Oil spills pollute oceans and cause irreparable harm to biodiversity. They occur when oil is released into the environment, especially oceans, through activities like petroleum production, transportation by tankers, and well discharges. Major spills kill thousands of birds, sea turtles, and marine mammals by coating their bodies, contaminating habitats, and releasing toxic fumes. The largest spill was the 2010 Deepwater Horizon spill, which released 134 million gallons of oil into the Gulf of Mexico over 87 days with severe environmental and economic impacts.

1. Oil spill
Release of oil into the sea or other water body
By Akash Mahanty
@akamhy

2. Oil spill pollute the oceans, kill animals living in these oceans and cause irreparable
damage to the biodiversity in the vicinity of these spills.

3. What are oil spills?
Oil spills can be defined as the release of liquid raw/natural petroleum
hydrocarbons into the environment, especially into the sea.
Oceanic oil spills became a major environmental problem in the 1960s, chiefly as
a result of intensified petroleum exploration and production on continental
shelves and the use of supertankers capable of transporting more than 500,000
metric tons of oil.
Huge oil spills from wrecked or damaged supertankers are now rare because of
stringent shipping and environmental regulations. Nevertheless, thousands of
minor and several major oil spills related to well discharges and tanker
operations are reported each year, with the total quantity of oil released annually
into the world’s oceans exceeding one million metric tons.

4. Oil spill image taken from a helicopter

5. Impact of oil spills
Oil has a direct impact on water itself. The
chemical composition of oil mixes with the
water and creates a new substance known as
"mousse." This mousse becomes even more
sticky than oil alone, causing it to stick to
organisms and materials much more readily.
Mousse resembles food for a number of
animals and also attracts certain curious birds
and marine life. For people attempting to clean
the slick, the oil-water mixture is very hard to
dispose of and eventually retains very little
value as oil itself.

6. How oil spills harm birds, dolphins, and other wildlife
An oil spill is a disaster on many levels. Ocean creatures that swim in
deep waters are less affected by spills. But oil disasters near coastlines
often do the most harm to shorebirds and marine mammals who live at
the ocean's edge and on its surface. These creatures live right where the
floating oil accumulates, the coastlines.

7. Effect on Shorebirds
Coastal birds can be especially vulnerable because the oil covers the surface
of the ocean, where they feed, and washes onto beaches, fouling their nesting
areas.
When birds become covered in oil, it renders their feathers useless for keeping
them insulated and warm. Birds also instinctually preen themselves to remove
anything on their feathers, which exposes them to ingesting toxic amounts of
oil.
Oiled birds returning to their nests also can contaminate their eggs and chicks
with oil.

8. A Bird covered in oil

9. Dolphins are migratory and will often swim to safer waters if
they smell or taste oil. But the playful mammals have been
sickened and killed by spills, which can spew toxic fumes
from the petroleum chemicals floating on the ocean's
surface.
Effect on Dolphins

10. Dead dolphins, left one is cleaned off the oil and the right one isn’t.

11. Oil spills also can be deadly for blue whales, gray whales,
humpbacks and other species. Exposure to toxic oil
fumes has been recognized to kill whales and dolphins
even years later.
Effect on whales

12. A humpback whale swims through an oil spill

13. When sea turtles surface in a slick, they can inhale oil and its vapors into their
lungs; gulp oil into their mouths, down their throats, and into their digestive tracts
while feeding; and become coated in oil, to the point of becoming entirely mired
and unable to swim.
Fumes may result in irritation of the turtle's eyes or mouth, and internal damage
such as irritation to the respiratory system injured tissues or pneumonia.
High concentrations of oil kill the adult crabs, while lower amounts can harm their
babies and eggs.
Effect on turtles and crabs

14. A heavily-oiled young turtle, that would have died if not rescued.

15. Cleaning up and recovery of oil spills
Different methodologies can be adopted to clean up oil spills.
- Using Oil Booms
The use of oil booms is a straightforward and popular method of controlling oil
spills. Equipment called containment booms acts like a fence to prevent the oil from
further spreading or floating away.
- Using Skimmers
Once the oil has been confined by using oil booms, skimmers or oil scoops can be
deployed onto boats to remove the contaminants from the water surface. Skimmers
are machines specially designed to suck up the oil from the water surface like a
vacuum cleaner. They are used to physically separate the oil from the water to be
collected and processed for re-use.

16. - Using Sorbents
Sorbents are materials that soak up liquids by either absorption or adsorption. Both
these properties make the process of clean-up much easier. Materials commonly used
as oil sorbents are hay, peat moss, straw or vermiculite.
- Burning In-situ
Oil floating on the surface is ignited to burn it off. This in-situ burning of oil can
effectively remove up to 98% of an oil spill, which is more than most other methods.
- Using Dispersants
When the spilt oil cannot be contained by using booms, the only option left is to
accelerate the disintegration of oil. Dispersal agents, such as Corexit 9500, are
chemicals that are sprayed upon the spill with the help of aircraft and boats, which aid
the natural breakdown of oil components.

