rst stock enhancement trial
for giant freshwater prawns results in
recaptures of about 5,500 kilograms
The giant freshwater prawn (Macrobrachium
rosenbergii) is indigenous to South and Southeast
Asia and parts of Oceania. There are two sources
of freshwater prawn production. The rst is natural
production from rivers, lakes and reservoirs.
The second is from aquaculture in ponds and
pens which requires high investment for seed,
feed, labour and management. Globally, yields
range from 336 to 2,338 kg/ha/yr (Ahmed et al.,
2008). While natural production is lower than
aquaculture production, it bene ts poor shers,
where post larvae are widely released for stock
enhancement in freshwater water bodies (New,
2002; Sripatrprasite & Kwei Lin, 2003; Kutty
et al., 2010). Southeast Asian countries with
stock-enhancement programmes include Brunei
Female giant freshwater prawns
December 2011 Catch and Culture Volume 17, No. 3
Stock enhancement
Gravid female prawn
Darussalam, Indonesia, Malaysia, Myanmar,
the Philippines and Thailand. In South Asia,
programmes in India have been considered
successful and are ongoing (Kutty et al., 2010;
New & Kutty, 2010). The estimated recapture
rate of these programmes has ranged from 1% to
7% (Kutty et al., 2010; Sripatrprasite & Kwei Lin,
The giant freshwater prawn is native to Cambodia,
inhabiting several million hectares of nutrient-rich
oodplains of the Bassac River in Takeo province,
the Mekong River in Prey Veng province, the
Tonle Sap River in Kompong Chhnang and Kandal
provinces as well as Phnom Penh and part of the
Tonle Sap Lake. After spawning in the brackish
water of the Mekong Delta of Viet Nam, the post
larvae migrate into Cambodia’s oodplains and
up to Kompong Chhnang province, as noticed
by Chinese envoy Zhou Daguan during the 13th
century (see back cover), for nursing, foraging
and grow-out. The prawn shery used to be very
abundant in Kompong Chhnang, Kandal and
especially Prey Veng, Takeo and Phnom Penh
with an estimated catch of 100 tonnes per year
during the 1980s. Cambodians continued to
enjoy rich catches until the middle of the 1990s.
Nowadays, the species is being harvested mostly
in Takeo and Prey Veng provinces, primarily along
the Vietnamese border, with an estimated catch
of about 30 tonnes per year. The drastic decline
of 70% cannot supply growing local markets due
to heavy shing pressure and habitat degradation.
The catch from Fishing Lot Nos 17 (Bangkang
Vear) and 16 (Chrawlay) on the Tonle Sap in
Kompong Chhnang and from the bag-net “dai”
shery along the Tonle Sap in Kandal and Phnom
Penh has declined steadily. By 2005, there was
virtually no catch from these shing areas. In other
words, total freshwater prawn production declined
across the country and the distribution range of the
species fell from six to two provinces.
First trial and monitoring results
Faced with this critical situation, the Fisheries
Administration of the Ministry of Agriculture,
Forestry and Fisheries initiated the rst trial for
a stock-enhancement programme of the once
abundant prawn in the Tonle Sap River on
September 28, 2010. The administration released
some 120,000 sixty to ninety-day-old post larvae
(PL60 & PL90) into Fishing Lot No 17 to improve
and increase the population in Cambodia. It was
hoped that the released post larvae could survive
predation and migrate into the huge nutrient-rich
oodplain surrounding the shing lot and other
areas of Tonle Sap for foraging and grow-out to
improve stocks.
After stocking, the regular sh catch monitoring
program of the Inland Fisheries Research and
Development Institute (IFReDI) of the Fisheries
12 Catch and Culture Volume 17, No. 3 December 2011
Stock enhancement
Administration recorded the number and weight
of prawns caught along the Tonle Sap River from
Kompong Chhnang to Phnom Penh between
November, 2010 and March, 2011. The rst
positive and promising result came on November
25, 2010 when Fishing Lot No 7 on the Tonle
Sap in Kompong Thom province, which had not
caught any prawns for the 50 years, reported a
catch estimated at about 180 kg. Fishing Lots
Nos 6, 8 and 17 in Kompong Chhnang recorded
300 kg. This meant that the stocked post larvae
of prawns in the Tonle Sap River migrated
upstream beyond the oodplain of Kompong
Chhnang to the oodplain of Kompong Thom for
foraging and grow-out in the Tonle Sap Lake. In
addition, stocked prawns were caught by small
and medium-scale shers around the Tonle
Sap in Pursat, Kompong Thom and Kompong
Chhnang provinces which had no catches for
many years. The estimated catch was 0.5-1.0
kg per season per sher or 36 kg in Pursat, 223
kg in Kompong Thom and 100 kg in Kompong
Chhnang. Furthermore, each of the 63 dai shers
along the Tonle Sap River in Kandal and Phnom
Penh recorded estimated catches ranging from
0.5 to 2.5 kg per day with an average of 73 kg per
dai per season or 4,604 kg in total. In the four-
month period from October 28, 2010 to January
28, 2011, the total estimated catch of stocked
prawns harvested by all types of shing gear along
the Tonle Sap River in Pursat, Kompong Thom,
Kompong Chhnang, Kandal and Phnom Penh was
5,443 kg (Figure 1) with a gross value of
$81,645. It is worth noting that the net pro t was
$77,645 for four months after stocking, with an
economic ef ciency rate of 19.41. The weight of
stocked prawns caught from the River ranged from
50 g to 200 g, with an average weight of 142.48 g
(Figure 2). Records showed that prawn could be
harvested within four months of stocking with an
estimated recapture rate of 29%. This is a very
high recapture rate which is due to the very large
size of released post larvae (PL60 & PL90 or sub
adult prawns), the very productive oodplain of the
Tonle Sap and the very short period of recapture
compared to many stock enhancement programs
in Southeast and South Asia (Kutty et al., 2010).
Conclusions and recommendations
This rst trial shows that the freshwater prawn
stocking programme initiated by the Fisheries
Administration was successful. The programme
should be continued and expanded to replenish
depleted stocks due to over shing and intrusions,
increase production for consumer needs and
improve socio-economic conditions of shers
Kompong Thom
Kompong Chhnang
Phnom Penh
Figure 1: Production of giant freshwater prawn recaptured (kg) by different provinces of the Tonle Sap River and its
associated oodplains
December 2011 Catch and Culture Volume 17, No. 3
Stock enhancement
and communities. This will help to reduce poverty
and improves people’s livelihoods and national
prosperity as stated in the Strategic Planning
Framework for Fisheries (2010–2019), the
National Strategic Development Plan (2009–
2013) and the Royal Government of Cambodia’s
Rectangular Strategy II.
* His Excellency Dr Nao Thuok is Director General of the
Fisheries Administration of the Ministry of Agriculture,
Forestry and Fisheries, Dr So Nam is Director of
the Administration’s Inland Fisheries Research and
Development Institute (IFReDI) and Mr Chheng Phen is a
Deputy Director of the Institute.
Ahmed N & Troell M (2010). Fishing for Prawn Larvae in
Bangladesh: An Important Coastal Livelihood Causing
Negative Effects on the Environment. AMBIO, published
online: 25 Feb 2010.
Ahmed N, Demaine H & Muir JF (2008). Freshwater prawn
farming in Bangladesh: history, present status and future
prospects. Aquaculture Research, 1:14
Kutty MN, Nair CM, Numbudiri NN, Sathish Prasad, New
MB (2010). Enhanced sheries of freshwater prawn - Status
and Potential. Powerpoint presentation of World Aquaculture
Society Forum 2010, 1-5 March 2010, San Diego, California.
New MB & Kutty MN (2010). Commercial freshwater prawn
farming and enhancement around the world. In MB New,
Valenti WC, Tidwell JH, D’Abramo LR & Kutty MN (eds)
Freshwater prawn; biology and farming. Wiley-Blackwell,
Oxford, England.
New MB (2002). Farming freshwater prawns- A manual for the
culture of the giant river prawn (Macrobrachium rosenbergii).
FAO Technical paper No. 428.
