Traditional fishermen near Paravur Lake at Kurumandal in Kollam district are a worried lot. Fish catch has been depleting of late, they say, attributing it to an illegal fishing method being practised upstream and in mangroves: the use of the poisonous fish berry, locally called nanju .
“When the monsoon sets in, it used to be chakara [large congregations of fish],” says Johnson S., a traditional fisherman who has been fishing in Paravur Lake for 36 years now. “Now there is nothing. We used to sell fish worth ₹1,000 daily, but the catch is worth only ₹300 or so.” Business is so dull that traditional fishers are now shifting to jobs that promise better returns, including driving rickshaws.
The seeds of the fish berry Anamrita cocculus (a wild woody climber) are acutely poisonous. They contain picrotoxin, a piscicidal agent, sometimes used as a pesticide. Dried seeds are carefully mixed with mud and soaked in slow-flowing water. Most aquatic organisms in nanju -mixed waters die and float to the surface. Fish are picked from this and sold in markets for consumption. In an hour, anywhere between 10,000 and 20,000 fish can be harvested with this method: easy and lucrative.
Ecological disturbance
Nanju is mixed in reed beds and mangroves where water currents are low, says Bineesh B., a traditional fisher. “You can even spot frogs and snakes quickly moving away from these waters.” “It is usually done in the cover of night. When we go fishing in the morning and see the dead fish, we know nanju has been used.”
A lot of Green chromide or pearlspot ( karimeen ) and snappers ( chembally ) are caught this way, say fishers. Shrimp farms also use nanju to clear fields of fish, which eat shrimp eggs and juvenile shrimp. Once fish die, this water is flushed out into the river and this causes fish death too, say the fishers.
Blisters are formed on the body if it comes in contact with water polluted with nanju , and one’s eyes and nose smart under its potency, says Johnson. “We do not eat fish caught using nanju because it causes inflammation and itching. But those who fish with nanju sell it anyway.” In children, side-effects include nausea and vomiting.
Now the price of the fish berry has also increased, say fishers. “One kilogram cost only ₹60. Now it costs ₹350,” says fisherman Rajeev G.
Illegal fishing method
“Fishing with nanju is not permitted according to the Kerala Marine Fishing Regulation Act,” says C. T. Suresh Kumar, Deputy Director of Fisheries at Kollam. “The method is in practice in Paravur in Kollam. Panchayat ward members have been asked to take responsibility and crack down on this.”
“We have been conducting awareness classes for three years now, but some people still practise this.”
