No Evidence of Industrial Effluent in Ennore Fish Deaths, Says Minister

The mass death of fish and aquatic life in the Kosasthalaiyar River at Ennore in North Chennai was likely caused by a sudden depletion of dissolved oxygen in the water, Tamil Nadu Environment Minister V.K. Rajeev said on Friday.

Responding to a call-attention motion raised by opposition parties in the Assembly, Rajeev rejected allegations that industrial effluent discharge was responsible for the ecological crisis reported near the Ennore Estuary.

According to the minister, preliminary investigations indicate that a sharp decline in dissolved oxygen levels may have caused the fish to suffocate. He added that sewage mixing into the river could also have been a major contributing factor.

“There is no evidence so far that the fish deaths were caused by the discharge from industries in the vicinity,” the minister said.

The incident came to light on August 15, when residents in the Ennore area noticed fish struggling and gasping for air in the river. The following day, local fishermen reported seeing large numbers of dead fish floating in the Kosasthalaiyar River, with carcasses subsequently washing ashore near the estuary.

Officials estimate that approximately four to six tonnes of fish and other aquatic organisms may have been affected by the incident, triggering concern among local fishing communities and environmental groups.

The opposition parties, however, raised concerns over the possible role of industrial activities in the Ennore region, which has long faced environmental concerns related to pollution, industrial development and wastewater discharge.

The government’s preliminary assessment has instead focused on water quality and oxygen depletion as the immediate cause. Further investigation and scientific analysis of water samples are expected to help determine the precise factors behind the sudden decline in oxygen levels.

The incident has renewed attention on the ecological health of the Kosasthalaiyar River and the need for regular monitoring of water quality in the environmentally sensitive Ennore region.