Officials are scrambling to contain the spread of crayfish in Phayao Lake in Thailand’s Phayao province, after local fisherfolk have been finding them in increasing numbers in their traps.
Phayao Lake is the largest freshwater lake in Northern Thailand and the fourth largest in the country.
Phutana Chompooming, deputy governor of Phayao, has launched a campaign encouraging locals to catch the crayfish to eat, to help suppress what is regarded locally as an invasive species.
He also issued a strict order forbidding anyone from releasing crayfish into Phayao Lake or other public bodies of water.
By law, violators face a fine of up to 2 million baht. Anyone wishing to breed this non-native species must comply with the regulations by seeking prior permission and registering with the provincial fisheries office.
The spread of crayfish, also known as red claw crayfish (Cherax quadricarinatus), in Phayao Lake has drawn close attention from various local agencies after the species kept turning up in traps on Tuesday.
Fisherfolk currently catch about 1 to 2 kilograms of crayfish per trap retrieval, selling them in the local market for 200 to 250 baht per kilogram.
While the species is in high demand and generates income for residents, officials and environmentalists worry that further proliferation could decimate native aquatic species and devastate the lake's delicate ecosystem.
Assoc. Prof. Dr. Apinun Suvarnaraksha, dean of the Faculty of Fisheries Technology and Aquatic Resources at Maejo University, has stated that the crayfish present in Phayao Lake are likely the result of aquarium hobbyists dumping their pets.
“The crayfish is an invasive alien species characterised by its resilience, strength and rapid reproduction rate,” Apinun explained. “As predators, they feed on a wide variety of organisms, including aquatic plants, small fish, frogs, shrimp and snails, posing a direct threat to the local aquatic ecosystem.”
Furthermore, their high adaptability allows them to thrive in new environments, raising fears that they could spread via tributaries and eventually breach the Mekong River system.
Apinun stressed that urgent cooperation is needed to control the crayfish population, alongside continuous research into their long-term impact on the region's biodiversity.
