A description of the importance of inland fisheries in the Lower Mekong Basin. The linkages between human and natural systems on the aquatic and terrestrial natural resources systems

1. Commercial and
subsistence fisheries in
the Mekong River basin
Linkages between human and natural systems on the
aquatic and terrestrial natural resources systems

2. Mekong river basin
• Large tropical river 4,900 km long
• Originates in China, passing through Thailand,
Lao PDR, Cambodia and Vietnam
• Comprising:
• Mainstream & tributary rivers
• Huge floodplains
• Permanent and seasonal ricefields and wetlands
• Natural and man-made waterbodies
• Reservoirs, lakes,
• Tonle Sap great lake
• Mekong Delta
• Until relatively recently mainstream mainly
uninterrupted (except in China)
• although many dams on its tributary rivers
Mekong River
Basin

3. The value of the
fisheries of the Mekong
Basin

4. Mekong River - the largest inland fishery
in the world?
• Reported to be between 2.0 – 2.6 million tonnes
• Probably an underestimation of actual catch
• Largest connected freshwater fishery in the world
• ~17 - 22 % of total official global inland capture
fisheries catch
• Mekong River Commission now estimates total
production at 3.9 million tonnes (2008)
• Valued at between US$3.9-7 billion
• 60 million people who live in the lower Mekong Basin
• 80 percent rely directly on the river system for their food
and livelihoods Drying Pangassius, Mekong
river, Lao PDR

5. Fish in diets & nutrition
• Freshwater fish are a crucially important source of
nutrition
• Cambodia and Laos having amongst the highest fish
protein consumption of non-island states
• Increasing evidence from consumption surveys
• Lao PDR and Cambodia
• 47 percent and 80 percent of animal protein from
freshwater aquatic animals
• 90 percent is derived from capture fisheries
• FW fish and fish products
• culturally preferred
• easily accessed by the poor
• Improve otherwise poor rice-based diets (micronutrients,
vitamins) Wild & cultured fish

6. Small-scale fisheries
• Found throughout the basin
• Range from fishing in the mainstream using a huge variety of
gears
• Highly skilled fishing to simple collection
• Foraging in rice fields and swamps
• Can be all year round or highly seasonal
• Not just fish - crustaceans, amphibians, molluscs,
insects, reptiles
• Products eaten, bartered or sold
• Important to livelihoods of millions
• The contribution to the household nutrition is considerable
• A coping strategy at certain times of the year
• One of the most valued non timber forest products
• Men, women and children
Household fishing gears,
Great Lake, Cambodia

7. Small-scale fisheries (2)
• Most small-scale inland fisheries are open access
• Often traditional rights to fish and arrangements
between villages
• Slowly broken down with economic growth and
development
• External threats to floodplain fisheries and
ricefield fisheries
• roads, irrigation, drainage, pesticide use, erosion and
control of flooding
• Also overfishing on water bodies as populations
increase
• Environmental impacts, loss of flow and habitat
almost certainly outweigh the impacts of fishing.

8. Large-scale fisheries
• Relatively rare in the Mekong basin
• Fishing Lots in the Great Lake
• Dai fishery (fixed bag nets) in the Bassac
river
• Private fishing concessions on reservoir
fisheries
• Fixed trap gear on the Khone falls
• Often highly contentious
• Transparency of licensing
• Loss of access to small-scale fishers
• Can be argued they prevent tragedy of
commons
• by limiting access of all and thus overfishing
• However little evidence that they actually
limit own effort

9. Easy to see how development policies
bypass inland fisheries
• Neglecting the food and nutritional security
aspects of using water to raise fish
• Need win win scenarios
• reservoir design and minimum flows
• fish passes (that work)
• Rice-fish, sustainable aquaculture
• Innovative floodplain/habitat connectivity
• water management balance for industry agriculture
and fisheries
Fish traps, Mekong river,
Lao PDR

10. Threats to fisheries

11. Fishing is not typically the primary impact on inland
fishery resources
• Dam, dike and levee
construction
• Diversions, abstraction
• Damming
• Draining of wetlands
• Deforestation/land use changes
• Pollution
Most of these are related to water quantity and quality: “environmental flow”
Most solutions are rarely “fishery management solutions”
• Navigation
• Urbanization
• Acid deposition
• Exotic species
• Climate change
• Overharvesting

