Propeller Project -
Tonle Sap Lake, Cambodia

The Tonle Sap Propeller Project is a pioneering economic impact assessment focused on the daily struggles faced by fishermen, tour operators, and community boat operators who rely on the Tonle Sap Lake’s waters and canals for their livelihoods. The report was undertaken in a joint collaboration between Ocean Recovery Alliance, NGO2 Bambooshoot Foundation and Angkor University which undertook the surveys itself. A recurring issue for these boat users is the entanglement of plastic waste and old fishing nets in their propellers, which forces boat operators to halt their journey and untangle their propellers. In many cases, this requires tools like hacksaws or knives, and sometimes even physically jumping into the water to clear the obstruction. Each of these incidents wastes valuable time and can lead to additional maintenance costs, ultimately disrupting the core activities of fishing and tourism on the lake.

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The Propeller Project, the first of it's kind, surveyed almost 643 local boat owners and users across four communities: Kompong Phluk, Kompong Khleang, Chong Khneas, and Me Chrey. The findings provide a detailed look into the economic and operational impacts caused by entanglements of plastic pollution and old fishing gear, which significantly affect those who use the lake for commerce, transportation, and leisure.
 
The research reveals that 98.13% of participants encounter issues with plastic or old lost or discarded fishing nets during boat travel, with the problem being most prevalent during the low-water season (95.80%). In fact, out of the 643 survey participants, each with an average of 7.5 minutes of time spent per day untangling propellers, they collectively lose 70 labor-hours per day with stopped boats. When this number is extrapolated to the entire lake, the man-hours lost per day are in the thousands. This is an economic cost to life on the lake which has not previously been accounted for or considered in the past, and the hope is that this report will help bring awareness and solutions to communities making their livelihoods on the lake, which includes impacts to tourism and time lost by the tourists themselves.
 
The Tonle Sap is unique globally, due to the way it floods and recedes in a slow six-month cycle each year, and it is the largest freshwater lake in Southeast Asia. It spans from 2,500 kilometers during dry season, and 16 000 kilometers during monsoon season as it floods the Mekong River and forces the Tonle Sap to flow in the opposite direction while filling the lake. The filling of the Tonle Sap also floods the nearby floodplains, creating optimal conditions for a wide range of aquatic and terrestrial species and breeding and feeding grounds for migratory birds and fish.
 
Often considered Cambodia’s “Inland Ocean,” this freshwater lake in Southeast Asia, located in the middle of Cambodia, and is considered the heart of Cambodia, where the river lake borders five provinces. Based on the seasonality of the water levels, the lake can increase or decrease in size by a factor of 15 times, with an average depth of approximately nine feet (3m). The lake’s ecosystem is unique, functioning as a dual-directional river and serving as a natural reservoir and a vital sanctuary for birds, fish and wildlife. It impacts over 1,000,000 people directly who rely on the Tonle Sap for their livelihoods, and indirectly impacts over 4,000,000 people within the country.