Cauvery oil spill hits bird life amid final phase of clean-up

CHENNAI: The oil spill from Mettur Thermal Power Station into the surplus water stream of the Cauvery River has turned into a nightmare for the winged visitors and their habitats.

With several species of birds spotted with their feathers soaked in oil spills and changed to black colour, the situation poses health risks to the species though the clean-up work is at the ending stage.

Elaborating on the issue, SV Ganeshwar, the director of Salem Ornithological Foundation (SAF) said, “Many birds in the vicinity were found coated with oil slick and compromised feather integrity. They faced difficulties in flying and preening and their feeding patterns were also disrupted in areas where oil covered the water’s surface. Immediate rescue of the affected birds is the need of the hour.”

During the preliminary assessment, the ornithologists found bird species like the Indian Pond Heron, Purple Heron, Grey Heron, Little Cormorant, and Crow with visible oil slicks. More birds could have become vulnerable to various health concerns because insectivorous birds such as warblers, bush chats, robins, and babblers feed on the contaminated vegetation and dead insects in the oil spill area.

Though the clean-up works are under way over the last few days, the oil spill may have a profound impact on shorebirds and migratory birds like Common Sandpiper, a rapidly declining species in Tamil Nadu, but documented frequently around the oil spill area and most recently on December 17. It is to be noted that the migratory season which began in November will end in March.

Further explaining the adverse effects on the bird species, SV Ganeshwar said if these birds breed, the eggshells exposed to the oil spill can result in embryo mortality as the chemicals in oil may be absorbed into eggs causing developmental abnormalities.

Also Read: Oil spill from Mettur plant spreads deeper into Cauvery, raises safety concerns for drinking water

“Oil exposure can cause hormonal disruptions in adult birds, affecting their mating behaviour and fertility. If adult birds feed oil-contaminated prey to their chicks, it may also lead to poisoning or starvation. Long-term exposure to these toxins can cause liver and kidney damage, immune suppression, and reduce the lifespan of birds,” added SV Ganeshwar.

As part of the contingency plan, environmentalists suggested that temporary measures should be taken to prevent the birds from entering the oil spill area rather than addressing the issue after they get affected. “The mere presence of human beings can stop nocturnal birds from venturing into the stream,” highlighted V Deepak of Suzhal Arivom, an environmental organisation.

An oil spill occurred in the middle of the surplus stream of the Cauvery River on December 20. A field study conducted by Suzhal Arivom revealed that the oil spill had spread up to one kilometre.

With weather forecasts indicating rainfall across Tamil Nadu in the coming days and the Mettur Dam nearing its full capacity of 120 feet, the Mettur Thermal Power Station authorities have been working overtime by engaging local fishermen to remove the oil spill on the stagnant stream.

The oil spill has almost been cleared from the water body, said an official of the Mettur Thermal Power Station. “Along with the oil spill, the debris in the Cauvery River surplus water stream has also been cleared. The pending work in patches along the shore would also be completed entirely by today (Saturday),” the official said, requesting anonymity.