Sripatrprasite P and Kwei Lin C (2003). Stocking and
Recapture of Freshwater Prawn (Macrobrachium rosenbergii
De Man) in a Run-of-River Type Dam (Pak Mun Dam) in
Thailand. Asian Fisheries Science 16 (2003): 167-174
Figure 2: Proportion of giant freshwater prawn recaptured (%) from the Tonle Sap River by different weights (g)
Weight of prawn (g)
Proportion (%)
0 50 100 150 200 250
14 Catch and Culture Volume 17, No. 3 December 2011
Habitat on Phu Quoc island
New species, Clarias gracilentus,
is believed to be indigenous to the
Vietnamese island of Phu Quoc and
southeastern Cambodia
A sh resembling the slender walking cat sh
(Clarias nieho i) has been found to be a new
species from the Clarias genus of walking
cat shes, the largest genus in the Clariidae family
of airbreathing cat shes. Specimens of the sh
were collected by Nguyen Van Tu of the Faculty
of Fisheries at Non Lam University in Ho Chi Minh
City during an ichthyological survey of Phu Quoc
island off the southeast coast of Cambodia. While
it is not part of the Lower Mekong Basin, the island
is administered as part of Kien Giang province in
the Mekong Delta.
Tu and two colleagues, Ng Heok Hee from
the Raf es Museum of Biodiversity Research
in Singapore and Dang Khanh Hong of the
Agriculture and Fisheries Extension Center in
Kien Giang, have subsequently described the new
species in a paper that appeared in taxonomy
journal Zootaxa earlier this year.
The authors noted that the new species, Clarias
gracilentus, is also found in southeastern
Cambodia and brings to 20 the number of Clarias
species recognized in Southeast Asia out of 56
Singapore, Vietnamese researchers
describe new species of walking cat sh
December 2011 Catch and Culture Volume 17, No. 3
Clarias gracilentus
Clarias gracilentus
species worldwide, mostly in Africa. The Southeast
Asian species are divided into two species
complexes based on their body forms. The slender
walking cat sh complex of elongated eel-like
shes now includes the new species as well as
Clarias nigricans, discovered in the Mahakam
River Basin in the Indonesian part of the island
of Borneo in 2003, and Clarias pseudonieuho i,
which was discovered in Borneo in 2004.
Vietnamese news reports say the provincial
Department of Science and Technology in Kien
Giang has allocated almost $10,000 to study the
new species to see if it is suitable for breeding.
Further reading:
Ng HH, Dang KH and Nguyen VT (2011). Clarias gracilentus,
a new walking cat sh (Teleostei: Clariidae) from Vietnam and
Cambodia. Zootaxa 2823: 61–68
16 Catch and Culture Volume 17, No. 3 December 2011
Hydropower development
Further study on impact of Mekong
mainstream development required
Water and environment ministers agree in
principle to approach Japan to assist with
a study to provide a more complete picture
of the impact of hydropower projects
The Mekong River Commission Council Members
concluded on December 8 that there is a need
for further study on the sustainable development
and management of the Mekong River including
impact from mainstream hydropower development
The Council Members, comprising water and
environment ministers from Cambodia, Lao PDR,
Thailand and Viet Nam, agreed in principle to
approach the Government of Japan and other
international development partners to support the
conduct of further study.
The agreement was made in response to the
outcome of a verbal discussion by the four Prime
Ministers of the MRC Member Countries—
Cambodia, Lao PDR, Thailand and Viet Nam,
at the 3rd Mekong-Japan Summit held on the
sideline of the 19th ASEAN Summit in Bali,
Indonesia in November 2011.
At the Bali meeting, the four national leaders
discussed the need for conducting further study for
the sustainable management and development of
the Mekong River and its related resources.
The four ministers made this conclusion at their
annual gathering to discuss the prior consultation
process for the proposed Xayaburi hydropower
project (see box on opposite page) along with other
administrative and management matters.
“The outcome today demonstrates the Member
Countries’ continued commitment to work together
in the regional spirit of the Mekong Agreement
to bring about economic development without
compromising sustainability of livelihoods of their
peoples and the ecology,” said Mr Lim Kean Hor,
Council Member Chairperson and Cambodia’s
Minister of Water Resources and Meteorology.
“Further study will provide a more complete picture
for the four countries to be able to further discuss
the development and management of their shared
resources,” he said.
In addition to Mr Lim Kean Hor, other MRC Council
Members gathered at the meeting were Mr
Noulinh Sinbandhit, Lao Minister of the Ministry of
Natural Resources and Environment, Mr Preecha
Rengsomboonsuk, Thai Minister of Natural
Resources and Environment, and Mr Nguyen Minh
Quang, Vietnamese Minister of Natural Resources
and Environment.
Artist’s impression of the proposed Xayaburi hydropower dam, northern Lao PDR
December 2011 Catch and Culture Volume 17, No. 3
Hydropower development
Procedures for Noti cation, Prior Consultation and Agreement
The 1995 MRC Mekong Agreement established the Procedures for Noti cation, Prior Consultation
and Agreement (PNPCA), which states that Member Countries must notify the MRC’s Joint
Committee in the event they wish to engage in any major infrastructure developments (such as
hydropower schemes) on the mainstream Mekong or tributaries, particularly if those developments
may have signi cant trans-boundary impacts on people or the environment downstream.
The PNPCA process itself is the formal mechanism in place to enable one or more individual Member
Countries to submit an individual project for the 4-country regional consideration. In the case of the
Xayaburi dam project, the Government of Lao PDR noti ed the MRC to begin the PNPCA process.
The MRC received the noti cation of the Xayaburi hydropower development project from the
Government of Lao PDR in September last year. Under the PNPCA, the four countries consult each
other on the proposal and then reach a conclusion, within six months since the noti cation, on how to
proceed with the project.
Since the noti cation, the countries have conducted national consultations with related stakeholders
including potentially affected communities to gauge their views and perspectives on the project. The
MRC Secretariat also commissioned a team of environmental experts to review documents including
the Environmental Impact Assessment submitted by the Government of the Lao PDR.
This consultation process is one of a number of protocols in the 1995 Mekong Agreement to promote
cooperation in sustainable management of the basin’s water resources and avoid regional disputes
The Xayaburi hydropower project would be the rst such project on the Mekong mainstream
downstream of China and would be capable of generating 1260 megawatts of electricity, mainly for
export to Thailand.
The Xayaburi dam is located approximately 150 km downstream of Luang Prabang in northern Lao
PDR. The dam has an installed capacity of 1,260 MW with a dam 810 m long and 32 m high and has
a reservoir area of 49 km2 and live storage of 225 Mm3. The primary objective of the Xayaburi dam
project is to generate foreign exchange earnings for nancing socio-economic development in Lao
PDR. The developer is Ch. Karnchang Public Co. Ltd. of Thailand who negotiated a tariff agreement
with EGAT in July 2010.
The MRC acts as a facilitating body for this PNPCA process. It is the intergovernmental body
responsible for cooperation on the sustainable management of the Mekong Basin whose members
include Cambodia, Lao PDR, Thailand and Viet Nam. In dealing with this challenge, the commission
looks across all sectors including sustaining sheries, identifying opportunities for agriculture,
maintaining the freedom of navigation, ood management and preserving important ecosystems.
After the six-month period required for the PNPCA’s prior consultation process, the four Member
Countries met to discuss the proposed Xayaburi project at the Special Session of the MRC Joint
Committee in April 19, 2011 held in Vientiane, Lao DPR. However, the countries could not come to
a common conclusion on how to proceed with the project because there is still a difference in views
on the matter. The Joint Committee Members agreed that the matter be tabled for discussion at the
ministerial level or the MRC Council.
18 Catch and Culture Volume 17, No. 3 December 2011
Third edition of better management
manual for Vietnamese cat sh farmers
New version based on feedback from
farmers and other stakeholders
Australia’s Collaboration for Agriculture and Rural
Development (CARD) Project has published
a third version of a manual designed to get
Vietnamese cat sh farmers in the Mekong Delta to
adopt better management practices.
The new version incorporates revisions based on
feedback and experiences from 11 demonstration
farms, from among 89 surveyed (see red dots on
map below), that volunteered to adopt a draft of
the second version. The manual is supplemented
by simpli ed, easily comprehensible and
adaptable instructions and advice to farmers and
booklets for regular record keeping.
It also includes
numerous consultations
that the project team had with
the volunteer farmers and other
stakeholders as well as revisions
made at a national workshop with all
stakeholders in Long Xuyen in November, 2011
(see Catch and Culture, Vol 16, No 13).
CARD, funded by the Australian Agency for
International Development (AusAID) says the
farmers will be provided with handbooks that
summarize the third version. These will feature
simple Vietnamese translations together with
standardised record-keeping booklets for use
on farms. Considered as primary dissemination
material for farmers, the handbooks aim to
facilitate industry-wide adoption of better
management practices by farmers raising Sutchi
river cat sh (Pangasianodon hypophthalmus) in
Viet Nam.
