About: Mauritius Oil Spill

About: Mauritius Oil Spill

  • Cause
    • In July, a Japanese ship ran aground and got stuck on a coral reef off Maurtius coast.
    • The ship was carrying about 3,800 tons of Very Low Sulphur Fuel Oil and 200 tons of diesel oil. Most of the oil from the vessel has been pumped out.
    • But, in August, the ship began leaking oil resulting in an oil spill of over 1,000 tonnes into the Indian Ocean lagoon.
    • So far, about 460 tons of oil has been manually recovered from the sea and coast.
    • In the middle of August, the ship also broke apart.

  • Concerns
    • Rather than the size of the oil spill, it was the area where it happened which was a cause for concern.
    • The accident had taken place near two environmentally protected marine ecosystems and the Blue Bay Marine Park Reserve which is a wetland of international importance.

In Focus: Oil Spills

Definition & Causes of Oil Spill

  • Contamination of seawater due to an oil pour, as a result of an accident or human error, is termed an oil spill. 
  • Major causes of oil spills include-
    • Offshore drilling and production operations
    • Oil spills or leaks from ships or tankers- Over time, the production of petroleum products rose significantly which has resulted in massive transportation and associated oil spills. Oil accounts for over half the tonnage of all sea cargo.
    • Routine maintenance of ships 
    • Land drainage and waste disposal- For example, from the improper disposal of used motor oil.
    • Natural seepage from the seafloor

  • The number of oil spills has been increasing with the increasing rate of oil transportation, ageing of oil tankers, as well as an increase in the size of oil tankers.
  • While massive and catastrophic spills receive most of the attention, smaller and chronic ones occur on a regular basis as the number of sea vessels getting commuting has increased phenomenally with increase in global trade.

Examples of Oil Spills

  • Some of the world’s largest oil spills include-
  • The Persian Gulf War oil spill of 1991- The Iraqi forces quit their invasion of Kuwait. After that, for blocking the forces from the United States, the Iraqi forces left the oil pipelines and wells of oil open and set it to fire. In this more than 380 million gallons of oil was poured into the northern Persian Gulf by Iraq’s forces. The fire was so massive that it continued unabated for four months.
  • The 2010 Deepwater Horizon oil spill in the Gulf of Mexico- It is also considered to be among the largest known accidental oil spills in history. Starting April 20, 2010, over 4 million barrels of oil flowed over a period of 87 days into the Gulf of Mexico.

Impact of Oil Spills

  • Impact on Marine Life
    • Oil spills affect marine life by exposing them to harsh elements and destroying their sources of food and habitat.
    • Further, both birds and mammals can die from hypothermia as a result oil spills. For instance, oil destroys the insulating ability of fur-bearing mammals, such as sea otters.
    • It also decreases the water repellency of birds’ feathers, without which they lose their ability to repel cold water. Without the ability to repel water and insulate from the cold water, birds and mammals will die from hypothermia.
    • Juvenile sea turtles can also become trapped in oil and mistake it for food.
    • Dolphins and whales can inhale oil, which can affect lungs, immune function and reproduction.
    • Many birds and animals also ingest oil when they try to clean themselves, which can poison them.
    • When exposed to oil, adult fish may experience reduced growth, enlarged livers, changes in heart and respiration rates, fin erosion, and reproduction impairment.

  • Impact on Public Health
    • Public health impacts include illnesses caused by toxic fumes or by eating contaminated fish or shellfish.
    • There are also other less obvious public health impacts including losses and disruptions of commercial and recreational fisheries, seaweed harvesting and loss of revenues due to forgone tourism.

Prevention of Oil Spills

  • To prevent oil spills the responsibility lies with the industries for abiding by the regulations and governments for putting in place adequate rules to prevent their occurrence.
  • Integration of preventive measures in an industrial process, operation, or product should be a part of the cost of daily operations.
  • To prevent oil spill on ships, they should be equipped with all required precautionary measures and the crew on the ship should be accustomed to oil spill safety drill prior to the voyage. These safety measures will help in catering accidents which break-in during the voyage without any prior warning.

Clean-Up of Oil Spills

  • Oil Containment Booms
    • Oil Booms are the most common and popular equipment used in oil clean-up. These are also called “Containment Booms” which encloses the oil to a smaller area and not let it spread further.
    • This method is employed when the area of spill is comparatively smaller and where wave velocity is constant because fluctuating tides make it difficult for an oil boom to perform clean-up properly.

  • Skimming
    • Skimming involves removing oil from the sea surface before it is able to reach the sensitive areas along the coastline.
    • Once the oil is bounded by oil booms it can be extracted or skimmed easily with the help of skimmers or oil scoops.
    • These are the mechanical equipment which works on the same principle as a vacuum cleaner.
    • It sucks all the oil which is spread over the confined surface of the water in oil booms.

  • Sorbents
    • The materials which can adsorb or absorb the liquid are termed as sorbents.
    • It is an easy process of oil cleanup.
    • Most common sort of sorbents are peat moss, vermiculite (straw) and hay. These are highly useful for the small spills with the highest efficiency.

  • In-Situ Burning
    • In this method, the floating oil is set to fire by igniting it safely.
    • It is the most proficient method of oil clean-up as it can efficiently remove 98% of total spilt oil.
    • However, this method is not eco-friendly as it releases toxic gases from the burning of oils to the environment.

  • Release of Chemical Dispersants
    • When oil cannot be confined with booms then chemical disintegration of oil is done using dispersants.
    • After disintegration, the surface area of oil molecules increases and it becomes easier for them to form a bond with water.
    • This will take the bonded molecules deeper in water and make them available for microbes which degrade them later on.
    • Releasing chemical dispersants helps break down oil into smaller droplets, making it easier for microbes to consume, and further break it down into less harmful compounds.