Gulf or BP Oil Spill Physical Methods GRAND ISLE, La. -- Brown pelicans congregate on containment boom that surrounds Queen Bess Island, a few miles north of Grand Isle, La. August 25, 2010. The island is a sensitive nesting area for brown pelicans. More about the Gulf oil spill can be found in our Gulf oil spill featured story. Credit: Petty Officer 3rd Class Cory J. Mendenhall, U.S. Coast Guard When oil spills into the ocean, it is difficult to clean up. When you have 3.19 million barrels to clean up, it is even harder. Part of the difficulty is that no two spills are alike. The amount and type of oil (whether crude or refined) affects how it spreads, and a spill in seawater spreads differently than freshwater. Local environmental conditions also play a huge role: currents, tides, weather, wind speed and direction, air temperature, water temperature and presence of ice all affect how the oil spreads and how well cleanup workers can access the spill area. This variability makes it difficult to plan for spills ahead of time. The most basic method of clean up is to control the spread of the oil using physical barriers.

When oil spills in water, it tends to float to the surface and spread out, forming a thin slick just a few millimeters thick. (A very thin slick is called a sheen, which often looks like a rainbow and can be seen in parking lots after a rainstorm.) Cleanup workers first surround the slick with floating booms to keep it from spreading to harbors, beaches or biologically important areas like marshes. Then they can use different tools to remove the collected oil. Often they will drive skimmers, boats that skim spilled water from the water's surface, through the slick. After most of the oil is removed by skimmers, workers use sorbents to mop up the trace amounts left behind. Sorbents either absorb oil like a sponge or adsorb oil, which means that oil sticks to its surface. They come in three main types: natural organic materials like peat moss, straw, hay and sawdust; natural inorganic materials like clay, volcanic ash, sand, or vermiculite; and synthetic sorbents made of materials similar to plastic like polyurethane, polypropylene, and polyethylene.

Which type is used will depend on the particular spill, as some types of sorbents work best on different types of oil and under different weather conditions. Another option is to speed up the oil's natural biodegradation using dispersants. (See next section.) Striped dolphins swim among emulsified oil patches on April 29, 2010 in the Gulf of Mexico, a few days after the Deepwater Horizon oil spill. Credit: NOAA There were some immediate impacts to the animals of the Gulf of Mexico that could be seen with the naked eye: pelicans black with oil, fish belly-up in brown sludge, smothered turtles washed up on beaches. But not much time has passed since the spill, and it will take many more years of monitoring and research to understand what happened. Strandings of both dolphins and sea turtles increased significantly in the years following the spill. "From 2002 to 2009, the Gulf averaged 63 dolphin deaths a year.

That rose to 125 in the seven months after the spill in 2010 and 335 in all of 2011, averaging more than 200 a year since April 2010," reported Reuters in 2015 . Since then, dolphin deaths have declined, and long-term impacts on the population are not yet known. Kemp's ridley sea turtle nests have gone down in the years since the spill, and long-term effects are not yet known. Seabirds were initially harmed by crude surface oil—even a small bit of oil on their feathers impeded their ability to fly, swim and find food by diving. Seabird losses may have numbered in the hundreds of thousands , but reliable estimates are hard to come by. Looking beyond the sea, researchers are currently studying how oil may have affected land birds that live in the marshes along the Gulf coast . Invertebrates in the Gulf were hard hit by the Deepwater Horizon spill—both in coastal areas and in the deep. Shrimp fisheries were closed for much of the year following the spill, but these commercially-important species now seem to have recovered. Deep-water corals grow very slowly and can live for many centuries.

Found as deep as 4,000 feet below the surface, corals near the blowout showed signs of tissue damage and were covered by an unknown brown substance, later identified as oil from the spill. Laboratory studies conducted with coral species showed that baby coral exposed to oil and dispersant had lower survival rates and difficulty settling on a hard surface to grow. The impact of the spill on fish communities is still largely unknown. Lab studies have shown that oil can cause heart defects in the developing larvae of bluefin tuna and other fish , but we won't know if this occurred in the wild until after those larvae would have grown up. Some fish larvae populations actually grew after the spill , as they had more food in the form of oil-eating microbes. There were some reports of deformed wildlife after the spill. For years following the spill there were reports of fish with lesions and deformities, and some reports of eyeless and deformed shrimp after the spill. However, consuming Gulf seafood is now completely safe. An autonomous underwater vehicle from the Monterey Bay Aquarium Research Institute (MBARI) being launched from the NOAA Ship Gordon Gunter in the Gulf of Mexico.

Credit: Yanwu Zhang © 2010 MBARI In May 2010, the Monterey Bay Aquarium Research Institute (MBARI) sent a high-tech robotic submersible to the oily waters of the Gulf of Mexico. Like other autonomous underwater vehicles (AUV), the robotic sub was programmed at the surface to navigate through the water on its own, collecting information on deep oil plumes from the Deepwater Horizon spill as it traveled. Although satellites and aircraft helped show the extent of the spill at the surface, researchers hoped that the AUV would allow them understand what was happening farther down in the water column. During the NOAA-sponsored expedition, MBARI's AUV mapped part of a plume 1,000 meters (3,300 feet) below the surface, and collected water samples at various depths. The resulting data helped the researchers identify a persistent deep oil plume and link the oil in this plume to its source: the Deepwater Horizon blowout. Drifters deployed into the Gulf of Mexico sent location information back to scientists through a GPS satellite. Some of the 5.7 million data points about the drifters locations are seen in this map of the Gulf.

Credit: Photo courtesy of CARTHE Once the over 200 million gallons of oil began spewing out of the damaged wellhead—where did it go? Keeping track of that much oil—especially as it sinks into the deep sea—is a difficult task that can't be done with eyes alone. Along with visual tracking, computer models of the oil's movement helped researchers get a better sense of what path it took and where it ended up. To build the models, researchers first had to understand where ocean eddies, currents and waves carried the tiny oil particles. To understand surface water movement better, researchers set small, yellow boards made of wood afloat on the ocean's surface and asked beachgoers to report where they found these “drift cards” when they washed up on shore. This citizen scientist endeavor provided general information about how far the waves can carry a floating object and specific data points that can be used to improve models of where the oil disperses. Further data collection has been ongoing since the spill by the Consortium for Advanced Research on Transport of Hydrocarbon in the Environment (CARTHE).