Launched in 2007, the three-year project to
develop better management standards was
overseen by the Ministry of Agriculture and Rural
Development. It was undertaken by the Research
Institute for Aquaculture No 2 in Ho Chi Minh City
in collaboration with the College of Aquaculture
and Fisheries at Can Tho University in partnership
with the Department of Primary Industries in the
Australian state of Victoria and the Network of
Aquaculture Centres in Asia-Paci c (NACA) based
in Bangkok.
that the pro
ect team had with
August 2011 Catch and Culture Volume 16, No. 2
Climate Change in the Lower Mekong Basin:
Impacts on Floods & Fisheries
Impact vulnerability in the Lower Mekong
How might the oods and
sheries of the Lower
Mekong Basin be impacted
by climate change?
This policy brief examines
this question in the context of
planned basin development
activities drawing upon recent
research ndings.
A recent study1 ranked the
vulnerability of national
economies to the impacts
of climate change on their
sheries using indices of
exposure, sensitivity and
adaptive capacity. The
study ranked Viet Nam and
Cambodia as two of the
most vulnerable countries
in tropical Asia (ranking
27 and 30 respectively),
along with Bangladesh,
Pakistan and Yemen.
Their vulnerabilities arise
from the combined effect
of predicted warming,
the economic and
dietary importance of
their sheries and their
comparatively limited
capacity to adapt. Lao
PDR was also found to be
vulnerable but its ranking
at 37 may underestimate
its true relative vulnerability
because its sheries are
likely to be grossly underestimated in
the statistics employed for the study.
Thailand ranked 82 in the study
because, despite the signi cance of
its sheries, it is better able to cope
with climate change impacts, having
a higher gross domestic product, a
more diversi ed economy, and lower
rates of poverty.
The study described above clearly
demonstrates the vulnerability of
the sheries of the LMB to climate
change. But what might be the
nature and scale of climate change
impacts on the sheries resources in
a warming basin with increasing, but
more variable, precipitation?
Impacts of climate change on
sheries resources are likely to
arise through complex behavioural,
physiological and habitat change-
related responses. These may
be exacerbated by the effects of
adaptive coping strategies pursued
by other sectors, particularly those
that compete for water1,2,3,4. Whilst
there is a large and growing
literature on climate change impacts
associated with marine systems,
far fewer studies have examined
impacts on freshwater systems and
their sheries, particularly in tropical
Catch and Culture Volume 17, No. 3 December 2011
Expected higher temperatures in the
future have the potential to reduce oxygen
solubility in water but can raise the oxygen
and food intake demand of sh as their
metabolic rates are raised5. Higher water
temperatures, particularly during the
winter months, can favour the survival
and poleward spread of parasites and
bacteria. Combined, these responses have
the potential to reduce sh growth in food
limited environments, as well as rates of
sh survival. Studies have shown that the
reproductive success of tropical species can
also decline under elevated temperatures5.
Populations inhabiting regions where
temperatures already exceed their
thermal optima, and stenothermal species
with narrow thermal tolerances, are
therefore most at risk of impact from rising
temperatures. Stenothermal species may
therefore be displaced to regions where
water temperatures more closely match
their thermal optima and be replaced by
more temperature-tolerant eurythermal
species such as common carp (Cyprinus
Higher temperatures could also reduce the
productivity of large lakes and reservoirs
by thermal strati cation and stabilisation of
the water column reducing the availability
of nutrients in the surface layers, thereby
impacting on sh production. Sudden
overturn of cold anoxic deep waters created
through these processes can cause sh
mortalities 4,5.
Changes to river ow in response to
changing spatial and temporal patterns
of precipitation are expected to impact
on sh stocks inhabiting river systems3,4.
Flows affect habitat availability, system
productivity, and also sh population
processes i.e. growth, survival and
It has been suggested that changes in
primary production and transfer will have
a key impact on sheries2. Increasing
ows during the ood season translate to
more extensive and prolonged oodplain
inundation, potentially increasing overall
system productivity in river systems
including the sh component6,7. Longer,
more extensive oods are likely to provide
greater and more prolonged feeding and
opportunities for sh11,12. In response,
improved growth should also favour survival
and reproductive potential.
However, not all species may bene t.
Increasing river ows may hamper
upstream spawning migrations, erode
spawning beds or sweep eggs and juveniles
past downstream nursery and feeding
habitat. Overly-rapid changes in water level
can also lead to diminished reproductive
success of channel-margin spawning and
nest-building species. Changes to the
timing of ows also have the potential to
disrupt spawning behaviour13.
The dry season is a period of great stress
to many river sh species arising from
diminished feeding opportunities and water
quality, and elevated risk of predation or
Greater precipitation and water availability
during this period might favour sh survival
and ultimately exploitable biomass, whilst
drier conditions would have the converse
effects14,15. However, increasing dry
season water levels may diminish primary
production and habitat diversity within
the system by permanently inundating
fringing forests and vegetation leading
to permanent die-back and by effectively
reducing the size of the ood margin or
‘aquatic-terrestrial-transition-zone’ (ATTZ)
for nutrient re-cycling6.
Increasing hydrologic variability in river
systems could select for generalist species
that are better able to exploit a wide range
of resources and tolerate to a wide range of
environmental conditions leading to the loss
of locally adapted or specialist species5.
Lower ows combined with sea level rise
could increase saline intrusion into river
deltas. This might displace stenohaline
species with narrow salinity tolerances
further upstream and increase the upstream
range and biomass of more salinity tolerant
euryhaline species including those that
depend upon brackish water environments
to complete their life-cycles e.g. the
giant freshwater prawn (Macrobrachium
rosenbergii). Changes in species
composition might therefore be signi cant
but the net effect on wild sh production and
shing opportunities might be small 9,10.
Higher temperatures
have the potential to
reduce rates of sh
growth and survival,
as well as reproductive
Longer and more
extensive ooding
in a warmer basin is
expected to bene t sh
growth and survival
but, may diminish
reproductive success
for some species.
Salinity in the delta
might change but the
net effect on wild sh
production is likely to
be marginal.
Climate change impacts on inland sheries
August 2011 Catch and Culture Volume 16, No. 2
No mechanistic models currently exist
with which to predict the net effects of all
of these potential responses and their
interactions. The task of understanding
the impacts of climate change on sheries
production is therefore very daunting4.
However, empirical models applied at the
community level might offer a practical
alternative 4,16.
A recent study17 adopted this empirical
approach to examine how predicted
precipitation and evapo-transpiration-driven
changes to ow, indicated by extent and
duration of ooding under different climate
change and basin development scenarios,
may affect exploitable sh biomass in the
Tonle Sap-Great Lake (TS-GL) system.
The TS-GL is the largest wetland in
Southeast Asia and supports productive
sheries and dependent livelihoods both
locally and regionally due to the migratory
nature of the species of sh that seasonally
inhabit the system.
The study assumed that the predicted
response for this system would be
applicable throughout the lower basin.
The predicted response of sh biomass
in the TS-GL System to hydrological
conditions each year under six different
scenarios of basin development and
climate change were examined (Table 1).
The 20-year Future Development
Scenario includes the construction of
31 tributary and 11 mainstream dams,
and the expansion of irrigation projects
by some 2 million hectares according to
the Basin Development Plan (BDP). This
development has the potential to modify the
hydrology of the basin through storage and
abstraction effects. Future precipitation
in the basin was predicted under future
emissions scenarios A2 and B218.
Both minimum and maximum water levels,
and the ood indices combining annual
ood extent and duration, are predicted
to increase over the next 40 years as
a consequence of climate change, but
not signi cantly at the 5 % level. These
increases will be greater under the A2
compared to the B2 emissions scenario.
However, given the extent of their between-
year variability, and the predicted marginal
changes to their values under each
scenario, the study concluded that ow-
mediated effects of climate change on sh
biomass in the TS-GL system during the
next 40 years are unlikely to be detectable
(Figure 1).
Basin development activities were
predicted to have a signi cant effect on
minimum (dry-season) water levels, raising
them by approximately 30 cm depending
upon the climate change scenario.
However, the study also concluded that
these increases would have little effect on
sh biomass.
Volume 16, No. 2
impacts of
climate change
“... ow-mediated
impacts of climate
change on sh catches
during the next 40
years are unlikely to be
Predicted impacts on sheries in the LMB
ln Biomass Index 2 (kg/day)
Catch and Culture Volume 17, No. 3 December 2011
Table 1 Climate change and basin development scenarios examined
Scenario Title Development CC Development/Comments
S1 Baseline Scenario 1985–2000 x x
S2 Baseline Scenario A2, 2010–2050 x A2 Future Emissions
S3 Baseline Scenario B2, 2010–2050 x B2 Future Emissions
S4 20 Year Future Development 1985–2000
S5 20 Year Future Development A2, 2010–2050 
A2 Future Emissions
S6 20 Year Future Development B2, 2010–2050 
B2 Future Emissions
CC: climate change effects
Development: basin development project effects
included in scenario
x not included.
