The dynamics behind oil spills: causes, consequences and prevention
On July 25th, the japanese MK Wakashio ship hit a coral reef on the Southeast coast of Mauritius. The vessel split in two, threatening to release the 200 tons of diesel and 3800 tons of heavy fuel oil it contained. Having already leaked more than 1000 tons of oil and diesel, this oil spill has been dubbed one of the biggest environmental disasters, and potentially the worst that has ever affected the island of Mauritius.
The MV Wakashio after it split in two
This catastrophe has brought attention to oil spills in general. Following LearnBlue’s #SaveMauritiusWater Campaign, this article will focus on explaining the causes and effects of oil spills, along with how prevention can be undergone.
What Are Oil Spills?
As the name implies, oil spills are the release of petroleum products such as diesel, kerosene or oil into the sea and land due to accidents or human negligence. Spills of the sort are usually associated with the sea, but they can also occur on land. Oil spills can go from a few gallons to millions of gallons in severity, and often take years to clean. Some of the biggest oil spills in history are the Gulf War oil spill in 1991, the Fergana valley spill of 1992, or the Ixtoc oil well spill of 1979.
There are many types of oil spills, including:
- Class A oil or Non-persistent Light Oils: It is the most toxic of oils, harmful to both marine forms of life and humans. Very volatile, it spreads easily and has a strong smell. Examples of class A oil include crude oil, jet fuel or gasoline.
- Class B oil or Persistent Light Oils: Less toxic than class A oils, these are non-sticky and moderately volatile. They can cause long-term contamination and are highly inflammable. Examples of this type of oil include kerosene, heating oil or low-quality crude oil.
- Class C oil or Medium Oils: These are thick and heavy oils that do not dilute into water and seep into soil fast. They produce a sticky film and can cause damage to waterfowl or fur-bearing mammals. Their contamination of areas can be severe and long-term if cleaning is not conducted fast enough. Medium oils include variants of crude oil and bunker B oils.
- Class D or Heavy Oils: Considered solid oils, these are the least toxic but harden when heated and have very little to no evaporation or dissolution, making cleanup near impossible. Heavy Crude Oils, No. 6 Fuel Oil or Bunker C oil are examples of class D oils.
- Sinking Oils or Non-floating oils: These are a thin type of oil that penetrates into the soil and water easily. It sinks fast, so when it is spilled in the water, it is highly unlikely to damage the shoreline, but can have severe consequences on sediments.
There can be many different causes for oil spills, such as natural occurrences like earthquakes in a region where oil is drilling, oil transportation, careless oil drilling or drainage systems, war or sporting activities. When human causes are behind oil spills, they are most likely due to negligence and lack of awareness, lack of proper technology or maintenance, or accidents.
Consequences and effects of oil spills:
Oil spills have disastrous effects proportional to their size and the type of oil that was leaked. First, they affect the environment: Sea animals are considered to be the most affected by oil spills: they can die due to a lack of oxygen in the sea, starve because their sense of scent is obstructed by the oil or have their furs covered in oil, leading to a loss of the insulating properties of the fur and death.
A bird caught in oil
Sea plants can also die because of the lack of oxygen, and coral reefs, the habitat of 25% of sea creatures are bleached by oil, and eventually die as well.
Bleached Coral in Hawaii
Source: The Inertia
Oil spills are also harmful to the general quality of the air: the chemicals in petroleum products can have effects on the health of humans and animals when inhaled and can induce heavy air pollution such as soot particles. Moreover, environmental consequences can stem from the cleaning process after a spill. The consequences of oil spills are also social and economical: the contamination of water can result in a lack of clean drinking water or new waterborne diseases, putting many communities at risk. Local economies dependent on tourism are also particularly vulnerable to oil spills: the number of tourists can decrease after this kind of disaster, therefore heavily impacting revenue sources for the affected region or country.
Prevention and cleanup
Cleanup and recovery from an oil spill can be long, expensive and difficult and depends on the type of oil spilled, the temperature of the water, and the types of shorelines and beaches involved. Some methods for cleaning up include controlled burning to reduce the amount of oil in the water, using dispersants to dissipate oil slicks, skimming, dredging, or vacuuming and centrifuging. Coagulated oil that is left on the beach or shore can be picked up by machinery.
An oil spill clean-up
Source: Enviro Fluid
Despites incidents happening on a yearly basis, oil spill prevention has proven itself effective as the number of yearly spills has considerably decreased. In the 1970s, there were about 70 oil spills per year, whereas in the 2010s, the number had decreased to 6.2 per year on average. For prevention and control purposes, many countries have a government agency designed to take care of stringent practices, which need to be followed in order to avoid oil spills and undertake immediate action in case of any spill. Key international bodies such as the United Nations Environment Program World Conservation Monitoring Center (UNEP-WCMC), and oil industry associations such as the Association of Petroleum Industry Cooperative Managers (APICOM) are also designed to prevent and prepare for oil spillage. Ships that carry oil have to be particularly careful of the routes they follow to avoid reefs or structures that could cause the vessels to spit. Oil spills are impossible to prevent completely, which highlights how necessary it is that we review our current unsustainable lifestyle and industry and turn towards practices that are not as destructive on the environment.