K Bharathi, President, South Indian Fishermen Welfare Association, said that the incident had been happening over the last few days.
“There were big fish and small fish coming to the shore. We suspect that it is due to the effluents being dumped into the sea, through an old pipeline belonging to the Chennai Metro Water. This is clearly untreated sewage. The estuary is a critical area which is supposed to be protected, as this is the place where the tidal movement occurs, creating the environment for fish breeding. Among the dead fish, we also found some river fish, which had come for breeding. There could be more than a 100 kilo of fish washed ashore, since most of these were big-sized fish,” said the fisherman leader, adding that samples have been taken by various organisations including National Institute of Ocean Technology (NIOT) and Central Institute of Brackishwater Aquaculture (CIBA).
The fishermen said that the health risks could only be ascertained after the samples are tested by the Fisheries Department and other agencies. “For now, we are worried about the future as a huge quantity of dead fish is rotating between the sea and the waterbody. In addition, the estuary is the key area for their breeding. We hope that the fish stock doesn’t get affected in the future,” added Bharathi.
(Two workers removing a bulk of dead fish at the shore near the Adyar creek in the city)
Dr SV Alavandi, Principal Scientist, CIBA, said, “We have taken the samples and people have said that there has been sewage disposed into the sea. We have also taken samples of water and soil quality to check. We will also be looking for any pathogen or disease presence in the fish. Within a day or two, we will get a clear idea of the situation.”
Environmentalist Nityanand Jayaraman said that the tide was turning on Sunday, when the dead fish had started washing ashore. “The high tide was moving into the estuary area and the southern side of it had more contamination from the upstream. There is a little cove where the water gets collected. People were fishing and taking out quite a few dead fish and dumping them on the shore. Most of the dead fish are Mullet, Tilapia which move into the estuary from the sea to breed. There was a strong stench of sewage, which could be attributed to regular households,” said the environmentalist, adding that in 2015 and 2016, similar incidents had occurred, leading to a massive fish kill.