Our Work

Tonle Sap is often called Cambodia’s “beating heart.” Every wet season, this vast lake overflows, flooding nearby plains, forests, and farmland. That natural pulse supports the country’s most important fisheries, fosters nesting grounds for endangered birds, and sustains millions of Cambodians. However, a changing climate, erratic water levels, and illegal fishing have strained its delicate ecology. A 2020 Fisheries Administration survey showed that fish stocks in key areas declined significantly, and conservationists noted worrying drops in certain bird populations.

In 2021, the EU-funded “Our Tonle Sap” project began a four-year collaboration to reverse these trends. Six provinces—Battambang, Banteay Meanchey, Siem Reap, Kampong Thom, Kampong Chhnang, and Pursat—launched a wide range of field interventions to restore wetlands, protect threatened species, and promote sustainable livelihoods. Our teams collected baseline data on fish stocks, water quality, and bird habitats, then worked with community-based organizations (CBOs), farmers, and local governments. The overarching goal was to reinforce the lake’s natural defences and improve household incomes in ways that last.

Below, we detail how we gathered data, reforested the floodplain, helped fish stocks rebound, adopted climate-smart agriculture, curbed wildfire threats, strengthened wildlife conservation, diversified incomes with sustainable agriculture, and integrated these efforts into local policy.

A Wide-Angle Approach Spanning Four Years

Baseline Assessments and Community Engagement

The project began with a close look at existing conditions. Field researchers collected quantitative data on fish stocks, water quality, and land-use patterns across six provinces. They also interviewed local authorities, community-based organizations, such as community fisheries (CFis), community protected areas (CPAs), Agricultural Cooperatives (ACs) and civil society representatives to identify pain points:

Concentrated Illegal Fishing

Rangers and residents flagged areas where destructive nets and electric gear persisted.

Degraded Flooded Forests

This information helped shape precise targets for restoration and guided decisions about patrol routes, reforestation plots, and pilot programs for climate-smart agriculture.

Limited Access to Markets

Many crucial wetlands had been cleared for farmland or damaged by wildfires.

Farming cooperatives and women-led small businesses struggled to reach buyers for eco-friendly products.

Habitat Restoration

FLOODED FORESTS AROUND THE TONLE SAP NURTURE VITAL BIRD AND FISH POPULATIONS, REDUCE EROSION, AND BUFFER THE FLOOD PULSE. THE PROJECT INTERVENED ON MULTIPLE LEVELS:

Small-scale nurseries raised over 115,000 native saplings (e.g., Barringtonia acutangula and Diospyros species) for eventual planting. Community members planted these seedlings across 192 hectares of former forest sites. Selective thinning and weeding on an additional 283 hectares allowed natural seedlings to regenerate in patches where the soil was still fertile.

Project ecologists recorded early increases in local biodiversity, including sightings of endangered waterbirds. Replanted zones also acted as microhabitats for fish spawning, which supported more robust fisheries in adjacent waters.

Local Oversight

Families living near reforestation zones took turns patrolling these sites. Communities and our field teams set up Telegram channels to report illegal cutting, logging, or new fire risks. This grassroots vigilance reduced damage during the dry season and improved survival rates of young saplings.

Seedling Propagation and Replanting

Enhanced Floodplain Health

Fisheries Management

Tonle Sap’s fish provide over half of Cambodia’s dietary protein, so a decline in fish stocks reverberates far beyond the lake’s immediate shoreline and its communities. The Our Tonle Sap project tackled this concern on several fronts, including:

Patrols and Enforcement

Community rangers and Fisheries Administration staff used mobile data applications to record illegal gear and track hotspots. Many patrols took place at night to intercept large-scale netting and electric shock fishing. Confiscated equipment included hundreds of meters of fine-mesh nets, known to trap juvenile fish.

Degraded Flooded Forests

Awareness Campaigns

Many crucial wetlands had been cleared for farmland or damaged by wildfires.

Teams held village-level workshops to explain legal gear limits and share sustainable catch methods. Participants commented on better cooperation among fishers, who recognized that preserving fish stocks benefited everyone.

Climate-Smart Agriculture

Sustainable Rice Platform (SRP)

Farmers adopted improved seed selection, composting, and precise water controls to optimize yields without heavy pesticide use. Data from 24 pilot villages showed a jump in average rice yields from around 3.5 to 6 tonnes per hectare. Reduced inputs and better access to premium markets boosted household incomes.

Drought and Flood Resilience

Some communities tested alternate wetting-and-drying irrigation schedules to reduce water waste. Others built small reservoirs to capture rain when the lake’s water level fell below normal. These strategies mitigated the unpredictability of Tonle Sap’s flood pulse while cutting costs.

