Oil spill will deformkill marine species, reveals a 2017-study

CHENNAI: Oil spill from the Chennai Petroleum Corporation Limited (CPCL) into Kosasthalaiyar River and Ennore Creek may prevent fishermen from earning a livelihood for at least 3 months, but its impact on marine life is long-term.

A scientific study conducted after the 2017-oil spill in Chennai revealed that the spillage will kill marine life and cause deformities.

An official attached to the department said that the sand close to the sea is completely spoiled by the oil spill. “During the times of high tide, waves bring oil and leave traces on the sand. This deposited oil would penetrate into the sand to reach several feet and stay for a long time,” he warned.

The official also pointed out that organisms at the bottom of the food chain would die immediately without oxygen and due to toxicity. “Organisms in the upper level, like turtles, will be affected while consuming the poisoned prey. Fish breathe through their gills by allowing water to run through. Water polluted by oil will affect the gills and they may swallow oil during the process. Oil slick will hinder movement of fish, crabs, turtles and other organisms,” he explained.

Apart from the marine organisms, death of cattle, dogs and cats also have been reported from residential areas near Ennore as the rainwater mixed with crude oil flooded the streets. Prabhakaran Veeraarasu, an environmental engineer attached to Poovulagin Nanbargal, accused the authorities of not being transparent in releasing the details.

“They’re saying that crude oil spilled. But there is no clarity on the stage of crude oil. Whether the spilled oil is used or not is unknown. TNPCB (Tamil Nadu Pollution Control Board) should define other parameters of the oil. What amount of benzene, toluene or hydrocarbon was present in the oil should be made public,” he averred.

Prabhakaran also raised a valid concern that the technology to clean the sand has not yet come to India. “The chances of cleaning the sand completely are low and this impacts marine life longer,” he rued.

Meanwhile, a survey conducted by researchers of University of Madras in areas affected by the 2017-oil spill found out that organisms like fish, turtles, crabs and other crustaceans were found dead. Dead Olive Ridley turtles were washed ashore and the turtle eggs had become black due to the adhesion of oil in the ‘High Impact Zone’, while only a few turtles were seen on the shoreline of the other zones.

It also revealed that seaweeds were seen predominantly affected in the coastal region and were washed away by the sludge making them brown and black. The habitat between Ennore to Marina Beach completely collapsed.

“In-depth histological studies on gills, hepatopancreas and eggs of the crab Grapsus Albolineatus, showed structural deformities with irregular gill tips and lower haemocytes counts in the gill samples,” the study said.

Making the situation worse is the nesting season of Olive Ridley turtles in the east coast including Tamil Nadu coast, which is just 2-3 weeks away.

“Olive Ridley turtles will nest 100-200 metres from the tide. It’s not clear whether the oil deposited on the beach sand for a few metres would affect them. We have to wait until the season starts,” a conservationist said.

On the other hand, a forest department official said that the turtle nesting along the Chennai Coast is sporadic and the spillage will not affect the nesting. However, the State government is yet to release the findings of a committee formed to assess the nesting sites in Ennore region.

TD Babu, marine biologist and member of the District Green Committee, elaborated: “The estuaries are a sensitive ecosystem and the impact of such incidents will be serious and long-term on the aquatic animals. The State government should have SOP (Standard Operating Procedure) to handle such incidents and teams should be kept ready throughout the year as oil spills are occurring frequently.”