Environmental pollution has been the topic of discussion among the scientists and all other people as environmental pollution is the reason of impending doom that Earth is facing in the future. To be precise it is not the doom of Earth but the doom of the entire animal kingdom. It is predicted that after the apocalypse or Doom’s Day first the Human species will be eliminated from earth and then the small domestic animals. It might not be the process of one day however, the way human kind is treating the dear earth it seems to be inevitable. Water pollution is one of the major threats to the animal kingdom. Already various countries of the earth are facing scarcity of drinking water however; the major pollution to the seawater has major impact on the environment as well.

Deepwater horizon oil spill is said to be the worst case of oil spill of the history. It happened in 2010 in the Gulf of Mexico and is called as Gulf of Mexico oil spill of 2010 as well. In the present essay the environmental impacts and the long lasting effects of the deepwater horizon oil spill is discussed. 


Deepwater Horizon is a mobile floating drilling rig owned by Transocean and built by Korean Company Hyundai Heavy Industries. It has the capacity to operate in water up to 10,000ft deep. During the time of the incident it was said to be drilling a deep exploratory well which was approximately 5,100 feet deep in water. This well is in the Macondo Prospect in Mississippi Canyon Block 252 (MC252) of the Gulf of Mexico. It is the exclusive economic zone of the United States. The Macondo well is positioned approximately 41 miles (66 km) off the Louisiana coast. On April 20th, 2010 the drilling rig exploded due to high pressure by methane gas which expanded into the drilling riser and to the drilling rig from the well. At the time of explosion 126 people were on board out of which 11 went missing and never found during days long rescue mission. Around 4.9 million barrels of oil was spilled in the Gulf of Mexico at the rate of 8000 barrels of crude oil per day. The house energy advisor Carol Browner called it the “worst environmental disaster the US has faced”.  This spill was even greater than the Exxon Valdez oil spill (approximately 20 times greater).     

Environmental Impact

The spill as said was the worst event of oil spill in the history of US where around 4.9 million gallon of oil was spilled causing devastating effect to the environment and major water pollution leading to a number of individualized effects. In this section, these effects are discussed.

Impact on Marine Life

The major negative impacts were upon the marine life due to the oil spill. More than 400 species living in the Gulf of Mexico were threatened. Several endangered species of turtles such as the Kemp's ridley turtle, the loggerhead turtle, the green turtle, the hawksbill turtle, and the leatherback turtle were harmed.  More than 1,200 fish, 1,400 mollusks, 1,500 crustaceans, 29 marine mammals and 4 sea turtles were harmed as well. The huge amount of oil spill that was observed is enough to change the chemistry of the sea with unforeseeable effects and is enough to wipe out the marine life deep at sea. The actual number of marine mammals affected due to the oil spill might be 50 times higher than the estimated amount (Barron 2012, p.315). The toxins released due to the oil spill in the water body caused deaths in fishes due to cardiac arrest. Prior to the oil spill about 0.1% of the fishes had lesions in this area however, after the incident the lesions were observed among 20% of the fishes which later on increased by 50% as an after effect of the oil spill. A disturbing numbers of mutated fishes were observed in the Gulf displaying oozing sores. Not only fish but also shrimps and crabs were found born without eyes. Crabs also showed soft shells instead of hard shells and one fifth sized even when full grown, clawless and spike less shelled crabs (Whitehead et al. 2012, p.20298). Oil broke down by the effects of wave releases chemical toxins more harmful than crude oil.   

Impact to the Corals

Deep-sea corals around the well were heavily damaged. Moreover, the spill was so huge that it covered a huge area in the sea endangering several unique species of corals. In 2012 deceased coral reefs, size of half of a football field in the Gulf was found and was said to be caused due to the spill. Around 30 colonies of corals were damaged close to the Deepwater Horizon well indication to the fact that these huge deaths and damage of the coral reefs were the result of the oil spill (White et al.2012, p.20303).

Impact to the Dolphins

After the spill, the month of February in 2011 was the first Birthing season of the Dolphins. It was observed that dead bodies of baby dolphins were washing up to the sea shores of Mississippi and Alabama and the death of these baby dolphins were attributed to the oil spill incident of the Deepwater Horizon (Schwacke et al.2013, p.93). It was speculated that the dolphins started aborting or the spawns were still born for some reason. Later the reason was attributed to the toxins produced in the water due to the oil spill. Initially at the time of spill, 90 dead dolphins were counted but by January 2011, additionally 200 dead dolphins were counted. In 14 months duration around 406 dead dolphins washed up to the shores (Incardona et al.2014, p.E1510). It was found on the autopsy that 15 out of these 406 dead bodies had oil traces in them. A study conducted by NOAA in 2011 suggested that dolphins that ingested petroleum were suffering from low weight, low blood sugar.  Some of them presented with liver and lungs cancer.  The effect of the oil spill on dolphins was long lasting. Even after 3 years of the incident, the dolphins continued to be ill and dying (Venn-Watson et al.2015). In 2013, the journal of the Environmental Science and technology published a report stating that 23 Dolphins captured from Southern Louisiana (24km) stretch were found to be ill. One of these was a pregnant female, which was carrying a dead fetus. Half of the captured population was dying and suffering from liver disease, pneumonia, loss of teeth. However, the study could not prove any relation with the oil spill. Later on, in 2016, a report published by an independent research team, suggested that 88% of the stillborn babies (accounting for about 360 babies) had under developed or abnormal lungs compared to the other areas (15%); clearly pointing to the long lasting and devastating affect the oil spills has on the water body and to the life of dolphins (Rooker et al. 2013).

