Status of Aquatic Biodiversity in the Mekong

1. Status of Aquatic Biodiversity in the Mekong The Second Module of the BDP/MDBC Training Course 21st May 2003 The Mekong River Commission Secretariat Annexes

2. “..the Mekong River Basin and the related natural resources and environment are natural assets of immense value…” 1995 Mekong Agreement

3. Mekong River Basin • Upper Mekong Basin (UMB) • China • Myanmar • - 18% of total flow • Lower Mekong Basin (LMB) • Laos • Thailand • Cambodia • Viet Nam • - 82% of total flow

4. Main geographic regions of LMB • Mountains of the north and east

5. Main geographic regions • Mountains of the north and east • Isan (Korat) Plateau

6. Main geographic regions • Mountains of the north and east • Isan (Korat) Plateau • Great Lake and Cambodian plains

7. Main geographic regions • Mountains of the north and east • I-san (Korat) Plateau • Great Lake and Cambodian plains • Delta

8. July July January October April Highly seasonal vegetation Vegetation index shows vegetation greening and dry-off.

9. Diverse ecosystems • tropical rainforest, deciduous forest, dry woodland, grassland, wetland, mangroves • wetlands of Great Lake and floodplains • Biodiversity • >1200 species of fish • Abundant water birds • Rare species Irrawaddy dolphin, Javan rhinoceros

10. Working with Fisheries Agencies Lao PDR NAFRI ( LARReC) Cambodia Department of Fisheries Vientiane Phnom Penh CNMC LNMC TAB Udon Thani Ban Me ThuotHCM City TNMC VNMC Thailand Department of Fisheries (Inland Fisheries R&D Bureau) Viet Nam Ministry of Fisheries ( RIA.2 and RIA.3)

11. Fisheries in the LMBsome data - 1200 - 2000 fish species – possibly 2nd richest river system in the World - 80% of people involved (full- and part-time)

12. Fisheries in the LMBsome data - Catch is about 2% of total world capture fishery, marine and freshwater - Value about US$1,400 million direct value only

13. Fish Production Estimates • Total inland fish & OAAs  2.0 million tonnes • Capture Fisheries  1.75 Mt • Aquaculture  0.25 Mt Estimation methods 1. Consumption studies(above figures) 2. Wetland productivity( 150 kg/ha/yr) 3. Landing surveys(difficult)

14. Fish Production Estimates

15. Inadequate Information on Aquatic Resources • Single ecosystem • Trans-boundary • Dynamic nature • Overlooked in the past • Conventional methodologies give limited results • Lack of communication

16. Threats on Aquatic Resources • Growing population ~ 2% • ~ 2025…~ 90 millions • Natural change of habitats • Human interventions: fishing pressure, development of water management schemes, pollution, etc.

17. Threats to the Fisheries Sector: General: Habitat Destruction Constraints to migration Pollution (in future) Exotic fish species Local: High Fishing Effort Illegal fishing methods Mitigation: Cross-sectoral: Integrated water use planning Information on resources Fisheries Sector:Regional management National protection Local co-management Indigenous fish aquaculture

18. Flood Pulse River fishes depend upon flooding for their production and diversity, because flooding creates a productive habitat, and provides nutrient-richsilt.

19. Black fish spawning Feeding & Growth Migration from floodplain Migration to floodplain White fish migrates and spawns within river channels

20. AMFC/DoF Songkhram Mekong River Habitat availability (wetlands) inRED– from radar Wetlands Villages asbluedots size = number of active fishing households Villages Songkhram River

21. Number of species reported to use deep pools at each station Chiang Khong Loei Khone Falls Kratie

22. Mekong Flood Plains • give the high fish production • Deep Pools • Provide dry season shelter • Mainstream and Riverside Wetlands • Provide the spawning areas • Fish Migrations • Over 500-1000 km or more bring fish • - from the spawning areas upstream into the flood plains during the rainy season; • Back up into the deep pools in the mainstream when the rain stops and the flood plains dry out; • Out to spawn in the mainstream and the riverside wetlands when the rain starts again

23. Migration patterns for Helicophagus waandersii

24. Capture fisheries outlook Opportunities: • The Mekong aquatic ecosystems and fisheries are in good shape • The fisheries are (locally) under stress, but no indication that maximum yield has been attained • The knowledge base for informed manage-ment is coming in place at all levels

25. Capture fisheries outlook Opportunities: • Increased recognition by politicians of inland fisheries importance and awareness of problems • Enabling institutional frameworks for joint management, co-management and integrated management in place • Enhanced fisheries (stocking) feasible through co-management initiatives

26. Capture fisheries outlook Threats from within the sector: • Use of habitat destructive fishing methods • Unsustainable fishing practices: - fishing in sensitive areas - fishing at sensitive times - targetting juveniles • Badly considered species introductions

27. Capture fisheries outlook Threats from outside the sector: • Habitat alterations • Physical barriers to fish migration • Changes in quality and quantity of water in sensitive habitats (pollution/flooding) • The fisheries ”message” does not get across to planners in more powerful sectors

28. WMD Impacts and Mitigation Direct impacts on fish passage, barrier effect Fishways, or other fish passage measures Water quality effects due to stratification, toxicity and reduced productivity Destratification or multi-level offtakes • Hydrological impacts, impacts on fish behaviour, habitat etc. • Riparian flows, regulating ponds Trapping of nutrients, organic material and sediment, loss of productivity Not mitigated at present, Research Needed

29. MITIGATION OF EFFECTS OF WATER MANAGEMENT ON FISHERIES Structures: Dams, dikes, weirs, reservoirs Problems for fisheries: Dams: Hindrance to fish migrations, Reservoirs: Still water body, anoxic bottom conditions, rapidly changing water level Downstream: Anoxic water outlet, changed water temperature, lack of sediment, etc. Potential Effect: Loss of income, employment and food security, biodiversity.

30. MITIGATION METHODS: Downstream effects: Changed water intake to turbines; In-reservoir: Bubbling systems Improved management of water level, etc. Passing the dam: Fishways AIR BUBBLING SYSTEM (Champagne Method) Destratification of reservoirs North Pine Reservoir Area: 22 Km2, Depth: 35 meter Diffusers Dam Pump house

31. Convention on Biological Diversity “Prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species” (article 8 h)

32. FAO - Responsible Fisheries • Precautionary approach • Impacts of introductions often irreversible and unpredictable • “…the introduction of aquatic organisms for aquaculture should be considered as a purposeful introduction into the wild…” • Minimise risk of environmental effects

33. Present Status • Valid ecosystem concerns • Adequate legal instruments, policies and recommendations • Incomplete implementation • Need to enhance implementation and monitoring

34. Present Status • Existing knowledge needs to be consolidated • Capacity to implement is asymmetric • Implementation of policies needs support and monitoring • Institutional cooperation through Networking

35. Issues for BDP • Achieving sustainability will require an integrated approach to managing water, land, and ecosystems • Protecting ecosystems requires integrating biodiversity conservation and ecosystem management into local and national economies

36. Issues for BDP • Participatory ecosystem-based catchment management is a fundamentally new approach to using, developing, and conserving water resources • Allowing ecosystems to perform their functions requires that users let certain amounts of water stay within the ecosystems

37.  MITIGATION Passing the dam: Fishways Tonle Sap River 50,000 fish per minute Vertical slot fishway, 7m 5,000 per 24 hrs Fish lift, 15 m 3,800 fish per 24 hrs *********

38. THANK YOU Chumnarn Pongsri Mekong River Commission Secretariat Chumnarnp@mrcmekong.org