The state government has claimed that the civic body has been cleaning up oil-contaminated sand at coasts in Colaba and INS Kunjali in Navy Nagar following the oil spill off the Mumbai coast.
Next week, the International Tanker Owners Pollution Federation (ITOPF) comprising international marine pollution experts, which cleaned up Elephanta Caves, will carry out the final clean-up at the site.
Over the last few days, tar balls and fresh traces of oil have been spotted at Colaba coast. The state environment secretary Valsa Nair Singh said: “Oil could have reached the coast while stabilising MSC Chitra a few days ago. The ship had oil in its tanks and sea water got into it and then flowed out.”
Scientists said the tar balls would not have an impact on the beach. “A tar ball is a hardened residue of the degraded oil. So it’s more of a nuisance for the public. In water, it could be harmful to very small organisms,” said SN Gajbhiye, scientist in charge, regional centre, National Institute of Oceanography, Mumbai.
On Tuesday, activist Sumaira Abudlali of AWAZ Foundation wrote to Chief Minister Ashok Chavan stating that there was every likelihood of entry of oil into the food chain and the effects are long-lasting.
“On behalf of citizens of Mumbai, we request you to share results of any tests conducted by the Food and Drug Administration on fish to test for levels of mercury, cadmium or other heavy metals, ” the letter read. Experts said tar balls reaching the shores was a regular phenomenon and a result of increased traffic of oil containers in the Arabian Sea.
“The sea is a major route for oil tankers who make their journey from gulf countries to different parts of the world,” said Gajbhiye. “Since the empty containers cannot be washed in territorial waters, they are washed in the high seas. Tar balls on the beaches is a regular phenomenon with very little to do with the recent oil spill.”
Scientists said that after an oil spill, 30 per cent of the oil gets evaporated and 30 per cent gets dissolved. The rest keeps floating and starts hardening because of the weathering process to form tar balls. With winds travelling from sea to land between February to October, tar balls start depositing on different shores from Karnataka to Gujarat.