Figure 1 Estimates of the mean loge-transformed
sh biomass index for the TS-GL System corre-
sponding to the predicted ooding conditions for
the six scenarios. Error bars give 95% con dence
intervals around the mean.
The barrier impacts of
dams are likely to be
more signi cant than
those arising from
climate change and
may prevent sh from
adapting to climate
Improving impact predictions
This study of climate change impacts on
sheries has made no attempt to quantify
the potential impacts on sh biomass
caused by changes to water temperature
in the basin, or salinity changes in the delta
caused by changes to ow. The predicted
impacts may therefore be conservative.
A more comprehensive assessment
would require greater knowledge and
understanding of the physiological
responses, tolerances and potential
behavioural adaptations of the species
of sh and the likely response of the
ecosystem as a whole. On the other hand,
given the plasticity in their reproductive
strategies to changes in temperature, their
typical high critical thermal maxima, and
the small temperature increases predicted
for the tropics, the effects of temperature
on tropical species are likely to be marginal
compared to those arising from altered ow
regimes5. Furthermore, whilst changes to
species distribution in the delta may arise in
response to salinity conditions under future
climatic conditions, the net effect on wild
sh production and shing opportunities is
also anticipated to be marginal.
Flow vs barrier-related impacts
Planned basin development activities
will not only modify the hydrology and
associated productivity of the river system
but are also, particularly in the case of
dam construction, likely to obstruct sh
migrations between critical habitat and raise
natural mortality rates in sh populations
as a consequence of sh passage through
turbines and other dam structures19. These
additional barrier and passage effects
should be given careful consideration in
addition to the climate change or basin
development mediated ow-related impacts
included in the study described here.
Indeed, these barrier effects are likely to be
signi cant and become ever more important
in a warming basin because they will
diminish opportunities for sh to migrate to
areas with appropriate thermal conditions.
Even if opportunities for migration were
maintained, sh would have to cope with a
new physical environment and compete for
space potentially bringing about changes in
species composition in favour of generalist
species and altering ecosystems5.
* Dr Halls is Director of Aquae Sulis Ltd, a sheries
management and development rm based in Bath,
United Kingdom
Balancing the threats
1 Allison, E.H., Perry, A.L., Badjeck, M.C., Adger, W.N., Brown, K., Conway, C., Halls, A.S., Pilling, G.M., Reynolds, J.D., Andrew, N.L. &
Dulvy, K.N. (2009). Vulnerability of national economies to the impacts of climate change on sheries. Fish and Fisheries 10: 173-196.
2 Easterling, W.E., P.K. Aggarwal, P.Batima, K.M. Brander, L.Erda, S.M. Howden, A. Kirilenko, J. Morton, J.-F. Sousanna, J. Schmidhuber
& F.N. Tubiello (2007). Food, Fibre and Forest Products. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution
of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Canbridge University Press,
Cambridge, UK, 273-313.
3 FAO (2008). FAO expert workshop on climate change implications for sheries and aquaculture. FAO Fisheries Report 870: 32pp.
4 Brander, K.M. (2010). Impacts of climate change on sheries. Journal of Marine Systems 79: 389-402.
5 Ficke, A.D., Myrick, C.A., & Hansen, L.J. (2007). Potential impacts of global climate change on freshwater sheries. Reviews in Fish
Biology and Fisheries 17: 581-613.
6 Junk, W.J., Bayley, P.B., & Sparks, R.E.(1989). The ood pulse concept in river- oodplain systems. In Proceedings of the International
Large Rivers Symposium, Vol 106, Edited by Dodge, D.P. pp 110-127.
7 Welcomme, R.L (1985). River Fisheries. FAO Fisheries Technical Paper 262: 330pp.
8 Welcomme, R.L. & Halls, A.S. (2004). Dependence of Tropical River Fisheries on Flow. In: Welcomme, R.L. & Petr, T. (Ed.)
Proceedings of the 2nd International Symposium on the Management of Large Rivers for Fisheries. Vol 2, pp. 267-284. Bangkok: FAO.
9 Bates, B.C., Z.W. Kundzewicz, S. Wu & J.P. Palutikof (Eds) (2008). Climate Change and Water. Technical Paper of the
Intergovernmental Panel on Climate Change, IPCC Secretariat, Geneva, 210pp.
10 Barlow, C. & Burnhill, T. (undated). The consequences of climate change on the sheries of the Mekong River system. Unpublished
report, 2 pp.
11 Halls, A.S. Lieng, S., Ngor, P. & Tun, P. (2008). New research reveals ecological insights into the dai shery. Catch & Culture 14: 8-12.
12 Halls, A.S., Paxton, B.R., Hall, N., Pengbun, N., Lieng, S. & Pengby, N. (2011). The Stationary Trawl Fishery of the Tonle Sap-Great
Lake, Cambodia. MRC Technical Paper No. XX, Mekong River Commission, Vientiane, XXpp. ISSN: XXXX-XXXX.
13 Welcomme, R.L., & Halls, A.S. (2001). Some considerations of the effects of differences in ood patterns on sh populations.
Ecohydrology and Hydrobiology 1: 313-321.
14 Welcomme, R.L. & Hagborg, D. (1977). Towards a model of a oodplain sh population and its shery. Environmental Biology of
Fishes 2: 7-24.
15 Halls, A.S. & Welcomme, R.L. (2004). Dynamics of river sh populations in response to hydrological conditions: a simulation study.
River Research and Applications 20: 985-1000.
16 Jennings, S. & Brander, K.M. (2010). Predicting the effects of climate change on marine communities and the consequences for
sheries. Journal of Marine Systems 79; 418-426.
17 Mainuddin, M., Hoanh, C.T. Jirayoot, K., Halls, A. S., Kirby, M., Lacombe, G. & Srinetr, V. (2010). Adaptation Options to Reduce the
Vulnerability of Mekong Water Resources, Food Security and the Environment to Impacts of Development and Climate Change.
CSIRO, October 2010.
18 IPCC (2000). IPCC Special Report. Emissions Scenarios. Summary for Policy Makers. IPCC 2000, 27pp.
19 Halls, A.S. & Kshatriya, M. (2010). Modelling the cumulative impacts of mainstream dams on migratory sh populations in the lower
Mekong basin. MRC Technical Paper No. 25. Vientiane, Mekong River Commission.
December 2011 Catch and Culture Volume 17, No. 3
Management changes
New management at Department of
Fisheries in Thailand
Two former members of the MRC Technical
Advisory Body for Fisheries Management
(TAB) assume senior positions in Thailand
Wimol Jantrarotai has been appointed director
general of the Thai Department of Fisheries,
succeeding Somying Piumsomboon who has
retired. Dr Wimol was previously inspector general
of the Ministry of Agriculture and Cooperatives.
Before that, he was deputy director general of the
Dr Wimol has conducted outstanding sheries
research, especially in the development of sh
nutrition. He used to head the Thai councils for
the Network of Aquaculture Centres in Asia-Paci c
(NACA) and the Center for Fisheries Development
in Southeast Asia (SEAFDEC). He is also a former
member of the MRC Technical Advisory Body for
Fisheries Management (TAB).
Three years after joining the department in 1981,
the young sheries biologist won a scholarship from
the Ananda Mahidol Foundation for master degree
studies at Auburn University in Alabama which
led to a PhD. After returning to the department in
1990, he served as director of sheries affairs and
senior sheries expert before becoming deputy
director general of the department in 2007 and the
ministry’s inspector general in 2009.
Dr Wimol completed his BSc in Fisheries ( rst
class honors, gold medal) at Kasetsart University.
In other developments, Somwang Pimolbutr has
been appointed as one of three deputy directors
general. Mr Somwang was previously director of
the Inland Fisheries Research and Development
Bureau, a position he held since 2008. Before
that, he served as director of sheries centers in
many provinces, including Chainat, Ayuddhaya,
Pattani, Nakorn Sawan and Suphan Buri.
Mr Somwang has also served as a TAB member.
He is also well known for his research into various
indigenous sh species and was the rst person
to succeed in breeding the Boeseman croaker
(Boesemania microlepis), a highly commercial
species known as pla ma in Thai.
After completing his BSc in Fisheries at Kasetsart
University in 1976, Mr Somwang joined the
Department of Fisheries in 1977. He was
promoted as the rst director of Mae Hong Son
sheries station in 1988.