CARTHE has more high-tech "drift cards:" their “drifters” are small buoy-like instruments with GPS, which ping their locations to satellites as they drift on ocean currents. Their location gets tracked for weeks or months at a time and provide an unprecedented amount of location-based data for modeling. This information can be used to better predict oil movement in case of future spills. Video of Bob the Drifter - A Waterlust &amp;amp; CARTHE film about ocean currents An environmental chemist collects samples of oil in the Gulf of Mexico from the Deepwater Horizon spill. The resulting chemical “fingerprint” of the oil will help determine the origin of other samples. Credit: J. Short, Oceana, and S. Senner, Ocean Conservancy After the Deepwater Horizon spill, oil was mixed throughout the ocean and made its way to coastal and deep-sea sediments. Researchers continue to collect samples from both the water and the sediment to determine if oil is present, and where exactly it came from. Chemical analysis of oil found after a spill can be used to determine its original source.

In the case of Deepwater Horizon, tracking the origins of oil slicks that appeared after the well was capped proved helpful in determining if a new leak might have sprung. One-meter-tall plastic drifters are released into the Gulf of Mexico in 2012. Over 300 of these drifters were released and their location information was sent to researchers every five minutes through GPS satellite. Credit: Photo courtesy of CARTHE About a month after the Deepwater Horizon oil spill (while the oil was still leaking out of the Macondo wellhead) BP announced that they would provide $500 million to fund an independent research program that would study the impacts of the spill on the environment and public health. With this funding, the Gulf of Mexico Research Initiative (GoMRI) was formed as a 10-year independent research program. The GoMRI research board, which is independent from BP, makes funding and research decisions, and as of early 2014 over $175 million has been distributed to research institutions, many of which are located in Gulf states.

At the outset, the twenty-person GoMRI board adopted five main research themes to focus on: physical movement of the oil and dispersant, degradation of the oil and its interaction with the ecosystem, environmental effects of the oil and dispersant, development of technology for improved response and remediation, and the effects of oil and dispersant on human health. GoMRI funded studies have examined where the oil went after the spill , and how the oil affected many types of marine life, including deep-sea coral ecosystems, seabirds, and jellyfish, to name just a few. Read more about GoMRI research: The Smithsonian's Department of Invertebrate Zoology has a collection of over 57,000 specimens from over 5,700 sites in the Gulf of Mexico, which are now catalogued on Google Earth Credit: Smithsonian Institution NMNH Department of Invertebrate Zoology As scientists in the Gulf collect organisms potentially affected by the oil, they will need to compare them to animals from previous decades to identify how they have changed, if at all. Here's where Smithsonian Collections can play a role. Soon after the Deepwater Horizon oil spill, Smithsonian Collections staff plotted invertebrate holdings from the Gulf onto Google Earth.

Since 1979, invertebrate specimens have been deposited in the national collections of the National Museum of Natural History's Department of Invertebrate Zoology . In the Gulf of Mexico, more than 57,000 invertebrates (points on the map) from 5,789 distinct collecting sites from 14 Mineral Management Service survey programs (point colors) have been cataloged. Following the Deepwater Horizon incident in late April 2010, collections staff updated the files to reflect the latest areas affected by the spill in real-time. “The points on the map represent less than half of our Gulf of Mexico holdings, the rest—approximately 75,000—still need to be processed and cataloged,” said Bill Moser, museum specialist. Dr. Chris Reddy, an environmental chemist from Woods Hole Oceanographic Institution, studies oil spills and their long-term impacts. Credit: History Channel &amp; Smithsonian Institution At Woods Hole Oceanographic Institution in Massachusetts, Chris Reddy studies the long-term effects of oil spills, as well as natural oil seeps that occur off the coast of Santa Barbara, California.

In this video , watch as he digs beneath the surface in Wild Harbor salt marsh in Cape Cod, Massachusetts to find layers of oil from a spill that occurred more than 40 years ago. This leftover oil continues to impact the wetland's ecology and wildlife. “When this spill first occurred in 1969, about a month after I was born, people thought that it would only last a week,” he says. And to the naked eye, the marsh looks beautiful and pristine. But oil has persisted in the sediments and continues to adversely affect the marsh’s mussels, crabs, and grasses. “ Oil can last for a long time and has a lot of biological impact.” In June 2010, Dr. Reddy testified before a Congressional panel (pdf) investigating the Gulf oil spill. Workers contracted by BP load oily waste onto a trailer on Elmer's Island, just west of Grand Isle, La., May 21, 2010. Credit: U.S. Coast Guard photo by Petty Officer 3rd Class Patrick Kelley In the immediate aftermath of the Deepwater Horizon oil spill, concerns about public health focused on people coming into direct contact with the oil and dispersants.

The Centers for Disease Control and Prevention offered safety advice to Gulf Coast residents and relief workers and the EPA conducted toxicity tests on dispersants. However, long-term questions about oil spills and their impact on human health remain. The National Institutes of Health began to address these in a study that is tracking 33,000 cleanup workers and volunteers for a decade. The research will assess whether exposure to crude oil and dispersants has an effect on physical and mental health. As the days, weeks, and months progressed the indirect impacts related to seafood consumption also gained attention. The chemicals in oil that are of most concern to humans are called polycyclic aromatic hydrocarbons (PAHs). Some of these are known to cause cancer. The U.S. Food and Drug Administration is charged with monitoring the levels of PAHs in Gulf Coast seafood. It works in conjunction with NOAA, the EPA, and state agencies to determine which fisheries are safe to open and which ones should be closed. In order for a fishery to be reopened, it must pass both a "smell" test and a chemical analysis . Seafood cannot go to market if it contains harmful levels of PAHs or if it emits an odor associated with petroleum or dispersants.

Fishing area closures peaked on June 2, 2010 , when 88,522 square miles of the Gulf of Mexico were off-limits. On April 19, 2011, NOAA announced that commercial and recreational fishing could resume in all of the federal waters that were affected by the spill. Rescuing Animals in the Oil Spill One of many Kemp’s ridley sea turtles (Lepidochelys kempii) recovering at the Audubon Aquarium of the Americas, after the 2010 Gulf of Mexico oil spill. Turtles were cleaned and nursed back to health with the help of New England Aquarium staff. Credit: New England Aquarium Pictures of pelicans, sea turtles, and other Gulf of Mexico wildlife struggling in oil were among some of the most disturbing images of the Deepwater Horizon oil spill disaster in 2010. According to the U.S. Fish and Wildlife Service, thousands of “visibly” oiled animals (pdf) —which include birds, sea turtles , and marine mammals—were collected by authorities in the vicinity of the Deepwater Horizon oil spill.

