DEDURU OYA, Sri Lanka (AP) – An invasive species of fish, the snakehead, is steadily threatening the livelihoods of local fishermen in the northwestern village of Deduru Oya. This species is voraciously consuming traditional fish and shellfish in the Deduru Oya reservoir. Local fishermen are striving to convert this challenge into an opportunity.
Over the last two years, fishermen have observed a significant decline in their typical catches. They report an influx of snakehead fish, a species previously unseen in Sri Lanka. Local officials speculate that these fish may have entered the country via imported ornamental fish, which were likely released into the reservoir by their owners once they outgrew their tanks.
Dr. Kelum Wijenayake, an academic specialized in this area, explained that the snakehead fish holds a dominant position in the local food chain, with no existing predators in the ecosystem of Sri Lanka. The Deduru Oya reservoir provides ideal conditions for their breeding, characterized by abundant food and a lack of natural enemies.
Snakehead fish are unique in their adaptation; they often come to the surface to inhale air, allowing them to survive in low-water conditions. With sharp teeth and powerful jaws, they are aggressive feeders, posing a significant threat to the local aquatic ecosystem that has evolved over millennia. Dr. Wijenayake noted that these fish typically grow much larger than native freshwater species, with local fisherman Nishantha Sujeewa Kumara recounting a catch weighing 7 kilograms (15 pounds), in contrast to the usual native species, which rarely exceed one kilogram.
Ranjith Kumara, the secretary of the local fishers association, recalled his first encounter with the snakehead fish, which came from a hobbyist angler's catch. He noted the difficulty of catching snakeheads with nets; instead, they require angling techniques. “We began fishing in this reservoir in 2016, and we were catching small prawns and other high-value varieties, which are now quite rare,” he added.
In an attempt to manage the invasive snakehead population, local authorities organized fishing competitions aimed at removing them from the ecosystem, but this initiative has thus far proven ineffective. Nevertheless, local fishers express optimism, viewing the invasive species as a potential economic asset.
Ranjith Kumara suggested that authorities promote angler tourism as a viable control method, which could also provide alternative economic opportunities to the primarily fishing and farming community. Fisherman Sujeewa Kariyawasam has begun producing salted and dried fish from the invasive snakehead species. Although the market demand for fresh snakehead fish remains relatively low, he noted that the dried version has gained popularity due to its culinary appeal.
"I am working to develop this business further. As the demand increases, more snakeheads will be caught for production, which will help control their population," Kariyawasam stated.
Local fishers are adapting to the rapid changes in their ecosystem caused by the snakehead invasion, transforming challenges into opportunities for economic growth. With innovative strategies and community efforts, the fishermen of Deduru Oya hope to turn the tide against the invasive fish, while also preserving their traditional fishing practices and livelihoods.
