Tonle Sap Lake (TSL), the largest lake in South East Asia, is under increasing pressure from pollution, land-use change, climate change, and development activities in the lake, its basin and the Mekong Basin. Recent changes in the lake hydrological system and its floodplains are becoming a great concern for hundreds of communities relying on the lake resources for their livelihoods. The lake has already been experiencing abnormal fluctuation of its unique inflow-outflow system. This has been affecting the inflow of water, sediments, nutrients and migratory aquatic animals which are essential for the ecosystem productivity and fishery-based livelihoods. The lowered fish catch directly impacts the economic profile of the low-income fishing communities living in the lake’s floating villages and increases their vulnerability. Pollution from point and non-point sources, eutrophication, poor sanitation, and disposal of untreated wastewater has caused deterioration of water quality in certain parts of the lake. This was found to increase incidences of water-borne diseases, and impact on the ecosystem and the fishery.
Advancing our understanding of the interlinkages between the lake’s environment and community livelihood is critical to ensure sustainable development, conserve the ecosystem, and enhance the resilience of the communities that are dependent on the lake’s resources. Updated approaches to scientific investigation and use of the latest and most effective techniques should be applied to assess existing and emerging environmental challenges, while findings and potential countermeasures should be conveyed to decision makers and relevant stakeholders.
Japan International Cooperation Agency (JICA) and Japan Science and Technology Agency (JST) have supported the project “Establishment of Environmental Conservation Platform of Tonle Sap Lake” under the Science and Technology Research Partnership for Sustainable Development (SATREPS) program of the Japanese government. Under the scheme, a transdisciplinary research consortium involving universities and research institutes in Japan and Cambodia and governmental agencies in Cambodia has implemented the project. In Japan, the project is led by Tokyo Institute of Technology (Tokyo Tech) in collaboration with the Institute for Global Environmental Strategies (IGES) and Yamagata University (YU). In Cambodia, the Institute of Technology of Cambodia (ITC) is leading the project in collaboration with the Ministry of Environment (MOE), Tonle Sap Authority (TSA), the Ministry of Water Resource and Meteorology (MOWRM), Ministry of Education, Youth and Sports (MOEYS), and the Royal University of Phnom Penh (RUPP).
The objective of this policy report is to share and disseminate policy relevant research findings of the project with relevant stakeholders in Cambodia and Japan, as well as other countries facing environmental challenges similar to TSL. The report focuses on the problems faced by local people due to recent environmental changes in the lake. It draws attention to both research gaps, and the scientific methods that can be used to address environmental problems in TSL. This report is divided into seven chapters covering relationship between the socio-economic conditions of the local communities and TSL environment, including the impact of environmental changes on livelihoods and fisheries, hydrological changes in the Mekong River as well as in TSL Basin, variability in water quality and sedimentation, and health risks caused by heavy metals, pesticides and microbial pollution. It is hoped, the report will help to inform researchers, policy makers and decision makers, and other relevant stakeholders in Cambodia about the identified environmental problems. These identified issues and recommendations are expected to be useful for advancing future research and monitoring of the state of the environment, while relevant agencies of the government could take necessary mitigation measures to solve these problems.