Many of the animals were already dead, but for those found alive, dozens of organizations, including the Smithsonian’s National Zoological Park and the New England Aquarium (NEA), were mobilized to rescue, rehabilitate, and later release animals affected by the spill. National Zoo personnel were dispatched to the Gulf largely to assist with the process of relocating animals affected by the spill and helping to identify future release sites for those rescued. Dr. Luis Padilla, a Zoo veterinarian who helped with a pelican release in Texas , and Dr. Judilee Marrow were among those who assisted in the Gulf. NEA staff who helped to rehabilitate sea turtles rescued from the Gulf oil spill offered a behind-the-scenes view on the aquarium’s Marine Animal Rescue Team Blog . The blog described how rescuers in boats and spotter planes were “looking for rounded mounds on the surface of the oil, which usually means that there is a turtle floating under the surface of the oil." The rescue team, based at the Audubon Aquarium of the Americas in New Orleans, treated dozens of endangered sea turtles, such as Kemp's ridley, loggerheads, green sea turtles, and hawksbills.

To learn more about how oil affects marine life, watch this video from the Pew Environment Group that explains the impact of oil on marine life throughout the water column and check out this fact sheet from U.S. Fish and Wildlife which summarizes “Effects of Oil on Wildlife and Habitat.” (pdf) We may not know the full effects of the spill on animals - both big and small - for years to come. (See "Ecosystem Effects." ) Credit: Select Committee on Energy Independence and Global Warming In testimony before a committee (pdf) of the U.S. House of Representatives, Dr. Sylvia Earle, National Geographic Explorer-in-Residence and former chief scientist of NOAA, offered specific suggestions for addressing the catastrophic oil spill in the Gulf and delivered an impassioned call for greater investment in ocean research—including more expeditions to explore the Gulf’s deep waters, establishing permanent monitoring stations and protocols, and encouraging tri-national collaboration among scientists and institutions around the Gulf. “No one has descended to the greatest depth in the Gulf of Mexico, about three miles down in the Sigsbee Deep near Yucatan.

In fact, no one knows for sure exactly where the deepest place in the Gulf is, or if they do, proving it has been an elusive goal,” she said. Deepwater Horizon Owner Settles With U.S. Over Oil Spill in Gulf of Mexico - The New York Times The New York Times Energy & Environment |Rig Owner Will Settle With U.S. in Gulf Spill Search Continue reading the main story The driller whose floating Deepwater Horizon oil rig blew out in 2010, causing a massive oil spill , has agreed to settle civil and criminal claims with the federal government for $1.4 billion, the Justice Department announced Thursday. The Deepwater Horizon exploded, burned and sank in April 2010. Eleven men were killed and millions of gallons of oil flowed into the Gulf of Mexico and fouled the shores of coastal states. The well, known as Macondo, was owned by British oil giant BP, which settled its own criminal charges and some of its civil charges in November for $4.5 billion.

While this settlement resolves the government’s claims against Transocean , that company and the others involved in the spill still face the sprawling, multistate civil case, which is scheduled to begin in February in New Orleans. In a deal filed in federal court in New Orleans, a subsidiary, Transocean Deepwater, agreed to one criminal misdemeanor violation of the Clean Water Act and will pay a fine of $100 million. Over the next five years, the company will pay civil penalties of $1 billion, the largest ever under the act. As part of the criminal settlement, Transocean also agreed to pay the National Academy of Sciences and the National Fish and Wildlife Foundation $150 million each. Those funds will be applied to oil spill prevention and response in the Gulf of Mexico and natural resource restoration projects. The agreement will be subject to public comment and court approval. The company agreed to five years of monitoring of its drilling practices and improved safety measures.

Continue reading the main story In a statement, Transocean Ltd., the Switzerland-based parent of the rig owner, said that the company thought these were “important agreements” and called them a “positive step forward” that were “in the best interest of its shareholders and employees.” Of the 11 men killed on the rig, the company said, “their families continue to be in the thoughts and prayers of all of us at Transocean.” Advertisement The company announced in September that it had set an “estimated loss contingency” of $1.5 billion against the Justice Department’s claims. Shares of Transocean Ltd. rose nearly 3 percent on the news, to close at $49.20. In a statement, Lanny A.

Breuer, assistant attorney general for the Justice Department’s Criminal Division, suggested that Transocean had played a subservient and lesser role in the disaster to that of BP: “Transocean’s rig crew accepted the direction of BP well site leaders to proceed in the face of clear danger signs — at a tragic cost to many of them.” He said that the $1.4 billion “appropriately reflects its role in the Deepwater Horizon disaster.” Under a law passed last year, 80 percent of the penalty will be applied to projects for restoring the environment and economies of gulf states. Photo Firefighting boats worked to contain the blaze at the Deepwater Horizon platform off the coast of Louisiana in April 2010. Credit U.S. Coast Guard, via Getty Images That fact was applauded by a coalition of Gulf Coast restoration groups, including the Environmental Defense Fund and the National Audubon Society. A joint statement called this “a great day for the gulf environment and the communities that rely on a healthy ecosystem for their livelihoods.” Still, the penalty struck some experts in environmental law as somewhat light. David M.

Uhlmann, who headed the Justice Department’s environmental crimes section from 2000 to 2007, praised the size of the civil settlement, which he said “reflects the scope of the gulf oil spill tragedy.” He argued, however, that the criminal penalty should have been at least as onerous, “given Transocean’s numerous failures to drill in a safe manner, which cost 11 workers their lives and billions of dollars in damages to communities along the gulf.” The settlement, he said, should have included seaman’s manslaughter charges, which were part of the BP settlement. Please verify you're not a robot by clicking the box. Invalid email address. Please re-enter. You must select a newsletter to subscribe to. Sign Up Privacy Policy As for the company’s role in following the lead of BP, he said, “following orders is not a defense to criminal charges.” At the Environmental Protection Agency, Cynthia Giles, assistant administrator for the office of enforcement and compliance assurance, called the settlement “an important step” toward holding Transocean and others involved in the spill accountable. “E.P.A. will continue to work with D.O.J.

and its federal partners to vigorously pursue the government’s claims against all responsible parties and ensure that we are taking every possible step to restore and protect the Gulf Coast ecosystem,” she said. The multistate trial over claims in the Deepwater Horizon cases that have not been settled are scheduled to begin in February. Stephen J. Herman and James P. Roy, lawyers who represent the steering committee of plaintiffs in the cases, said that Thursday’s settlement did not change the case, and that the plaintiffs thought that BP, Transocean and Halliburton “will be found grossly negligent” at trial. Advertisement Continue reading the main story BP continued its longstanding argument that the accident, in the words of the spokesman Geoff Morrell, “resulted from multiple causes, involving multiple parties,” and that other companies had to shoulder their share of the blame. Transocean, Mr.

