Fishermen use mobile app to track endangered fish in the Mekong

Perched on the edge of his boat, Seun Rin, fisherman in Koh Knhnear, Cambodia, gently cruises to the riverbank with a bucket of water brimming with the day’s catch. Before he can decide which fish to send to the market and which to bring home to his family, he opens App Threatened Fish on his phone.

He scrolls the app’s list of 18 fish species, 12 are endangered species and six are those reported to have drastic population decline in the last 20 years. If he has, or suspects he has caught one of them, he makes a record of it by documenting the time and location of the catch, as well as its size, weight and three pictures for verification.

Seun Rin is one of the 30 fisher people in Cambodia taking part in a pilot project to collect data on the little-known fish species of the Mekong River, led by the Faculty of Fisheries and Aquaculture at the Royal University of Agriculture (RUA), with funding support from the Critical Ecosystem Partnership Fund and IUCN and technical support from SHOAL Conservation. 

“This app is designed to strengthen our communities' involvement in protecting endangered fish species,” explains Pin Kakada, RUA’s Project Coordinator. Previously, RUA worked with local communities to record data on paper. The app was designed to improve efficiency. By establishing a repository on the health and population trend of endangered fish species, RUA hopes this data will inform conservation efforts at a national level. “This information is crucial for the community, local authorities, national policymakers, and others to use in strengthening efforts to protect endangered fish species.”

Fish conservation is not new in Koh Khnhear, a riverside village of just over 200 households. The community has an active six-person patrol team working throughout the year to combat illegal fishing and the use of illegal fishing gear. “There is a lot of work involved because our community has both a core zone and a buffer zone,” explains An Ho, Koh Khnhear’s Village Chief. The buffer zone is made up of flooded forests and islands that are critical habitats for fish. In the core zone, where deep pools offer refuge for fish to feed and breed, fishing is completely prohibited according to community regulations.

When RUA approached An Ho about the possibility of piloting App Threatened Fish in Koh Khnhear, he jumped at the opportunity. “I think it is very important and beneficial for the community and Cambodia as a whole to understand the catch and fish species in our community.” He believes that research is essential for understanding fish migration and key to combatting illegal fishing in the area. An Ho selected his four top fishermen for the pilot project and hopes more will be able to join them in future.

On a visit to Koh Khnhaer in January 2025, IUCN met with the four fishermen taking part in the pilot project to learn about some of the progress and challenges. They shared that the app is easy-to-use but face some connectivity challenges and noted that the app requires a lot of data. Though selected based on their fundamental understanding of endangered fish species, the four fishermen all shared that they’ve learned more about their local ecosystem since using the app. Other community members have also gotten involved by sharing pictures when they think they’ve caught one of the 18 threatened species for the four fishermen to record through the app.  

The pilot began in mid-December 2024. To date, 790 records of 12 threatened species were reported through the app by 30 fisher people across six villages in Cambodia. More catch is continuing to be recorded daily by all participating fishers. RUA are closely monitoring this data to identify patterns as well as changes in the population trends of all the species listed.

IUCN continues to support organisations that empower communities, whose livelihoods depend on a healthy river, to do their part in conserving the majestic species of the Mekong. “I want to know if these species exist in our part of the river,” said Suen Rin. “We need to join efforts to protect them for future generations.”