The Chennai Oil Spill which occurred nearly ten days ago has caused dreadful damage to the marine life in the region. Several sections of the sea water have blackened after the spill affecting oxygen supply to the aquatic species. Over a dozen dead Olive Ridley turtles washed ashore and so did oil smothered crabs. However, several newspapers reported that authorities denied the oil spill resulted in the death of the turtles.
On January 28, two cargo ships namely M T BW Maple and M T Dawn, Kanchipuram collided off the Kamrajar harbour in Tamil Nadu. The latter was carrying 32,813 tonnes of petroleum oil lubricant which suffered a rupture that led to the oil spill.
The initial figure put out by the port was only about 1 tonne of oil was split during the accident, but on Thursday, Indian National Centre for Ocean Information Services (INCOIS), estimated that over 40 tonnes of oil sludge which was still spreading may touch 100 tonnes. However, authorities claim that 90 per cent of the clean-up is already done.
The environmental crisis caused by the ‘accidental’ spill only reflects the lack of coordination between maritime board, the state disaster response team and the port authorities. From an initial denial that a spill had occurred, followed by a failure to inform the coast guard and emergency response containment wasn’t quick enough as the oil spread over 30 km south of the port within 24 hours.
Chennai based Wildlife conservationist Nishanth Nichu said, “A few days before the incident, while we were walking on the beach, they were hundreds of crabs rubbing between our legs, but last week we saw only 10-15 smothered with oil. This is the core breeding season for Olive Ridley turtles to come to the shore and lay eggs and go back. These mother turtles will have a tough time with oil slick sticking to their base.The sea grass with oil stuck to it will have fishes suffering as well”
“70 per cent of the clean-up is completed. The situation is quite okay compared to last week. Chennai port is not ready to deal with marine disasters. If it had to happen in the mid sea it would have blocked sunlight and been a much bigger ecological disaster,” he added.
Around 74 km-long coastline in and near Chennai has been affected. The Coast Guard began clean-up operations at various locations and more than 2000 people undertook the cleaning work at Chennai Fishing Harbour, Marina Beach, Besant Beach.
When some of the suckers failed to remove the thickening sludge, volunteers began physically removing blobs of oil deposited along the beaches.
Why do spills happen?
Spills happen due to bad weather (hurricanes, storms, and earthquakes), intentional acts of violence (like war, vandals or dumping) and human mistakes. Accidental causes such as collisions and groundings generally give rise to much larger spills, with nearly 84 per cent of the incidents involving quantities in excess of 700 tonnes. When the oil spill occurs on the sea surface, it spreads to form a thin film called oil slick. Chennai oil spill might become the largest ever in the southern peninsula.
How to handle oil spills using oil spill modelling?
Modelling is only a predictive tool and cannot readily replace the need to monitor a spill physically in the event of an actual incident. This can be effectively verified from visual observations or remote sensing applications. Modelling exercise provides a clear idea about oil movement and will enhance the decision making strategy for necessary response.
As per the Allocation of Business Rules 1961, Ministry of Earth Sciences (MoES) is responsible for coordination and regulatory measures for prevention, conservation and protection of the ocean. Accordingly, Ministry has taken up a R&D programme to understand the movement of oil in marine environment and identifying the resources at risk using two mathematical models of different level of complexity. One is a generic model, developed to predict the movement of oil and its fate in the Indian Ocean. The other is habitat specific model for detailed trajectory and impact analysis on marine resources.
Use of GIS in Estimation
Information on bathymetry, circulation pattern, movement of oil, oil concentration and thickness, quantity of dispersed oil etc., may be incorporated in the maps. Also details about ecologically sensitive areas such as coral reefs, seagrass beds, mangroves, salt pans, mudflats, beaches and nature of shoreline, wildlife protected areas and fishing activities may be layered
Bioremediation- Cleaning up the oil spill
An alternative to oil spill clean-up is through the use of microbes. Biodegradation is a natural process whereby bacteria or other microorganisms act upon organic molecules to break them into simpler substances. When these microbes are added to contaminated environments, such as oil spill sites, they can accelerate the natural biodegradation process. Use of these naturally occurring microbes to clean up oil contaminated environments is termed as bioremediation.
Bioremediation methods too have a sizeable number of limitations. Their effectiveness can be tested along the coastal areas, but not at open sea. Conducting and monitoring open sea experiments is extremely difficult as the winds, waves, and currents create a constantly changing environment.
With regard to Chennai oil spill, Indian Oil Corporation (IOC) has delivered bio-remediation material for treatment of the collected oil sludge for safe disposal.
Major oil spills in India
In October 2013, a pipeline in the Oil and Natural Gas Corporation’s Uran plant developed a leak on spilling about 5,000 litres of crude oil into the Arabian Sea that spread about 10km along the coastline and caused considerable water pollution.
In August 2011, MV Rak which was carrying 60,000 metric tonnes of coal, 290 tonnes of furnace oil and 50 tons of fuel oil, sank off Mumbai coast.
In January 2011, ONGC’s Mumbai-Uran trunk pipeline burst spilling oil across four sq.km off the Mumbai coast.
In August 2010, MSC Chitra collided with the Khalijia, off the coast of India, near Mumbai. The slick reached the beaches of Alibaug, Marva and the Elephanta caves in Mumbai threatening the mangrove belt along the coastline.
Disaster planning and safety are vastly different on paper and in real life. Also, most of the machinery that is usually used to clean up oil spills in India is not suited to be used in shallow waters. Therefore the question that arises is if ports have a real emergency response in place to tackle oil spills.