Morrell said in a statement, “is finally starting, more than two-and-a-half years after the accident, to do its part for the Gulf Coast.” He then turned his attention to the other major contractor on the well, and said, “Unfortunately, Halliburton continues to deny its significant role in the accident, including its failure to adequately cement and monitor the well.” Beverly Blohm Stafford, a Halliburton spokeswoman, said that the company “remains confident that all the work it performed with respect to the Macondo well was completed in accordance with BP’s specifications for its well construction plan and instructions,” and so Halliburton, she said was protected from liability through indemnity provisions of its drilling contract. “We continue to believe that we have substantial legal arguments and defenses against any liability and that BP’s indemnity obligation protects us,” she said. “Accordingly we will maintain our approach of taking all proper actions to protect our interests.” Correction: January 3, 2013 An earlier version of this story misstated the size of the spill. It was not the nation’s biggest oil spill.

A version of this article appears in print on January 4, 2013, on Page B1 of the New York edition with the headline: Rig Owner Will Settle With U.S. In Gulf Spill. Order Reprints | Today's Paper | Subscribe Legal Ramifications of the BP Gulf Oil Spill - International Wildlife Law Contact Us Legal Ramifications of the BP Gulf Oil Spill A fatal explosion took place on the Deepwater Horizon Oil Rig just off the Louisiana coast on April 20, 2010. Eleven workers died in the explosion. When the rig sank, it created one of the largest oil spills experienced in all U.S. history. As much as 25 thousand barrels of crude oil spilled daily into the Gulf of Mexico causing unprecedented environmental destruction. Billions of dollars of damage occurred to property owners and Gulf Coast businesses. Those who were adversely affected included commercial fishermen, their crew members, seafood processing and packaging industries and their workers, oyster and shrimping fields, small boat and dock owners, owners of waterfront property, the tourism industry, marina owners and operators, the local restaurant industry, and coastal city, county and state governments. Basically all property owners and businesses in the Gulf Coast areas suffered.

Although BP proposed a $7.8 million settlement of damage and medical claims brought about by the spill, thousands of individuals and businesses have opted out of the deal. Some of those who have chosen to opt-out would not have qualified as part of the class action lawsuit anyway. According to Scott Dean the agreement is "fair and reasonable and amply meets all the legal requirements for final approval. "The settlement is a superior alternative to continued lengthy litigation, provides numerous unique claimant-friendly benefits, and fulfils BP's commitment to pay all legitimate claims stemming from the Deepwater Horizon accident." Several attorneys representing large numbers of claimants don't hold such a positive view of the settlement. It could take years to resolve all the claims for those who choose to opt-out, if they pursue their cases individually. In talks with the Department of Justice (DoJ) and other agencies about a final settlement, BP has shown a willingness to discuss reasonable terms, but still continues to prepare for a trial. The trial has been scheduled for February 2013 charging gross negligence on the part of BP for causing the oil spill. This charge alone could cost BP $21 billion under the Clean Water Act.

The company has already spent $14 billion on clean-up along the Gulf Coast and $8 billion in claims. BP could end up paying as much as $17 billion if the court decides that they showed пїЅgross negligenceпїЅ by failing to take reasonable steps that would have averted the spill. It is estimated that 4.2 million barrels of oil remained in the Gulf after BP clean-up extracted 800,000 barrels from the waters. A decision of пїЅgross negligence would take the amount of their fine from $1,100 per barrel to as much as $4,300 per barrel. This would cost the company an additional $13 billion. In order to have more funds readily available BP has begun re-arranging their Russian assets. They have sold half of TNK-BP for $12.4 billion in cash and a 19.75% stake in Rosnett, a state-controlled oil company. TNK-BP had paid no dividends to BP over the past year and this new part ownership in Rosnett will give them a relationship with a more controlled Russian government oil resource.

The American Petroleum Institute is trying to become involved in the federal lawsuit since environmental groups are going after stricter standards regarding chemical dispersants such as those used in the BP oil spill. This group contends that any new restrictions on dispersants could impact planned response to future oil spills. Their brief says this could lead to removal of some or all of the 59 chemical dispersants currently in the National Contingency Plan regarding oil spills. Obama administration officials contend that dispersants used during the BP Gulf oil spill actually prevented the massive spill from doing even more damage to the environment. However, a group of Alabama scientists published a study they conducted that said those dispersants killed plankton and continue to disrupt the aquatic food chain in the Gulf of Mexico. The lawsuit filed by the environmentalists said the EPA needs to study the impact of dispersants to determine which ones are safe to use in future oil spills. The varied aspects of the litigations stemming from the 2010 BP oil spill will undoubtedly continue in the courts for several years to come, even after the class action portion of the case has been concluded.

April 20, 2010 : Massive oil spill begins in Gulf of Mexico Introduction On this day in 2012, an explosion and fire aboard the Deepwater Horizon oil drilling rig in the Gulf of Mexico, approximately 50 miles off the Louisiana coast, kills 11 people and triggers the largest offshore oil spill in American history. The rig had been in the final phases of drilling an exploratory well for BP, the British oil giant. By the time the well was capped three months later, an estimated 4.9 million barrels (or around 206 million gallons) of crude oil had poured into the Gulf. The disaster began when a surge of natural gas from the well shot up a riser pipe to the rig’s platform, where it set off a series of explosions and a massive blaze. Of the 126 people on board the nearly 400-foot-long Deepwater Horizon, 11 workers perished and 17 others were seriously injured. The fire burned for more than a day before the Deepwater Horizon, constructed for $350 million in 2001, sank on April 22 in some 5,000 feet of water.

Before evacuating the Deepwater Horizon, crew members tried unsuccessfully to activate a safety device called a blowout preventer, which was designed to shut off the flow of oil from the well in an emergency. Over the next three months, a variety of techniques were tried in an effort to plug the hemorrhaging well, which was spewing thousands of barrels of oil into the Gulf each day. Finally, on July 15, BP announced the well had been temporarily capped, and on September 19, after cement was injected into the well to permanently seal it, the federal government declared the well dead. By that point, however, oil from the spill had reached coastal areas of Louisiana, Mississippi, Alabama and Florida, where it would inflict a heavy toll on the region’s economy, particularly the fishing and tourism industries, and wildlife. Scientists say the full extent of the environmental damage could take decades to assess. In January 2011, a national investigative commission released a report concluding the Deepwater Horizon disaster was “foreseeable and preventable” and the result of “human error, engineering mistakes and management failures,” along with ineffective government regulation.

