What are the tarballs that have resurfaced on Mumbai?

Syllabus: General Studies Paper 1

Context:

Mumbai saw black oil-emanating balls lying on the shore. The popular beaches were covered in sticky tarballs that gave off a foul fuel smell.

More in the news

• In August 2021 alone, the Brihanmumbai Municipal Corporation (BMC) removed over 20,000 kg of tarballs from Juhu and Versova beaches.
• Earlier this month, several popular beaches in Goa were covered with a black sticky carpet.

About the Tarballs

• Tarballs are dark-coloured, sticky balls of oil that form when crude oil floats on the ocean surface.
• Tarballs areformed by weathering of crude oil in marine environments.
• They are transported from the open sea to the shores by sea currents and waves, according to a recent research paper.
• Some of the balls are as big as a basketball while others are smaller globules.
• Tarballs are usually coin-sized and are found strewn on the beaches.
• However, over the years, they have become as big as basketballs and can weigh as much as 6-7 kgs.
• BMC, which has cleared the beaches of the tarballs, said the tarballs stick to the cleaning machinery and are very difficult to wash off.

How are these tarballs formed?

• According to the recent study of the National Institute of Oceanography (NIO),
  • Wind and waves tear the oil slick into smaller patches that are scattered over a much wider area.
  • Various physical, chemical and biological processes (weathering) change the appearance of the oil.

Why are tarballs found in Monsoon?

• The oil comes from the large cargo ships in the deep sea and gets pushed to the shore as tarballs during monsoon due to wind speed and direction.
• All the oil spill in the Arabian sea eventually gets deposited on the western coast in the form of tarballs in the monsoon season when wind speed and circulation patterns favour transportation of these tarballs.

The Indian Express Link:

https://indianexpress.com/article/explained/mumbai-beaches-tarballs-explained-7510246/