CHENNAI: Fisherfolk in nearly eight villages along the Kosasthalaiyar River near the Ennore estuary woke up to a massive fish kill on Sunday, with an estimaed four to six tonnes of fish, prawns and crabs found dead along the river and washed ashore. While residents suspect chemical pollution from nearby industries, officials said the cause was yet to be established. Species including madavai (flathead grey mullet), kendai (carp), keluthi (catfish), oodan, neththili (anchovy), kelanga (ladyfish) and kola were among those found dead.
Fisherfolk staged a protest near Thalankuppam in Ennore, demanding that the government identify the cause, take action against those responsible and provide compensation and permanent alternative employment. More than 8,000 families in Nettukuppam, Thalankuppam, Ennore Kuppam, Mugathuvar Kuppam, Sivanpadi Veedhi Kuppam, Periya Kuppam, Chinna Kuppam and Kattukuppam depend on fishing in the area, they said.
When TNIE visited the area on Sunday, the water appeared clear, but dead fish lay strewn along the banks and floated in the river. A foul smell hung over the area. Fishermen said they had not spotted a single live marine species along a stretch of at least 6km of the river since morning.
“At around 1 pm on Saturday, many fish were found floating in the river. Several of us, including my husband, went fishing at that time. The fish were half-dead and struggling to breathe. We sensed something was wrong, but did not expect such a large number to die the next day,” said Anjali D (39), a resident.
Fishermen said the incident brought back memories of the 2023 CPCL oil leak, after which fish and prawn populations took more than a year to recover. “Now, we have to wait until a new generation of fish or prawn grows to ensure a good catch and livelihood. This could take at least six months or even a year,” said M Elan (47), a fisherman from Mugathuvar Kuppam.
RL Srinivasan (46), of Kattukuppam, said smaller fish kills had occurred earlier, but never on this scale. He alleged that untreated sewage from the Buckingham Canal was already entering the Kosasthalaiyar and that industrial activity was worsening the situation.
The protest ended after Tiruvottiyur MLA N Senthil Kumar assured the protesters that samples would be tested. The Tamil Nadu Pollution Control Board (TNPCB) and fisheries department collected fish and water samples for analysis.
Social activist S Vishanth (39) of Ennore, said, “The area is mainly used for prawn catching and there were no major numbers of fish earlier. All of a sudden, on Saturday, each fisher caught semi-conscious fish worth up to `15,000. It also raises concerns over the negative health impacts on those who might consume it,” he said.
TNPCB chairman Anurag Mishra said there were no visible signs of an oil spill or industrial effluent discharge. “Our officials have taken dead fish and water samples for testing. We will know the actual cause in a day or two,” he said.
NGO study
Meanwhile, a study by the Save Ennore Creek campaign and Kattukuppam fishers reported heatwave-like conditions in the Kuruvimedu and Railway Bridge canals along Ennore Creek .
Temperatures of 40.8°C and 40.6°C were recorded at four sampling locations between 585 metres and 1,045 metres from the discharge point of NTECL Vallur.
The campaign said prolonged exposure to hot water could increase fish metabolism and oxygen demand even as warmer water holds less dissolved oxygen, causing stress, impaired growth and reproduction, disease susceptibility and death
(With inputs from SV Krishna Chaitanya @ Chennai)