In November 2012, BP agreed to plead guilty to 14 criminal charges brought against it by the U.S. Justice Department, and pay $4.5 billion in fines. Additionally, the Justice Department charged two BP managers who supervised testing on the well with manslaughter, and another company executive with making false statements about the size of the spill. It is anticipated that BP, which has set up a $20 billion fund to compensate victims of the spill, will pay billions of dollars more in environmental penalties in the future. Article Details: April 20, 2010 : Massive oil spill begins in Gulf of Mexico Author April 20, 2010 : Massive oil spill begins in Gulf of Mexico URL Deepwater Horizon accident and response | Gulf commitment | BP U.S. Deepwater Horizon accident and response Deepwater Horizon accident and response Deepwater Horizon accident and response The Discoverer Enterprise arrives to install the capping equipment - July 2010 On the evening of 20 April 2010, a gas release and subsequent explosion occurred on the Deepwater Horizon oil rig working on the Macondo exploration well for BP in the Gulf of Mexico.

Eleven people died as a result of the accident and others were injured. We deeply regret this loss of life and recognize the tremendous loss suffered by the families, friends and co-workers of those who died. The fire burned for 36 hours before the rig sank, and hydrocarbons leaked into the Gulf of Mexico before the well was closed and sealed. The accident involved a well integrity failure, followed by a loss of hydrostatic control of the well. This was followed by a failure to control the flow from the well with the blowout preventer (BOP) equipment, which allowed the release and subsequent ignition of hydrocarbons. Ultimately, the BOP emergency functions failed to seal the well after the initial explosions. We regret the impacts on the environment and livelihoods of those in the communities affected. We have, and continue to, put in place measures to help ensure it does not happen again.

How we responded We acted to take responsibility for the clean-up, working under the direction of the federal government to respond swiftly to compensate people affected by the impact of the accident, to look after the health, safety and welfare of the large number of residents and people who helped respond to the spill, and to support the economic recovery of the Gulf Coast’s tourism and seafood industries impacted by the spill. We have conducted studies with federal and state natural resource trustees to identify and define the injury to natural resources in the Gulf of Mexico. Extensive oil spill response BP, government agencies and others worked together to control the spill and minimize its impact on the environment and human health by containing, removing and dispersing the oil offshore, and by implementing strategies to protect the shoreline and clean up oil that came ashore. At its peak in 2010, the response effort involved the mobilization of approximately 48,000 people, the coordination of approximately 6,500 vessels and the deployment of approximately 2,500 miles (13.5 million feet) of boom to contain or absorb the oil.

As at the end of December 2014, BP has spent more than $14 billion and workers have devoted more than 70 million personnel hours on response and clean-up activities. The U.S. Coast Guard ended the remaining active clean-up operations in the Deepwater Horizon area of response in April 2014. If residual oil from the Deepwater Horizon incident is later identified and requires removal, BP will take action at the direction of the Coast Guard. In addition, we have committed long-term funding for independent research to improve our knowledge of the Gulf of Mexico ecosystem and better understand and mitigate the potential impacts of oil spills in the region and elsewhere. Attestation The information on this page forms part of the information reviewed and reported on by Ernst & Young as part of BP's 2014 sustainability reporting. View the full assurance statement .

1000+ images about BP Oil Spill on Pinterest | Oil spill, Gulf of mexico and July 4th Learn more at iliketowastemytime.com Deepwater Horizon, known around the globe as the “BP oil spill”; this massive tragedy happened in the Gulf of Mexico back in April 2010 when a geyser of seawater erupted from the marine riser onto the rig. It took the lives of 11 people and left 17 others injured. More Massive oil spill begins in Gulf of Mexico - Apr 20, 2010 - HISTORY.com Massive oil spill begins in Gulf of Mexico Share this: Massive oil spill begins in Gulf of Mexico Author Massive oil spill begins in Gulf of Mexico URL Publisher A+E Networks On this day in 2012, an explosion and fire aboard the Deepwater Horizon oil drilling rig in the Gulf of Mexico, approximately 50 miles off the Louisiana coast, kills 11 people and triggers the largest offshore oil spill in American history. The rig had been in the final phases of drilling an exploratory well for BP, the British oil giant.

By the time the well was capped three months later, an estimated 4.9 million barrels (or around 206 million gallons) of crude oil had poured into the Gulf. The disaster began when a surge of natural gas from the well shot up a riser pipe to the rig’s platform, where it set off a series of explosions and a massive blaze. Of the 126 people on board the nearly 400-foot-long Deepwater Horizon, 11 workers perished and 17 others were seriously injured. The fire burned for more than a day before the Deepwater Horizon, constructed for $350 million in 2001, sank on April 22 in some 5,000 feet of water. Before evacuating the Deepwater Horizon, crew members tried unsuccessfully to activate a safety device called a blowout preventer, which was designed to shut off the flow of oil from the well in an emergency. Over the next three months, a variety of techniques were tried in an effort to plug the hemorrhaging well, which was spewing thousands of barrels of oil into the Gulf each day.

Finally, on July 15, BP announced the well had been temporarily capped, and on September 19, after cement was injected into the well to permanently seal it, the federal government declared the well dead. By that point, however, oil from the spill had reached coastal areas of Louisiana, Mississippi, Alabama and Florida, where it would inflict a heavy toll on the region’s economy, particularly the fishing and tourism industries, and wildlife. Scientists say the full extent of the environmental damage could take decades to assess. In January 2011, a national investigative commission released a report concluding the Deepwater Horizon disaster was “foreseeable and preventable” and the result of “human error, engineering mistakes and management failures,” along with ineffective government regulation. In November 2012, BP agreed to plead guilty to 14 criminal charges brought against it by the U.S. Justice Department, and pay $4.5 billion in fines. Additionally, the Justice Department charged two BP managers who supervised testing on the well with manslaughter, and another company executive with making false statements about the size of the spill.

It is anticipated that BP, which has set up a $20 billion fund to compensate victims of the spill, will pay billions of dollars more in environmental penalties in the future. Related Videos Deepwater Horizon oil spill of 2010 | oil spill, Gulf of Mexico | Britannica.com Deepwater Horizon oil spill of 2010 oil spill, Gulf of Mexico Written By: Gulf of Mexico Deepwater Horizon oil spill of 2010, also called Gulf of Mexico oil spill of 2010, largest marine oil spill in history, caused by an April 20, 2010, explosion on the Deepwater Horizon oil rig—located in the Gulf of Mexico , approximately 41 miles (66 km) off the coast of Louisiana —and its subsequent sinking on April 22. Debris and oil from the Deepwater Horizon oil rig after it sank on April 22, 2010. U.S. Coast Guard The explosion The Deepwater Horizon rig, owned and operated by offshore-oil-drilling company Transocean and leased by oil company BP , was situated in the Macondo oil prospect in the Mississippi Canyon, a valley in the continental shelf.

