ecological threat in Cambodia

The Tonle Sap is the largest freshwater lake in South East Asia, comprising a rich, biodiverse environment that supports huge numbers of plants, reptiles, mammals and birds, including the largest colonies of freshwater birds in the region. In 1997 the area was designated a UNESCO Biosphere Reserve.

There are 170 floating villages on and around the lake. This lake is incredibly important for the welfare of the Cambodian people because it supplies 70% of the protein in the form of fish.


Cambodia is a very poor country and consumption of the lake’s resources is intense. Habitat destruction of the lake’s flooded forests, poaching, pollution and illegal fishing practices decimate fish stocks and degrade the environment. This in turn impacts upon people’s capacity to earn a living, sustaining themselves and their families.

Enter Osmose.

Osmose is an organization working in the area since 1999. Realizing that you can’t conserve the environment without helping people, Osmose’s goal is to support both the conservation of the Tonle Sap environment and the sustainable livelihoods of the floating village communities.

The Osmose project has been remarkably successful in its community education program and its ecotourism program.


Bird numbers had declined because poverty forced people to collect the eggs before they could hatch. Now those same people are employed as rangers committed to protecting the eggs they once collected. Consequently the birds have returned in great numbers. One example is the Oriental Darter, on the brink of extinction but now a common sight.


However there is a new threat to the ecological balance and the welfare of the people who live on and around the lake.

The Chinese have built a number of dams upstream on the Mekong River. The Cambodian, Thai and Laos governments – that all share the Mekong - are also planning dams in their efforts to modernize their countries and create hydroelectricity.

The fish in Tonle Sap are migratory. They spawn upriver in the Mekong then swim downstream and grow to maturity on the lake. Dams on the Mekong prevent this and people who depend on the lake are rightly worried. I was there at the start of the rainy season and the lake water level was unusually low.

You can have lots of fish and birds on Tonle Sap Lake in Cambodia or you can have dams on the Mekong River to produce hydroelectricity. You can’t have both.