Deepwater Horizon Oil Spill

On April 20, 2010, the Deepwater Horizon semi-submersible Mobile Offshore Drilling Unit experienced a large explosion and fire, while drilling in the Macondo Prospect oil field about 40 miles (60 km) southeast of the Louisiana coast. The blast caused an underwater wellhead to erupt and started a massive offshore oil spill in the Gulf of Mexico, which flowed for three months. The environmental disaster is considered the largest in U.S. history. In all, the event resulted in the release of approximately 4.9 million barrels or 205.8 million gallons of crude oil. It is the largest accidental marine oil spill in the history of the petroleum industry. The spill continues to cause severe damage to marine and wildlife habitats, as well as the Gulf’s fishing and tourism industries.
By late November 2010, 320 miles (510 km) of the Louisiana shoreline was closed because of the spill. In January 2011, eight months after the explosion, an oil spill commissioner reported that tar balls continue to wash ashore, wetlands are fouled and dying, and crude oil remains visible off the Gulf of Mexico coastlines. Scientists have reported immense underwater plumes of dissolved oil not visible on the surface, as well as an 80-square-mile (210 km) “kill zone” surrounding the damaged BP well, where it looks like everything is dead on the seafloor. The disaster has put hundreds of endangered animal species at risk.
The North Atlantic Bluefin Tuna, prized for sushi and sashimi, regularly travels across the Atlantic seaboard to spawn in the Gulf of Mexico. Five of the world’s seven sea turtle species live, migrate and breed in the Gulf region. Kemp’s ridley is the world’s most endangered species of sea turtle. Ten days after the accident, scientists recorded 156 sea turtle deaths, most of the victims were Kemp’s ridleys. The grass beds south of the Chandeleur Islands are very close to the oil spill. These grasses are a nursing area for a large number of shark species. Oil spills pose an immediate threat to marine mammals because they need to surface and breathe. Some other notable creatures at risk are Louisiana oysters, shrimp, blue crab, and a huge collection of birds, including the Brown Pelican.
One of the biggest unknown factors surrounding the spill is related to the dispersants BP used to fight the oil. Dispersants are a collection of chemicals that rapidly disperse large amounts of certain types of oil from the sea surface by transferring it into the water column. The oil is effectively spread over a larger volume of water and taken off the surface of the ocean. Dispersants can delay the formation of persistent oil-in-water emulsions. The problem is that laboratory experiments show that dispersants have increased the toxic hydrocarbon levels in fish by a factor of up to 100 and may kill fish eggs. Some people believe that BP used these chemicals because they wanted the oil out of sight and mind.
BP didn’t want people to see the oil collecting on the surface of the water, so they made the premature decision to use the dispersants. A dispersant was used in an attempt to clean up the Exxon Valdez oil spill of 1989. During that spill, fisheries didn’t see a dramatic decline in business right away. However, four years after the disaster, the herring market made a strong decline. Since that time, there has been a steady downward trend of the salmon fisheries in the area where the Exxon Valdez spill occurred, which is Prince William Sound, Alaska. This has concerned environmentalists who have predicted that the damage caused by the Deepwater Horizon oil spill is only beginning to impact the world economy and sea life.