Oil Pollution

What is Crude Oil Pollution?

Crude oil pollution occurs when the liquid form of petroleum leaks into an ecosystem due to anthropogenic (human) causes.

Oil spills release a large amount of oil into marine and coastal waterways, with devastating consequences. These spills may come from oil tankers, oil rigs and offshore platforms and usually significantly damage local wildlife and economies, particularly those dependent on fishing.

What are the Causes of Oil Pollution?

There are several potential causes of oil pollution, with oil spills being one of the most common. Up to half of all oil spills can be attributed to human error, such as:

• collisions between tankers and other vessels

• and accidents related to fatigue or inadequate training.

Many spills are also caused by technical problems, such as failing or malfunctioning equipment. Oil pollution can also come from terrestrial sources, such as motor vehicles and runoff oil, which may leak into rivers, wetlands, and, eventually, the ocean.

What are the Effects of Oil Pollution?

Oil pollution has a wide variety of adverse effects on the environment, wildlife, and humans. Oil pollution affects everything from the soil and water to the living organisms that rely on the ecosystems for survival. The following are just some of the ways in which oil pollution negatively affects ecosystems.

Effects of Oil Pollution on Soil

There are several ways that oil pollution can impact soil. Since the soil quickly absorbs oil, it can alter its permeability and change its natural composition. The oil then kills many naturally occurring microorganisms in the ground, resulting in the proliferation of oil-resistant microorganisms. All of this results in a soil that renders natural vegetation and agricultural crops more challenging to grow and less resistant to diseases and pests. Furthermore, negative health consequences can occur once animals (including humans) ingest these plants. Oil has carcinogenic qualities that can have a toxic effect on living organisms.

Effects of Oil Pollution on Water

It is estimated that around 3.8 million litres of oil contaminate the world's oceans annually. Since oil is insoluble and cannot dissolve in water, it forms a sludgy mass that suffocates marine life, such as fish. It blocks sunlight from penetrating the ocean's surface, killing ocean plants that rely on photosynthesis. In addition to oceans, oil contaminates freshwater lakes, rivers, and wetlands.

Effects of oil pollution on wildlife

Oil has immediate and long-term negative impacts on ecosystems and the wildlife species that reside within them.

• On a physical level, oil can accumulate in the feathers and wings of birds, rendering them unable to fly.

• Oil can also suffocate and poison wildlife, in addition to causing many other health issues.

• Oil also destroys the habitat that nature depends upon through soil degradation and vegetation loss.

When oil seeps into the soil and kills microorganisms, it depletes the ecosystem of its primary producers. Since primary producers are the base trophic level in an ecosystem, losing these species causes problems in all higher trophic levels, even apex predators.

Effects of Oil Pollution on Humans

Oil pollution can negatively impact the health and economies of human populations. The contamination of drinking water is perhaps the most direct way oil spills may affect human health.

• Some short-term effects of drinking oil-contaminated water may include:

  • Gastrointestinal upset, diarrhoea, vomiting, and throat irritation.

• In the long term, drinking oil-contaminated water can increase the risk of cancer development and cause problems with the immune system.

Controlling Oil Pollution

There are several ways of controlling oil pollution and mitigating the damage it causes. The following are just a few ways to control oil pollution.

Recycling used Oil

Used oil is a major contaminant of the Earth's waterways, and one way to minimise this contamination is by recycling and reusing oil rather than obtaining new oil.

Used oil also requires less energy to produce and lowers the detrimental environmental impact.

Proper Maintenance of Equipment

Preventable accidents cause most oil spills, and ensuring the proper maintenance of the associated equipment is vital to its prevention. This includes:

• better and more thorough training of technicians,

• frequent inspections,

• and the implementation of computerised maintenance management systems (CMMS) that will continuously assess equipment for potential problems.

Improved Tanker Design

Another way to mitigate oil pollution is by using more soundly built tankers, thus minimising the chance of an oil spill.

• Double hulls, for example, create extra space between the oil cargo and the environment.
• At the same time, twin engines allow tankers to avoid potential dangers even in the event of a single-engine failure.
• Bund walls on land provide oil-proof protective barriers that can sustain high-pressure levels.

Example of Oil Pollution

The Sundarbans is the world's largest mangrove swamp, a UNESCO World Heritage site located in the Bay of Bengal and consisting of a massive delta formed by the Brahmaputra, Meghna, and Padma rivers.

The mangroves provide vital habitat for many globally and locally threatened species, including the Bengal tiger (Panthera tigris), saltwater crocodile (Crocodylus porosus), and Ganges river dolphin (Platanista gangetica). In addition to being a haven for wildlife, the mangroves provide an essential source of livelihood for the roughly three million people living in the area.

On 9th December 2014, a catastrophic oil spill occurred in the Bangladeshi portion of the Sundarbans when the Southern Star VII tanker collided with another vessel and spilt all of its 350,000 litres of oil into the mangroves. Over less than a month, oil from the spill had contaminated over 500 square kilometres of the Sundarbans, with levels of contamination reaching between 30 and 170 times the maximum safe level, seeping into the forest floor and killing large numbers of essential microorganisms. In addition, in the days following the spill, dead dolphins and otters were found, as well as oil-slicked crocodiles. The spill also hit fish stocks particularly hard, losing vital financial and food resources for the local human population.

Since the spill, dolphins have reportedly become rare within the mangroves, and saltwater crocodile hatchlings have been poisoned. Even years later, wildlife in the Sundarbans has yet to recover fully.