17. Oil Booms, containing the spill Skimmers, suck up the oil from the water surface

18. Sorbents Burning In-situ Dispersants

19. Worst Oil Spills
- The Amoco Cadiz Oil Spill (1978)
- The Castillo de Bellver Oil Spill (1983)
- The Incidents at the Nowruz Oil Field (1983)
- The Kolva River Spill (1994)
- The Mingbulak (or Fergana Valley) Oil Spill (1992)
- The Atlantic Empress Oil Spill (1979)
- The Ixtoc 1 Oil Spill (1979)
- BP’s Deepwater Horizon Oil Spill (2010)
- The Persian Gulf War Oil Spill (1991)

21. Deepwater Horizon Oil Spill
Deepwater Horizon oil spill, also called Gulf of Mexico oil spill, largest marine oil
spill in history, caused by an April 20, 2010, explosion on the Deepwater Horizon oil
rig—located in the Gulf of Mexico, approximately 41 miles (66 km) off the coast of
Louisiana—and its subsequent sinking on April 22.

22. BP’s Deepwater Horizon Oil Spill

23. Deepwater Horizon Oil Spill - Environmental effects
The Deepwater Horizon oil spill released 134 million gallons of oil into
the Gulf of Mexico over a period of 87 days, fouling 1,300 miles of
shoreline. The scientists concluded that the Deepwater Horizon oil
spill killed thousands of marine mammals and sea turtles, and
contaminated their habitats.

24. Deepwater Horizon Oil Spill - Settlements
The civil and criminal proceedings stemming from the explosion of Deepwater
Horizon and the resulting massive oil spill in the Gulf of Mexico began shortly after
the April 20, 2010 incident and have continued since then. They have included an
extensive claims settlement process for a guilty plea to criminal charges by BP, and
an ongoing Clean Water Act lawsuit brought by the U.S. Department of Justice and
other parties.
A federal judge, ruling on the Clean Water Act suit in September 2014, found that BP
was primarily responsible for the oil spill as a result of its deliberate misconduct and
gross negligence. The finding means that the company may be subject to $18 billion
in penalties in addition to the $28 billion already paid out in claims and cleanup costs.
Such penalties are far larger than the $3.5 billion BP had allotted to the case, and
could have grave implications for the company.

25. The Gulf War Oil Spill: A Man-made Disaster
Starting in January of 1991, large quantities of oil began to spill into the Persian Gulf. Early
reports from Iraqi forces claimed that the spill had been caused by the United States sinking
of two oil tankers. It was later revealed that in a desperate military move, Iraqi forces had
opened oil valves of the Sea Island pipeline, releasing oil from numerous tankers. The goal of
this spill was to impede US troops from attempting beach landings, but in the end the spill
simply resulted in over 240 million gallons of crude oil being dumped into the Persian Gulf.
This spill is one of the first times in military history where a natural resource and specifically
pollution was used as a tactic of war. Though it is hard to know the full scale of the spill for
certain, many scientists believe it to be one of the worst in human history. The effect on
marine life and on the shores was extensive and the region is still feeling the effects of the
spill, manifested in a loss of biodiversity and uninhabitable coastlines.

26. The Gulf War Oil Spill

27. The Gulf War Oil Spill: The Cleanup
The majority of crude oil that was spilled in the Gulf traveled south down the
coastline. Most of it remained behind Abu Ali Island located north of Jubail, Saudi
Arabia. 706 kilometers of coastline in Saudi Arabia were covered in oil; 366 km
were categorized as heavy and 220 km as moderate. Much of the cleanups were
hindered due to wartime conditions and the reconstruction that followed. Oil
continued to spill out of contaminated coastal sediments for over a year after the
war; though by the end of July, a majority of the floating oil had been removed.
Lighter bits of oil continued to seep into the Gulf for over a year after all of the
floating oil had been recovered.

28. The Gulf War Oil Spill: Conclusion
A year after Kuwait's liberation from Iraqi forces, hundreds of miles of
coastline were still slathered in over a foot of oil, and fires fueled a
smoke cloud covering ~1.3 million square miles. All of these harmful
pollutants were in the water, land, and air. Some of the oil spilled deep
into the sea, burrowing up to 40 cm in the sand and mudflats. It
remains there to this day. This disaster does not just highlight the
responsibilities humans have in managing oil wells, rigs, pipelines, and
tankers, it demonstrates how carelessness with a non-renewable
energy source and pollutant, purposeful or not, can have devastating
long-term environmental impacts that cannot be undone.