Nopphadon Phuwaphanit has succeeded Mr
Somwang as director of the Inland Fisheries
Research and Development Bureau. He
was previously head of provincial sheries at
Prachauob Kirikhun and director of the Coastal
Fisheries Research Institute in Songkhla province.
He has graduated a BSc in Fisheries from
Kasetsart University and a master’s degree from
University of the Philippines.
* Mr Theerawat is an MRC Fisheries Programme Of cer
Dr Wimol
Mr Somwang
Mr Nopphadon
24 Catch and Culture Volume 17, No. 3 December 2011
CP Hong Kong arm expects Viet Nam
acquisition to be key growth driver
Thai feed mill giant Charoen Pokphand
sees bene ts from increased Vietnamese
production of corn and soybeans for use as
feed raw materials
CP Pokphand Co Ltd, the Hong Kong-based
investment arm of Thailand’s Charoen Pokphand
Group, has invested more than $600 million to
acquire a controlling interest in CP Vietnam Ltd, an
integrated livestock and aquaculture company with
a signi cant presence in the Mekong Delta.
Listed on the Hong Kong Stock Exchange since
1988, the Bermuda-incorporated company already
has 78 feed mills in China where its aquatic, swine
and poultry feeds have received national awards.
The deal, completed in July, involved CP
Pokphand buying Modern States Investments
Ltd, a British Virgin Islands company that controls
70.8% of CP Vietnam, for $HK 4.375 billion ($US
608 million). Modern State is controlled by the
Thai group, the country’s leading agricultural
In releasing its interim nancial results in August,
the Hong Kong company said the acquisition would
accelerate the expansion of its business, which has
mainly focussed on China until now. “From 2011
to 2015, the Vietnam government has set annual
growth targets of 7.5% to 8.5% as part of the ve-
year growth plan for its local livestock industry,” the
company said.
“To achieve these goals, the Vietnamese
government has been facilitating the modernization
of its livestock industry, and increasing the
production of corn and soybean for use as
feed raw materials. With this favourable market
environment, the group is con dent that its newly-
acquired Vietnam operation will stand to bene t.”
CP Vietnam began its aquaculture business in
1999, three years after establishing a subsidiary to
cover southern Viet Nam and six years after it rst
entered the local market with a subsidiary covering
the north of the country. The two companies
merged in 2009 with operations spanning
feed production, breeding and farming to food
processing and packaging.
In addition to three shrimp hatcheries, three shrimp
farms and nine sh farms, CP Vietnam has three
aquatic feed mills in Can Tho, Ben Tre and Dong
Nai provinces with a combined capacity of nearly
0.61 million tonnes a year. It also has an aquatic
food processing and cold storage plant in Dong Nai
and four livestock feed mills in various provinces
with plans to invest almost $170 million on another
six by 2014.
When the deal was rst announced, Dhanin
Chearavanont, chairman of the Hong Kong
company, said the acquisition would position it as
the leader in the commercial feed and industrial
farming market of Viet Nam. “We expect the fast
growing business in Viet Nam to become a key
growth driver and to contribute to a broader and
more diversi ed income base for the group going
forward,” Dhanin said, adding that the company’s
goal was to become a “signi cant player in Asia’s
promising agri-food market.”
During the rst six months of 2011, sales of CP
Vietnam jumped 45.3% from a year earlier to VND
13.3 trillion ($US 665 million). For the full year
ended 2010, the company posted a net pro t of
VND 964 billion ($US 50 million) on sales of 22.1
trillion ($US 1.05 billion).
CP Vietnam’s sales in the rst half of 2011
represented more than half the Hong Kong
company’s sales to external customers of $US
1.14 billion in the same period. More than 95% of
revenue was from China, with the rest coming from
the United States and other countries.
* Mr Starr is editor of Catch and Culture
December 2011 Catch and Culture Volume 17, No. 3
CP Vietnam feed, farming and processing operations
Livestock Feed Mill
Dong Nai
Aquatic Feed Mill
Livestock Feed Mill
Aquatic Food Processing and
Cold Storage Plant
Livestock Food Processing Plant
Binh Duong
Livestock Feed Mill
Ben Tre
Aquatic Feed Mill
Can Tho
Aquatic Feed Mill
Tien Giang
Livestock Feed Mill
In addition to four livestock feed mills and 2,300
farms, CP Vietnam operates three aquatic feed
mills in Viet Nam as well three shrimp farms,
six shrimp hatcheries and nine sh farms. Feed
products are distributed through more than
1,300 dealers while food products are distributed
through both traditional and modern channels.
Aquatic food products are exported primarily to
overseas markets such as the European Union,
Japan and other Asian countries.
26 Catch and Culture Volume 17, No. 3 December 2011
Cambodia’s potential for reservoir sheries
After ve years in Bangkok as Director-General
of the Network of Aquaculture Centres in Asia-
Paci c (NACA), an inter-governmental agency that
promotes rural development through sustainable
aquaculture, Sena De Silva recently returned to
Australia where he is Honorary Professor at the
School of Life and Environmental Sciences at
Deakin University in Victoria. Professor De Silva
began his career working on sh populations in
reservoirs in Sri Lanka. He later also worked in
Scotland and Singapore before nally settling in
Australia. He has acted as principal investigator
on many reservoir sheries development projects
in Sri Lanka, Viet Nam and Lao PDR over the
past 25 years and has published widely in the
eld. He has also worked extensively on sh
nutrition and is an expert on aquaculture planning
and development as well as climate-change
impacts on aquaculture. Catch and Culture
recently interviewed the professor, an honorary life
member of the World Aquaculture Society, about
the potential for reservoir sheries in Cambodia in
light of proposals for two hydropower projects on
the Mekong mainstream in northeast Cambodia.
Catch and Culture: What are the different
systems of sh production in reservoirs in the
Professor De Silva: Basically, you have four.
The rst is where you harness the natural
production through natural recruitment and the
sheries thereof. When reservoirs are not good
enough for sustainable natural production, stock
enhancement can be used. A third system is to
partition off reservoir coves with nets or bamboo
fences and stock with suitable species. There’s
a huge drawdown in reservoir coves and the sh
can be harvested as the water level recedes.
Such systems can be up to two hectares and are
suitable for community sheries. You also have
cage culture and variations of these four systems.
Catch and Culture: What would be the most
suitable systems for dam reservoirs, in particular
for large mainstream dams such as those
proposed for Stung Treng and Sambor?
Professor De Silva
Professor De Silva: In mainstream dam
reservoirs where the water ow is quite high, the
chances of enhancing sh stocks is quite low
compared with standing water bodies in normal
reservoirs. I don’t think aquaculture will be feasible
in mainstream dam reservoirs.
“I don’t think aquaculture will be
feasible in mainstream dam
reservoirs ... there are lots of technical
constraints and you probably won’t get
cost-effective returns. ”
Catch and Culture: What are the constraints and
limitations of each production system?
Professor De Silva: With mainstream dams, there
are lots of technical constraints and you probably
won’t get cost-effective returns. In culture-based
sheries, feed is not a problem as the sh
consume what’s available naturally. Regardless of
whether you have stock-enhanced sheries, cage
culture or reservoir cove sh culture, you’ll have
to have production of suitably-sized ngerlings
as seed stock. There’s also a need to consider
exotic sh production. People have to be trained
in activities such as stock enhancement at the
community level. Hatchery managers also have
to be trained. Stock-enhanced and culture-based
December 2011 Catch and Culture Volume 17, No. 3
sheries also require rules for things like the type
of shing gear that can be used and how and
when the sh are harvested. Issues such as water
quality and availability or soil acidity will be very
speci c to each site. My experience in most of
Asia is that none of these issues are problems.
“Fingerling supplies are always
a problem. People need to be
conscious that it can only be done
through proper hatchery production.”
Where you do have problems is when you have
an explosion of cage culture in a reservoir which
could lead to build up of nutrients in the sludge,
resulting in deteriorating water quality over a
period of time and nally leading to sh kills
when the upwelling occurs. Reservoir coves are
more suitable for community-managed culture-
based sheries. But while water quality may not
initially be a problem, increased anthropogenic
developments in the catchments and the resulting
discharge could be a problem for water quality
in the future. At the socio-economic level, most
reservoir aquaculture is at the community level
such as culture-based sheries with the exception
of cage culture by private entrepreneurs. So
there’s a need for co-management measures.
With reservoir coves, communities need to be
interested and enthusiastic about stocking sh.
Catch and Culture: What are the challenges
related to supplying ngerlings?
