PANAJI: Scientists at Goa-based National Institute of Oceanography (NIO) have found that the source of tar balls deposited along the Gujarat coast are from Bombay High oil fields or nearby rigs.
Tar ball is the remnant of oil spills formed in the sea after weathering processes.
The research conducted by NIO scientists on the tar ball samples collected from South Gujarat's Tithal, Maroli, Umbergaon and Nargol beaches found that its probable source locations are in the vicinity of Bombay High oil fields.
NIO is an institution of Council for Scientific and Industrial research (CSIR), and is a central government entity.
Scientists conducted fingerprint test on the tar ball samples and various oil samples collected from the Bombay High, Cairn and Niko firms to reach a conclusion.
The results were further compared with the published data of Middle East Crude Oil (MECO) and South East Crude Oil (SEACO) and they were not matching, cementing the claim that the oil was from Bombay High and surrounding oil rigs.
The findings have been published in the American Chemical Society s Journal "Environmental Science and Technology".
The researchers also found that winds, tides and currents play a major role in transporting tar balls to the Gujarat
"But the question is whether it is the operational spill in the Bombay high oil fields or natural seepage from the basin, which is the cause for the formation of the tar ball," reads the paper, which examined the tar balls that surfaced on
these beaches in July 2012.
The scientists of the CSIR-NIO said that detailed research has to be conducted to answer the question whether it is due to natural seepage, transportation of crude oil or operational spills in the water.
Tar balls appearance is a common phenomenon during pre monsoon to monsoon (April to September) along the west coast of India from Gujarat in the North to Karwar in the South.
The NIO has also initiated similar study on the tar balls collected from Goa beaches in 2013, whose initial results, have also pointed out that the Bombay High might be the source of pollution.
"But we will be able to say with authenticity about the source only after research is complete," said the scientists.
Bombay High is an offshore oilfield, which is 160 km off the coast of Mumbai.
The oil operations are run by Oil and Natural Gas Corporation Ltd.
After realising the environmental concern of the tar ball deposits, which is detrimental to the tourism potential on the west coast, the Department of Science and Technology, Govt of India has provided funds to set up a Fingerprint Laboratory at the CSIR-NIO, which will continue analysing the tar balls and other pollutants in a bid to ascertain their source of origin.