The oil well over which it was positioned was located on the seabed 4,993 feet (1,522 metres) below the surface and extended approximately 18,000 feet (5,486 metres) into the rock. On the night of April 20 a surge of natural gas blasted through a concrete core recently installed by contractor Halliburton in order to seal the well for later use. It later emerged through documents released by Wikileaks that a similar incident had occurred on a BP-owned rig in the Caspian Sea in September 2008. Both cores were likely too weak to withstand the pressure because they were composed of a concrete mixture that used nitrogen gas to accelerate curing. Fireboat response crews battling the blazing remnants of the offshore oil rig Deepwater Horizon in … Video courtesy of the U.S. Department of Energy Once released by the fracture of the core, the natural gas traveled up the Deepwater rig’s riser to the platform, where it ignited, killing 11 workers and injuring 17.

The rig capsized and sank on the morning of April 22, rupturing the riser, through which drilling mud had been injected in order to counteract the upward pressure of oil and natural gas. Without any opposing force, oil began to discharge into the gulf. The volume of oil escaping the damaged well—originally estimated by BP to be about 1,000 barrels per day—was thought by U.S. government officials to have peaked at more than 60,000 barrels per day. Leaking oil Triangle shirtwaist factory fire Although BP attempted to activate the rig’s blowout preventer (BOP), a fail-safe mechanism designed to close the channel through which oil was drawn, the device malfunctioned. Forensic analysis of the BOP completed the following year determined that a set of massive blades known as blind shear rams—designed to slice through the pipe carrying oil—had malfunctioned because the pipe had bent under the pressure of the rising gas and oil. (A 2014 report by the U.S.

Chemical Safety Board claimed that the blind shear rams had activated sooner than previously thought and may have actually punctured the pipe.) Map depicting the effects of the Deepwater Horizon oil spill, caused by the explosion of an oil rig … Encyclopædia Britannica, Inc. Efforts in May to place a containment dome over the largest leak in the broken riser were thwarted by the buoyant action of gas hydrates —gas molecules in an ice matrix—formed by the reaction of natural gas and cold water. When an attempt to employ a “ top kill,” whereby drilling mud was pumped into the well to stanch the flow of oil, also failed, BP in early June turned to an apparatus called the Lower Marine Riser Package (LMRP) cap. With the damaged riser shorn from the LMRP—the top segment of the BOP—the cap was lowered into place. Though fitted loosely over the BOP and allowing some oil to escape, the cap enabled BP to siphon approximately 15,000 barrels of oil per day to a tanker.

The addition of an ancillary collection system comprising several devices, also tapped into the BOP, increased the collection rate to approximately 25,000 barrels of oil a day. Britannica Stories Ringling Bros. Folds Its Tent In early July the LMRP cap was removed for several days so that a more permanent seal could be installed; this capping stack was in place by July 12. Though the leak had slowed, it was estimated by a government-commissioned panel of scientists that 4,900,000 barrels of oil had already leaked into the gulf. Only about 800,000 barrels had been captured. On August 3 BP conducted a “ static kill,” a procedure in which drilling mud was pumped into the well through the BOP. Though similar to the failed top kill, mud could be injected at much lower pressures during the static kill because of the stabilizing influence of the capping stack. The defective BOP and the capping stack were removed in early September and replaced by a functioning BOP. Disasters of Historic Proportion The success of these procedures cleared the way for a “ bottom kill,” considered to be the most likely means of permanently sealing the leak.

This entailed pumping cement through a channel—known as a relief well—that paralleled and eventually intersected the original well. Construction of two such wells had begun in May. On September 17 the bottom kill maneuver was successfully executed through the first relief well. The second had been intended to serve as a backup and was not completed. Two days later, following a series of pressure tests, it was announced that the well was completely sealed. Claims by several research groups that subsurface plumes of dispersed hydrocarbons had been detected in May were initially dismissed by BP and the National Oceanic and Atmospheric Administration (NOAA). However, it was verified in June that the plumes were in fact from the Deepwater spill. The effect of the microscopic oil droplets on the ecosystem was unknown, though their presence, along with that of a layer of oil several inches thick discovered on portions of the seafloor in September, cast doubt on earlier predictions about the speed with which the discharged oil would dissipate. Bacteria that had adapted to consuming naturally occurring gas and oil seeping from the seabed were thought to have consumed a portion of it.

Cleanup efforts The petroleum that had leaked from the well before it was sealed formed a slick extending over thousands of square miles of the Gulf of Mexico. To clean oil from the open water, 1.8 million gallons of dispersants —substances that emulsified the oil, thus allowing for easier metabolism by bacteria—were pumped directly into the leak and applied aerially to the slick. Booms to corral portions of the slick were deployed, and the contained oil was then siphoned off or burned. As oil began to contaminate Louisiana beaches in May, it was manually removed; more difficult to clean were the state’s marshes and estuaries , where the topography was knit together by delicate plant life. By June, oil and tar balls had made landfall on the beaches of Mississippi , Alabama , and Florida . In all, an estimated 1,100 miles (1,770 km) of shoreline were polluted. Controlled burn of oil spilled in the Deepwater Horizon disaster, Gulf of Mexico, May 6, 2010. The … EPA Facebook Twitter YouTube Instagram Pinterest The various cleanup efforts were coordinated by the National Response Team, a group of government agencies headed by the U.S.

Coast Guard and the Environmental Protection Agency (EPA). BP, Transocean, and several other companies were held liable for the billions of dollars in costs accrued. Coast Guard cleanup patrols ultimately drew to a close in Alabama, Florida, and Mississippi in June 2013 and in Louisiana in April 2014. Aftermath and impact Economic prospects in the Gulf Coast states were dire, as the spill affected many of the industries upon which residents depended. More than a third of federal waters in the gulf were closed to fishing at the peak of the spill, due to fears of contamination . A moratorium on offshore drilling, enacted by U.S. Pres. Barack Obama ’s administration despite a district court reversal, left an estimated 8,000–12,000 temporarily unemployed. Few travelers were willing to face the prospect of petroleum-sullied beaches, leaving those dependent on tourism struggling to supplement their incomes. Following demands by Obama, BP created a $20 billion compensation fund for those affected by the spill. A year later nearly a third of the fund had been paid out, though lack of oversight allowed government entities to submit wildly inflated claims, some unrelated to the spill.

By 2013 the fund was largely depleted. Workers contracted by BP cleaning up oil on a beach in Port Fourchon, La., May 23, 2010. PO3 Patrick Kelley/U.S. Department of Defense Britannica Lists & Quizzes Editor Picks: Exploring 10 Types of Basketball Movies Recovery was incremental. As oil dispersed, portions of the gulf began reopening to fishing in July, and by October the majority of the closed areas were judged safe. State governments struggled to draw attention to unsoiled or newly scrubbed beaches with advertising campaigns, often drawing on funds from BP. Oil continued to wash ashore in many areas, and much of it could not be removed, either because of logistical reasons—mats of submerged oil and organic matter collected in tidal zones that were difficult to reach—or because cleaning it up would inflict greater harm on the ecosystem. The drilling moratorium, initially set to expire in November 2010, was lifted in mid-October, though new drilling permits were not issued until February of the subsequent year following mounting government and industry pressure to increase domestic oil production.

