The Deepwater Horizon oil spill is considered to be the largest accidental marine oil spill in the history of the petroleum industry. The spill occurred in the Gulf of Mexico on April 20, 2010. The spill was the result of the explosion of the Deepwater Horizon offshore drilling rig. When the rig exploded, it created a sea-floor gusher of oil that flowed freely for three months. It resulted in 11 people killed and 17 others injured. In addition to the injuries and loss of human life, there were detrimental impacts to the environment both long and short term. By the time the leak was capped, there had been 4.9 million barrels of crude oil released.
The amount of pollution that resulted from this spill is still being determined and may never be fully realized. Many different types of pollution resulted from the spill. The main causes of damage in the spill were petroleum toxicity, oxygen depletion, and the use of Corexit dispersant. This type of damage to the ecosystem is the result of primary pollution. It is classified as a primary pollution because it was emitted directly into the ecosystem from an identifiable source.
Air pollution is also a factor in the spill. According to "National Oceanic and Atmospheric Administration" (2011), “The amount of air pollutants in the atmospheric plume generated by the Deepwater Horizon oil spill was similar to a large city” This is also a primary pollutant. Once the hydrocarbons mix with sunlight, they will create ozone, which is a secondary pollutant. It is considered a secondary pollutant because it was produced in the atmosphere by a chemical and physical process from a primary pollutant (crude oil emissions).
The results of the spill have had numerous effects both long and short term on the environment and the wildlife in the area. The Gulf of Mexico is a very productive area for many different types of species. The location of the oil spill was near the outflow from the Mississippi River.
This is a nutrient rich area where 1,728 species feed and reproduce. Many species were breeding at the time of the spill, which exposed vulnerable larvae and young to toxic oil. The count of dead animals directly resulting from the spill includes: 6,104 birds, 609 sea turtles, and 100 marine mammals. This number only includes the animals collected. The actual count is likely to be much higher. The majority of the animals that die either sink or get eaten, therefore only a fraction wash up on shore or get spotted at sea.
The long term effects of the spill will be hard to detect, but they could be much more harmful. If oil stays in ocean marsh sediments, plants and animals will be exposed to its effects over time. The oil will eventually enter the food chain through the sediment and plants. Studies have found toxins form the Exxon Valdez oil spill in animal in Alaska up to 20 years after the spill. In a spill of this magnitude, there are many different ways to approach the cleanup. In this case, one of the main clean up procedures used was the application of a chemical dispersant.
The chemical dispersant does not actually remove the oil, it breaks it down into small droplets. Another way to remove the oil from the water is by using skimmers. This is a process in which a machine siphons the oil off the top of the water. It is a difficult process because the longer the oil sits on the water the more the viscosity changes. Eventually the oil becomes too thin to siphon off the top and the skimmer takes on more water than oil. When the oil reaches the coastlines, the cleanup procedures change.
In the case of this spill, much of the coastline was able to be protected because it happened nearly 50 miles offshore. Crews were able to set up containment boom around areas of concern. Many of the areas the spill reached were highly environmentally sensitive therefor physical methods of cleanup were not used. Physical methods such as wiping with absorbent materials, pressure washing, raking, excavating, or bulldozing can be more harmful to the area. In these cases, the natural process is preferred. This includes evaporation, oxidation, and biodegradation.
Since the Deepwater Horizon spill, there have been new safety measures and regulations put in place to stop disasters like this from happening again. One of the causes for the explosion was a faulty blowout preventer on the rig. The blowout preventer controls and monitors the flow of oil in the well. They are essential to the safety of the operation. New regulations require stricter inspections on blowout preventers. The Department of Interior imposed many new regulations on drilling and workplace safety practices. They also required rig operators to have a comprehensive impact program in place to reduce organizational errors that could cause accidents or spills.
Disasters such as this remind the world the dangers of its reliance on fossil fuels. Not only are they a non-renewable resource, they have a largely negative impact on the environment. As technology advances, there is hope that the Earths reliance on fossils fuels can shift in the future to more sustainable resources. Wind, solar, and hydro, energy sources are all great examples of alternative energy. I believe that these sources need to be further examined in order to solve the Earths energy crisis.
References National Oceanic and Atmospheric Administration. (2011). Retrieved from http://www.noaanews.noaa.gov/stories2011/20111219_dwhairquality.html