Effect of Methane

The crude oil spilled from the well-contained 40% methane. Typically, other oil spills contain 5% methane. Methane is toxic as it suffocates the marine life thereby creating huge dead zones in the sea due to oxygen depletion caused due to dissolved methane in the water. Dissolved methane combined with dissolved oxygen causes benzene emission along with other toxic compounds to the sea (Joye 2015, p.592).

Oil entry to the food-chain

The dispersants of the sea break oil into small enough droplets to enter the food chain as observed in case of the tiny blue crab larvae in which oil traces were found under the shells. Orange blobs of oil were observed under the shells of almost all the larvae. Through the zooplankton the spilled oil entered the marine food chain and later to the land food chain. Traces of oil were found within the bodies of fish eating birds and land animals affecting harmful outcomes. Microscopic planktons were killed by the oil dispersants (Graham et al.2010).

Effect of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons or PAHs are often linked with oil spills and have huge toxic effects on water body and animal health. PAHs are known to contain carcinogens that can cause cancers to liver and lungs. As already stated, dolphins and other marine animals suffered cancers to the liver and lungs thereby pointing to the contribution of PAHs to the marine toxicity (Barron 2012, p.315). Moreover, PAHs can cause immediate death to the marine animals in high amount and continued exposure to even in low amounts leads to cancer. Later researches conducted on the after effects of oil spills to the gulf coast showed that the amount of PAHs in the water body is 40% higher than the usual amount (Allan, Smith and Anderson 2012, p.2033). It was suspected that abundant use of dispersants used by Deepwater Horizon increased the bioavailability of the PAHs. After the spill, huge amounts of PAHs were available to the biological community of the water body causing harmful and potentially fatal effects. PAHs can also contribute to cardio toxicity leading to Cardiac arrest sustained by the fishes and Dolphins in the Gulf Coast. The increased bioavailability of PAHs resulted in the ingestion of PAHs by marine animals and planktons thereby leading to entry of PAHs to the food chain (Allan, Smith and Anderson 2012, p.2033).  

Impact of the Oil cleanup

Not only the oil spill, but also the oil cleanup resulted in harmful effect to the environment. The cleanup processes used for cleaning the oil spills are chemical in nature and hugely impacts the marine life and water body. Not only the marine life but also plants in the land were destroyed by the irresponsible activities by the cleanup crew. Dispersants were used for cleanup process and heavy use of dispersants by the company for cleanup further broke down the oil and increased the bioavailability of oil and PAHs thereby causing entry to the food chain further solidifying the long-term harmful effects (Mendelssohn et al.2012, p.563).

Remaining oil in the water

Despite the continued efforts of restricting the oil in the sea and cleaning up the already spilled oil, 79% of the oil spilled by the Deepwater Horizon remains in the Gulf of Mexico until this day. Studies conducted on the after effect of the oil spill show that thousands of pound of spilled oil and dispersants accumulate each day in the resort areas. The released governmental reports although stated that little amount of oil remained in the sea except for 2.5km area around the well, but contradictory reports were found by independent studies. According to the official governmental reports, 0.1% oils remained on the sea however on a report published in 2012 showed that 565,000 pounds of oiled material exists. It is believed that around 1 million barrels of oil remain under the sea.

Strategy used to prevent the Impacts

To control the oil spill and for the oil cleanup process, dispersants were used. However, dispersants caused other harmful effects as already discussed. Nearly 2 million gallons of dispersants were used to clean up the spilled oil. Corexit 9500A and Corexit 9527A dispersants were used for cleanup and both of these dispersants were listed under the federal guidelines. These dispersants contained solvents and surfactants. While the solvents mix the chemicals the surfactants help in emulsification of oil and water leading to the breakdown of oil into smaller droplets by bacteria. However, this caused long lasting harmful effects as the smaller oil droplets and increased amount of PAHs entered the food chain leading to mutation, cancer and various other illnesses in the marine organisms (Kujawinski et al.2011, p.1298). Moreover, surfactants have their own range of harmful effect on the chemistry of marine water.


Oil spills from oil mines are a common phenomenon causing harm to the marine and land environment. However, devastating incidents such as the incident of Deepwater Horizon caused long-term harmful environmental impact on the water body and marine life. Even after almost seven years since the incident, the effect is observed on the energy and environment policy. In conclusion, it can be recommended that security and safety measured to the oil drilling must be emphasized more by the companies and government so that not only the immediate effect of the spills can be avoided but long lasting effects can be avoided as well.