The emergence of BP chief executive Tony Hayward as the public face of the oil giant further inflamed public sentiment against the embattled company. The Englishman—who at one point remarked, “I’d like my life back”—was derided for his alternately flippant and obfuscating responses in media interviews and while testifying before the U.S. Congress . He was replaced in October. By the next year, the company had lost almost a quarter of its market value and had hemorrhaged over $40 billion in costs associated with cleanup and recovery. The National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, formed by Obama in May 2010, faulted the Obama administration’s response to the spill in a report issued in October. The commission’s final report, issued in January 2011, attributed the spill to a lack of regulatory oversight by the government and negligence and time-saving measures on the part of BP and its partners. A report released in September by the Joint Investigation Team of the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) and the U.S. Coast Guard emphasized BP’s ultimate responsibility for the disaster.

(BOEMRE had supplanted the Minerals Management Agency, which had regulated drilling before the spill, in June 2010.) The report noted that, although the defective concrete cap had been installed by Halliburton, decisions about the installation process made by BP had been the cause of the failure. The investigation further found that BP and Transocean employees aboard the rig had—while engaged in testing procedures—ignored early indications of a problem and thus missed opportunities to prevent a full-scale blowout. Though representatives of BP conceded that the company was responsible for some of the factors contributing to the spill, they stressed that their partner companies were also to blame. Halliburton and Transocean similarly pointed to failures on the part of the other parties involved. Legal action Eyjafjallajökull volcano Charges, settlements, and penalties A formal civil and criminal investigation into the spill was initiated in June 2010 by the U.S. Department of Justice (DOJ). In August 2010 Louisiana district court judge Carl Barbier was appointed to oversee the consolidated proceedings relating to the spill, which had prompted numerous lawsuits and precipitated a morass of complex legal entanglements, private and public.

The DOJ sued BP, Transocean, and Anadarko, a minority owner of the well, in New Orleans civil court in December 2010 for violating the Clean Water Act and Oil Pollution Act. In early March 2012 BP agreed to settle claims made by the plaintiffs’ steering committee, the consolidated representative body for many of the individual victims of the spill, for at least $7.8 billion. (The move followed the postponement of a trial scheduled in late February in Louisiana district court.) The monies were to be drawn from the compensation fund mandated by the Obama administration. Previously managed by lawyer Kenneth Feinberg—who had also overseen the compensation fund for victims of the September 11 attacks —the fund was transferred to court control as part of the accord. In addition to covering economic losses sustained in the wake of the spill, the settlement mandated the payment of medical claims (which had previously been denied by the fund) and provided for 21 years of further medical monitoring and care, allowing for the delayed onset of symptoms and illnesses. BP remained liable for substantial additional claims by local and state entities as well as by the federal government.

An effort by the company to appeal the agreement, which received final approval in December 2012, was rejected by the U.S. Supreme Court in December 2014. In November 2012 BP reached an agreement with the DOJ to plead guilty to 14 criminal charges, among them 11 counts of felony manslaughter, and violations of the Clean Water and Migratory Bird Treaty acts. The agreement carried penalties and fines amounting to more than $4.5 billion, of which nearly $1.26 billion would go to a discretionary fund overseen by the DOJ, some $2.4 billion to the National Fish and Wildlife Foundation (NFWF), and $350 million to the National Academy of Sciences (NAS). BP also agreed to pay more than half a billion dollars to the Securities and Exchange Commission for misleading its shareholders about the magnitude of the oil spill. The deal was approved in January 2013. Later in November 2012, the EPA suspended BP from entering into any new federal contracts. That suspension, initially thought to be temporary, was reinforced in January 2013.

In February the EPA also issued a separate suspension to the BP subsidiary that had operated the well, the Dallas-based BP Exploration & Production Inc., citing a violation of the Clean Water Act. In August 2013 the company filed suit against the EPA in Texas federal court, asking that the ban be lifted. It was not lifted until March 2014; the company successfully bid on 24 federal contracts later that month. In January 2013 Transocean agreed to a $1 billion civil penalty under the Clean Water Act. Approximately $800 million of that amount was earmarked for restoration projects in the gulf, and the remainder was paid to the federal government. The company also pled guilty to criminal violations of the Clean Water Act, resulting in a $400 million criminal penalty. Of that money, $300 million was evenly divided between restoration projects administered by the NFWF and an offshore oil safety research endowment administered by the NAS. The remainder funded a liability trust to be drawn upon in the event of later spills. In May 2015 Transocean resolved claims made by the plaintiffs’ steering committee for some $211.7 million.

In July 2013 Halliburton agreed to pay a $200,000 penalty after pleading guilty to criminal charges that its employees had destroyed evidence related to the spill. It settled claims with the plaintiffs’ steering committee for some $1.1 billion in September 2014. In November 2015 Anadarko was judged liable for some $159.5 million in civil penalties for its role in the disaster. Charges against individuals In April 2012 the first criminal charges to come out of the disaster were filed against a former senior drilling engineer for BP. Kurt Mix, who had worked for BP until January 2012, was charged in federal court with obstructing justice for deleting hundreds of text messages concerning the flow rate of oil despite having received legal notification to preserve the correspondence. Some of the messages were forensically recovered; one contained a flow rate estimate three times higher than what BP had publicly attested to at the time. He was convicted in December 2013. In November 2012 two senior officers on the Deepwater Horizon oil rig, Robert Kaluza and Donald Vidrine, were charged with manslaughter.

David Rainey, the former vice president for exploration in the Gulf of Mexico, was charged with obstructing Congress and making false statements to law enforcement concerning the rate at which oil was leaking from the rig. The Supreme Court refused to hear a 2015 appeal by the latter official to dismiss the obstruction charge. To the dismay of many observers, none of the individuals who were charged with criminal offenses related to the spill ultimately received prison sentences. Rainey was acquitted in June 2015. Mix was granted a retrial owing to juror misconduct and instead pled guilty to misdemeanor computer fraud charges. He was sentenced to probation and community service in November 2015. The manslaughter charges against Kaluza and Vidrine were dropped in December 2015 at the request of the prosecution. Vidrine pled guilty to a misdemeanor charge of pollution under the Clean Water Act and in April 2016 was sentenced to probation, community service, and the payment of a fine. Kaluza pled not guilty to the same charge and was cleared in February 2016. The civil trial The civil trial of BP, Halliburton, and Transocean began in late February 2013 in New Orleans.