Professor De Silva: Fingerling supplies are
always a problem. People need to be conscious
that it can only be done through proper hatchery
production. In most countries, the production of fry
is okay. Arti cial reproduction is state of the art for
many cultured species and is not a problem since
many have high fecundity. The next stage, from fry
to ngerlings, is where the bottlenecks occur. It’s
not just lack of technical know-how. It’s also lack
of space and not being able to use available water
resources for fry to ngerling rearing in a judicious
Stock enhancement at Boeung Chunlen Reservoir
28 Catch and Culture Volume 17, No. 3 December 2011
What are cultured-based sheries?
Culture-based sheries are not a new concept nor a new practice. Culture-based sheries, as a rule,
involve ownership either singly, as in the case of farmer lessees of small reservoirs in Vietnam and/or
collectively, in the form of a cooperative or a similar organisation, such as the case in oxbow lakes in
Bangladesh and seasonal tanks (small water bodies that retain water only for 6–9 months in the year)
in Sri Lanka. As such, culture-based sheries fall into the realm of aquaculture
On the other hand, culture-based sheries may not have received the attention they deserve from
aquaculture developers and planners because they are often not perceived to fall within the realm of
conventional aquaculture. In culture-based sheries, not only is the ownership de ned, but there is
also intervention in the life cycle because the practice can be sustained only with regular stocking.
What is important, however, is that culture-based sheries are considered to have a very high
potential for contributing increasingly and signi cantly to aquaculture production, particularly in
developing countries. This has further positive implications in the current era, particularly in the light of
increasing competition in most places for land and water for traditional, intensive forms of aquaculture
practices with other uses.
Culture-based sheries, on the other hand, use existing water resources—which may be natural such
as oxbow lakes, or man-created for other purposes such as reservoirs and farm dams and therefore
compete minimally, if at all, with other uses. Culture-based shery practices are essentially non-
consumptive practices of primary resources, in particular water, in contrast to the more conventional
aquaculture practices such as pond culture.
Moreover, culture-based sheries often do not involve external inputs, such as feed, and therefore are
environmentally less perturbing than traditional aquaculture practices. The only downside with regard
to culture-based sheries, if at all, is its dependence on exotic species to a large extent, already
introduced either accidentally or for other purposes in most nations.
It is also important to make a distinction between culture-based sheries and sheries enhancement,
although the former is a mode of enhancement. Fisheries enhancement in the broader sense
includes, for example, sea ranching and/or the introduction of a species that is capable of reproducing
in the water body and, with time, forms suf ciently large populations that could be exploited
commercially. A good example of the latter is the introduction of tilapia species into perennial
reservoirs in Sri Lanka, which with time have become the mainstay of the relatively large artisanal
shery of these reservoirs . Once established, these water bodies do not require regular stocking of
these species.
Source: De Silva, S.S. (2003). Culture-based sheries: an underutilised opportunity in aquaculture development.
Aquaculture 221: 221-243
way. The region also needs to look at proper
broodstock management so we don’t impact on
genetic diversity of the counterpart wild stocks.
Catch and Culture: Can you see any problems
related to environmental impacts, hybridization or
invasive species?
Professor De Silva: Let’s face it, any
farming system, on land or in water, will have
environmental impacts. The challenge to us is to
keep such impacts to a minimum so that future
generations will not be deprived in harnessing
the ecosystems to their bene t as a food source.
In respect to reservoir sheriesreservoirs being
man-created and having already brought about
environmental changesit would be detrimental
to have stock enhancement without due care
December 2011 Catch and Culture Volume 17, No. 3
being taken with the genetic diversity of stocks.
Apart from cage culture, the chance of arti cially-
bred stocks intermingling with natural stocks is
high. And if cage culture explodes, the nutrient
load of the water will be affected. I don’t think
hybridization would be a problem. As for invasive
species, this term is used in a very loose sense,
especially in the West. Tilapia has been introduced
into Asia and it’s a very important food sh. But
there’s no explicit scienti c evidence that it has
had a detrimental impact, as the Mekong River
Commission itself has pointed out. But we usually
try to promote the use of indigenous species in
future activities. But keep in mind that our current
knowledge of genetics has to be applied in our
attempts to use indigenous species. Science has
progressed much further than in the era when
biodiversity impacts were attributed to loss of
strains and species.
“For reservoir sheries in general, the
main cost is the ngerlings. Other costs
are labour including harvesting. ”
Catch and Culture: What about production costs
and what are the production prospects for each
system of reservoir sh production, particularly for
large mainstream dams such as Stung Treng and
Professor De Silva: For reservoir sheries in
general, the main cost is the ngerlings. Other
costs are labour including harvesting. Apart from
cage culture, the sh grow fending on what’s
available in the water and there are no feed costs
whereas feed ranges between 50 and 70 percent
of production costs in other types of aquaculture.
There has been very little research on production
costs in reservoirs on mainstream dams and very
little is known.
“With respect to pangasius, I don’t
think it can be replicated in any other
country, to the same intensity”
Catch and Culture: Can the successful cases
from Viet Nam (pangasias) and Lao PDR (Nam
Ngum reservoir) be easily replicated in Cambodia?
Professor De Silva: With respect to pangasius, I
don’t think it can be replicated in any other country,
to the same intensity, producing on average 250-
400 tonnes per hectare per crop. It’s more to do
with Vietnamese culture and entrepreneurship
as well as the simple fact that they can pump the
water in and out of their ponds. We don’t know for
how long this could be kept going but I don’t think
it can be replicated. And I don’t think we should try
to. This does not preclude pangasid aquaculture
being developed in other countries. There are
indications that it is being developed, for example,
in India, using the ponds that were once used
for Indian carp culture. But here again no where
near the intensity and productivity gains as in the
Mekong Delta in Viet Nam. Nam Ngum reservoir is
very different to those proposed mainstream run-
of-river dams in Cambodia. The latter are unlikely
to be productive like the former. As such, the
scenario in Nam Ngum is unlikely to be replicated
in the proposed reservoirs in Cambodia.
“I don’t think cage culture is
appropriate for Cambodia. That’s
why we’re focusing on culture-based
Catch and Culture: What are the production
prospects for existing water bodies in Cambodia?
Professor De Silva: I think there are plenty.
Cambodia, like Laos, has many small water
bodies of 10 to 15 hectares with changing water
levels, mostly rain fed although some are riverine.
These water bodies are also the heart of village
communities for drinking, water buffaloes, cooking
and washing. These water bodies should be
enhanced for community-based sheries through
culture-based sheries which, in essence, are
an extensive form of aquaculture, a form of stock
and recapture with the ownership rmly de ned.
When I was still at NACA, we developed a project
to develop culture-based sheries in Laos and
Cambodia. ACIAR is nancing this three-year
project which is expected to start in the rst half
of 2012 and cost $A640,000. I don’t think cage
culture is appropriate for Cambodia. That’s why
we’re focusing on culture-based sheries as the
only input where, apart from labour, the major
input is the ngerlings.
30 Catch and Culture Volume 17, No. 3 December 2011
Viet Nam to set up high-growth economic
zone in four Mekong Delta provinces
Contribution of agriculture, forestry
and sheries to economic output in the
southwest corner of the delta is expected
to be halved over the coming decade as
the government targets rapid expansion of
manufacturing and service sectors
Vietnamese Prime Minister Nguyen Tan Dung has
decided to establish a key economic zone in the
Mekong Delta that is targeted to account for 40%
of the country’s gross domestic product (GDP) by
The Vietnam News Agency (VNA) reported on
December 5 that the new zone would comprise
Can Tho City and An Giang, Kien Giang and Ca
Mau provinces. An Giang shares a border with
Kandal and Takeo provinces in Cambodia while
Kien Giang borders the Cambodian provinces of
Kampot and Kep. The zone is targeted to grow
25% faster than national GDP over the next 10
years, the VNA report said.
VNA said the zone would focus on industry and
services and rely less on agriculture, forestry and
sheries. Industrial and construction activities are
targeted to rise from 29% of economic output in
2010 to 40% in 2020 while the services sector
is expected to increase from 42% to 45% in the
same period. The agriculture, forestry and sheries
sector is targeted to decline from 29% to 15%.
At the same time, the ratio of trained workers is
targeted to jump from 38% of the labour force in
2010 to 65% in 2020 with annual income rising
from $1,200 per capita to a targeted $3,000, the
report said.
VNA said the zone would focus on developing
three thermal power plants with a capacity of up
to 9,400 megawatts, fueled by gas from elds
off the southwest coast. It said the government
was also putting priority on developing transport
infrastructure in the zone including Phu Quoc
island, which borders the Cambodian province of
Cat sh processing in the Mekong Delta is one of the region’s leading export industries. This company, Can Tho Import Export Seafood Joint Stock
Company (Caseamex), also processes giant freshwater prawns and is one of Viet Nam’s top ten exporters of aquatic products.
