PHNOM PENH: The growing conflict between humans and water snakes in Cambodia’s Tonle Sap Lake – a vital ecosystem and the largest freshwater lake in Southeast Asia – has reached a critical point, threatening the lake’s biodiversity. 

The slithery water snakes are falling victim to bycatch and the rising commercial demand, from human consumption to feeding crocodiles, is slowly depleting the snakes in Tonle Sap, known for its rich marine ecosystem.

Marine conservationists say water snakes are critical to the lake’s biodiversity, serving as prey for predators, helping regulate aquatic species and providing resources for local communities. 

Angkor Centre for Conservation of Biodiversity Country Director Christel Griffioen told Bernama the Tonle Sap Lake’s water snake population is under serious threat and the current rate of catching them is not sustainable. 

“Most snakes are caught during their breeding seasons, which makes it harder for them to recover and could lead to further declines. 

“Some species, like the endemic Tonle Sap water snake (Enhydris longicauda) are still common but face growing risks because they are being overharvested for crocodile farms, food and trade,” said Griffioen.

The Angkor Centre and the School for Field Studies, with the support of the Ministry of Environment and the Ministry of Agriculture, Forestry and Fisheries have been conducting extensive studies to assess the water snake population in Tonle Sap Lake since 2019.

The timing is crucial as increasing pressure on the lake's resources, habitat changes due to altered hydrology and seasonal harvesting are threatening these species, including the vulnerable Tonle Sap water snake that is endemic to the lake, say researchers. 

Local communities in some areas are turning to water snakes as an alternative source of protein and the snakes have become a popular dish – served as cooked dry meat sold in rural stalls. 

While fishermen sell to snake traders to supplement their income as the niche market is growing. 

School for Field Studies Associate Professor Dr Megan English told Bernama that water snakes are frequently caught as bycatch by fishermen.

“Water snakes are frequently caught as bycatch alongside fish, making them a convenient and accessible resource for local communities.

“Historically, they have been used as an affordable supplement for feeding crocodiles, particularly when fish supplies are low. However, in recent years, water snakes have increasingly been consumed by people living around the lake and in other parts of Cambodia,” she said.

English says large crocodile farms reportedly consume about 300 kg of the snakes per week. 

She expressed concern about the harvesting of water snakes in the Tonle Sap Lake region. Data from 2004 to 2005 indicates that over 770 tonnes or about 6.9 million individual snakes were traded annually, making it the largest water snake trade in the world.

Griffioen says: “To protect these snakes, it is important to reduce harvesting during their breeding seasons, avoid catching large female snakes that produce many young and educate communities about the species that are in danger.”

-- BERNAMA