In Deduru Oya, Sri Lanka, an invasive fish species known as the snakehead is significantly impacting local fisheries by preying on traditional fish and shellfish populations. Fishermen in the northwestern village have observed a marked decline in their usual catches over the past two years, coinciding with the rapid proliferation of the snakehead fish, which is unfamiliar to the region.
Local authorities suspect that the snakehead, a species commonly found in countries like Thailand and Indonesia, may have arrived in Sri Lanka through imported ornamental fish. The fish, likely released into the reservoir when they outgrew their tanks, have found a suitable breeding ground in Deduru Oya, where they face no natural predators and have an abundance of food. Dr. Kelum Wijenayake, a researcher studying the invasive species, noted that the snakehead has no natural enemies in Sri Lanka’s ecosystem, which allows it to thrive.
The snakehead fish not only outcompetes local species for resources but also grows significantly larger than native fish. Fisherman Nishantha Sujeewa Kumara shared that he once caught a snakehead weighing 7 kilograms (15 pounds), compared to native fish that typically weigh less than a kilogram. Ranjith Kumara, secretary of the area’s fishers association, mentioned that prior to the arrival of snakehead fish, they were able to catch a variety of high-value species, such as small prawns, which have become increasingly rare.
Despite efforts by authorities to organize angler competitions to reduce the snakehead population, these initiatives have not been successful. However, local fishermen are looking for ways to turn this growing threat into an economic opportunity. Ranjith Kumara has suggested promoting angler tourism as a viable means of population control, which could provide supplementary income for villagers reliant on fishing and farming.
Fisherman Sujeewa Kariyawasam has taken to processing the invasive species into salted dried fish, noting that while fresh snakehead fish may have limited market appeal, the dried variety is considered a delicacy. He expressed optimism about the growing demand for this product and aims to expand his business, which may simultaneously help manage the snakehead population.
The innovative approaches taken by local fishers in response to the challenges posed by the snakehead fish illustrate resilience and adaptability in the face of environmental change. By transforming a potential ecological crisis into an economic opportunity, the community is finding ways to sustain their livelihoods while addressing the threats to their ecosystem.