December 2011 Catch and Culture Volume 17, No. 3
Economic zone proposed for Can Tho, An Giang, Kien Giang and Ca Mau
High-growth economic zone
International boundary
Lower Mekong Basin boundary
32 Catch and Culture Volume 17, No. 3 December 2011
Training the gender trainers
MRC Fisheries Programme continues to
support the Network for Promotion of
Gender in Fisheries
Women have been recognised as an integral
part of the sheries sector. Their contribution is
signi cant and their involvement in some activities
is greater than that of men. Fisheries development
plans in the Lower Mekong Basin must therefore
take the role of women fully into account.
In 2000, women in sheries “focal points” were
formed along with a network that became known
as the Network for the Promotion of Gender
in Fisheries (NGF). In 2004, the Swedish
International Development Cooperation Agency
(SIDA) began funding a three-year project
under the Technical Advisory Body for Fisheries
Management (TAB). The aim of the TAB Gender
and Women in Fisheries project was to help line
agencies in the four MRC countries integrate
gender issues into sheries management. The
MRC Fisheries Programme has continually
supported NGF activities including 12 annual
meetings and a regional workshop on Gender
Awareness and Mainstreaming in 2009.
Effective promotion of gender equality in sheries
development requires training of trainers (TOT)
on gender aspects and tools. In December, 2011,
the MRC Fisheries Programme and the Integrated
Capacity Building Programme (ICBP) therefore
organised a regional TOT workshop on Gender in
Fisheries Development as part of the NGF Action
Plan for 2011-2012. Twenty- ve people took part
in the workshop, which was held in Khon Kaen
in northeast Thailand. Among the 21 women and
four men were representatives of National Mekong
Committees, NGF members and sheries of cers
from the four countries.
The workshop aimed to strengthen skills for
training in gender mainstreaming in sheries
development. It also aimed to share experiences,
knowledge and lessons learnt while developing
an action plan for participants to apply the skills
gained from the training course into their work.
Regional workshop on training of trainers on Gender in Fisheries Development, Khon Khaen, December 1-3, 2011
December 2011 Catch and Culture Volume 17, No. 3
Gender Tree
impact on health, education social status,
income, information, land, credit accessibility.
impact on gender progress
Maintained by:
education, family, state/Law, religion,
economic system, media
Norms Tradition
Four men and 21 women took part in the regional workshop on training of trainers on Gender in Fisheries Development
34 Catch and Culture Volume 17, No. 3 December 2011
Three Modules for Gender-Sensitive Training
Key contents Activities
Raising gender
awareness Background of gender and development in sheries sector/agencies and policy makers
Pre-attitude assessment on gender concept
Revising expectations, small rules and objectives
Gender difference and inequality
Revising gender concepts & some important terminologies
Identi cation gender
problem and solutions Gender problem identi cation & analysis
Problem solving in programmatic and organisational practices
Incorporating gender in
practices and planning Why sheries development activities need gender equality and women’s empowerment
Planning priorities and support needs
The main approach was to train the trainers in
both theory and practice. The contents of the
workshop covered three main topics:
1. Giving future gender trainers experience in
gender-sensitive training (see three modules
2. Methods and practical training skills; and
3. Designing a sequenced gender training plan
that identi es objectives, targets, lessons
and methods engaged.
This regional workshop bene ted participants
with three main outcomes. First, they now have
a better understanding of gender mainstreaming
in integrated water resources management as
well as sheries management and development
so they can consider gender issues in work plans
and activities. Second, the participants understood
technical skills for gender-sensitive training and
practised exercises for organising, preparing, and
facilitating training sessions. Third, the participants
are now able to design gender-training plans
based on identifying gender problems.
In addition, participants agreed on important
points in moving toward upcoming NGF training
in the four countries. At the same time, the
workshop represented an output under the Project
Implementation Plan of the Fisheries Programme
for 2011-15 which aims to develop the technical
and administrative skills and knowledge of
sheries managers. It was also a good example
of collaboration between two MRC programmes in
promoting gender mainstreaming in the Mekong
* Dr Malasri is Fisheries Management and Governance
Specialist at the MRC Fisheries Programme
By linking gender into sheries management,
training of trainers will:
Provide overview
of gender
in sheries
Provide tools and
practical skills for
participants to
plan and conduct
agreement on
plan for
training to be
Conceptual Framework of Workshop
TOT targets government and inter-governmental
representatives doing gender mainstreaming in
sheries to communicate work to wider audiences
NGF seeks way to build team to promote gender
mainstreaming in sheries across MRC countries
Dr Amornrat Serwatana Kul, chair of the Gender Working Group at the
Thai Department of Fisheries (right), delivers opening remarks to the
workshop following a welcome address by MRC Fisheries Programme
Management and Governance Specialist Dr Malasri Khumsri (left)
December 2011 Catch and Culture Volume 17, No. 3
Kong Sovanara
Kong Sovanara has joined the MRC Fisheries Programme as aquaculture
specialist. Mr Sovanara was previously head of the Fisheries Department at Prek
Leap National School of Agriculture in Phnom Penh. Before that he headed the
school’s Of ce of Planning and International Relations and also served as vice
head and lecturer at the school’s English Centre. His areas of expertise include
hatchery techniques, growout production, genetics and stock improvement,
aquaculture system design and management as well as feed and nutrition. He
joined the staff of the school’s sheries section in 1994 as a lecturer in aquatic
chemistry and English. In addition to Cambodia, Mr Sovanara has studied in
Australia, Canada and New Zealand. He has a Master’s Degree in Applied Science
in Aquaculture from James Cook University in Australia, completed in 2009, and
a Master of Science in Aquaculture and Aquatic Resources Environment from
the Royal University of Agriculture, completed in 2006. He also has a Bachelor
of Fisheries Science from the Royal University of Agriculture and a Bachelor of
Education from the Royal University of Phnom Penh.
Kong Sovanara
Peter Degen has been appointed chief technical advisor to the MRC Fisheries
Programme, succeeding Kent Hortle who returned to Australia in July. Mr Degen,
a German national, has been working in Cambodia since 1997 when he joined the
MRC in Phnom Penh as senior socio-economist and technical advisor to projects to
manage capture sheries in Cambodia and reservoir sheries in the Lower Mekong
Basin. Before that, he worked in Ecuador and Peru for nine years, primarily as an
artisanal sheries advisor. Since leaving the MRC in 2002, Mr Degen has worked
with several sheries-related projects in Cambodia, notably as a communities
sheries and rural livelihoods specialist for FAO and ADB-funded projects around
the Tonle Sap Lake. Before returning to the MRC, he worked as team leader on a
World Bank-funded livelihoods project in Siem Reap. Mr Degen is a full member
of the Asia Fisheries Society and the International Association for the Study of the
Commons. He has a Master’s Degree in Anthropology and Rural Sociology from the
Universities of Cologne, Sevilla, La Paz and Bonn.
Peter Degen
Peter Degen
Of ce of the Secretariat in Phnom Penh (OSP)
576 National Road #2, Chak Angre Krom,
PO Box 623, Phnom Penh, Cambodia
Tel: (855-23) 425 353 Fax: (855-23) 425 363
Of ce of the Secretariat in Vientiane (OSV),
Of ce of the Chief Executive Of cer
184 Fa Ngoum Road,
PO Box 6101, Vientiane, Lao PDR
Tel: (856-21) 263 263 Fax: (856-21) 263 264
Zhenlafengtuji is the original title of the oldest rst-hand account of the Angkor civilisation. Written by
Chinese envoy Zhou Daguan, who visited the city in 1296-97, a direct translation from Chinese to English did
not become available until 2007 when “A Record of Cambodia” was published. The excerpts above from the
translation by Peter Harris indicate the diversity of sh and other aquatic animals more than 700 years ago. The
“Freshwater Sea” refers to the Tonle Sap Lake. “Prawns from Zhanan” is believed to refer giant freshwater prawns,
possibly from Kompong Chhnang. “Zhenpu” is on the coast of southern Viet Nam, possibly near Vung Tau.
“Of their sh and turtles,
black carp are the
commonest. Other sh
that are plentiful include
common carp, gold sh
and grass carp.”
“There are (gobies) — the
large ones weigh up to
three pounds. Otherwise
there are very many sh
whose names I don’t know,
all of them coming from
the Freshwater Sea. …”
“There are also swamp eels
and freshwater eels from
the lakes.”
“Prawns from Zhanan
weigh a pound and a half
or more each. The goose-
necked barnacles from
Zhenpu may be eight or
nine inches long …”
“The razor clams look
very ne. They get
clams, mud clams and
pond snails just by
scooping them out of the
Freshwater Sea …”
“There are crocodiles as
big as boats. They have
four feet and look exactly
like dragons except they
have no horns.”
