Tonel Sap

The biodiversity present in Tonle Sap Lake is both extraordinary and distinctive. Surrounding the lake are diverse ecosystems, including mangroves, tropical forests, marshlands, and grasslands, which serve as habitats for a wide variety of animal species. The Prek Toal Bird Sanctuary, situated at the western edge of the lake, is well-equipped to cater to both novice and seasoned birdwatchers. In addition to rare avian species, the lake is home to reptiles, fish, mammals, and insects that contribute significantly to its rich biodiversity. Among the endangered species found in this region are the Siamese Crocodile, Crab-eating Macaque, Spot-billed Pelican, and Milky Stork.

Additionally, the lake hosts a unique water snake species known as the Tonle Sap Water Snake (Enhydris longicauda), which is also classified as endangered. Each year, approximately 6.9 million snakes are harvested from the lake, encompassing around 14 different species. These snakes serve as a primary food source for the birds inhabiting the area, and a decline in their population could have catastrophic consequences for the lake’s biodiversity. The harvesting of snakes has increased due to a decrease in fish populations, leading many fishermen to turn to snakes as an alternative food source, while the rising number of crocodile farms has further intensified this practice.

In 1997, UNESCO designated the region as a biosphere reserve, which facilitated the establishment of laws and regulations aimed at conserving the area.

The exact population residing on and around the lake remains uncertain; however, it is reported that approximately 40% of these individuals live below the poverty line. The majority of the communities are characterized by extreme poverty and are primarily composed of Vietnamese or Cham people. Life on the lake can be both isolating and harsh, with limited access to adequate education and healthcare, and residents face significant challenges from environmental exposure.

• Stilted and Floating Villages: The inhabitants of this region must exhibit adaptability and mobility. Frequently, they relocate their homes and essential structures to various locations in response to the seasonal fluctuations of water levels. Many villages employ a mix of permanent buildings, stilted houses, and movable dwellings that can be shifted with the tides. These settlements are commonly referred to as stilted and floating villages.
• Fishing and Farming: For most families residing on Tonle Sap Lake, fishing is a seasonal occupation, while the surrounding grasslands are used for grazing cattle and small-scale agriculture. The cyclical nature of the lake is vital for food production, ensuring sustenance for the local population. Additionally, a significant portion of the fish harvested from the lake is distributed to feed people across Cambodia, playing a crucial role in the national economy, contributing to 16% of the GDP.

The Khmer New Year, celebrated annually in April, marks the conclusion of the harvest season in Cambodia. This period allows families to relish the fruits of their labor before the onset of the rainy season, which typically begins in June. As the rains commence, the water levels in the Mekong River rise, resulting in a reversal of flow from Tonle Sap.

Under normal circumstances, water from Tonle Sap Lake flows through the Tonle Sap River, eventually merging with the Mekong and Tonle Bassac Rivers. However, during the peak of the rainy season, elevated water levels force the water to flow back toward the lake. This phenomenon is truly remarkable, as the lake acts as a vast reservoir, increasing in size by as much as five times and extending into the adjacent wetlands. Consequently, Tonle Sap becomes the largest freshwater lake in Southeast Asia.

As the dry season approaches in November, Tonle Sap Lake reaches its full capacity, and the ecosystem thrives. Water levels in the Mekong River recede, reversing the flow once more. The Water Festival, known as Bom Om Touk (which translates to “boat festival”), signifies the end of the rainy season. Rice farmers, who have diligently cultivated one or two rice crops during the rainy months, celebrate this festival as a precursor to the rice harvest. Traditional ceremonies for pounding rice, referred to as Ombok, take place, and it is customary to consume the pounded rice during this festive time.

Tonle Sap Lake serves as a vital resource for Cambodia, supporting a rich biodiversity that sustains numerous lives. However, in recent years, the water levels of the lake have alarmingly decreased due to insufficient rainfall during the wet season, increased industrial demands on water resources, and drought periods linked to climate change. These developments pose serious threats to the future of Cambodia.