Fishermen who set out to sea from several locations in the district on Saturday returned with shredded nets and little or no catch. Shoals of puffer fish prowling the coastal waters are wreaking havoc, damaging fishing nets, preying on other species and causing heavy loss to traditional fishermen.

Fishermen who set out to sea from Veli to Poonthura reported the maximum damage caused by the predatory species. Fishworkers estimate that the loss would run into lakhs of rupees. “The net is bitten and shredded to pieces by the puffer fish, leaving the fisherman with no option but to buy a new net. Other fish caught in the net are picked clean, leaving only the bones,” says T.Peter, State president, Kerala Swathantra Matsya Thozhilali Federation (KSMTF). Last year, the proliferation of puffer fish was reported from Kollam. The problem usually lasts for a week.

Puffer fish is known by several names in local parlance, including ‘yaava,’ ‘petha’ and sea frog. It is drawn to the small fish caught in nets. Once it gets entangled in the net, it uses its beak to break free. In the process, the net is often irreparably damaged. Scientists aver that the migration of puffer fish to coastal waters is a normal phenomenon. A predatory species, it mostly migrates for food. It is endowed with a hard, sharp beak instead of teeth.

Local fishermen however suspect that the sudden emergence of puffer fish in large numbers is triggered by the resumption of trawling after the monsoon ban. They believe that the seabed disturbance caused by bottom trawling could be driving them to migrate to the coastal waters.

"Puffer fish feed mainly on the mussels and shellfish that inhabit coral reefs, cracking them open with their sharp beaks. The decline in the shellfish population, post- tsunami, could be another factor that has led them to migrate to new areas", Mr.Peter says.

Yet another reason, fish workers presume, is the practice of dumping coconut peduncles off the coast to create an artificial reef that acts as a breeding ground for several commercially important species including the squid. A section of fishermen opposed to the practice believe that such peduncle reefs attract puffer fish along with squid.

The simmering tension between the groups has often led to open hostility, threatening peace in the coastal areas KSMTF has called for a scientific study to assess the reason for the proliferation of puffer fish. It is also demanding a special package to compensate the fishermen for the losses.