Cargo ship sinks near Kerala coast: What can be the impact of oil spills and how are they cleaned up?

Indian Express

7 days ago

The threat of a possible oil spill looms large in Kerala as a cargo ship, which was carrying diesel and hazardous substances, sank off the state's coast on Sunday. The Liberia-flagged MSC ELSA 3, a 28-year-old vessel, was sailing from Vizhinjam port in Thiruvananthapuram to Kochi when it capsized around 25 km southwest of Alappuzha.
The ship went down with more than 600 containers, some of which washed ashore on Monday. So far, no oil spill has been reported. Indian agencies, including the Coast Guard, have initiated pre-emptive action to deal with the situation.
Oil spills can severely damage the marine ecosystem as they can result in the death of fish and other organisms, and destroy mangroves and coral reefs. If an oil spill takes place near the coast, it can affect the livelihood of fishermen and disrupt the local economy.
Such spills are dangerous because oil is lighter than water and it keeps floating on the surface of the sea, forming a thin layer called slick. This layer spreads rapidly over the surface as it is carried by wind and ocean currents. Moreover, most of the components of the spilled oil remain suspended in water which can lead to long-term harm. That is the reason why after an oil spill, a quick clean-up with human intervention is necessary.
The MSC ELSA 3 was carrying at least 84.44 metric tonnes of diesel and 367 metric tonnes of furnace oil, according to the Coast Guard. A simulation done by the Hyderabad-based Indian National Centre for Ocean Information Services (INCOIS) showed that if all of this diesel and furnace oil leaked into the sea, there was a high probability that these chemicals would drift towards the coast of Kerala. The entire coastal stretch between Alappuzha and Thiruvananthapuram districts could be affected, the simulation revealed.
Grinson George, director of Central Marine Fisheries Research Institute (CMFRI), told The Indian Express that the oil spill would lead to 'short-term impacts, mostly on small scale and artisanal fishermen who work closer to the coast'.
He said that oil smothering — when a coat of oil covers marine organisms — could threaten marine species and impact pelagic fish breeding in the region.
Authorities are also concerned about other hazardous substances that MSC ELSA 3 was carrying. The vessel had at least 12 containers of calcium carbide — a toxic chemical that can form explosive gases when it reacts with water. These gases are a health risk for humans and marine life.
Each oil spill has unique aspects as it is influenced by the nature and chemical composition of the oil that gets leaked. Usually, before planning the clean-up, experts try to observe the colour of the oil slick (under sunlight seen as black, rainbow, brown or colourless) which can indicate the possible composition and extent of the spill.
During the clean-up process, pillows made of oleophilic (oil-attracting) materials are first deployed at the site of an oil spill. These materials act like a sponge and absorb oil (not water) from the surface. This helps clean up large portions of undivided oil slicks.
Then, sheets made of cotton, or a material which has properties similar to cotton, are deployed to absorb the leakage.
Another method for removing the oil is to use specialised motors which can pump out water. However, these motors are deployed only when an oil spill has taken place over calm waters such as a lake.
As oil does not mix or dissolve in water, an entire clean-up of this emulsified liquid is not an easy task. The process is very costly and labour-intensive, and can sometimes extend to months.
Also, in water bodies such as rivers and the sea, the perpetual flow of the water can pose a challenge.
Experts suggest that in the case of MSC ELSA 3, if an oil leak takes place, it would be crucial to not let the oil slicks reach near the shores.
Deepak Apte, a leading marine biologist, told The Indian Express, 'Monsoon has made an onset and the currents are towards the shore. With the monsoon tides and surges, access to shore areas will be difficult for clean-ups if the oil slicks reach the coast.'
An award-winning journalist with 14 years of experience, Nikhil Ghanekar is an Assistant Editor with the National Bureau [Government] of The Indian Express in New Delhi. He primarily covers environmental policy matters which involve tracking key decisions and inner workings of the Ministry of Environment, Forest and Climate Change. He also covers the functioning of the National Green Tribunal and writes on the impact of environmental policies on wildlife conservation, forestry issues and climate change.
Nikhil joined The Indian Express in 2024. Originally from Mumbai, he has worked in publications such as Tehelka, Hindustan Times, DNA Newspaper, News18 and Indiaspend. In the past 14 years, he has written on a range of subjects such as sports, current affairs, civic issues, city centric environment news, central government policies and politics. ... Read More