The 2010 Deepwater Horizon oil spill in the Gulf of Mexico is the worst environmental disaster in the United States, almost 20 times greater than the Exxon Valdez oil spill. The federal government is still in the process of conducting its Natural Resource Damage Assessment. But 5 years later, even if the public opinion seems to have forgotten about the issue, a lot of research has been conducted to understand the effects of the spill and its long term consequences. In fact, more than 500 million dollars were donated by BP to record all data related to the incident. “We’re looking at as much as three petabytes of data,” said Larry McKinney, executive director of the Harte Research Institute for Gulf of Mexico Studies at Texas A&M University. In this article, I will try to summarize the impact the spill has had on the environment and assess the success of the different techniques used.
According to the satellite images, the spill directly impacted 68,000 square miles (180,000 km2) of ocean after 87 days of continuous spill.
Concerns were also raised about the appearance of underwater, horizontally extended plumes of dissolved oil
“Estimates of the residual ranged from a 2010 NOAA report that claimed about half of the oil remained below the surface to independent estimates of up to 75%. In 2013, some scientists at the Gulf of Mexico Oil Spill and Ecosystem Science Conference said that as much as one-third of the oil may have mixed with deep ocean sediments, where it risks damage to ecosystems and commercial fisheries”
The biggest victims of this pollution are the endangered species that now find themselves one step closer to extinction. Loggerhead turtles for example, after all the efforts that were put into saving them ( be it through population projection studies or the use of turtle excluder devices ) have seen their population decrease considerably. Since 2010, more than 2,000 sea turtles have stranded in the Gulf of Mexico. Typical stranding levels are 240 sea turtles per year. So this high rate is clearly due to the spill.
Although some argue that the effect of the spill on the maritime species is less than what was initially predicted, it is nonetheless considerable. A record high number of dolphin deaths and illnesses in the northern Gulf of Mexico coincident with the Gulf oil disaster was recorded. Unique and highly diverse seaweed habitats harboring deep-sea shrimp, crab, and lobsters suffered a dramatic die-off, reducing diversity by more than 85 percent. Mammals that have ingested oil, suffer from ulcers and internal bleeding. Countless species of fish, sea grass and corals have died of poisonning and or lack of nutrients. Their offsprings also suffer from heart defects due to the contamination which only reduces their fitness. The decrease in population size is only the symptom of the considerable reductions of resources available because of water pollution. The water pollution was also shown to weaken the animals immune system. The oil’s toxicity is also believed to have hit egg and larval organisms immediately, diminishing or even wiping out those age classes, which caused population dips and cascading food web effects.
The effect of oil contamination isn’t only seen in marine flaura and fauna: Nearly 1 million coastal and offshore seabirds are estimated to have died as a result of the oil spill. In 2012, some migrating ducks and geese that have survived have carried chemicals north all the way to Minnesota. The oil coating birds’ feathers, causes them to lose their buoyancy and the ability to regulate body temperature.
The shore was also contaminated. Researchers calculated that some 22,000 tons of oil washed up on the shores of the Gulf Coast. Many beaches are still contaminated to this day from Louisiana’s coast and along the Mississippi, Florida, and Alabama coastlines. Relentless efforts have been made to clean the beaches but it is a colossal work. Approximately 47,000 people were mobilized after the incident. As of January 2013, 935 personnel were still involved. By that time cleanup had cost BP over $14 billion.
The fundamental strategies for addressing the spill were containment, dispersal and removal
The effectiveness of the efforts made to contain the effects of the spill is debatable: Containment booms stretching over 4,200,000 feet (1,300 km) were deployed, either to corral the oil or as barriers to protect marshes, mangroves, shrimp/crab/oyster ranches or other ecologically sensitive areas. Booms extend 18–48 inches (0.46–1.22 m) above and below the water surface and were effective only in relatively calm and slow-moving waters. Booms were criticized for washing up on the shore with the oil, allowing oil to escape above or below the boom, and for ineffectiveness in more than three to four-foot waves.
The use of Corexit dispersant is even more polarizing. A recent study led by University of Georgia marine scientists, showed that the use of chemical dispersants such as Corexit meant to stimulate microbial crude oil degradation can in some cases inhibit the microorganisms that naturally degrade hydrocarbons.
It seems that in 5 years, the spill’s effects will indeed be long lasting. But the data that was acquired will be valuable in remediating the disaster.