Group 1: Tonle Sap Location: Roberto

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Group 1 Tonle SapLocation Roberto

• Mr. Carl Middleton
• Mr. Chea Chan Tou
• Mr. Eric Guerin
• Mr. Ganesh Pangare
• Mr. Hiek Sopheap
• Mr. Hourt Khieu
• Mr. Kaviphone Phouthavongs
• Ms. Sarah Turner
• Mr. SyVann Leng
• Mr. Suppakorn Chinvanno

Facilitators 1. Terry Hills 2. Radhika Dave
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Tonle Sap Core Values (1a)

• Ecosystem Services
• Fisheries Productivity, Nutrient Flow/Deposition
  on Floodplains, Regulation of Flood Pulse
• Habitats
• Fish Sanctuaries, Flooded Forest, Dry Season
  Ponds, Floodplain
• Species
• Many vulnerable and endangered species eg.
  Mekong Giant Catfish

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Tonle Sap - Development Trends (1b)

• Fishing
• Increasing use of nets, brushwood as
  catch-per-unit effort increases, raising
  introduced species, seasonal migration from
  uplands for fishing during dry season
• Agriculture
• Clearing of the flooded forest, increase use of
  pesticides, increased fertilizer use
• Tourism
• Increased tourism, but benefits are not shared
  with local communities in Tonle Sap, increased
  pressure on natural resources, increased waste
  generation
• Hydropower
• Larger systems cannot mitigate against migration
  problems, but well-designed smaller systems may

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Climate Change vs Core Values (2)

• Looked at set of exposures
• Temp increase
• Summer length increase
• Increased intensity and variability of
  precipitation during the wet season
• Reduced precipitation and increased length of dry
  season
• Increased maximum monthly flows
• Reduced minimum monthly flows

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Climate Change vs Core Values (2)

• Looked at set of exposures
• Temp increase
• Summer length increase
• Increased intensity and variability of
  precipitation during the wet season
• Reduced precipitation and increased length of dry
  season
• Increased maximum monthly flows
• Reduced minimum monthly flows
• but, need to understand the seasonal hydrology

Water Level
Jun
Jan
Dec
Rainy Season
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Climate Change vs Core Values (2)

• Ecosystem Service Fisheries Productivity
• Increased productivity likely if higher flow
  during wet season and lower flow during dry
  season, but decreased productivity if low flow
  during wet season and higher flow during dry
  season.
• Increased temp algal blooms, more fishfood, fish
  mortality at lower water level
• Habitat Dry Season Pools vulnerable to changes
  in temperature and summer length
• Habitat Floodplain Increased Temp reduced
  rice productivity, change in pest vectors
• Habitat Flooded Forest resilient to water level
  changes, forest fire vulnerability, surface area
  available for flooded forest growth will change
  depending on new hydrological regime.
• Fish Species Increased temperature leads to
  higher O2 and food intake demands increased
  uptake of pollutants, increased flows may hamper
  upstream spawning migrations, erode spawning beds
  or sweep away juveniles and eggs, changes to flow
  timing may affect spawning behavior.

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Tonle Sap Resilience and Adaptation

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Principles Resilience to future change for
communities and biodiversity

• Reduce non climate pressures on natural
  ecosystems to maintain ecosystem services and
  build climate resilience for ecosystems
• Maintain existing habitats and prevent spread of
  invasive species
• Mainstream climate change knowledge into all
  govt agencies at local level, sub national,
  etc(also, need awareness of consequences of
  hydropower dams)

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Actions Resilience to future change for
communities and biodiversity

• Alternative income and livelihoods option
• Floating Villages ecotourism, handicraft
• Uplands/floodplain alternative livelihoods to
  reduce pressure on lake
• Maintain existing habitats for fish and other
  species reforestation programs to provide
  longer-term food security
• Balance of Education, Livelihood Options,
  Community Engagement and Enforcement. (use of
  appropriate fishing gear, awareness of values,
  monitoring, linkages and rules).

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Actions (Contd)

• Review and revise zoning of the Tonle Sap based
  upon modeled analysis and validation
• Identify different cultivars of rice and fruit
  varieties that are more flood / drought tolerant
• Improve early warning system provide seasonal
  forecast information to communities

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Next Steps Information Needs

• Baseline ecological information on current status
  of species and habitats (fish, reptiles, birds,
  mammals) and how these will respond to climate
  change.
• Understand the functional ecology of flooded
  forests
• Assess feasibility of alternate livelihood
  options, water filters, alternative fish cooking
  units
• Improved modeling and analysis of climate change
  and hydropower consequences to the Tonle Sap
  system and communities
• Observed climate data lacking Expand weather
  station network