Thiruvananthapuram: Chief Minister Pinarayi Vijayan said that the preliminary investigation carried out to find the cause of the mass fish kill in the Periyar river in Ernakulam rules out the discharge of chemical effluents from the factories situated on the river coast. 

Responding to the submission put forward by T.J Vinod, the chief minister informed the Assembly that the investigation did not find any of the five sanctioned industries to have discharged treated water. 

The surveillance team of the state Pollution Board conducted the inspection in the industries located in Elur and Edayar regions. The chief minister also said that it was found that the oxygen level in the water was less than the level required for the fish to survive.

When the Pathalam regulator-cum-bridge opened its shutters due to heavy rains, a large quantity of low-oxygen water gushed out from the top of the regulator. The initial inspection found that this was the reason for the mass fish death.

The Pollution Control Board will submit a detailed report only after receiving the report from the Kerala University of Fisheries and Ocean Studies regarding the fish death. The preliminary assessment is that there has been a loss of fish worth Rs 13.56 crore. The chief minister also informed that appropriate action will be taken as soon as the instructions are received regarding granting compensation to the fish farmers.