Full-text available
Fish are heavily influenced by the nature of the flood regimes of the rivers in which they live. These fluctuate naturally from year to year but recently increasing pressure on water for a wide range of uses other than fisheries has led to human activities that have substantially altered the flood regimes of many rivers throughout the world. This has resulted in the loss of fish production and biodiversity. There are now efforts to mitigate for these changes that include release of artificial floods from dams or polder sluices. The typical flood curve contains several characteristics that may influence the survival and growth of the individual fish species. Understanding of these characteristics will help design appropriate flood curves and maximize benefits from the water available.
Conference Paper
Full-text available
The Flood Pulse Concept in River—Floodplain Systems Wolfgang J. Junk Max Planck Institut für Limnologie, August Thienemann Strasse 2, Post fach 165, D-2320 Pion, West Germany Peter B. Bayley and Richard E. Sparks Illinois Natural History Survey, 607 E. Peabody Dr., Champaign, IL 61820, USA Abstract JUNK, W. J., P. B. BAYLEY, AND R. E. SPARKS, 1989. The flood pulse concept in river-floodplain systems, p. 110-127. In D. P. Dodge [ed.] Proceedings of the International Large River Symposium. Can. Spec. Publ. Fish. Aquat. Sci. 106. The principal driving force responsible for the existence, productivity, and interactions of the major biota in river—floodplain systems is the flood pulse. A spectrum of geomorphological and hydrological conditions produces flood pulses, which range from unpredictable to predictable and from short to long duration. Short and generally unpredictable pulses occur in low-order streams or heavily modified systems with floodplains that have been leveed and drained by man. Because low-order stream pulses are brief and unpredictable, organisms have limited adaptations for directly utilizing the aquatic/terrestrial transition zone (ATTZ), although aquatic organisms benefit indirectly from transport of resources into the lotic environment. Conversely, a predictable pulse of long duration engenders organismic • adaptations and strategies that efficiently utilize attributes of the ATTZ. This pulse is coupled with a dynamic edge effect, which extends a "moving littoral" throughout the ATTZ. The moving littoral prevents prolonged stagnation and allows rapid recycling of organic matter and nutrients, thereby resulting in high productivity. Primary production associated with the ATTZ is much higher than that of permanent water bodies in unmodified systems. Fish yields and production are strongly related to the extent of accessible floodplain, whereas the main river is used as a migration route by most of the fishes. In temperate regions, light and/or temperature variations may modify the effects of the pulse, and anthropogenic influences on the flood pulse or floodplain frequently limit production. A local floodplain, however, can develop by sedimentation in a river stretch modified by a low head dam. Borders of slowly flowing rivers turn into floodplain habitats, becoming separated from the main channel by levées. The flood pulse is a "batch" process and is distinct from concepts that emphasize the continuous processes in flowing water environments, such as the river continuum concept. Flooclplains are distinct because they do not depend on upstream processing inefficiencies of organic matter, although their nutrient pool is influenced by periodic lateral exchange of water and sediments with the main channel. The pulse concept is distinct because the position of a floodplain within the river network is not a primary determinant of the processes that occur. The pulse concept requires an approach other than the traditional limnological paradigms used in lotic or lentic systems. Résumé JUNK, W. J., P. B. BAYLEY, AND R. E. SPARKS. 1989. The flood pulse concept in river-floodplain systems, p. 110-127. In D. P. Dodge [cd.] Proceedings of the International Large River Symposium. Can. Spec. Publ. Fish. Aquat. Sci . 106. Les inondations occasionnées par la crue des eaux dans les systèmes cours d'eau-plaines inondables constituent le principal facteur qui détermine la nature et la productivité du biote dominant de même que les interactions existant entre les organismes biotiques et entre ceux-ci et leur environnement. Ces crues passagères, dont la durée et la prévisibilité sont variables, sont produites par un ensemble de facteurs géomorphologiques et hydrologiques. Les crues de courte durée, généralement imprévisibles, surviennent dans les réseaux hydrographiques peu ramifiées ou dans les réseaux qui ont connu des transformations importantes suite à l'endiguement et au drainage des plaines inondables par l'homme. Comme les crues survenant dans les réseaux hydrographiques d'ordre inférieur sont brèves et imprévisibles, les adaptations des organismes vivants sont limitées en ce qui a trait à l'exploitation des ressources de la zone de transition existant entre le milieu aquatique et le milieu terrestre (ATTZ), bien que les organismes aquatiques profitent indirectement des éléments transportés dans le milieu lotique. Inversement, une crue prévisible de longue durée favorise le développement d'adaptations et de stratégies qui permettent aux organismes d'exploiter efficacement 1 'ATTZ. Une telle crue s'accompagne d'un effet de bordure dynamique qui fait en sorte que l'ATTZ devient un « littoral mobile'<. Dans ces circonstances, il n'y a pas de stagnation prolongée et le recyclage de la matière organique et des substances nutritives se fait rapidement, ce qui donne lieu à une productivité élevée. La production primaire dans l'ATTZ est beaucoup plus élevée que celle des masses d'eau permanentes dans les réseaux hydrographiques non modifiés. Le rendement et la production de poissons sont étroitement reliés à l'étendue de la plaine inondable, tandis que le cours normal de la rivière est utilisé comme voie de migration par la plupart des poissons. 110
Full-text available
Anthropogenic global warming has significantly influenced physical and biological processes at global and regional scales. The observed and anticipated changes in global climate present significant opportunities and challenges for societies and economies. We compare the vulnerability of 132 national economies to potential climate change impacts on their capture fisheries using an indicator-based approach. Countries in Central and Western Africa (e.g. Malawi, Guinea, Senegal, and Uganda), Peru and Colombia in north-western South America, and four tropical Asian countries (Bangladesh, Cambodia, Pakistan, and Yemen) were identified as most vulnerable. This vulnerability was due to the combined effect of predicted warming, the relative importance of fisheries to national economies and diets, and limited societal capacity to adapt to potential impacts and opportunities. Many vulnerable countries were also among the world’s least developed countries whose inhabitants are among the world’s poorest and twice as reliant on fish, which provides 27% of dietary protein compared to 13% in less vulnerable countries. These countries also produce 20% of the world’s fish exports and are in greatest need of adaptation planning to maintain or enhance the contribution that fisheries can make to poverty reduction. Although the precise impacts and direction of climate-driven change for particular fish stocks and fisheries are uncertain, our analysis suggests they are likely to lead to either increased economic hardship or missed opportunities for development in countries that depend upon fisheries but lack the capacity to adapt.
South-eastern Australia is experiencing prolonged drought, record temperatures and devastating forest fires due to the rising impacts of climate change. The lower lakes of the Murray River estuary are rapidly drying up due to low rainfall, poorly managed and over-allocated irrigation quotas. Heat wave conditions have been experienced in many communities. Coastal communities are also facing increased challenges by the climate change impact of gradual rise in sea levels. The Department of Sustainability and Environment Climate Change Adaptation Program has implemented a Future Coasts Project for accessing the impacts of climate change. A seamless digital elevation model is being produced to model the impact of sea level rise, storm surges, inundation and erosion to determine appropriate management and mitigation strategies. Similar climate change projects in the coastal zone have been commenced by the Department of Planning and Infrastructure in Western Australia and the Department of Environment and Climate Change in New South Wales.
A model is developed which describes the way in which the fish populations of African rivers and their fisheries are influenced by the different types of flood Regime. Ichthyomass and fish catch are dependent on both the extent of flooding during high water and the amount of water remaining in the system during the dry season. The relative number and individual weight of fish are determined by the intensity of flooding, whereas the total number surviving to the next year depends more on the low water regime. Catch per unit effort falls with increasing difference between areas flooded at high and low water. A negative log-log relationship exists between catch and the ratio of maximum area flooded to minimum area of water remaining in the system. This relationship of catch to flood ratio may form the basis for a general index for the evaluation of both year-to-year variations within a floodplain, and differences between floodplains. Lines of equal catch are also derived for various combinations of high and low water areas; these might be used as guidelines for the hydrological management of tropical flood-plains.
Increasing multi-sectoral demands on water resources have led to water abstraction and transfer activities, and the construction of dams and embankments that have significantly altered the flood regimes of rivers throughout the world resulting in the loss of fish production and biodiversity. The current emphasis on sustainable development and biodiversity conservation is leading efforts to mitigate these impacts by means of interventions such as the release of artificial floods downstream of dams and the manipulation of water levels within impounded floodplains.