The federal government, as well as individual states and entities, was among the plaintiffs. The trial was intended to determine liability under the Clean Water Act and Natural Resource Damage Assessments under the Oil Pollution Act, addressing charges not covered by previous settlement agreements. The proceedings were arranged in three phases. The first, which ended in April, was to assess the degrees to which the three companies were culpable. Of particular import was the distinction between “gross negligence” and “negligence”; the former designation would result in fines approximately four times higher than those assessed for the latter. The second phase of the trial, which began in late September, was intended to establish the volume of oil released by the spill and whether the preparedness and damage-control efforts of the involved parties were adequate. It ended in late October. The third phase, in which damages would be determined, finished in February 2015. The ruling on the first phase, announced in September 2014, found BP to be 67 percent culpable for the spill and thus grossly negligent. Transocean was held 30 percent liable and Halliburton 3 percent liable; both companies were deemed negligent.

The ruling on the second phase, announced in January 2015, set the legal amount of oil for which the involved parties would be liable at 3.19 million barrels. BP had claimed that approximately 2.45 million barrels had leaked, while the U.S. government contended that 4.19 million barrels had spewed into the gulf. In July 2015, in the wake of a rejected Supreme Court appeal regarding the maximum fines for the disaster, a tentative settlement was reached between BP, the federal government, and the five states affected by the spill, with BP estimating that it would cost the company $18.7 billion. A finalized settlement of $20.8 billion was announced in October 2015, bringing the third phase to a close. It was the largest financial penalty ever leveled by the U.S. government against a single company. However, some observers noted that a substantial portion of the settlement could be written off on the company’s taxes as a business expense and consequently questioned the severity of the punishment. The settlement was formally approved in April 2016. Environmental costs Thousands of birds , mammals , and sea turtles were plastered with leaked oil.

There was speculation that a spike in cetacean strandings and deaths that was recorded by NOAA beginning in February 2010 was further exacerbated by the spill. Typical causes of such widespread fatalities, including morbillivirus and toxins from red tides , were ruled out, and there was an unusual incidence of Brucella infection in stranded dolphins, leading researchers to suspect that contaminants from the spill had made cetaceans more vulnerable to other environmental dangers. A December 2013 study of living dolphins in Barataria Bay , Louisiana, found that roughly half were extremely sick; many suffered from lung and adrenal disorders known to be linked to oil exposure. Some 1,400 whales and dolphins had been found stranded by the end of 2015, a figure representing only a tiny percentage of the animals affected. Though the number of dead animals had begun to taper off, substantial decreases in dolphin fertility persisted. It was thought that the strandings represented the largest mortality event to occur in the Gulf of Mexico.

A dead bird covered in oil from the Deepwater Horizon oil spill in the Gulf of Mexico, East Grand … Charlie Riedel/AP Birds were particularly vulnerable to the oil’s effects, and many perished—from ingesting oil as they tried to clean themselves or because the substance interfered with their ability to regulate their body temperatures. The brown pelican , recently delisted as an endangered species, was among the species most affected. A 2014 study projected that perhaps 12 percent of the brown pelicans and more than 30 percent of the laughing gulls in the area hit by the spill had been wiped out. According to another 2014 study, up to 800,000 birds were thought to have died. Even individuals not directly contaminated by oil were affected. A 2012 study determined that white pelicans that had migrated from the gulf to Minnesota to breed were producing eggs that contained discernible amounts of compounds that were traceable to the BP spill. Eggs containing traces of contaminants were found in Iowa and Illinois as well.

Animals that were found alive in the wake of the spill were transported to rehabilitation centres and, after being cleaned and medically evaluated, were released into oil-free areas. Concerns about the offspring of sea turtles that nested on the gulf coasts of Alabama and Florida led wildlife officials to dig up thousands of eggs and hatch them in a warehouse for later release on the Atlantic coast. By late 2012 some 1,700 turtles had been found dead. A long-term satellite tracking study released in May 2013 showed that the endangered Kemp’s ridley sea turtle was likely severely affected, as its preferred foraging territory was within the area damaged by the spill. It was estimated that up to 65,000 imperiled turtles had died during 2010 alone, mostly as a result of oil contamination. It was also estimated that some 300,000 turtles, some of which were originally from breeding populations in other parts of the world, were in the region of the spill when it occurred, leading scientists to point out the global impacts of the disaster. The impacts on smaller species were more difficult to determine.

Numerous species of fish and invertebrates spawned in the gulf, and it was thought likely that some would succumb to the toxic effects of the oil. A 2014 study showed that the larvae of commercially important fish species, including tuna, likely developed heart defects after exposure to polycyclic aromatic hydrocarbons (PAHs) from the oil. Areas of the seabed that had been coated by by-products of bacteria were essentially dead zones; many sedentary organisms had suffocated or been sickened by the material, and most mobile organisms had fled. Reefs outside a 12-mile (19-km) radius from the Deepwater well appeared largely unaffected, but those within were heavily stressed. Laboratory studies suggested that oil and dispersants made coral reproduction more difficult. Coral larvae, which are initially mobile, attached to mature corals at much-reduced rates following exposure to the substances. Tests also determined that oil and dispersants were fatal to rotifers, microorganisms crucial to the gulf food web. A modeling study released in February 2016 suggested that the activity of oil-eating microbes was negatively affected by blooms of other species of microbes that preferred to feed on the dispersants.

An April 2014 mission conducted by the research group Ecosystem Impacts of Oil and Gas Inputs to the Gulf (ECOGIG) aboard the submersible Alvin —which had famously been involved in investigating the wreckage of the Titanic —noted some ecological recovery of oiled areas of the seafloor, though detectable oil levels in sediment cores remained the same as they had been four years earlier. It was hoped that extensive revisions to offshore-drilling regulations, prompted by the spill and issued in April 2016, would mitigate the likelihood of future disasters. The Deepwater Horizon oil spill in pictures Images of the Deepwater Horizon oil spill. Deepwater Horizon oil spill of 2010 Fireboat response crews attempting to extinguish the blaze aboard the Deepwater Horizon oil rig, set off the previous day by an eruption of natural gas. The U.S. Coast Guard collecting oil with a skimming boom off the coast of Mobile, Ala. Sand covered with oil on Pensacola Beach, Fla. Heavily oiled brown pelicans (Pelecanus occidentalis) captured at Grand Isle, La., waiting to be cleaned. U.S. Pres.

Barack Obama inspecting a tar ball from the Deepwater Horizon oil spill on the beach in Port Fourchon, La.

Question: Which BP rig sank in April 2010, causing a massive oil spill in the Gulf of Mexico?
Answer: Deepwater Horizon