Field Schools

Groups of 15–20 farmers met weekly with project agronomists to analyze plant diseases, refine compost formulas, and share local solutions. The peer-learning format encouraged adoption of new techniques and built trust in climate-resilient methods.

WILDFIRE IS A GROWING THREAT TO FLOODED FORESTS, GRASSLANDS, AND SETTLEMENTS AROUND THE TONLE SAP. DRY, EXPOSED BRUSHLAND CATCH FIRE QUICKLY WHEN WATER LEVELS DROP. THE PROJECT STRENGTHENED LOCAL CAPACITIES TO PREVENT AND CONTAIN WILDFIRES:

Bengal Florican Monitoring

Project teams surveyed grassland patches used for breeding, noting nesting success rates and local threats like land conversion. Patrol data indicated that protected areas under active community watch saw reduced disturbance during nesting season.

Tonle Sap is home to numerous threatened birds, including the Bengal Florican—one of the world’s rarest bustards—and large waterbirds such as Greater Adjutant and Painted Stork.

Wildlife and Bird Conservation

Nest Protection Schemes

Some sites offered incentives for villagers who located and safeguarded ground nests. Simple measures like marking nest zones or re-routing foot traffic helped chicks fledge successfully.

Wetland Bird Recovery

At critical rookeries, reforested patches provided safer roosts for species such as Spot-billed Pelican. Observers logged a modest uptick in nesting pairs during the 2023 breeding season. Continued water-level fluctuations remained a concern, but these efforts prevented further habitat losses in project zones.

Fire Management

Wildfire is a recurring threat to flooded forests, grasslands, and settlements along Tonle Sap. Dry, exposed soils catch fire quickly when water levels drop. The project strengthened local capacities to prevent and contain wildfires:

Risk Mapping

Community councils highlighted fire-prone zones, especially areas close to farmland or heavily dried brush in the floodplain. GPS data guided the installation of small firebreaks to slow spreading flames.

Community Firefighting Teams

Volunteers and local rangers received basic training in safe fire suppression. A network of watchpoints and village contacts signaled early alerts via Telegram, which drastically lowered response times.

Reduced Impact

Fewer large-scale fires were reported in certain pilot communes, and reforested zones under active watch saw minimal burn damage. Residents noted that consistent surveillance and quick action prevented wildfires from turning into major catastrophes.

Eco-Tourism and Livelihood Diversification

Households often rely on fishing, farming, and seasonal labor for survival. Broadening income options can motivate better resource stewardship:

Nature-Focused Ventures

Several villages launched homestays and guided tours that intended to spotlight the region’s one-of-a-kind bird colonies and wetland flora. Tourists paid fees that funded conservation patrols and local infrastructure.

Women-Led Cooperatives

Visitor Impact Management

Project trainers introduced product development skills and marketing techniques. Some groups specialized in fish-based snacks, craft items, or organic produce. Members reported up to 25% higher revenues, which allowed them to invest in gear and adopt more sustainable practices.

Organizers restricted visitor numbers in sensitive habitats. Waste management rules, posted in multiple languages, minimized littering. Locals reported positive tourist feedback and a willingness to pay for eco-friendly services.

Policy Integration and Local Leadership

Progress hinged on supportive governance. Our Tonle Sap collaborated with commune councils, provincial authorities, and community-based organizations (CBOs):

Technical advisors helped councils redirect spending toward canal repairs, nursery expansions, and volunteer ranger stipends. Structured planning minimized duplication among overlapping donor initiatives.

Workshops gave local administrators tools for conflict resolution, data interpretation, and transparent reporting. Elected leaders who once lacked conservation experience became knowledgeable advocates for Tonle Sap’s wetlands.

Local Regulations

Officials drafted or updated policies to protect newly reforested plots, secure breeding zones, and formalize community-driven land management. Over 30 CBOs worked with district representatives to incorporate these rules into commune investment plans.

Budget Prioritization

Capacity Building

Our Impact

The project planted thousands of saplings, improved fish stocks in target areas, and stabilized certain bird populations through nest protection programs. Farmers reported higher rice yields, and eco-tourism gave households a buffer against economic shocks. Commune councils adopted more forward-looking regulations, and local leaders continued building on the project’s momentum.

However, challenges remain. Some grassland-dependent birds face ongoing habitat encroachment, and external forces—like upstream dam construction—affect flood cycles. Yet the project’s blend of field evidence, community engagement, and policy coordination proved that Tonle Sap’s natural systems can be strengthened. Future initiatives will hopefully refine these approaches, share lessons with neighboring regions, and push for broader policy reforms that protect Cambodia’s largest lake well into the future.

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