In a written reply in Rajya Sabha, Minister of State for Environment Prakash Javadekar said tar balls have been observed in Goa sea beaches almost every year during the south west monsoon season.
"National Environmental Engineering Research Institute (NEERI) has carried out studies related to 'Analysis and Source Apportionment of Tar Balls Deposited on the Coast of Goa'.
"The findings also revealed that the source of the tar balls could be oil exploration activities from offshore oil installations, natural phenomenon from the sea bed or the sea going vessels passing through the area," Javadekar said.
Javadekar said deposition of tar balls was not confined to one location and occur between central west coast (Goa) to North West Coast (Gujarat). In Goa, major appearances of tar balls is mostly in South Goa beaches like Velsao, Betalbatim, Colva, Benaulim, Varca and Agonda and North Goa beach stretches like Calangute, Sinquerium and others.
He said while there are no international guidelines specifically addressing the issue of tar balls, International Convention on Prevention of Pollution from Ships popularly known as MARPOL provides regulations and guidelines for prevention of pollution from ships including oil pollution which has been suspected as one of the sources of tar balls in Goa beaches.