Oil Spills

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Oil spills refer to oil of any type being released into the natural environment due to human activity. It can be a result of a mistake or carelessness. It can also be done on purpose to cause harm.

The Deepwater Horizon oil spill, also called the BP Oil Spill, the Gulf of Mexico oil spill or the Macondo blowout, is a massive ongoing oil spill in the Gulf of Mexico, now considered the largest offshore spill in U.S. history. The spill stems from a sea floor oil gusher that followed the April 20, 2010 Deepwater Horizon drilling rig explosion. The explosion killed 11 platform workers and injured 17 others.

The gusher, estimated to be flowing at 12,000 to 100,000 barrels (500,000 to 4,200,000 US gallons; 1,900,000 to 16,000,000 litres) per day, originates from a deepwater wellhead 5,000 feet (1,500 m) below the ocean surface


The 20th century has witnessed several large oil spills. In March 1967, in the UK the Torrey Canyon ran aground off Cornwall spilling 80,000 tonnes (919,000 barrels) of crude. In 1970, in Sweden at least 438,000 barrels of oil spilled in a collision involving the Othello in Tralhavet Bay.

Why should I be aware of this?

  • Oil spills adversely impacts wildlife and their habitats in many ways.
  • Oil spills that occur near the shoreline cause the maximum harm.
  • It impacts the food chain and biodiversity too.
  • Not all spills are man-made. Crude oil is made by the earth from decayed plants and animals which lived millions of years

All about oil spills

Oil can be categorized into five groups, ranging from very light to very heavy oils. Most oils are less dense than water and tend to float as a thin layer on the surface of the water. Once in the water, oil undergoes weathering, a process that describes the physical, chemical, and biological changes that occur when oil interacts with the environment.

An oil spill which occurs near a coastline will always impact more living organisms than one which occurs in the open ocean. This is simply because coastal areas are home to much more concentrated and diversified populations of marine life than the open ocean.

The severity of the injury caused to an organism depends on the type and quantity of oil spilled, the season and weather, the type of shoreline, and the type of waves and tidal energy in the area of the spill.

Oil can escape into the natural environment both on land and sea.

Causes of oil spills

  • Tanker accidents -- Tanker accidents release large volumes of oil into the ocean. These oil spills tend to be very harmful because of the sheer volume of oil released at once, posing a serious threat to marine ecosystem and seabirds.
  • Runoff from land -- One of the most common causes of oil spills is actually runoff from the land. Numerous land-based engines such as those used to run cars function on petroleum fuel and use petroleum based lubricants. All of these substances are slowly released, accumulating on roads and in the ground and ultimately ending up in the ocean. The problem is compounded by people who do not dispose of things like used motor oil safely. Many drains run directly to the sea.
  • Natural seepage -- Oil spills can also be caused by natural seepage, especially in the ocean. As tectonic plates shift, they may release oil from reserves trapped deep beneath the ocean floor. Natural seepage can also be accelerated through human activity such as drilling.
  • Extraction and storage of oil -- Extraction and storage of oil is accompanied by seepage and spills. Offshore drilling routinely creates low level spills, and can sometimes cause a massive gush of petroleum. On land, storage tanks and pipes can be damaged by things like hurricanes, resulting in leaks of all sizes, and in the ocean, bunkering can lead to the release of large amounts of oil.

Impact of oil spills

When oil enters the ocean it quickly begins to change and disperse. Though oil is toxic, it becomes less so with time. Winds and waves help spread and disperse the oil.

  • When oil spills and mixes with water it can contaminate drinking water, kill fish and poison wildlife.
  • Just one quart of oil may pollute up to 150,000 gallons of water!
  • Oil is harmful to shellfish, finfish, marine mammals and waterfowl who live near the spill.
  • Oil spills are expensive to clean up.
  • In addition, damage to fisheries places a hardship on those who make their living by fishing.

Preventive measures

The petroleum industry undertakes measures such as the use of negative pressure pipes and storage containers to reduce the likelihood of oil spills. These measures protect both the environment and the profits of the oil company.

Oil spills and the environment

Animals get poisoned and die or get blinded if oil enters their lungs or liver. Birds die if their feathers are covered by oil spills. Oil spill is a major cause of killer whales becoming an endangered species. Fish, shrimp, and crabs, penguins and other water birds, sea otters, sea lions, seals, and killer whales swallow the oil and they die of suffocation. Some also breathe in the poisonous fumes. The bodies of these marine animals become coated with oil.

Oil from open ocean spills can end up contaminating beaches hundreds of miles away. Oil spills can harm marine life in three different ways.

  1. Poisoning after ingestion
  2. Direct contact
  3. Destroying habitats.

Effects on the Food Chain

Each tier of the marine food chain can be affected by an oil spill. Oil floating on the water may contaminate plankton (very small, swimming or floating plants and animals). When small fish eat these plankton, they also eat the oil. Bigger fish, bears and humans who eat these fish will ingest oil too. Marine animals and birds can eat oil or it can get on their fur and feathers. When oil gets on a bird's feathers, the feathers lose their insulation capability and the bird can't adjust its body temperature and dies. Oil may obstruct the germination and growth of marine plants.

90 degrees -- What we do not know yet?

  • A mat of nanowires with the touch and feel of paper could be an important new tool in the cleanup of oil and other organic pollutants. The scientists say they have created a membrane that can absorb up to 20 times its weight in oil, and can be recycled many times for future use. The oil itself can also be recovered. Some 200,000 tons of oil have already been spilled at sea since the start of the decade.[1]
  • In a setback for efforts to protect endangered coral reefs from oil spills, researchers in Israel report that oil dispersants -- the best tool for treating oil spills in tropical areas --are significantly more toxic to coral than the oil they are used to clean up. Their study urges caution in the use of these materials.[1]
  • Seagulls may become living sentinels to monitor oil pollution levels in marine environments, according to scientists in Spain.[1]

Unlearn

Contrary to popular belief, only a small percentage of global oil spills are related to tanker accidents such as explosions, hull failure, running aground, and collisions.

CopperBytes

  • The largest spill yet occurred in 1979 when about 147 million gallons of oil gushed from an offshore well platform in the Gulf of Mexico.
  • In the last 30 years, there have been more than 50 big oil spills.
  • The Exxon Valdez spilled oil over 1300 miles (2100 km) of shoreline in Alaska.
  • The Shetland Islands were completely prepared for an oil spill, with lots of high-tech equipment. BUT when the Braer oil spill happened in 1993, the weather was so bad, they couldn't use any of it.
  • Nature helps clean up oil spills. Bacteria can eat oil. Waves help wash oil off beaches.
  • The oil spill that wreaked havoc in the Kerch Strait leading to the Black Sea in early November will take at least 5 to 10 years for the marine environment to recover, says WWF. The spill has also threatened birds. About 11 endangered species inhabit the area around the strait, including the Dalmatian pelican and great black-headed gull, and many more migrating birds will be wintering in this area in the coming months.[1]

References

  • Oil Spills
  • Oil spills in the sea
  • What Causes Oil Spills?
  • How do spills happen
  • Oil Spill Concerns
  • Oil Spills
  • History
  • Effects of Oil Spills on Wildlife and Habitat

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