12. Tropical floodplain and river fisheries
depend on flow and flooding
• Huge natural variation in water flows seasonally
and inter-annually
• Built into the ecology and behavior of the species
• Timed to monsoon and seasons
• Passage to leave rivers streams and perennial water
bodies
• Migrations upstream for spawning
• Downstream larval drift
• Invasion of flooded fields and wetlands during
monsoon and flood season
• Rapid spawning and huge area for nursery, very fertile
• When this disrupted, loss of recruitment, lower
survival

13. Loss of connectivity, water flow
in floodplains
• Economic and agricultural development often
partitions floodplains’
• Agriculture
• Drainage of wetlands for agriculture
• Irrigation - small weirs and water control structures
limit fish ability to move across floodplain
• Flows changed buy water storage
• Increase use of agricultural pesticides and fertilizers
• Urbanization, rural infrastructure
• All weather, flood-proof roads also partition
floodplains
• Channelization of rivers and flood protection limit fish
access to former flood plains
• Tendency to build at ground level and increases
partitioning effect
• Greater intolerance to flooding generally
Irrigation structures in
the the Mekong Basin

14. Large Dams affect rivers
• Damming rivers and mainstream alters flow
• Flow smoothing changes the flood pulse (less
flooding area)
• Scouring/erosion and deposition patterns change
• Backflow that creates Tonle sap could be
impacted if many dams built
• Also impacts on saline intrusion into the Mekong
Delta
• Flooding and floodplain habitats altered
• Interferes with migration and spawning
triggers/behaviour
• Loss of iconic large migratory species
• Possibly other species also impacted
• Food webs

15. Large dams value
• Dammed in China and more recently
mainstream dams are being developed
• Tributary rivers also dammed
• There are currently 11 proposed dam construction
projects in the lower Mekong Basin
• Total potential for hydropower is estimated at
53,000 MW
• only about five percent is currently installed
• Economic value of US$235 million per year
• Potential total value of full capacity $4-5 billion/yr?
• Estimated decline of that freshwater capture
fisheries in the lower Mekong River Basin
• ~880,000 tonnes in 2030 if dam construction
proceeds as planned.
• approximate economic value $ 440-880 million

16. Navigation & dredging
• Navigation of the river a traditional way of
moving heavy materials north and south
• Dredging is another activity that can result
in loss of habitat for spawning, degraded
water quality and sedimentation
• May be rather localized but can impact
spawning effectiveness
• Controversial clearance of rapids to
improve navigation
• China/Thailand
• Little consultation/ no EIA
• Changes water flows ands took place in area
that was considered important for Giant
Mekong catfish

17. Climate effects
• Basin-wide models predict a variety of effects
• Higher temperatures leading to loss of some fish species
• changing rainfall patterns affecting peak monsoonal
flows and thus spawning and migration
• Unseasonal rainfall resulting in out of season flooding
• All of these impacts will be exacerbated by water
management structures and their use for
hydropower and irrigation
• Knock on effects to river hydrology and habitats and
thus to fisheries
• Lower flow and sea level rise will result in saline
intrusion in Delta area
• Impacts on agriculture and livelihoods, changes in
species compositions
• Possible shift to brackish water tolerant crops and fish
species
Traditional rainfed and
irrigated terrace rice, Mae
Hong son, North Thailand

18. If fisheries are so important, why do
we continue to impact them?
Flood season, Great Lake, Cambodia

19. What is driving hydropower expansion?
• Demand for power in growing SE Asian economies
• little oil, coal and gas
• Seen as climate friendly (no CO2 emission)
• Many Mekong tributary rivers already dammed
• Hydropower and/or irrigation
• With the move away from large hydropower dam
loans by the World Bank and others
• Private sector has played main role in investment
• Private sector Dam consortia (Build Operate and Transfer -
BOT)
• Environmental Impact Assessments - highly controversial
• Less international scrutiny on projects

20. Conflicting (under-)valuations
• Hidden nature of inland fisheries means they are often over looked
and undervalued
• Official estimates of production do not line up with research/MRC
estimates
• This may be convenient when trying to cost other uses of water
• Easier to downplay contribution to economy, livelihoods and food security
• Reduces cost of mitigation of large dams etc.
• Makes irrigation or other water management actions appear more valuable
• Replacement costs may give a better indication of what there is to be
lost if fisheries are impacted
• How do you measure the impact?
• What are the costs of lost fisheries, biodiversity and livelihoods?
• Do the national economic benefits outweigh the losses?
• Still impossible to value the real cost of biodiversity, cultural
importance of fisheries and hidden ecosystem services
Dredgingfor snails,
Great Lake, Cambodia

21. Replacement cost of dams on food
security
• Loss of 880,000 tonnes of fish
• Equivalent replacement costs through use of
livestock
• larger water and environmental footprint
• Water and land required to rear equivalent
livestock considerable
• 20-30% of the total basin area?
• Even using aquaculture
• 880,000 tonnes of freshwater fish would require
feeds and water
• Does not factor in accessibility by the rural
poor

22. What mechanisms exist to
secure these fisheries?
Bas relief showing aquatic life , Angkor Wat, Cambodia

23. Regional governance
• 1995 Agreement on the cooperation for the
sustainable development of the Mekong river
basin (1995)Cooperate on water for
development, prior consultation
• Structure and function of Council and the
Commission
• Maintain necessary flows and avoid excess flows
(hydro-peaking)
• Avoid harmful effects
• Provide freedom of navigation
• Appropriate consultation on developments on the
mainstream and tributaries and the great lake

24. Governance of transboundary water
• Countries are bound to cooperate and discuss actions
which impact neighbours
• Ultimately have sovereign rights
• Bound to undergo EIA, consultation
• Short term economic gain from electricity sales
outweigh long term interests of environmental
integrity, sustainability of fisheries, food security
• Transparency?
• Private sector consortia can apply “incentives “ in-country
• Some questionable aspects such as the longevity of
the dam
• Dams do not last forever, silt up, equipment ages
• What happens once dam is transferred (obsolete) back to
the national government
• Is this factored into the rosy financial projections?

25. Governance of large scale fisheries
• Most of the large fishing concessions in the
Mekong Basin are being removed as political
gestures
• E.g. Cambodian fishing lots
• Now open access regime, based around
community fisheries groups
• Little management in place, overfishing is rising,
loss of fishing access to ethnic Vietnamese fishers,
loss of revenue to government
• Was it a good thing?
• Does the inequitable situation of closed
access actually protect the fishery?

26. Mitigation of impacts to small scale
fishing
• Where connectivity is lost in floodplains
• Restoring connectivity between permanent water bodies and
floodplain/ricefield
• Using culverts, low weirs
• Increase water flows in critical seasons
• Strengthen community awareness of the importance of management
and value of habitat and refuges
• Allocation of fishing rights to water bodies
• Creation or protection of permanent refuges
• Promote local participation in setting of rules on fishing and how to sustain
recruitment ( co-management approaches)
• Stocking initiatives
• Work on external impacts
• Reduction of pesticide use in rice agriculture (Integrated pest management)
• Control of watershed erosion
• Other sources of habit removal or pollution
• Water managers (critical/minimum flows)
Rice-fish, fish ponds

27. Conclusions

28. Competition for water resources
• High investment projects have issues with
transparency, corruption and over-simplified
economic projections
• Fisheries are important to many, and they are
often poor
• Generally under-valued
• Limited voice and dispersed effect
• Low visibility allows simple national economic goods
argument to prevail
• Fisheries in aggregate economic value cannot compete
• However, replacement cost, impact on nutrition,
health, well-being and livelihoods is rarely factored
in

29. Mitigate environmental impacts,
engage with other water users
• Most impacts on inland fisheries are related to water
and habitat quantity and quality: “environmental flow”
• Most solutions are therefore rarely “fishery
management solutions”
• There are ways to mitigate impacts
• Engineering, social organizations, improve
transparency and governance
• Requires greater communication with agriculture,
water management and ultimately hydropower
• Regional agreements seem to be on decline as
economic drivers push for development
• Some good opportunities (‘win-win’) for innovation Freshwater flooded forest,
Songkhla Lake, Thailand